chemical changes & ,nutrient transformation in sodic/poor quality water irrigated soils

Chemical Changes & ,Nutrient Transformation in Sodic/Poor Quality Water Irrigated Soils

• Editors

~P.S. Yaduvanshi .. -R~. Yadav o.s. Bundela •

-~.1(ulsh reshtha-r Gurbachan Singh ..

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Sponsored by: Indian Council of Agricultural Research New Delhi, India

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Chemical Cbang~s and Nutrient Transformation in:

Sodie/Poor Quality Water Irrigated Soils

Summer School an

Chemical Changes & Nutrient Transformation in Sodic/Poor

Quality Water Irrigated Soils

27 September-17 October, 2008

Editors

N.P.S. Yaduvanshi RK. Yadav 0.5. Bundela N. Kulshreshtha Gurbachan Singh

Central. Soil Salinity Research Institute Karnal·132001 Haryana, India

http://www.cssri.org

Yaduvanshi, N P.S, Yadav, R.K, Bundela, D S., Kulshreshta, N and Singh, Gurbachan·(2008),' Chemical Changes and Nutrient Transformation in SodlrJPoor Quality Water Irngated SOils' Central So~ Salin~ty Research Ins Me, Kamal, India, p309

Sponsored by: Indian Council of Agricultural Research, KAB II, Pusa, New Deihl, India

Published by: Director Central Soil Salinity Research Insltute, Kamal-132001 Telephone: 0184-2290501 Fax' 0184-2290480 E-mail: [email protected] Website. http'" WNW cssri org

The views expressed In thiS bOOK are of authors. CSSRI, Kamal and ICAR, New Delhi taKe no liability for any losses resulting from the use of this book

Printed by: Intecl\ Pntlte($ & Publishecs, Kamal

Preface

Worldwide demand for foodgralns has Increased dramatically with exponential Increase In population over the last 50 years. Though prodl!ctlor of foodgralns In India has Increased nearly four times, from 50 million tonnes 1n/1950-51 to 209 million tonnes In 2005,06. but demand IS Increasing continuously as our present population of around"1 05.billion is.expected to nse to 1 39-billion by 2025 To meet thiS ever Increasing food demand, concerted efforls are needed to Improve agricultural production and productivity In normal SOil productIVe areas' on one hand and simultaneously strategies should be evolved to exploit the potential of marginal salt-affected lands and areas underlain with poor quality groundwater, on the otlJer !1a~d. Soil degradation problems like sodlcity and salinity, and inCidences of poor quality water occurrence are likely to Increase In near future because of extensive degradation of Salls With imbalanced and injudicious use of chemICal fertilizers, unscientific cultivation .of soil and' exploltailon of poor quality groundwater for. lITIgation without adopting ameliorative -measures. 'Emergence of multiple nl,Itrient deficienCies, deterioration of soli physical and chemical properties, and decll~e In factor productiVity causing lower crop Yields has become common Understanding the chemical changes and transformations of nutrients under salty environments help In scientific management of salt-affected soils and thus can playa major role In meeting the ever-increasing food demand

Recent estimates indicate that 6 73 m ha area in India is affected by soil salinity and alkalinity, and about 25 % of our geographical area has sodlc and/or saline groundwater. Some of the states like Rajasthan located in the Thar desert, more than 80% of the groundwater resources are of poor quality and are unfit for irrigation to agricultural crops Long period continuous Irngatlon With poor quality groundwater In field crops has resulted In large scale sallnlzabon and desertification in several regions of the country. Increasing food demand and Simultaneous decline In factor productiVity have become a matter of grave concern more so particularly under conditions of Impending climate change. Sustainable crop production on these degraded Salls under aforesaid situations requires information on efficient strategies for productive and beneficial use of poor quality surface or groundwater, their conjunctive use With avaliable fresh water, balanced and Integrated use of Inputs especially amendments, fertilizers, organics and green manures, adoption of appropriate resources conservation technologies and multl-enterpnse agnculture

As a follow up of the recommendations of an Indo-American team assisting ICAR In developing a comprehenSive water management programme during the Fourth Five Year Plan and to evolve sustainable practices for management of salt-affected marginal Salls and Irngatlon with poor quality water. the central Soil Salinity Research Institute (CSSRI) was established at Kamal In 1969. In a short,penod of 39 years, CSSRI has developed into one of the leading International centres of excellence in salinity research From the very beginning, the CSSRI has adopted a holistic and inter-disciplinary approach for reclamation and management of salt-affected Salls and JudiCIOUS use of poor quality water while keeping the farmers in center stage Over the years, more than 1 3 million ha salt-affected soils have been reclaimed by adoption of the technologills generated by the institute and the reclaimed area is contributing more than 8 million tonnes of additional foodgrain to the national pool

Considering the technologies developed, expertise available and the kind of research gOing on at the institute, Indian CounCil of Agricultural Research, New Delhi entrusted the organizalion of a Summer School on, 'Chemlcal changes and nutrients transformation In sadie/poor quality water Imgated soils' at the Institute Assistant professors from CAU & SAUs. and Scientists from ICAR Institutes participated In the school In the course curriculum, the emphaSIS was placed on praCtical exercises for analYSIS of different salts and nutnents along With conceptualtheoretical lectures and discussions Participants were exposed to various practices and techniques being followed for reclamation processes and chemical changes or nutnents transformations occurnng In salt-affected Salls and With use of poor quality lITIgation water Issues related to physiological mechanisms of salt tolerance In crop plants, sustainable management of salt-affected Salls and use of poor quality water were also dealt in the school. During the training period, lectures on vanous aspects were delivered by eminent sClentistSiprofessors of soli sCience.

agronomists and other specialists from CSSRI, Karnal as well as from,vanous Universities A' sincere attempt has been made to compile these lectures to fulfil the long fell need of information on nutnent ,changes of salt-affected sOils. ,

, , Here, we would like to take thiS opportUnity to express our sincere gratitude to Dr, A K.

Singh, DOG (NRM) and Dr. S P. Tlwan, DOG (Education), ICAR, New Delhi for shOWing. keen interest In this important aspect and sponsonng the Summer School on the't\>pic The editors also owe their sincere thanks to Dr. Gurbachan Singh, Director, CSSRI, Kamill for hiS constant encouragement and gUidance rendered dUfing the course of conceptualization and organlzatlon_ of summer school, and compilation of the book Our special thanks are due t6 all the learned contnbutors for shanng their knowledge with the participants 'of the training programme and providing the manuscripts well 'in lime. For the smooth organization of thiS training program, the administrative and technical support of the instllute staff IS very thankfully acknowledged, SpeC/al thanks are also due to other colleagues Mr. Sahib Smgh and Mr Madan Singh Poswal for their help during the training period and Mr, R K, Bhalla and Mr Bachhan Smgh for secretanal assistance. We sincerely believe that this publication would be of Interest and practical use to the participants and other researchers worKmg in the area of sustainable management and nutrients transformation In salt-affected soils

, N.P S. Yaduvanshl R K Yadav D S Bundels N. Kulshreshtha Gurbachan Singh

Preface

Salinity In Agriculture: An Overview

GurtJBchan Singh

ContentS

Natural Resources Management In Relation to Climatic Change

GurtJachan Singh

Extent and Nature of Salt-Affected Soils In India

R. C. Sharma & A K Mandai

Genesis of Saline and Sodlc Soils In Canal Irrigated Area of Desert Ecosystem

SK. Singh

Genesis, Taxonomy and Behaviour-of Sodlc Vertisols in India

S K SlIlgh

Chemical Changes In Submerged Sodlc Solis

N S. Pasncha

Redox System Controlling N & S Transformations In Sod'IC Soils under Submerged Condition

N S Pasncha

Transformation and Availability of N, P and K in Subme,.ged Sodic Soil P Day

Integrated Nutrient Management for Sustaining Crop Production under Sodle Solis

N P S YBduvanshl

Management of Land Degradation in Arid and SemI-Arid Areas

Khajanchi Lal & Gajender YBdaV

Nutrient Management for Sustaining Crop Production In Salt-Affected Soils Anand SWarup

Long-term Fertilizer Effects on Fertility of Soils and Productivity of Cropping Systems Anand SWarup

Input Use and Resource Conservation for Barley Production In Degraded Soils

AS. Kharub

Modelling Solute Transport In Alkali Solis M.J Kaledhonkar

Management of Saline Soils through Subsurface Drainage M J Ka/edhonkar & S.K Gupta

Management Strategies for Sustainable Crop Production In Saline VertisolS R.L Meana, R K. Yadav & Khajanchi Lal

Crop Tolerante to Waterlogging and Soli Salinity DP Sharma

Microbiological Properties of Soils In Relation to Salt Stress LalIta Batra

Tec~nologles for Efficient Use of Sodlc Water In Sustainable Crop Productlon OR Sharma -" -."

Tec~nologies for Emclent Use of Saline Water for Sustainable Crop ProduGlion

OR. Sharma

Page

15

28

34

38

48

52

56

61

66

72

77

79

85

95

103

loa

114

118

123

Recycling of Sallno Drainago Effluents for Crop Producllon 129 DP Sharma /

/ Implication of Fluoride Rich Irrigation Water on Agriculture and Public Health 136 , , D S Bunde/a & Kaplla Shekhawal

Deficit Irrigation-An Option for Crop Production under Water Scarce Conditions 142

R K YadBv & Kaplla Shekhawal

Characterization of Waste Water for Irrigation 147

R K Yadav & KhaJanchi Lal

Conjunctive Use of Sewage Water for Crop Production 152

KhaJanchl Lal, R.K Yadav & Gajend8r Yad8v

Bloremedlatlon of Wastewater for Removal of Heavy Metals through Microbes 159

PK Joshi

Modelling Techniques for Conjunctive Water Use Planni~g,ofSaline and Ca~al Water 161

M J Kaledhonkar

Fertig"tion for Quality Hortlcultural Produce 172

Salyendra Kumar & C,K SillIena I

Design of Surface Drip Irrigation System with Saline Water & Its Effect on Crop Growth & Yield 178

'c K Saxena & S K Gupta

Subsurface Drip Irrigation for Utilization of Sewage Water

RS Pandey

Scope of Skimming and Recharge of Groundwater In Salt-Affected Areas

S K Kamra

BlOdralnage for Combating Waterlogging and Salinity

J C Dagar, Jeet Ram & Gurbachan Singh

Utilization 01 Salt-affected 5\,115 and Saline Water for Agroforestry

J C Dag.r, Gurbachan Singh & 0 S Tomar

Tree Plantation In Sali~e aod Sodie Soils

o S Tom8r and R K Yadav

~raSlles for Alkali Soil and Their, Reclamation Effect

Ashok Kumar and R K Yadav

Organic MaHer and Nutrient Dynamics In Agro-forestry System under Salt-Affected Soil

P Dey and Gurbachan Singh

Soli and Water Management for Sugarcane Production In Sodlc Environment

V K An:lIa

Remote SenSing and GIS for Delineation and Characterization 01 Groundwater Zones

D S Bundela & C K Saxena

Remote Sensing and GIS for Appraising Salt-Affected Soils

Madhurama Sethi

169

196

203

207

212

218

224

227

230

238

GPS Technology lor Assisting Ground Truth !or Salt-Affected Salls 246

Madhuram8 Sethi & D S Bundela

Multi-enterprlse Agriculture to Improve Nutrlent"and Water Productivity In'Reclaimed Lands 254

AshokKumar

Cultivation 01 Non-Conventional Crops of Economic Value under Saline Environments

Vandana Lodha 256

Biomass and Biodlesel for Energy Production from Salt-Affected Lands

S K Shanns & N P,S Yaduvansh,

Breeding Wheat Varieties lor Salt Tolerance in India: Present Status and Future Prospec:ts I

NeeraJ Kulshreshlha

Resilient Rice Varieties for Reaping Higher Productivity lrom Sodic Soils /

RK GBulam

Physiological Mechanisms of Salinity ~nd Sodlclty Tolerance In Crop Plants

SK Shanna

Screening and Crop Physiology for Waterlogging Tolerance in ~alt-Affected SOils

S K. Shanna , , Physiological and Biochemical Roles Of Micronutrients under Sail Stress

AI, Qadar

Transfer of Technology Approaches in Management of Alkali Soils in Uttar Pradesh

RamAJore

Financial Appraisal and Socia-Economic Benefits of Salt-Affected Soil Reclamation

RS Tnpalh,

263

269

275

283

2BB

295

300

303

Salinity in Agriculture: An Overview

Gurbachan Singh c

Central 5011 Salmlty Research InsMllte, Krmal- 132!Jq1

Introduction

Salinity related land degradatIOn is becoming a senous challenge for food "and nutritional "secilnty In the developing world, As per FAO/UNESCO sOil map of the world, a total of 953 m ha (Table 1) covenng'about 8 per cent of the land surface is suffering from salinity/sodlclty (Szabolcs, 1979) 'The salt affected soils are reported to occupy 42 3% of, the land area of Australia, 21 0% of ASia, 7 6% 'of South Amenca, 4,6% of Europe, 3 5% of Afnca, '0 9% of North America and 0 7% of Central America (EI-Mowelhey, 1998) Australia has the world's largest area under salinHy which is eqUivalent to about one third of the total area of the continent (Rangasamy and Olasson, 1991) Recent estimates indicate that 674 m ha (NRSA, CSSRI, NBSSLUP, 2006) area in India IS affected by sOil salinity and alkalinity with state-wise dlstnbullOn of saltaffected soils (Table 2)

Table 1, Regional distribution of salt-affected' SOils Tn the world

Region Saline soil (m hal Sodlc sOil (m hal Total area (m hal " North Amenca 6 10 16 Mexico and Central America 2 2 South America 69 60 129 Afnca 54 27 81 South and West Asia 83 2 85 South and East ASia 20 20 North and Central ASia 92 120 212 Australia 17 340 357 Europe 51 Total 953

Source' Szabolcs, 1979 & 1980

The first approximation of ground 'water quality map of the country has been prepared (Fig 1) and about 25% of ground waters are sodlc andlor saline In the country More than 80% ,of the ground water resources are of poor quality In the state of Rajasthan located In the Thar desert and are unfit for IITIgallOn to agricultural crops, Continuous use of such waters over longer period for Irrigation of field crops IS resulting In large scale salinization leading to desertification In several regions of the country.

The salinity problem IS becoming more senous With expanding Irng3110n In and and semi-and regions without 3dequate prOVision for drainage Already a Sizable area in the country is waterlogged and sallnlzed ,n almost all the canal commands In several imgatlon commands, the water table IS nsing at the rate of 30 to 100 ern per year. The nature and seventy of the problem vanes from region to region depending upon the topographical Situation, hydrological and climatiC conditIOns, drainage availability, land use an~ cultural practices A detailed review of salinity related desertification In the country and strategies to cope up With salinity has been discussed In thiS paper.

Characteristics of Salt·Affected Soils

Salt-affected soils In India are broadly placed into two broad groups, sodle (alkali) SOils and saline SOils There are certain specific situations where sallne-sodlc SOils also do eXIst. Since the management of saline sodlc solis Will be more similar to that of the sodlc Salls, they are generally grouped With the SodlC SOil category. The only management difference for thel( reclamation IS that such soil needs extra water for leaching of soluble salts before amendment application The sadie SOils have higher proportion of sodium In

relation to other cations in soil solution and on the exchange complex. Growth of most crop plants on sodlc SOils IS a~versely affected because of impairment of phYSical conditions, disorder In nutrient availability and suppresSion of biological activity due to high pH, exceeding even 10 in severe cases, and exchangeable sod!um percentage of up to 90% or so (Kanwar and Shumbla, 1969). Salt solutions contain preponderance of sodium carbonates and bicarbonates capable of alkaline hydrolysis, thereby saturating the absorbing complex With sodium The sadie soils of the Indo-Gangetic plain are generally gypsum (CaSO. 2H,O) free but are calcareous, With CaCO, increasing with depth, wihlch IS present in amorphous form, In concretionary form, or even as an Indurate bed at abou11 m depth (Table 3). The accumulation of CaCO, generally occurs Within the zone of ftuctuatlng water table. The dominant clay mineral IS Ilhle The processes which target the dissolution

Che""cal Changes & NuiTient Transfonnalion In SodlciPoor Quailly Water Itrlgated $olls

of CaCO, have significant role In reclamation of alkali Or sodlc sOils. Crops like rice. helps in reclaiming sodlc soils (Chhabra and Abrol, 1977) These salls are deficient In organic matter, available N, Ca, illld·Zn.'Certain mlcro-nutnents present problems of either deficiency or tOXICIty ToxiCities of AI, Mn, and Fe sometimes. pose problems for wheat When over- Irngated and resutts.m yellowmg of the crop The major factors responsible for formation of alkali sOils in the Indo-Gangetic region Include' irrigation With ground waters containing excessive quanlilies of carbon~ta and bicarbonate Ions, nsa m groundwater due 10 mlroducllon of canal Irngallon and salt laden runoff from the adjolTling araas and undrained baSinS. The inland saline lands are Widespread in the eanal iITIgated, and and semi-and regions These SOils are charactenzed tly the presence of excess 'neulral ,soluble salts hke chlorides and sulphates of sodium, calCium and magnesium (Table 4). Sodium chlonde IS the dominant salt. Hlgh_ 50il,sali",ty~ IS o~en accompaTlled by high ·v.la'ter table, often \:-11th '" 2 m of SOil surface. Sub SOil waters are generally: salty and, ·therefore, ~their yse for~ irrlgatlOn,-pr~sents major consV~lnts to crop production In general, these SOils have good phySical properties but poor natural drainage. The, formalion of saline Salls IS generally. a~ssoclated With the flse In 'water table due to intioduction' of lITIgation and ~inadequate drainage - '". .

Table 2. State-wise dlstnbub9.~ of salt-affected so!l~ in India

State Area (in m ha ) GUjarat 2.23 Uttar Pradesh 1.37 Maharashtra 061 West Bengal 0.44 Rajasthan 038 Tamil Nadu 037 Andhra Pradesh 027 Haryana 023 Bihar 0.15 Punlab 015 Karnataka 0.15 Onssa 015 Madhya Pradesh 0.14 Andaman & Nicobar Islands 008 Kerala 000 Total 674

Source ReconCiled figures 01 NRSA, CSSRI and NBSS&LUP. 2006

• Fig. 1 Ground water quality map fa! Irngatlon In India

Salinity In 'Agnculture AA Ove~ ':., ~ c.' - -" ..

Table 3 Some Important propertles'of an'alkall sOil of Indo-Gangetic plain

Depth Honzon EGe, pHs GaCO,% Sand Silt Clay CEG ESP em dSlm <2mm % % % cmolclkg sOil,

0-10 Ap 2234 106 51 675 17"6 122 54 907

10-46 621 6.26 102 1 89 55.6 234 165 93 87,1

48-76 622 419 98' 94 460 295 222 94 88.3 76-104 B2ca 234 95 126 362 264 293' 12,6 849

104-163 'Gca 1 31 96' 138 ,_ 27,4 364 307 138 666

Table 4. PhysicO-chemlcal charactenstlcs of a saline 5011 from S.ampla site In Haryana

Depth Honzon pHs ECe Gypsum CaCO, % Sand Silt Clay CEC ESP dSlm % "2mm % % % cmolcl kg

0-17 Ap 7.15 42.3 120 Nil 66,4 192 144 ,102 43

17-48 8621 720 303 Tr Nil 600 200 192 166 66

48-81 lB22 7,15 241 -Ti, Nil 48 e .256 256, 189 47 81-122 ,B2C 720 226 Nil 085 04 224 272 204 53

122- C 7,15 229 Nil 21 600 2702 128 162 49 140

Salinity Related Degradation: Case Studies

Sharda Saflayak canar command area

Sharda Sahayak canal was Initiated In 1978 to provide irrigation In 1 67 m ha area In 21 dlstncts of Uttar Pradesh In north India After the Introduction of the canal, agriculture productivity malKedly Increased In the command area However, n~n-provisJon of drainage and'con~lnuous seepage from the canal r~sulted_ln rise In water table and subsequent upward flux of salts,to,the surface SOil layers In a-span of about three decades nearty 3.73 lakh ha area IS Inflicted With salts and rendered barren Out 01 thiS, nearly 1 5 lakh ha area has been estimated as sodlc SOil With shallow water table The present scenario IS that more than 1 km area adjacent to both Sides of the canal has gone out of cultivabOn and the famers have almost abandoned their lands In extreme cases more than 20 years old mango plantations started Withenng' and drying -The Regional Research Station of this Institute at Lucknow !ned several options to redalm these lands for successful agnculture The oplions tned Induded (a) Installalion of an Interceptor drain at a depth of about one metre to take out excess seepage'water from the canal for disposal elsewhere, (b) blo-<lralnage to achieve higher transpiration rates by Irees to lower the water table and to Intercept the seepage and also (c) options of Intercept drain and blodrainage Four years results of thiS expenmenl'lndlcated that none of these' options walKed satlsfactonly at the site The Intercepted drain did not walK because there was no outlet to take the drained water out of the affected area, After walKing satlsfactonly for Inilial few years, the drain got almost choked About a kilometer bell around the canal bank was planted With Eucalyptus trees known for very high transplrafion rates Because of very high salt concentrallon In the root zone SOil, the species failed to Yield reasonable leaf area for effective transpiration After about three years, many of the trees look_llke as If they are Just one year old plantation

To solve waterlogging problem In sadie areas', a new Innovatlon'lnvolvlng'multiple use of water for multl-enterpnse agnculture was tned on a fame(s field haVing one ha land holding at a distance of about 50 m from the Sharda Sahayak Canal The options tned included dlggmg of a pond 1.75 m deep In an area of o 33 ha for raising fishery, 0 23 ha for growing crops and 0 22 ha for groWing frUit trees mainly on the dykes of the pond The' frurt trees planted Included banana, guava and amia (Embllca' officlnallsl The system IS walKing very well and dUring first 7-8 months, the farmer could get Rs 7,0001- from the sale of agncultural produce The pond remained almost full With water for most of the time because of seepage from the canal The fish In the pond has a weight In the range 150 to 350 grams In about 4-5 months

Indira Gandhi Nohar Project (IGNP)

Indira Gandhi Nahar Project, earlier known as Ralasthan Canal Project. was launched to proVide Imgalion and drinking faCilities In the and north-west tract of RaJasthan. The project was undertaken 10 Imgate about 1 79 m ha area In the dlstncts of Ganganagar, Hanumangarh, Blkaner, Jalselmer, Jodhpur, Barmer and ChuilJ In Rajasthan The IGNP command area receives an annual rainfall of 300 mm In feeder canal area to less than 120 mm in Jalselmer area The potential evaporation vanes from 1600 to 2000 mm per annum

3

•

,

Chemical Changes & Nutnenllransforrnatlon In Sodlc{Pol?r QUality Water lmgated SOils

The region can be divided Into the 'flood plain 50115 (54% of the area) and aeolian 50115 (46% of the area) The flood plain Salls are'malnly fine sandy loams, deep calcareous, highly stratified With good water holding capaclt~, Roughl~ 10% SOils are saline or moderately alkaline The aeolian Sells In general, are coarse textured, deep and calcareous With low fertility and are highly succeptlble to wllid erosion SOils In Jamsar, LunKaransa!:' Soorsar, Dattor, Sailor dlst~butory and Khusar minor and Mohangarh 'are gYPslferous The gYPsllerous SOils are rn general shallow and found In rntra-dunal flats at low lYing areas Due 10 Ihe presence of hard and Impervious layer, ItS management IS little difficult

The introduction of Imgahon In desert ar~a brought'about a mini green r~volubon. and considerable prospenty to the fanners Some of the positIVe Impacts of introduction of Imgatlon In the desert Includes Improvement In micro climate, change In land usel In croPPing pattem, Improvement' of '5011 'and mOisture conditions and associated biological actiVities in the saris However, after few years of the introduction of liTigation, several negative effects emerged such as rise In the water table, waterlogging, fonnatlon of marshy lands, increased SOil salinity and decreased biodiversity The current estimates Indicate that about 0 18 m ha land is already affected by salinity and sodlclty In the IGNP command (Table' 5) The salt affected Salls In thiS command are mainly located In Anupgarh bra~ch, Suratgarh branch and Eastern block, The maximum area under salinlty/sodl~ty Is'in the Anupgarli branch because of poor Infiltration rate, 'high, bulk"denslty, poony developed structure, stratlficatron and hard crust fonnatlon rn the SOil The Salls are predominately clay to sl~y clay With medium sub angular blocky stNcture They are difficult io cuttlvate when dry and remain wet for longer time than nonmal soils Electncal conductrvlty In these Salls varres from 0 50 to 55 0 dSm" and pH from e 5 to 9,0, It has been observed that on both North and South Sides of IGNP canal feeder (Badopal, Dabll, Seelwala and Tlbl,areas), the ~ter table'lS, Within 2 m' In between Rawatsar and Maseetawali head, the problem IS mainly due to seepage of canal water whereas In Lunkamnser lift canal area, the problem IS of perched water table Similany, In part of Ghaggar flood area, the problem has developed due to water stagnation In the depreSSions Fluctuatrons in ground water table from 1996-97 to 2004-05 are depicted In Table 6 There 's decline In the waterlogged area dunng lasl 5-6 years mainly due to,subdued ramfall,and decreased availability of water In canal "

Table 5 Area (ha) of satt-affected Salls In IGNP

Satt affected Anupgarh Branch Suratgarh Branch Eastern Block class Area (ha) % of area Area (ha) % of area Area (ha) % of area Highly 73850 27 2 19930 17,1 37230' 237 Moderately 34580 12 7 7830 67 Total 108430 39.9 27760 238 ,37230 237

Source, UN()P, FA 0,(1971)

In Sizable part of IGNP, the ground water quality IS saline The EC of ground water vanes between 04 to 39 6 dSm" However, development of a fresh cushion of good quality water IS observed in the Ghaggar plain area, ThiS good quality water has tremendous scope for exploltalion for Irngatlon Similany; the chemical composition quality of water In the vl~mty of canals IS better With EC values of about 3 0 dSm" ThiS Indicates that a fresh water quality zone IS developing gradually and floatrng over the poor qua lily ground water

Since, there,'s no natural drainage system, more and more areas are getting watenogged' and sahnized resultmg In desertification A Sizable area has already gone out of cultivation and several VIllages have been abandoned In some of the extreme cases, people leel that they were better when the ""gatlon was not Introduced In the desert area Some of the techmques which need to be, adopted for reverting desertrficatlan Include adoption of better techniques of water management such as drip and spnnkler Imgallon, blo.aralnage to lower the waler table, fiXing water allowance as per Iff/gatlon capacrty of land and SOil profile, lining of unlined, water courses including personal fields, conjunctive use of surface and ground water resources, capa~ty bUilding of farmers and large scale adopllon of multiple use ,of water for multi, enterprrse agrtculture WIth malar. emphaSIS on saline aquacutture ,n already waterlogged areas Areas where water remains stagnated on the surface throughout the year can be developed as marrne eco-system or as a bird sanctuary There s~ems ample scope for promotion of blo-saline agnCulture Including cultlvabon of highly salt tolerant trees, bushes, grasses, aromallc and medICInal crops ,n thiS command

4

Salinity In Agnculture An Overview

Table 6. Waterlogged area In the IGNP command

5 Total area (ha) No Type of Area' Stage

96--97 97-98. 98-99 99-2K 2k-01 01-02 02-03 03,04 04-05 ,

1. Potenbally 297820 310056 29876Q 280023 225153 179170 164375 195000 168750 sensitive area II 17303 18067 '19666' 12184 1e3~ 24572 13481 16018 (water table 1 5- 6.0 m bgl)

2. Cribcal area 24140 28760 27960 26430 13425 11355 8750 9259 10625 (water table

II 3610 3792 .5088 2229 1261 453 317 476 1 Oto 1.5m ! b91)

3 Water logged 17220 22008 19492 18150 12672 10098 5755 2531 2968 area (water

II 1243 1243 1466 369 78 16 04 04 table wdh,n 00 to 10m)

Source: CAD Commissioner IGNP, Blkaner 2005-06

Saline aquaculture Induced soil and water degradaUon in south coastal belt

In coastal areas of AndHra Pradesh many nee fields are being converted Into brackish water fish farms due to high remuneration from aquaculture for more than the last deca'de Farmers draw brackish waler from the sea through creeks and drains Inlo the land and store millions of gallons of Ihis salt laden sea water on surface on big tanks ThiS activity IS practiced upto 10 km distance along Ihe sea coasl The stored sea water in ponds IS used for ralsong high value prawns Almost all the small and marginal fanneos and also the progressive and big fanneos are engaged In thiS practice as livelihood source. It IS reported that nearly 2 lakh ha area IS under saline aquaculture In the coaslal d,stncts of Andhra Pradesh The pumped sea water Into the fish tanks haVing sallmly 10 the range of 35~O dS/m IS blended With canal or ground water to lower Its salinity level to 18-20 dS/m which IS SUitable for culbvatlon of prawns The fanners generally take two crops of prawns In a year Initial Investment for undertaking thiS actiVIty IS around R$ 74-99 thousand per hectare Each crop of prawn matures In about 4 months and Yields about 2.5-3 3 tonnes per hectare of produce which gives a profit of nearly Rs 2.53 to 363 lakhs per hectare. A dIScusS/on w.lh the farmeos at the s.te revealed Ihat many of the small and marginal fanneos are abandoning thiS activity and more than 50% of the farmers already abandoned thel( prawn ponds They rever! back to nee culbvatlon bul are unable 10 grow a successful crop because of severe ssilOily problem In the pond Salls Probable reason advocated by the farmeos for abandOning thiS acbvlty IS the contamlnalion of pond waters Wllh some fatal virus due.!o Its mixing With drain. canal or creek water. The farmers further revealed that the whole crop of prawns IS finished Within few days of VIral infection. As such there IS no treatment for the.control of thiS v.rus once It Infects the prawns

Continuous cultivation of prawns In the coastal belt for about a decade now has resulted Into the senous problems of environmental degradabon. detenoralion In the 5011 and water quailly and assoclaled sOClo-economic concems Recenl stUdies conducted by the sCientlsls at Baptala centre of CSSRI Indicated that the adjoining cultivated fields are also affected severely due 10 salinization leading to reduction In crop y.eld. A survey conducted ,n the adjacent fields on Salls, wateos and plant samples revealed thai the presence ( of brackish water fish ponds resulled In bUIld-up of SOIl saiiOllY In nearby fields .n. comparison to the fields away from sahne aquaculture ponds Many of the farmers after,abandonmg thel( ponds are m.gratlng 10 other areas for employment and livelihood earning The .water.samples collected In' Guntur, PrakasarT) and Nellore dlstncts In.dlcated values of pH. EC and SAR'ln the range of 7.1-90, 0.58-340 dS/m and 076.-399 (m molen) ,respectively In most of the cases. the ground water quality IS changing Into the saline water. Similarly, the analYSIS of SOil samples COllected In Ihe adjOining fields of prawn culture ponds at a distance of 10 m and 20 m showed,ECe and pH values in the range of 0.6 -19 5 dSlm, 74-102.05-156 dS/m, 6 5-8 9 and 3 8-66 dS/m and 7 2 to B 5. respecbvely. in the dlstn~s of Guntur. Prakasam and Nellore

r In almost 90% of the cases ,In 'particular small and marginal farmers. the saline aquaculture IS not

successful However. there are some progressive farmeos who are continuously engaged In thiS bus.ness as a COrporate venture and have technical know how and capacity to deal With Viral Infection In Ihel( ponds are ~eltlng continuously good returns Some of them store the creek/canal water and treat Ihls water before filling In ponds 10 check .nfection .

<

Chemical Changes & NutrIent Transforrryation In Sodu:JPoor Quality Water Imgated SOils

Salinity In vertisols

Vertisols arid associates cover ~nearly 257 n1 ha oUhe earth's surface (Duda! and Bramao, 1965) of which abOut 72 m ha occur In India This shows that nea~y 22% of total geographical area of the country IS occupied by vertisols (Murthy, 1981) In the central reglon"of India kno~n as the Deccan Plateau, the salls are derived from weathered basalts mIXed to some extent WIth detntus fram other rocks ill other areas partlcula~y in the south, the salls are also denved from basIc metamorPhic rocks and calcareous clays' Similarly, In the western region, these are denved from marine allUVium that acCount for nearly 196m ha Of thiS about 1"12 m ha are affected by salinity and wate~ogging problems These salls are generally deep to very deep heavy textured with clay content varying from 40-70% Further, these, are also low in orgamc carbon content, high In cation exchange capacity, slight to moderate In sOil reactJOn and are generally calcareous In nature Vertisols, when kept fallow during Khanf season are exposed, t6 soil erosion hazards Because of their Inherent phYSico-chemical characteristics such as poor hydraulic conductiVity, low Infiltration rates, narrow workable mOisture range, deep and WIde cracks pose seriOUS problems even at low sallmly level However, the vertisols of Bara tract in GUJa",t are generally very deep (150 to 200 em), fine textured with clay content ranging from 45 to 68% with montmonlionlte dominant clay minerals The salls exhibit high shnnk and swell potential and develop Wlde cracks of 4-6 em extending upto 100 em depth The Salls are calcareous In nature haVing calaum carbonate ranging from 2 to 12% In the form of nodules, kimkar and powdery form In general, they exhibit alkaline reaellon In the recent past, Sardar Saravar Irngatlon Project Wlth a target to provide Irrigation for about 18m ha of command In GUJarat has been established The ground water quality In thiS region IS highly saline In about 90% area The salinity vanes from 2 to 117 dS/m With a mean of 30 7 dSlm The use of such high salinity water either directly or m conjunction With canal water for crop produelion IS thus limited The salts In the sub-sOil are prone to mobilize to-uppersurface WIth rismg ground water table Conditions are very favourable for secondary sallmzallon If Irrigallon IS praellced in traditional way The malor approach for salinity management in thiS reglcin~ WIll reqUire for prevention of nSEl of salinity rather than salimty reducllon alone Ralnfed farming systems with Iq-sllu and ex-sllu, rain water conservation, harvesting, storage, recycling and tapPing of perenmal flows and augmentation of ground water for supplemental Irrigation are some of the strategies for .booSling the agncultural productiVity. of vertisols In and and semi-and regions Another option IS to go for blo saline agnculture In these Salls A large number of medlanal, aromatic, all Yielding and petro crops have been Identified which can be cultivated WIth saline water IrTlgatlon(Smgh & Smgh, 1993, Smgh at a/, 1993) Some of the promiSing crops Included Sa/vadora, Matncana, dill (Anethum graveo/ens) and grasses like Aeloroups and Olcanthlum More vigorous efforts are reqUired to prevent irngatlon induced salinity In the vertisols Once such Salls are sa'hnlzed, these Will require huge Investment for reclamation . -

Use of poor quality waters In agriculture

India Wlth Its'4 2% share ~of global water resources IS 'supp,,-rting 16 7 per cent of global population Nea~y 85% 01 India's fresh water resources are being utilIZed In agnculture an'd the balance'15% In'domestlc and industnal sectors Quanllty and quality of ground waters are most important faCiors of high productIVIty and production In general, the areas demarcated by water scarcity sltuabon are also usually underlain by poor quality ground water resources The maximum area under saline and brackish ground waters in India occurs In the and and semi-and regions of RaJasthan, Haryana, Deihl, Punjab and Uttar Pradesh (MmhaS and Tyagl, 1998; Mmhas and Samra, 2003) Percentage use of poor quatlty ground water resources In different States IS given In Table 7 Because of scarcity of good quality water and Increasing pumping cost, brackish ground waters are being Increasingly utilized for irngated agnculture Because of more pumping of the ground water, many areas which were underlam with good quality aqUifers ar~ bemg contammated In several parts of the country Indlscnmlnate use of poor quality waters in the absence of proper sOII-water-crop-llvestock management practices IS posing a senous threat to sad, anl[l1al, human and enVIronment health BUild-up of salinity, sodlClty and toxlaty problems In soils Wlth Increased use of poor quality waters not only reduces crop productiVity but many times effects become so severe that lands even go out of cultivation Based on the research and experience in different agro-ecologlcal regions of India, lITIgation water resources were grouped Into the good, saline and alkali waters (Gupta st ai, 1994) (Table 6) Based upon the degree of restnctlons, two poor quality water classes were further sub-dlvlded each Into three sub groups Since each sub g·roup' needs speCific treatments and practices, thiS classrficatlon also serves the purpose of planning their development and management at micro niche level. However, different States are follOWing different claSSification of salinity of ground water for Irngatlon purposes i e the upper limit of salinity for Irrigation 'water In Haryana, Punjab, Delhr, Rajasthan (Western, Eastem), GUJarat and Uttar Pradesh are 6, 4, 3, 6, 6, 3 46 and 2 25 dSlm, respecbvely SUitable gUlde"nes based on 'chemical quality of water, SOil texture, crop tolerance, rainfall, concentration of solutions due to evapotranspiration for using saline ~and sodlc poor quality waters~to monsoonal agriculture have been developed and are presented In Tables 9 & 10

6

Salinity JJl Agriculture An OVerview

Table 7 Percentage of use of poor quality waters In different states ,

State % (estimated values) State % (estimated values)

Andhra Pradesh 32 ;' GUJarat 30

Hal)'ana 62 ~ Kamataka 38

Madhya Pradesh 25 • Rajasthan ~4

Uttar Pradesh 47 J

Table 8 Groupmg of poor quality ground waters for ,rngatlon m India

Water quality class Eciw SAR RSC Main Sub class (dS/m) (mmollL) (melL)

Good ,<2 <10 <25 Sallne Marginally sallne '2-4 <10 <2.5

Saline <4 <10 <2.5 Hlgh-SAR saline <4 <10 <2.5

Alkall Marginally alkali <4 <10 25-40 Alkall <4 <10 <4,0 Highly alkali Vanable <10 <40

Eaw = Electrical conductlvJty of ImgatJon water; SAR = Sodium adsorption ratiO and RSC = Residual sod lum carbonate

Table 9 GUidelines for uSing sallne groundwater

So,l texture (% clay

GUidelines for using saline waters Crop -tolerance Upper limits 9f EC,w (dS/m) In ramfall region

350 mm 350-550 mm 550-750 mm

Fme «30) S 1 0 1,0 1 5

ST 15 20 30 T '2.0 30 45

Moderately Fine (20-30) S 1 5 20 25

ST 20 30 45 T '40 60 80

Moderately Coarse (10-20)

S 20 25 30 ST 40 60 80 T 60 80, 100

Coarse (>10)

S 30 30 ST 60 75 90 T 10 100 125

Table 10. GUidelines for us,ng alkal~sOd,cwaters

SOil Texture % clay

I'IOe>30

MOderately F'ne(20-30) Moderately Coarse(10-20) Coarse

Upper limits of SAR (mole/htre) RSC (meqMre)

10 25-35 10 '15 20

7

35-50 50-75 75-100

Chemical Changes & Nutrlellt Trallsformation In Sadie/Poor Quahty Water Imgated Solis

Reclamation and Management Strategies

5trategleto manage sodic (alkall)'soilS: The chemical amendment based technology has been developed to reclaim the alkalilsodlc sOils (Singh et al ,2003) Various components of thIS technology Includes, field levehng, bundlng, sOil sampling to know the sodlclty status for wori<lng out amendment dose, applicallon of gypsumlpYrite as per requirement of the soil and Its mixing in upper 10 em 5011, keeping water pondlng'for 5-7 days, follOWing nee-wheat rotation for the first 3 to 4 years and groWIng sesbama dunng :summer as green manure crop after wheat haNest In Apnl By adopting thiS technology about 13m ha area has been reclaimed In the states of Punjab, Haryana and westem UP (Smgh' ef-al, 2007) The reclaimed area IS contributing 8-10 m tonnes additional food grains 10 the national foodgralns pool The sodlclty/alkali 5011 reclamallon technology gives a benefit cost ra!lo varying from 1 29 to 2.30 and an inte'lial rate of return 22 to 56% depending upon the level of subSidy provided by the govemment In addrtlon to food producllon and employment generation, the reclamation programmes have helped in minimizing floOd hazards, ,"creasing ground water recharge, reducmg InCidence of malana and water borne diseases, growth in agro..based 'and aUXiliary Industnes and increasing forest cover, Some of the constraints being expenenced In further adoption of thiS technology Includes, Increased cost of amendments and WIthdrawal of subSidy, reqUirement of repeat application of gypsum In areas With high reSidual sodium carbonate waters or wrth shallow brackish water Crops differ In their tolerance to SOil sodlclty (Abrol & Bhumbla, 1979) The relallve tolerance of crops and grasses to SOil exchangeable sodium per cent (ESP) IS given In Table 11

Table 11 Relalive tolerance of crops and grasses to SOIl ESP

Tolerant (ESP 35-50)

Karnal9rass (Leptochloa fusca)

Rhodes grass (Chlons gayana)

Para grass (Brach/ana mUllca)

Bemnuda grass(Cynodon dactylon)

Rice (Ol}'Za saf/va)

Ohamcha (Sesbanra aculeata)

Sugarbeet (Befa vu!gans)

TeOSinte (Euchlaena max/canal

Moderately tolerant (ESP 15-35)

Wheat (Tnt/cum aestlVum)

Barley (Hordeum vulgare)

Oat (Avena sativa)

Shaftal (TntollUm rasupmalum)

I,ucerne (Merflcago salIVa)

Tuml'p (Brass/ca rapa)

Sunflower (Hel1anthus annus)

Safflower (earlhamus tmctorius)

Berseen (TntollUm alexandnnum)

LI~seed (Unum uSlfat/ssimum)

Onion (AII1um cepa) Gralie (AJ/lUm satlVum)

Pea~ millet (Pennlsetum fypho/des)

Sensitive (ESP < 15)

Gram (C/eer anal/urn)

Mash (Phaseo/us mungo)

Chickpea (CICer ane~num)

Lenbl (Lens esc~lenta)

SOyabean (Glycme max)

Groundnut (Arachis hypogeaj

Sesamum (Sesamum onanfal)

Mung (Phaseolus auraus)

Pea (p/Sum sa!/vum)

COWpea (V/gna ungUlculafar

MaIZe (Zea mays)

Cotton (GosSYPlUm /'lIrsutum)

Salt tolerant varietles: A SIzable part of the salt-affected area In India IS In possession of small and marginal lamners who are themselves poor Under such sltualions, chemical amendments based redamatlon technology WIthout government subSidy IS nol sustamable Development of ssa tolerant vanetles of Important field crops IS an option of great promise for utilizatIon of such areas As most of these vaneues gives Significant yield WithOut or WIth little application 01 chemIcal amendments Several vanet,es of field crops like nce, wheat and mustard have been developed which have potential to yield reasonable economic return both In high pH alkali SOlis and also In saline Salls (Smgh & Shanna, 2006) In case of rlCI!, the most promising varlelies include CSR10, CSRI3, CSR19, CSR23, CSR27, CSR30 and CSR36 These vanetles can be cuU,vated In Salls With pH and EC range from 9.4 to 9 6 and 6-11 dSlm A list of salt telerant vanetles along With their level oftoleranee to SOil salinity and alkalinity IS given In Table 12

Reclamation of saline waterlogged soils

Sub-surface drainage technology has bilen developed to lower the water table In saline waterlogged areas (Datfa ef aI, 2000; ManJunafha 9f aI, 2004) The System conSists of a ne!work of concrete or ngld PVC pipes alongWlth filter Installed manually or mechanically at a deSIgned spacing and depth below SOil surface to control water table depth by dralmng excess water and dispOSIng tt out of the area by gravity or by pumpon9 from an open well, called sump The first approximation of the area covered under sub-surface drainage in India I~ given In Table 13

B

Salinity In Ag~cul1ure' An Overview

Table 12. Recommended salt tolerant varieties

Adaptab"lly Crop Tolerant varieties SOdlcpH. Saline ECe, Coastal sahne

dS/m ECe,dS/m Rice CSR 10', CSR II, CSR 12, CSR 13' S,6 -10 2 6-11

CSR1S, CSR23', CSR27', CSR30', CSR36' 94-98 6 11 CSR1, CSR2, CSR3, CSR4', CST7-I',

I 6-S 4 SR26B, Sumati'

,

Wheat KRL 1-<1', WH157 <S 3 6-10 Raj30n, KRL IS' <S.3 6-10

Barley DL200, Raina, BH97, Dl346 8 8-S 3 Indian Pusa Bold, Varuna 8 8-9 2 6~, mustard Kranti, CS52', CSTR3:iO-l". 6.6-9 3 6-9 (Raya) I

CSTS09-B 10, CS54' , 68-93 6-9 Gram Kamal Chana I <90 <60 Sugarbeet Ramonskaaya 06, Manbo Resistapely 95-10 <65 Sugarcane C0453, Co1341 <9.0 ECe -10

'Inslilule vanelies released by Cenlrel Vanelsl Release Commit/ee

The SOCIo-economlc analysIs of sub-surface drainage indicates that 126 mandays of employment are generated per hectare With a benefit cost ratio of 1 26 to 1 49 The intemal rate of return Vanes from 13 3 to 14.75% The large scale adopllon of thiS technol09Y has not taken place because of cost faclors, difficulty In maintenance of drainage system, need of communtty participation, highly skilled manpower, environmental problems of drainage effiuent disposal and reqUIrement of continuous energy to pump out the drainage effluent To address Ihese IsSueS involvement of farmers, shanng of conslrucllon and operating cosl and 90vemmenl subsidy seems v"al for success of sub-surface drainage technology.

Table 13 FIrst approximation of the area covered under sub surface drainage projects

State

RaJaslhan

PU"Iab

Karnataka

Andhra Pradesh

Madhya Pradesh Maharashlra Gujarat

Kerala Assam

Name of command

Chambal Indira Gandhf Nahar Pariyojana Westem Jamuna Canal Bhakra Canal SOClth ~st Pun/ao

Upper Knshna Tungabhadra MalparbhaiGhatparbha Naga~una Sagar Krishana Weslern Delta Unspecified Uncommanded/Neera canal Command/Others Mahl-Kadana Ukai-kakrapar Acid sulphate SOils' Tea gardens

Area covered, ha*

15,700 500 '1450<-3000' 1300+1000' 30+2000'

30 200 20 50 50 50 1000+1000' 150 80 30 15

Alternate land use systenis: A Sizable part of the saU-affecied SOils In india IS constiluted by the village community lands, lands along the roads, railway tracks and other government lands reserved for speCific PUrposes .• Reclamabon of such area for crop production IS posln9 problems because of community rights on such land resources These sites offer ample appartundres to raIse sa« telerant trees, bushes and grasses to produce fuelwoOd, fodder and energy An alternate technology of raising multipurpose forest tree planl!'tlon, fruit tree~, agroforestry systems and other high value mediCinal and aromatic crops seems qune feasible Several salt toleranl foresl and frull speaes have been Idenbfied which can be grown In highly sod,c and _ salme solis (Srngh al a/, 1994; Mrnhas al a/, 1997, romaral ai, 2003) The promiSing fQrest speCies mclude

9

Chemical Changes & Nutnent Transfor'!lation In SodlcJpoor Quality Water Irngaled Sorls

ProSOPIS juldlora, Acacia mlat/ca, Tamanx articulata and Casuanna eqUisetlfofla The comparative perfonnance of different tree species after 3, 5, 7 and 10 years after planting In terms of survival, diameter and lopped biomass ''S given In Table 14, ,

, Table 14, Comparative perfonnance of mulllpurpose trees at 3, 5,7 & 10 years after planting In a highly salty

/ 5011 , .

Tree speCies

Temllnalia afJuna

AzadllBchta mdlca ProSOPls Jullflora Pongamla pin nata Casuanna eqUisebfollll ProSOPIS alba Acacia mloilca eucalyptus temhcomls Plthecellob/Um dulce CasSIa slamea LSD (P=O,OS)

SUNMII ('!o) year after plantalion

3 5 7 10 100 100 100 100

100 98 ~3 93

100 100 100 100 100 100 100 100

99 98

60 50 100 97 100 99

97

50 95 99

97

50 95 99

100 100 100 100

98 96 96 96

DBH (em) year after plantation

3 5 7 10

4 &7 643 7 21 9 20

356

720 468

524

921 587

54 846

1064 1232 614 9,27

, , Lopped biomass

(kg trea') ,

3 5 7 10 1 B6 205 '327 615

120

442 218

124

6,12 313

1 56

693 368

240

1130 610

714 880 10141214317 544 606 634

480 610· 7,86

6.24 9,03 1084

687846420 1201 14 12 ,270 12,00 13,10 025

560 ,381 062

632 453 453

925 410 350

605 758 821 'lOIS 270 482 518 550

3 14 385 438 663 054 1.14 064 065

025 0.51 0.65 1 30. 1 08 076 080 1 12

Similarly, long lelTl1 field tnals In a highly sodlc 5011 revealed that Emblica officmalis, PsydlUm gual"va and Canssa carandus proved highly promising In tenms of growth perfonmance and frUlI produGlion (Singh at 81, 1997) SUMval, growth and frwt producMn data of several frUit speCies tned at ShiV" Fann of the Institute near Lucknow, Central India In a sOdlC 5011 of pH 100 IS given In Table 15 Te~ years financial analYSIS indicated that benefit - cost (6 C) ratio In case of Embllca was highest 2 79 followed by Canssa 1 62 and Guava 1.60

Table 15 Comparative perfonmance of eight frUit trees after 10 yearS of planting In a sodlC 5011

Planllng technique Frull species PII Plt-cum-augerhole

(90 em x 90 em x90 em) (45 em x 45 em x45 em) Survival (%) Height (m) Survival (%) Height (m)

Jamun (SYZlUm cumlnl) 100 482 100 505 Imll (Tamanndus mdlca) 96 345 96 354 Ka,raunda (Canss8 c8rondus) 96 165 100 196 Ber (llzyphuS maurltlana) 96 303 100 416 Guava (PsydlUm gvaJava) 111 303 100 315 Aonla (emMca offieinalis) 88 261 96 417 Mango (Mangl(era indica) 30 1.33 55 212 Pomegranate (Pumca granatum) 20 1 55 45 212

Mean 77 268 86 328

Salrne and sodle SOI/S reqUire special site management technrques for growrng deep rooted trees Accordingly, special site preparation techniques for growing forest and fruit trees have been developed and standardIZed, An augemole technique has been developed to break the calcium carbonate hard pan present In the profile of a sodlc soil at a deplh of about 1 m from the surface (Smgh, 1996) In thiS techmque, a hole of 20-25 em diameter and 100 to 120 em deep is dug out With a tractor mounted augerbore 'The dug out holes are refilled back With a mliture of anginal alkali 5011 blended With 3-4 Kg of gypsum, 8-10 kg of FYM and about 101<9 s,ll (mer sand) T\ns lechmque ensures more Ihan 90% Iree sUNlval In soils of pH 104 even after B-l0 years of plantmg A number of Village community lands were planted With' thiS technique under the SOCial forestry project funded by European Union and',mplemented by the slate forest departments For raising

10

Sahnlty)" Agnculture An Overview

fOrest trees In saline salls, trench method proves better than planting either on surface or on ndges (Tomar and Gupta, 1985) The sub-surface planting ensures belter survival and growth of trees In saline 50115 as the soluble salts move away from the roots of sapling and get depOSited on the ndges With evaporation Further, lITIgation to saplings In trenches provides less salty SOil and water regime, which favours survival and growth dunng the establishment stage '

·1 For raising frUit trees, the augemole technique has been further modified to faCilitate root growth both

In honzontal and vertical dlrechon (Singh Ilt ai, 1997) The deVised technique called plt-cum-augemole method Involves two phases 01 operallons In the first phase, a Pit 01 45 em x 45 em x 45 em dimenSions IS dug manually and In the second phase, In the center of thiS Pit, an augerbore of 20-25 em diameter and 120-140 em deep IS made to faCilitate root spread both In honzontal and vertical directions The dug out plt-cumaugerbores are refilled back with anginal SOIl plus 8-10 kg gypsum, 20 kg FYM and 20 kg nver sand ThiS techmque ensures more than 80% survival of fruit trees In a 5011 of pH around 10 By adopting thiS technique several fruit species have s~rvlved and identified for highly sodlc 5011

Agroforestry: Several grass speCies have mechanism to tolerate high salt concentration In the root zone 5011

Some of these highly tolerant grasses either exclude the absorplion of salts from the 5011 and/or depOSit the absorbedltranslocated salts at POints Within the plant system which do not allow them to Interfere In matabohc processes Such grasses have been Identified (Kumar, 1986) and a Jist according to the" level of salt tolerance IS given In Table 16 Grasses like Leptoeh/oB fusea has the potential to yield high biomass even at pH level of 10 4 and more. Similarly, Bnchana mullea IS another salt tolerant grass, which can be grown even under prolonged wate~ogged and sa~ s!\Uabon [Table 16),

Several expenments have been conducted at CSSRI, Kamal and elsewhere to study the performance of these grasses In association With salt tolerant trees hke Prosopls}ullllora and AcaCia mlotlC8 In a unified agroforestry system (Singh et ai, 1988, Singh, 1995). A field study conducted at Gudha expenmental farm for SIX years indicated that Leptochloa f~sca has the potential to Yield about 20 tonnes/ha of green biomass per annum when planted With Prosopis jU/lflora '" a SOil haVing pH of 104 Leptoch/08 grass has a special characterstlc that It starts dlsappeanng when sodlClty level In the soil decreases Thus, allOWing the regeneraUon of other moderately sail tolerant grasses and other annuals The results of thiS expenment clearly ,ndiCated that sodlc Salls can be reClaimed by groWing ProSOPIS }ullllora and Leptochloa fusca for five years Ounng thiS penod, the surface SOil IS reclaimed and .salt tolerant crops like Berseem (Tnfoltum alexendnnum), Egyptian clover, oats and senll can be groWin Without the apphcatlon 01 amendments Vanous components of thiS agroforestry system are.enumeraled In Figure 2

Table 16 List of promising grasses according to their level of tolerance to SOil pH

pH 104

100 96 92

88

Grass/forage crop

Kamal gras5 Rhodes grass GaHon pamc Bermuda/Dub grass Para grass Bluepamc Hybnd Napier Setana grass An)an grass GUinea grass Deenanalh grass

Botamcal name

Leptochlaa fusea Chlons gayana Pamcum m8Xlmum Cynodon aaelylon Brachlana mutlca PaOlcum ant,dolale Penmsetum purpureum Setana anceps Cenchros cillaris Pamcum maximum Penmsetum pedlee/fatum

pH value at which 50% or less than 50% Yield reduction occurred

11

Chemical Changes & Nutrient Transfonnatlon In SodlclPoor Quality Water Irngated SOils

Rcmoving trc!.-'t>

l VI.'heat .lind nal prnductwn

~ Soil may bccomt> sodJc_agaln

l

l ThlIlJtlng trues

l, , Crop production with trees continued

l Bette,. option

Fig, 2 Sllvi-pastoral model for reclamation of sodic salls,

Medicinal and aromatic crops: A number of Illedlcinal and aromatic crops have been screened for salinity and sodlcity tolerance In India, Crops like Isabgol (Plantago ovata) and Matncana can be successfully cultivated in soils having pH of 9,5 and EC between 8-10 dS/m (Dagar et aI" 2004; Dagar et el" 2006), Simliarly, dill (Anethum greveolens). a spice crop and Salvadora, a non-edible' oil tree can be grown In saltaffected vertisols very successfully Industnal species like Euphorbia and mulethi (Glycyrrhiza glabra) also have good scope for cultivation in salty enVIronments,

Soli reclamation: Salt tolerant trees and grasses when planted either In aSSOCiation or as sale plantations reclaim the sodlc soils over a considerable period of time, The mechanism for sodic soil reclamation by trees involves; a) dissolution of native calcium carbonate present in precipitated form in sodic solis by the biological activity of tree, grass roots, b) addition of leaf liHer and tum over of old roots which increase organiC carbon in the soil, c) penetration of water into the otherwise impermeable soil through the holes created by the decayed roots which faCilitates reaction with C02 evolved from root respiration and thus producing carbOniC acid ThiS acid, though weak In reaction Initiates the process of dissolution of native CaC03, The free Ca in the soil solution available through this reaction replaces the Ha ions, on the exchange complex and d) Initiation of biological activity in the SOil due to improved orgaOic maHer contents, moisture an'd fertility regime The degree of reclamation depends upon the kind of tree species, planting denSIty, the adopted management practices and fencing provided to the plantation 10 check en9roachment by humans and animals, Several experiments have been conducted in the past to study the reclamation effects of trees on phYSical, chemical and biological properties of sodic soils (Kauret al,2000; 2001a; 2oo1b), The results of a long term field experiment after 20 years (planted in 1970) in a soil haVing pH of 10 3 indicated that ProSOPIS julJllora has the maximum Impact on redUCing soil pH and EC and improvement In SOil orgaOic carbon and plant nutnents, The comparative effect of different tree speCies on SOil properties is gIVen in Table 17

Table 17 Ameliorating effects oltree plantation on alkali Salls

Species Onglnal pH2 OrgaOic C (%)

After 20 years of planting pH2 Organic C (%)

Eucalyptus tere/IComis 103 012 9,18 033 AcaCIa nilotica 103 012 903 0,55 Albizia lebbeck 10,3 0,12 8.67 047 Terminalla aljuna 10,3 012 6,15 0,56 Prosopis luliflora 10,3 012 8,03 058

When salt tolerant grasses are associated With trees, the reclaiming effect becomes much faster It has been proved that crops like gram, oats and wheat can be successfully grown on sodic Salls reclaimed by

12

Sahnlty In Agnrulture. An Overview

tree plantatJOns (Figure "3), Expenmental eVidences Indicated that productIVIty of these crops was much higher when salls reclaimed by trees were used In pots to raise these crops as compared to sodlc salls reclaimed by gypsum application (Bhojvald et al , 1996, Singh et al ,199B)

Fig 3 Sllvl-agncultural model for amehoratlon of sadie SOils

Blo-dralnage' Blodramage refers to a techmque of Iowenng ground water table In watenogged areas through the use of raising tree plantations This technique removes excess SOil water through the process of transpiration by trees uSing solar radiation energy It is a kind of preventive technique 'to aVOid the development of salinity and waterlogging problem In canal command areas The technique IS highly useful when the Salls are stili In the process of salinization due to nse In ground water level. However. If the Salls are already sallnlzed It has limited scope Several species of trees have been screened to study the" capaClty to transpire water from different salinity and water table depths The most promising species Identified for b,o· dra,"age Include Eucalyptus, Populus, Casuranta and 8ambusa Several programmes are In progress, throughout the country to reclaim waterlogged areas In canal commands through blodrainage

Bibliography

Abrol, I P and Bhumbla, DR 1979 Crop responses to differential gypsum applications In a highly sodlc SOil and the tolerance of several crops to exchangeable sodium under field condition Soli SCI, 127,79-85

Annual Report 2006·07 Central Soil Salinity Research Institute, Karnal

Annual Report 2006-07, Nabonal Bureau of 5011 Survey and Land Use Planning, Nagpur

Annual Report, 2006·07, National Remote Sensing Agency, Hyderabad

Bhojvald, P P , Timmer, V R and Singh, Gurbachan 1996 Reclaiming sodlc Salls for wheat production by ProSOPIS jullfiora(Swartz) DC afforestation in India Agroforestry System, 34 ' 139·50

CAD & iNM Report 2005·06 Command Area Development and Water Management Commissioner, IGNP, BIKaner, Rajasthan

Chhabra, Rand Abrol, I P 1977 Reclaiming effect of nee grown In sodlc SOil 5011 Sci 124' 49·55 Dagar, J"C, Tomar, 0 S and Kumar, y, 2006 Cultivation of mediCinal Isabgol(PIantago ovata) In different

alkali Salls In seml·and regions of northern India Land Degrad Develop, 17 , 275·283' Dagar, J C , Tomar, 0 S" Kumar, Y and Yadav, R K 2004 Growing three aromatic grasses In different alkali

50115 In seml·arid regions of northern India Land Degrad Develop 15 143·151 Datta, K KLang, C de and Singh, 0 P 2000 Reclaiming salt affected land through drainage In Haryana,

Ind", ,A finanCIal analysIS Agnc. Water Management, 46 55·71. Dudal, Rand Bramao, D L 1965 Dark clay Salls of tropical and subtropical regions FAO Agncultural

Development Paper No 8 FAO(Food and Agnculture Organlzallon), Rome

13

ChemICal Changes & Nulnent Transformation In SochcJPoor Quality Water !mgated SOlis

EI-Mowellhey, N 1998 Proc Intern Symp. "Sustainable Management of Salt Affected Salls In the And Ecosystmem" Cairo, Egypt 21-26 September, 1997, Pages 1:2 ' .

Gupta R K", Singh, N T and Sethi Madhurma 1994. Ground Water quality for Imgatlon In India CSSRI, Bul.

/ No 19. 13p •

Kanwar, J Sand Bhumbla, D R 1969 PhysIco chemical charactenstlcs of sodlc salls of Punjab and Haryana and their amelioralion by the use of gypsum Agrokem Talalt.18 315-320 ,

Kaur, B Gupta, S R and Singh, Gurbachan. 2001a 'Carbon 510rage and nitrogen cycling In sllvlpastoral system on sodlc soils In north western India Agrofor Sys ,54 13-20 "

" Kaur, B Gupta,S R. and Singh, Gurbachan 2001 b Bloamelioratlon of sodlc salls by sllvlpastoral systems In

north western India Agrofor Sys, 54 21-29

Kaur, B , Gupta, S R and Singh, Gurbachan 2000 SOil carbon microbial activity and nitrogen availability In agroforestry systems on moderately alkali solS in northern India Appl Soil Eco ,15 282-294

Kumar, Ashok 1986 Grasses In alkali soils CSSRI Bullelin 11, 96p Manjunatha, M V., Oosterbaan, R J, Gupta, $ K, Rajkumar, t{. and Jansen, H 2004 Performance of

subsurface drains for reclaiming waterlogged saline lands under rolling topography In Tungabadra imgatlon project In India Agnc Water Management, 69 . 69-82.

Mlnhas, P S and Samra, J 5 2003 Quality assessment of water resources In the Indo-Gangetic baSin part In India Bul No 212003(B)

Mlnhas, P 5 and Tyagl, N K 1998 GUidelines for IOigatlon With saline alkali waters Bul No 1198 35p

Mlnhas, P S , Singh, Y P , Tomar, OS., Gupta, R K. and Gupta, Raj K 1997 Saline water Imgatlon for the establishment of furrow planted trees In north westem tndla. Agroforastry systems, 35 177-186.

Rangasamy, P. and Olasson, KA 1991 Sodlclty and soil structure. Aust. J Soil Res 29935-952.

Singh, Gurbachan and Singh, N.T 1993 MesqUite for the revegetation of salt lands Bul No.18 Singh Gurbachan, Singh, N T and Tomar, 0 S. 1993 Agroforestry In salt affected 50115 Bul No 17

Singh, Gurbachan. 1 996 Effect of site preparation techniques on ProSOPIS jullflora In an alkali 5011 Forast Ecol Management, 80.267-78

Singh, Gurbachan, Abrol, I P. and Cheema, S S 1988 Agroforestry on alkali 5011· effect of planling methods and amendments on IMitlal growth, biomass accumulation and chemical composition of mesqUite (ProSOPIS Ju/lflora) (SW) (DC) With Inter-space planted With and Without Kamal grass (DlplBchne fusea Linn P Beauv) Agroforastry Systems, 7. 135-160 .

Singh, Gurbachan, Abrol, I P. and Cheema, S S 1994 Agroforestry techniques for the rehatlilitabon of salt lands Land Oegrad Rehab, 5 223:242 • '

Sln9h, Gurbachan, Dagar, J C and Singh, NT 1997 GroWing fruit trees In highly alka.l' sOlls'- a case study. Land Degradalion Rehabilitalion, B 257 -268.

Singh, Gurbachan, Gupta, S K, Sharma, D P and Tyagl, N K 2003 Reclamation and management of waterlogged salt affected Salls Technical Brochure, DOlft, MORD 0212003, Department of land Resources, Ministry of Rural Development, Gocl of India, 36 p

Singh, Gurbachan, Sharma, PC, Ambast, S K , Kamra, S K and Khosla, B K 2007 CSSRI A Journey 10 Excellence (1969-2006), Central SOil Salinity Research Institute, Kamal, p-156.

Singh, Gurbachan, Singh, Hannder and Bhojvaid. P P. 1998 Amelioration of sadie soils by trees for wheatand oat produclion Land Degrad Develop 9 536-45

Singh, K N and Sharma, PC 2006 Salt tolerant varieties released for saline and alkali Salls Central 5011 Salinity Research Insbtute, Kamal

Singh, Gurbachan. 1995 An agroforestry practice for the d~velopment of salt lands using ProsoPIS Juliflora and Leploch/oa 'usea Agroforastry Systems, 27 : 1-15

Szabolcs, I 1979 ReView of research on salt affected 50115 Natural Resource Research, IS, UNESCO, paris' SZabolcs, I 1980 Saline and alkali Salls - commonalities and differences. Proc Intern Symp Salt Affected

Sods, pp 1-6, ~eld at CSSRI, Kamal, 18-21 Feb, 1980 Tomar, 0 S and Gupta R K, 1985 Perfonnance of some forest tree species In sahne SOlis under-shallow and

saline water table candlbons. Pt Soil, 87 329-335. Tomar, O.S. Mlnhas, P 5, Sharma, V K., Singh. Y.P. and Gupta R K 2003. Performance of 31 tree species

and 5011 candilions In a plantation established With saline Irngalion Forast Eco/ Mgmt, 177:333-46 UNOP, FAO 1971. SOil Survey and Sad and Water Management Research and Demonstration in the

Rajasthan canal area Semi detailed 5011 survey of the SUratgarh branch area AGL _ SF/IND 24, Technical Report, 1 3. Rome

14

Natural Resources Management In Relation to Predicted Climatic Changes

Gumachan Singh Central SOil Salimty Research Institute, Kamal-132 001

Introduction

The nature has provided the mankind With four basIc resources of climate, water, sOil and biodiversity to meet the survival needs Rational use of these natural resources to meet the needs and not the greeds Will detelTmne the longeVity of Civilizations During more than the last three decades, these resources have been stretched and over explOited to meet food, 'fibre and shelter requirements of btirgeoOlng human and livestock populations Over explOitabon of water, SOil and biodiversity has resulted In thelf degradation In, terms of quality and availability The foodgram producllon In the country IS revolVing around 210 to 215 m~lion. tonnes since 2001-2002 oWing to the adverse Impact of weather abnormalities despite the' advanced technology Anthropogenic emisSions of green houSe gasses have conSiderably Increased due to faulty agncultural practices and have resulted.1n climate change and global warming of the' 'planet (S!",amllTathan, 2002, ' Ramaknshna, 2007) Carbon diOXide (CO,), methane (CH4), nltrous'oxlde (N,O), hydrofluoro-carbons (HFCs), perfiuoro-carbons (PFCs) and sulphur hexafluonde (SF6) are the SIX Important gases which are' responSible for the current global wannlng It has been reported that Increase In CO, concentrallon In the atmosphere dunng the last 50 years has almost surpassed the Increases reported dunng the last 1000 years_' The mean global annual temperatures Increased between 04 to 07°C during the last century. The year 2005 has been reported the warmest year so far Almost all the years in the current decade recorded extreme weather events, and the year 2007 has also been declared as one of the warmest years. Since last seveial years the wheat production In the country remained stagnated due to increase In temperature dunng reproduCtive phase of the crop across the wheat growing regions As per FAD records, the wheat stocks have exhausted to its lowest level since 1980 The reasons attnbuted for such a shortfall Include abnormal weather conditions In Australia, Ukraine, Argentina and RUSSia Melting of glaCiers, see level nse, submergence of Islands/coastal areas and change In rainfall and temperature patter~ over the next,century are predlctea ThiS change IS bound to affect water availability, bio-dlVersily patt~_m. demand a new set of land use 'pattem ",eluding enterpnses, commodities, crops and vanetles Global warming related ozone depletion has also been reported which may lead to Increased UV radiation With far reaching adverse Impact on earth's environment and human as well as livestock populations Including microbial communities Such effects of climate change have already started Impacling agncultural productIVIty In several agro-chmauc regions and sub-regions of the country The country expenenced one of the severest droughts of the last century during 2002 that lowered food grain production by more than 29 million tonnes The cold waves of 2002-03. 2005-06, 2007-08 caused Significant damage to winter crops m the states of Punjab, Haryana and western UP The heat wave of March, 2004 In northem states COinCided With the reproductIVe phase of wheat slowed down the translocabon of photosynthetic aSSimilates from vegetative parts to grains and lowered the production by more than 4 million tons Unexpected heavy rainfall (about 200 mm In 48 hours) dunng February, 2007 caused extensive damage to wheat and other Rabi crops In Haryana The monsoon behaViour In 2007 over Kerala was totally different to that of prevIous yea", and very heavy rains were observed between June and September leading to severe flooding In low lYing areas Like several past years May, 2008 has also expenenced low temperature and monsoon like weather condllions Predicted spatial redlstnbulion of preClp,talion, droughts, floods, heat waves, cold waves and water balance Will change the land use pattem, cropping systems, pests and dIseases

Net Impact on the productiVity Will be the resultant of contrasbng effects of Increased temperature and carbon diOXide concentration depending upon C3 or C. plants and their cultivation In temperate or troplca,l region. These concems are likely to proVide ample opportunities to the agronomists to plan and execute research to deal With future scenanos of climate to sustain agricultural productiVity and food and nutntlonal secunty In the 21· century

Impact of Climate Change on Agriculbure

The climate change Will affect crop Yield and croppmg patiern due to direct .effects of changes In atmosphenc concentrations of green house gases"ln general and CO" In particular (Aggarwal a~d. Sinha, 1993) Carbon diOXide IS a perfect example of a change that could have both positive and negative effects Carbon dioxide IS expected to have positive physiological effects through increased photosynthesIs. ThiS Impact should be higher on C, crops such as wheat and nce than on C. plants like maize and grasses It has been reported that under optJmum conditions of temperature and humidity, the biomass Increase could reach nearly 36% for a doubling of CO, This clearly Indicates that the direct effects of changes Will be through the change m temperature, preCipitation and radiation However. mdlrect effects Will bring changes In SOil mOisture and Infestation by pests and diseases because of nSlng temperature and relative humidity The dlrect.effects of Increased carbon dioxide concentrations In the atmosphere are conSidered to have promoling effect on the growth and productIVIty of crops as eicplallTed ea~ier The Indirect effects through the Increase In temperature

Chemical Changes & Nutnent Transformation In SodlclPoor Quality Water Irrigated SOI/S

Will reduce crop durallon, increase crop resplrallon rates, Increase evapotranSpiration, decrease fertilizer use effiCienCies and enhanced pest infestabon Possible Impact of climate change on wheat production In India has been Worked out by the climate sCientists for the penod between 2000 and 2070 (Fig I) There IS general consensus Ihal the Yield of main season (Khanf) crop Will Increase due 10 the effect of higher carbon diOXide levels (Aggarwal and Mall, 2002) However, large Yield decreases are predicted for the Rabl crops because of Increased temperatures One of the potenllal effects of climate change on agnculture will be the shifts In the sOWIng time and length of growing seasons, wiuch would alter sowing and halVesUng dates of plants, crops 'and vanelles High lemperature Induced higher evapotranspiration would call for much greater effiCiency of water and nutnents Changed ~ed ,flora and pests would require special met,hods of management and control, a challenge for agronomy and plant prot~ctlon community There may be i shift In cllmallc zones due to, Increased temperatures In mld-Ialrtudes, the shift IS expected to 200-300 km, lor every 1°C nse In temperature (IUCe, 1992) Morey and Sadhaphal (1981) reported a decrease of wheat Yield by 400 kg ha' for a umt Increase 01 1°C temperature and 05 hour sunshine Similar obselVabons were recorded by Hundal and Kaur (2007) under Punjab conditions Their analYSIS revealed that an mcrease of temperature from' hOlT11al. can decrease the wheal Yield in the fo)lowing oroer, '

• Temperature increase In the 4'" week of January decreased the Hraln Yield by a 99, 066 .. and a 70% per degree celCius lor wheat sown In the 4'" week 01 October, 1 'Week 01 November and 2"" week '01 Novembar, respeCllvely .

• A decrease In grain YIeld to the extent of, 2,88 and 187% per degree Increase'ln temperature occurred w]1en wheat was sown in t~e 4th week of October and 1'1 week of November, respectively .

• Increased temperature during the second lortnlght 01 FebruarY decreased wheat Yield by 2 4~,3 30, 2 I~ 1 26 and ,a 69% per degree .Increase when wheat was sown In the 4'" '>wek of October, 1 week, II ' week, 4'" week of November and 1" 'week 01 December, respectIVely, '

• MaXimum decrease to the tune of 240, 2 la, 298, 351 and 315% occurred when temperature rose dunng the first lortmght of March in case of wheat sown In fourth week 01 October, fi~t y;eek, second week, fourth week 01 November and first week of Decemtler, respectlve!y

• A Yield loss of 1 24, 2 15 'and 340% occunred In wheat sown In second week, lourth week of November and first week of December, respectively when temperature Increased during 2"" fortnight of March

80,r-----~----------~--------__,

_75.~~-w.r-.~~=-------------~ ,0

~.E 70 -1-0" •• ~

___ ............. ,_.,._ ... ....",_ ... _"_,.... ... Year,,,"

Fig 1 Possible Impact 01 climate change on wheat production In India

Cuddeford (2002) reported that the area under nce may show a declmlng Irend because several current, nee varietes may not set grain under enhanced temperature condllions . There Will also ba less water for flee cuilivalion which may necessitate the need of adopllon of water saving techniques such as System of Rice Intensification (SRI), aroblc nce, direct seeded nee, etc The effect Will be more pronounced In the drought prone areas where nce IS cullivated as ralnfed crop Samra and Smgh (2002), however, have suggested several strategies and contingent crop plans to moderate the Impact 01 subdued rainfall/drought In dlllerent agro-meterological sub divisions of the country Large scale Impacts of climate change on the oceans Will mclude, increase in sea level, mcrease m sea surface temperature, decreases In sea-Ice cover, changes In

salinity/alkalinity, wave climate and ocean CirculatIOn Further, wllh global walT11lng and assOCiated sea level nse, many coastal systems Will expenence mcreased levels 01 Inundation and storno flooding, accelerated coastal erOSion, 5ea water Intrusion into fresh ground water, encroachment of tidal waters Into estuanes and nver systems, elevated sea surface and ground temperatures Further, change 10 climate IS expected to

16


increase both the evaporlltlon and precIpitation If rate of evaporation exceeds the rate of preCIpitation, sOil becomes dner, lake levels will drop and nvers will carry less water, Warm water," lakeS and reservoirs WIll likely to mcrease the blue-green algae and other nUIsance lower plants that may reduce tHe levels of dissolved oxygen and adversely affect the fish productivity With nse In temperature many fish spe~les Will try 10 shift to find out the cooler regions, either they move Jpstream of fiver or m the grealer depths f;(esearchers forecast substantral shift In fish habitats, disrupt pattem of aquatic plant and animal dlstnbutlon and alter the fundamental eco-system process that will result m major ecological change Kumar and parikh (1998) worked oul economic loss between 9 and 25% for:a temperature nse of 2 to'3 5°C Similarly, 5anghl et 8/ (1998) predicted a loss of about 123% m net revenues for a flse of 2°C In temperature and 7% ,"crease '" rainfall, Coastal regions of GUjarat, Maharashtra and Kamataka are predicted to be most negatively affected On the other hand, West Bengal, Onssa and Andhra Pradesh are predicted to benefit (to a small extent) from global warming

International Scenario

Climate change occurs due to changes In composition and crrculatlon of vanous processes Involving atmosphere, oceans, hydrological cycle and land s,!rface Due to the emission of the green house gases earth's surface and the tropospHere becomes warmer oWing to absorption of Infrared radiation emitted by the earth's surface Carbon dioxide, methane, nrtrous OXide are the major gases responslple for green house emissions As per Food and Agnculture OrganIZation (FAO) calculations In 1997, the cOntnbutlon of green house gases to global warmrng IS 79% by carbon dioxide, 15% by nitrous OXide and 6% by methane SCientists at the Unrversity of Callfomla have worked out the global atmosphenc con.,entratlon of carbon dioxide between 1959 and 2000 Therr calculalrons Indicated continuous nse In CO, concentration between 1959 and 2000 (Fig 2) FAO In 1997 further made projections about future emissions of green house gases keeping 1990 Index as 100 (Fig 3) II has been estrmated that the global mean surface temperature has increased by 06 to a 7°e srnce the late 19'" century Most warming IS reported to hsve occurred 10 two distinct periods i e 1910 to 1945 and continuously Srnce 1976 The International Panel on Climate Change (IPCC, 2002) has projected that global average surface temperature are likely to nse by 1 4 to 5 e'c over the next tOO years (Fig 4) TM expected rrse In temperature IS predicted to be higher In hlgner latitudes than at equatonal regions Similarly, the IPCC further prOjected the annual temperature and preclpltatron trends 10

20'" century (Fig 5 & 6)

"JSO " '.,=" 13G r-

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" " .' " Ji " j:: • • =-: "-, _;;,,~ , " :~'" ,"-.J"'--~;:;

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FIg 2 Globalatmospherrc concentration of CO, (ppm)

17

Chemical Changes & Nutnent Transformation In Sadie/Poor Quality Water Irngated SOils

Index.. 1 990= 1 00

~ Carbon dioxide -~ Methane

-- Nitrous oXide

250

200

150

100

·1990 2000 2025 2050 2075 2100

Fig 3 Projected emiSSions of greenhouse gases

.. , 1 [J

IS

17

16

15

14

Pr(!ected global mean temperature rr,e ("C)

. oloD,] o.erage nenr surface lemperlllure

IPCC. pr0Jei:uons

1

I

. .1 ..-1 "" ,,,. ~ "''' ..., ... "'" - I

_I

F<g 4 Projected global average temperature (tPCC, 2001)

T""peratJre 1evlatr1ns ~Ci .. , .. ,

• -1 '>2 ••• ••• n

S(lJJte II'CC

,... ... . .... , i' t, - ••

.... ........ .::::::-::;:~::;a .... . ~ ., ...... _ ... , .. _ F

F'g 5 Annual temperature trends In 20111 century

Indian Scenario


. ,

Smut! IPCC

•• . •

<.1 ••••• ,,01> ...... ,. . . - ..... .; ..". ,.

•.. -=

.. . ", ...•. .".",j. .. ",~ .. .... , . ....... .

.. . .. '" . ...•.. ..

•

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Fig 6 Annual precIpitation trends In 20m century

The Central Research Insiliule for Dryland Agnculture (CRIDA). Hyderabad Ihrough Its All India Coordinated Research Project on agro·meteorology and dryland agnculture has worked out the trends In maXimum and minimum temperalure dunng the Khanf and Rabl seasons for Indian conditions Their calculations Indicate that there may be several location specific uncertainties In the minimum and maximum temperatures which may have adverse Impact on agncultural productivity The" calculations for trends In monthly rainfall In vanous sub-<l,v,s,ons In India indicate that rainfall may be more dunng December. January and February In case of westem RajastMn. Punjab and Haryana However. there may be slight decrease In October and November rainfall In several diVISions The analysIs was also made about trends of annual rainfall In India and shift In surplus rainfall for the penod 1871 to 1999 and 1960 to 99 Their observations Indicate a shift In surplus rainfall from west towards east Lal (2001) made calculations about the predicted climate change and their Impact on agncullure In India and the results are reported In Table 1 He reported an annual mean area averaged surface warming over the Indian subcontinent to range between 35 and 5 SoC over the region by 2080 These projections showed more wannmg In winter season over summer monsoon Rise In surface temperature In north India IS predicted 3°C or more by 2050 A marginal Increase of 7 to 10% In rainfall IS predicted over the sub·contlnent by 2080 Further the study revealed a fall In rainfall by 5 to 2S% In winter months and an Increase of 10-15% In summer monsoon rainfall over India These prOjected changes Will have both benefiCial and adverse effects on agnculture. environment and SOCIO--eeonomic set·up The growth Improvement In C3 plants could favour vegetative biomass at the cost of grain biomass. thus leading to a decrease In grain production Carbon dioxide IS believed by many sCientists to be potentially responsible for Increase of 10-15% for wheat, soybean and 6% for com and nce However. the Impact Will vary from country to country and region to region Wlthln the country To deVise strategies to manage such changes and to reduce vulnerability of agnculture. careful analYSIS of old climatiC data and linking climate wrth weather forecasllng and working out eeo·years. eeo·seasons. eeo·months and eco·weeks at each agncultural university and ICAR research Institute Will be reqUIred

Table 1 Climate change projections for India

Year Season Temperature change (0C) Rainfall change (%)

Lowest Highest Lowest Highest

2020s Annual 100 1 41 216 597 , .. , " Rabl 1.06 1,54 -1.95 436

i..rl

Khanf 087 117 1.61 510 2050s Annual 223 267 536 934

Rabl 254 318 -922 362

Khanf 181 237 7.18 10 52 20805 Annual 353 555 748 990

Rabl 414 531 -2483 -450

Khanf 291 452 1010 1518

Source Lal. 2001

18

a

Chemical Changes & Nutnent Transformatron In SodlcJPoor QualIty Water Irngated SOIls

It has been eStimated that mountain glaciers In the Himalayas and on the Tibet-Qinghai Plateau are meiling and could depnve the major rivers of India and China 01 the Ice me" needed to sustain them dUfing the dry season In the future The sCientists believe that water flows In Yellow fiver and Yangtze fiver basins where 1I1]gated agnculture depends heavily on nvers Will ,decrease and may have negative Impact on food produCtIon However, the sCientists at the National Institute of Hydrology (NIH, Roorkee) have studied the glaCiers In the Himalayas and the If studies indicate that situation IS not senous but there has been some decrease In the size of glaCiers at some locations

Rec.ent Case Studies

Drought of 2002

The geographical settmg of India makes It highly vulnerable to different kinds of riatural disasters About 57,28,12 and 8% of the geographical area are prone to earthquake, drought, flood and cyclone, respecllvely (Samra al aI, 2006) The drought at 2002 was one of \tie severest droughts of the last century Overa~ rainfall defiCiency for the country as a whole was 19% and 56% area received defiCient rains Out of 36 meteorological sub-dlvlsions In the country, 21 sub diVISions received deficient and scanty rainS The month of July received 49% less rainfall than the long range average Water storage In 71 major reservOirs was 33% less than the average of previous 10 years About 21 5 mllhon ha area was not sown and 47 milhon ha of sown crops was damaged, With a foodgTain shortfall of more than 29 million tonnes About 300 million people In 56% of the tolal geograpnlcal IIrea were affected A. loss of 1250 m,llion mandays of employmeCl\ was reported Ground water table In drought-affected area was declined by 2 to 4 m below the nonnal level Every day about 1 5 billion lilres of dnnklng water was transported by tankers and railways dunng droughl penod (Singh, 2006) Prasada Rao (2008) has studied the Impact of droughts on Indian foodgraln production from 1950-51 10 2007-08 (Fig 7) After seveTaI years of stagnation In foodgraln production the country IS expected to achieve all time high productlgn level of about 225 million tonnes dunng 2007-08 To maintain thiS produCtIon level With a vIsion to Mve 4% growth In agnculture In near future agncultural sCientists Will have to over work to deVise strategies for dealing With weather adversities One year of drought (lIke In 2002) has the potential to distUrb all our calculations and may put the country In food and nutritional crisis (Singh, 2007)

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~ ~ 0 ~ '" '" ~ '" ~

'1' '1 ~ '" ~ ~ 'I 9 9 ~ ~ ~ ~ " ~ ;; ~ ~ ~ ~ ~ '" '" 0 is 1l :0 ..

F'g 7: Impact of droughts on Indian faodgrains produCtIon from 1950-51 to 2007-08 , (Source Prasada Rao, 2008)

Cotd waves

An Important weather phenomenon that causes significant Impact on agncultural production year after year over the northem and norlh-<lastem regions 01 India IS the 'Weslem D,stur'oances' The mtensltylfrequency and the aenal eXtent of these disturbances significantly Influence the quantum of TalnfalVsnow over these regions dunng the Rabl season, lean season flow of rivers and occurrence of cold wave conditions In thiS process, they Influence overall hydrology, the dally maxlmuml minimum temperatures, range of sunshine hours and humidity. A good example of thiS IS the severe and prolonged cold wave condllions that prevailed over many parts of northern and north-eastem part of India dUfing the winter season of 2002-2003 which had conSiderably affected the survival and produCtIVity of seasonal and perennial crops (Slngh,2oo4) Except the southern region of the Indian Peninsula, most of the country, particularly the IndoGangetic Plains was affected by freezing and cold days InJunes haVing severe Impact on crops, frUit trees, fishery, livestock and even human beings Extreme fluctuations beyond normal vaflaMn In temperature due to

20


cosmic events and anthropogenIc actIVIties that alter cardonal pOints 01 crop growth slages are a major concem in agricultural management and productIon DU""9 December 2002 to January, 2003 dally maxImum and minimum temperatures at several places on north India remained unusually below the nonnal continuously for 3-4 v.eeks As a consequence of such phenomena, about 600 ha of orchards of mango and litchi were severely damaged," the ShlWallk belt of Punjab.(Table 2) The extent of damage vaned from 40-100% In mango to 50.80% In htchi With reduced fnllt size and poor quahty In guava, ber and klnnow (Samra st a/ ,

2002-03) -/ ,

Table 2 Effect of cold wave on fruit orchards In selected Villages of Hoshlarpur dlstnct. Punjab

Name of lanmer and F rUlt speCIes & age Area In Yield damage Damage to

Village aenes (%) plants ('I.)

Sh U.S Chatha Village Litchi (12 years) a 100 30-00

Mehlawah Sh J S Lah Bajwa Village Litchi (15 years) 2 100 30-00 Mehlawall Sh KS.GIII Mango(15 years) '10 100 60-80

Village Kharkan litchi (12 years) 5 100 60-80

Sh Ranjlt Singh Village Ma ngo (1 0 years) 45 100 a6-100

Kanlla Aonla (15 years) 10 100 80-100

Mr Ramjl Das Mango (8-10 years) 30 100 40-00

Village Dholwaha Sh J S Dhahwal Mango (8-10 years) 60 100 40-00 Village Dholwaha Mr Deepak Puri Mango (30 years) 5 100 100 Village Chohal Sh Jaspal Songh Mango (10 years) 6 100 60-80 VIllage MehmowaJ VIllage Sahmpur Mango (2-3 years) 5 100 100

Similar damage was also reported dunng 2005-06 and 2007-08 due to cold waves In northern states of India Excellent crops of tomato. potato. peas. mangold. dahlia. chrysanthemum. papaya and even guava were severely damaged The mean maximum and mlM/mum temperatures durong 2005-06. 2006-07 and 2007-08 at Kamal along WIth long lenn average are given in Fig. 8.9 &10 There was 100% loss of tomato crop, 72-80% In potato. 30-50% In WInter maize and peas. 50% in bnnja!. 100% loss to mangold and 30 to 40% In dahlia and chrysanthemum dunng WInter of 2007-OB SLmllariy. dynng 2002-03 cold waves assoCIated mortality rate In papaya ranged from 40-83% on the lower Shiwahk regions. plains of Uttar Pradesh. Bihar and north-east LikeWIse, Ln the Doon Valley of Uttarakhand plant mortahty was nearly 80% In less than two years old plantations. 15% In 2-4 year. 10% In more than 4 year old mango plantaliOns and damage of groWIng tiPS In matured trees The effect of cold ",jury was '" the order of mango > papaya > banana > htchl > pomegranate> Amla The mean minimum temperatures al Dehradun dunng this season and long teom average temperatures are shown In Fig 11

Early sown WInter maize In more than 36.000 ha was adversely affected by cold waves WIth about 70-80% loss on seed setling In Bihar Even boro rice of Assam was affected and crop took 10-25 days extra to mature as Compared to the nonnal year Cold waves also affected the fish productIVIty in Punjab, Haryana and Bihar In Naubatpur block of Patna. mortality In 4 months old fish was 87% on mingle, 33% In rohu. 7% In ~tla and 37% In the composrte culture Temperate fruits like apple, peach, plum and cherry. however gave

Igher Yields due to extended penod of chilling In 2003

d There are several Issues where the agronomists may playa SIgnificant role to moderate/mitigate the a ,:,:~e Impact of cold waves. Proper selection of crops and their varieties accordmg to site conditions, PI V;dlOg Wind breaks or shelter belts. frequent irngatlon. smoking. covenng young frUit plants WIth thatches or i as !C sheets. air mixing. maintaining maximum depth of water on fish pond and their aerallon are Some of Ihe arming manipulations for managing cold wave injUry (Singh. 2006)

21

Chemical Changes & Nutrient TranslomaUen In SodlcIPoor Quality Water Irrigated Sells

o~~~~~~~~~~~~~~~~~~~~ ~q~~~~~~~ren~mm~~~N~~~~~~~~~~~re o .., Ie

'" '" Date

1-Max Temp 2005-06 ~ M,n Temp 200SC-06 -.- Mean Max Temp - Me.an MIn Temp I F'9_ 8 Vanallon In maximum and minimum temperatures dUring December, 2005 to February, 2006

0. ..

Fig 9 Vanatlon In maximum and minimum temperatures dunng December, 2006 to March, 2007

10 - <0 ;;; " 0 '" 0 '" 0 so 0> '" 0> '" 0> ~ 0 " - '" '" " - N '" '" QI - _-N '" ::0 -, "- ,

on , '" ...

D ...

i--~ TEIT'Ip -- loki Temp _- Mal )1m Temp ___ M8Bn Mn TempI

Fig 10 Vanallon in maximum and minimum temperatures dunng December, 2007 to March, 2008

22

Natural Resources Management In Relaoon to Cllmabc Change

Fig .11. Dally mlnlln"um temperature of 2002-03 and long term average at Dehradun

Heat wave of March, 2004

Temperature plays an Important role "' the· growth and productiVity of thermo sensrtlve Winter season crops generally requlnng specific caidinallevels of heat dunng various growth stages Increased frequency of departures from n'ormal temperature and heat wave conditions has raised human causalities and agncultural losses In the recent decade Samra ami Singh (2004) studied the Impact of abnormal temperature nse In March, 2004 on several Winter crops Including wheat, mustaid and vegetables Highest nse from the normal In the dally maximum temperature was observed at Snnagar (a:12°C) (Fig 12) followed by Palampur (B-l0°C), Hisar (2-10°C), Ludhlana'(3-6°C), Jammu (1-6°C), Uttarekhand '(I-SoC) and Jalpur (I-SOC) Even minimum temperature dunng thiS penod was higher than normal In several places such as Snnagar, Palampur, Ludhlana and Pantnagar. As a result of that wheat production loss of 4 6 million tonnes was very close to the advanced prediction of about 44 million tonnes by modelling techniques (Aggarwal and Singh, 2004) The wheat crop matured 10-20 days In advance of nonnal period With reduced 1000 gre,n or test weight SOWIng of peas was advanced by one month due to earty melt of snow In Lahul valley, apples flowered 15 days earty In Chamba dlstnct and there was poor formation and filling of pods of rape seed and mustaid In Himachal Pradesh. Linseed Yield reduced by 50%, there was abrupt flowenng and excessive flower drop In peas, tomatoes, cole crops and fenugreek Oman and gart,c productiVity was reduced by 15-25% aSSOCiated With reduced bulb size. The forced matunty brought down seed productiVity of broocoll, canrot, reddish, tumlp by 10-15% Coconut, banana, caidamom, black pepper, cashew, etc. were affected In Kerala due to heat waves Induced lower humidity and SOil mOisture. Breeding of thermO-Insensitive cropslvanetles, frequent Imgallon, mulching to maintain high sad mOisture and spnnklers are called upon to miligale adverse effect of heat wave on production (Singh, 2006), Long distance open grazing of lactating ammals may be aVOided Frequenl walenng and balhlng of ammals Will enhance proper feeding of livestock

o '7~: " ~iuhitoim "E 20:' ::I -e 15 ... =- , ....... , 1!' • e 10 ~ s

O

,-

- --

• • • • • • • • • ......

:2. :3 '4' .5:' 5, .7., .. '.'_ , , 8, 9. 10 11 ':IZ'~3 .16 17" 16 19 22 " -,' ~D!I~(t , .

Fig 12. Maximum and minimum temperatures In March, 2004 (Srinagar)

Some of the weather abrasions are also favourable For example during 2007-08 continuous prolonged low temperature dunng the month of Febnuary and March contributed very Significantly In Improving ProductiVity of whea! in PunJab, Haryana and wesiem UP (FJg 10). Both Punjab and Haryana harvested bumper crop and exceeded thelf pnocurement largets by big margins due to prolonged continuous cold

23

Chemical Changes & Nutnent Transformation In SodlclPoor Quality Water Imgated SOils

weather The yield of early sown wheat was drastically reduced due to low temperature during flower stage However, normal and late sown wheat benefiled from the prolonged low temperature condition because of better tl/lenng, seed setting and Increased 1000 grain weight Different wheat varieties behaved differently to the seasOn temperature when planted at different dates For an example, HD2581 Yielded much higher when planted dunng mid November as compared to Its sOWIng on 2 November, 200~ at CSSRI farm, Kamal

Mltlgallon OptIons

There are several agncultural practices Which can be fine tuned to reduce the,emlsslon of green house gases from the agncultural fields, The agronomists can playa significant role by designing sUitable long term expenments to continuously momtor fluxes of water, energy, nutnents, gas exchange and salts In major crops and cropping systems In a changing scenario of climate for devIsing location specific strategies The practices which the agncultural sCientists need to research and promote Include effiCient management of crop residues, adoption of fuel and energy saving pracbces like zero tl/lage where about 50 htreslha diesel IS saved, sCientific water management In nce based cropping systems to moderate methane production, Integrated fertilizer management to reduce N20 production and precision agncullure practices etc (Slnghel ai, 2007) Pathak el a/ (2003) studied the effect of different fertilIZer treatments on methane emission from nce fields under saturated and Intermittent drying practices, !n a/l the fertlhze[ treatments. the emission of methane was almost 50% under intermrtlent 'drylng as compared to ~aturaled conditions (Table ,3) Wassmann 61 ai, (1993) reported that prefennented manure (blogas slurry) emits less methane as compared to solid manure

:appllcatlon (Fig. 13) Matching fertilizer application with crop demand. uSing advaneed fertlhzer techniques and adoption of optimum ""age, rrngatlon and dramage practices have tremendous potential to mitigate N,O em!sslon (Moslerel a/. 1998, Table 4). !<a'ra and Pathak. (2002) studied the emission of green house gases due to nee straw burning In north-west India They reported that bumlng of 8 25 million tonnes of nee straw resulted In emission of 1.73, a 02 and 003 on toones of CO,. methane and OItrous oxide. respectively (Table 5) These studies reveal that there IS tremendous scope to moderate green house gas emissions through the adoption of best management practices and through agronomic mampulatrons ASian Development Ban~ (ADB) In 1998 made calculations about the potential of forestry m carbon sequestration and therr results are 'reported In Table 6

Table 3, tntennlllent drying In nee reduces emiSSion of CH, (kglh~)

Treatment Saturated Intermittent drying

Urea 28 14

Urea + FYM 45 27

Urea + DCD 20 10

Control 24 8

Souree' Pathal< e/ al. (2003)

Tabte 4 Management practLoos and theIr N,0 e"'IS&lOn mrtrga,lIon poteflu:a{

Management practice

Match I'l supply With crop demand

Tighten N flow'cycles

Use advanced fertilization techniques

Optimize til/age, rrngabon and drainage

Total

Source, MOSier el a/ (1998)

24

Mrugallon (Tg N yr')

024

0.14

015

015

0,68

Natural Resources Management In Relation to ClimatIc Change

Table 5. E,mss,on of greenhouse gases due to nee straw burning in North West India

State Total Yield Residue CO, emisSion CH. emission M tonnes M lonnes I Mlonnes

Punjab 7.500 8250 1733 Haryana 1645 2029 0.426 UP. 13.109 14420 3028

Source Kalra and Pathak (2002)

Table 6 Carbon sequestration In forestry/agre-forestry

Oplions

Management Enhanced regeneration

Plantalion on pnvate lands (including "grolorestry/larm forestry plantations)

Source ADB, 1996

emissIon rate (IT1IJCH4m-2h-1

60

50 V 40

/_.../

3 o~ 0/ , 2

01/" oV.:

,

-J _

! r ,

Land category

Dense forest Marginally degraded land Totally degraded land

Marginal farmlands and non-forest degraded land

'"'"' I

I

- .~-,

L1 - · .. :,t I-- -;'

o..i:.~' - 10'-; ... combIned mm"'" .1IIIy -+

fel1lllzer ""am 0

femHlnled

Mtonnes

0016 0004 0'029

Potenlial area (million hectares)

1550 942 1257 2417

SOB"'"

Fig 13. Pre fermented manure (blogas slunry) emrts less methane (Wassmann et ai, 1993) .' ,

N,O-N emISSion Mlonnes

0033

0008 0058

Carbon pool (tonneS/ha) at the end of 40 years

77

171 138

83

Changing cropping calendars and pattem Will be the most workable solutIon for Immediate application to deal With climate change The options like introducing new cropping sequences, late or early matunng crop vanetles, matching the available growing season, conserving SOil moisture through appropriate tillage practices, mulching, oover crops and effiCient water harvesting techniques Will go a long way in dealing With changing cltmate scenario. Genetic manipulation nas ample scope to hamess the beneflts of increased CO, on crop growth and water use (Rosenwelg and Hillel, 1995) Another promising approach could be pyramiding 01 genes to enhance the adaptation capaclly of planls (Ral, 2007)

Some of the strategies to moderate the Impacts of climate ch_!lnge. on agnculture are summansed below

• Developing new plant genotypes for drought. heat and oold tolerance adapted to climatiC vanability and ranges There is a strong case to screen and dOClJment the already eXisting germplasm of crops, trees, ammals and even microbes about their location speCific response to such cnanges Based upon thiS screening,,Iocatlon speCific crop/variety calendars lor application according to changed Situation need to be developed. .

• 'DeVlslng agronomic practices which may moderate the. Impact of. predicted climate changes and promobon of conservanon agnculture practices such as zero tillage, bed planbng, residue. management and crop rotation

25

ChemIcal Changes & Nutnent TransformatIon In SodlaPoor Quahty Water Imgated SOI/S

• There Isa need to develop contingency plans to cope up With weather related abrsslons such as coid and heat waves and drought prone regions These contingent plans should be such Ihat can be practically Implemented on a short notce / . ,

• I Developing preCiSion and accurate forewarning mechanisms to reduce produclion nsks and for undertaking preventive measures There IS a strong case now to, go for developing and upgrading medium and long range forecasting systems (15,20 days In advance) so that farmers have reasonable time to respond to nsks. ~ , \ ,

• Identification of genes for tolerance to mOisture, heat and cold stresses 'and developing a canvas of transgemcs haVing tolerances to abiotiC stresses Biotechnological approaches such as pyramiding of genes should be a pnonty area of future research in climate change '

• RedUCing green house gas emissions )hroug~ carbon sequestrahon In different land use systems With major emphaSIS on raising tree plantations on degraded SOils Research on blo-clleseI/petro-crops such as Jatropha and Pongamia Which have potential to substitute fossil fuels needs stre'ngthenlng Since India cannot afford to divert cullivable area from grain crops to ethanoliblo-dlesel production, our prionty should be to extend cultivation of such plants on degraded lands which Constitute an area of about 107 m ha '

• Curtailing losses of methane and nitrous OXide from cultivated fields by Increasing use effiCiency of water, nutoents, energy and other agronomic manipulatlMs

• Manipulation of crop micro climate by means such as use of Wind breaks, tunnels or green houses to reduce the effects of climate change

• Genetic englneenngiblotechnologlcal tools which can convert C3 plants mto C. mode of photosynthesIs to top the Increased CO, in the environment for higher biomass production

• Develop Knowledge based deciSIon support s~stems lor translalmg weather mlorrnatlon mto operational management practices at dlstnct, block and Village Panchayat level.

• Benchmalklng of areas prone to climate change impacts on agnculture and livestock and periodiC mOnltonng to Initiate timely preventive action

• Establishment of automatic weather stations In all the 127 NARP zones to prOVide value added agromet adVISOry service to the faomers There is also a need to establish climate monrtonng towers/climatiC control lacilltles at select places," the country lor penodlc mOnltonng of water, energy, gases and salt fluxes These faCilities should be used for deSigning location speCific croPPlng/famnlng systems

• Promoting multl-enterpnse agnculture to reduce nsk and for assured livelihood seounty In areas prone to weather/climate abraSions. Nearfy 50% of the farmelS In India cultivate fess Ihan one ha land, Inlegrated farming system is a promising propos"'on for such small holding

• Improved management of livestock population including poultry through better management of feeding and livestock hOUSing Ammal sector IS the major contnbutor for methane to the enVIronment

• Improving the effiCiency of energy use In agnculture by uSing better deSigned effiCient machinery and Implements

• There IS a need to develop crop Insurance and early warning systems to reduce the Impact of climate change and achieVing stability In production There IS also a need to' develop weather-trop-livestock ~elatlonshlps and weather-crop modelling for forecasting pest and disease infestations

• 'There is a strong case to Intensify efforts for Incroaslng climate literacy among all stakeholders of agriculture and allied sectors, students, researchers, pohcy planners, sCience managers, Industries and faomers

Bibliography

Aggarwal. P.K. and Mall, R K. 2002 Climate change and nee'Ylelds in diverse agro-env"onments of India It Effects of uncertainties in scenanos and crop modets on Impact assessment Climate C~ange 52 ~ 331-343

Aggarwal, P K and Sinha, S K 1993. Effect of probable Increase in camon diOXide and temperature on productIVIty of wheat in India Indian Joumal of Agncultural Meteorology, 48(5) 811-814.

Aggarwal, P.K and Singh, Gurbachan 2004 Forecssting wheat production in light of Increased temperatures dunng March, 2004 Estimates submitted 10 DARE and DOAC, Koshl Bhawan, New Deihl (unpublished)

Cuddelord, VIJa)" 2002 Developmg Counmes Fa~ RadiO Netwolk Package 64 (1) July, 2002

26

Natural Resources Managemenlln Relallon to Climatic Change

Hundal, S Sand Kaur, PrabhJot 2007 Cllmatlc vanability and rts Impact on cereal productIVIty In India PanJab A simulation study Current sCience 92(4).506-511.

IPCC, 2001 Climate change 2001 Impacts, Adaptation and vulnerability Cambridge University »ress. 1032 pp I

IPCC. 2007. Interilovernmental Panel on Climate Change Working Group I Climate Change 2007 The PhYSical Science BasIs, IPCC Working Group I . /

J IPCC, 2007. Intematlonal Panel on Climate Change Working Group II Climate Change 2007 Impacts,

Adaptation and Vulnerability, IPCC Working Group II , lal, M 2001 Future Climate Change Implications for Indian summer monsaon and Its vanability Current

SCience 81(9) 1295

Morey, D K and Sadhaphal, M N 1981 Effect of weather elements on yield of wheat at Deihl Punjab Rao Knshl Vldyapeeth Research Joumal1 81-83

Mosier, A.R , Duxbury, J M, Freney, J R, Heinemeyer, a .and Minami, K (1998) AsSessing and mitigating N,O emiSSions from agncultural SOl!S Cllmab,,-Change 40' 7-38. 1998

Pathak H , ladha. J K Aggarwal, P K , Peng, S , Das S , Yadvlnder Singh, BIJay-Slngh, Kamra, S K , Mlshra, B., Sastn, AS R A,S, Aggarwal, H P., Das 0 K and Gupta, R K 2003a Climatic potential and onfann yield trends of nce and wheat in the IndO-Gangetlc plains Field Crops Res BO 223-234

Pathak, H , Prasad, S. Artl Bhatia, Shallnr Singh, S Kumar, J SlnSh, M C. Jain 2003b Methane emission from nee-wheat cropping system of India In relabon to Imgatron, fann'yard ma.nure and dicyandiamide application Agnc Ecosys Environ 97.309-316

Ral, Mangala 2007 PreSidential address at the National conference on Climate change and Indian agrlC1Jlture held at NASC Complex, New Delhi, October 11-12, 2007.

Ramaknshna, Y S. 2007 Invited lecture on observed Impacts On agnculture in recent past Nabonal conference on climate change and Indian Agnculture, NASC Complex, New Deihl, 11-12 October, 2007

Rao, Prasada 2008. Impact of weather extremes on Indian food grain producbon. In. Climate Change and agnculture over India (Ed. Prasada Rao et al ), p 1-12, CRIOA, Hyderabad

Samra, J Sand SlOgh, GurbaChan 2002 Drought Management Strategies Natural Resource Management DIvIsion, ICAR, New Deihl, 65 p

Samra, J S and Singh, Gurbachan 2004. Heat wave of March, 2004 Impact on agnculture. Natural Resource Management DIVISion, ICAR, New Deihl, 32p

Samra, J S , Singh, Gurbachan and Ramakrishna, Y.S 2002-2003 Cold wave of 2002-2003 Impact on, Agnculture Natural Resource Management DIVISion, ICAR New Deihl, 49 p

Samra, J Soo Singh, Gurbachan and Dagar, J C 2006. Drought management strategies In India, ICAR, New Deihl, pp 277

Sanghl, A, Mendelsohn, R and Dinar, A 1998 The climate sensibvlty of Indian agnculture In measuring the Impact of climate change on Indian agnculture edited by A Dmar el aI', Washmgton DC; World Bank

Singh, Gurbachan. 2006 'Use of Weather Infonnatlon for DecIsion Support on 'Crop Production An InVited expert lecture delIVered to the Heads of Knshi Vlgyan Kendra of Northern Region on July 14,2006 at PAU, ludhlana

Singh, Gurbachan 2007. Climate change and Indian agricu~ure Keynote address delivered on the World EnVIronment Day, Kurukshetra Umverslty, Kurukshetra, June 5,2007

Singh, Gurbachan, Singh, Samar, Jat, M land Shanna, 0 P 2007 PrecIsion fanning for water and nutrient use effiCiency under major cropping systems. Inter-Regional Conference on Water and EnVironmentENVIROWAT-2007, IARI, New Deihl

SIOgh, Gurbachan 2004 Climate Change Imp"ct on Agriculture Invited' lecture delivered to postgraduate students, Khalsa College, K~rnal, Appl 24, 2004

Swammathan, M S 2002 Climate change and sustamable agnculture Impacts and adaptation strategies In, Shukla, P.R, Sharma Subodh K and Venkata Ramana P. (Eds) Climate change and Indlll Tala Mcgraw HIli Publishing Co , New Deihl

27

Nature and Extent of Salt-Aff!)cted Soils in India /

R.C. Shanna- & A.K. Monda' Principal SCientist (Retlred)"-DivIsion of SOil and Crop Management Centml Soli SaliMy Research Institute Kamal. Haryana-132 001

Introduction

Salt affected sOils differ from arable soils WIth respect to two Important properties. namely. the soluble salts and the soil reaction A build-up of soluble salts In the soil may Influence lis behaViour for crop production through changes In the proportions 01 exchangeable ca~ons. SOil reactJon. the phYSical properties and the effects of osmobc and speCific Ion tOXICIty Satt- related properties of SOils are sublect to rapid change Therefore. to

·facilltate discussion on sOil management and the influence of the two common kinds of salts (neutrals and alkali saHs) on sOil properties and plant growth. saH affected SOils are broadly grouped as either saline or alkalI soils (Szabolcs. 1974. Abrol and 8humbla, 1978. Bhumbla and Abrol. 1979)

Saline Soils

Saline sOlis are oftenly recognised by the presence of white saH encrustation on the surface and have predom]nance of chlonde and sulphate of Na. Ca and Mg. In quantibes suffiCient to Inferfere WIth growth of most crop plants. SOil with neutral soluble salts has saturalion paste pH less than 8 5 The el~ctncal conductance of saturation extract of salme soils IS more than 4 dSm" at 25° C and exchangeable sodium pencentage (ESP) less than 15. The sodium adsorpbon ratIO SAR of the SOil solubon IS generaUy less than. 15 However. SOil salimsatlOn WIth neutral soluble salts of Na Invanably result In 5011 solulion SAR greater than 15 Such salls are termed SalineSadie (U S Salinity Laboratory Staff. 1954) Results of seveml field expenments In India and Iraq on sandy loam 50115 suggest a limited value of amendments In the reclamabon of saline-sodlc sOilS However. slgnl~cant

responses to applicatIOn of amendments can be expected In SOil With Inherent low pen-neability When salinity and SadlCIty occur together. limited eVidence suggests that the effect of the two factors on plant growth IS nonaddrt,ve and nonlnteractJve. and pnmarlly' sallMy effects limrt the growth Many saline-sadie salls contain soluble carbonates beSides the excess of neutral salts Such salls manifest alkali 5011 properties. It IS. therefore prudent that the sallne-sodiC sOils that do not contain soluble caroonates be grouped and managed as saline SOils and the rest of them grouped and managed like alkali so1/s Due to the presence of ,excess salts saline Salls remain flocculated and their hydraulic conductJvlty IS equal to or slightly more than that of Similar non-saline SOils Poor plant growth In saline soils results from high osmotic pressure of soil solution causing low physiological availability of water to the plant and direct tOXIC effects of indiVIdual Ions

Alkali Salls

Salls containing excessive salts of sodium carbonate and sodium bicarbonate and haVing suffiCient exchangeable sodium to Interiere With growth of most crops plants are' called alkali These have pH of the SOIl

• saturated paste mora than 85. ESP 15 or more and ECe limitless If resulting from salts capable of alkaline ~ydrolysls

How Alkali Soils are fanned?

The allUVium (parent matenal) nch In plaglodase feldspars under hydrolytic dlssolubon release high amount of sodIum Weathenng of alumino-silicate minerals through carbonation Yields solullons of bicarbonates and carbonates of alkali In addllion to Silica and alumina The bIcarbonates and carbonates migrate wrth the subterranean and surface waters and accumulate In undrained areas under and and semi-and conditIOns to form (Na,C03) alkali SOils

Na-Pnmary.mlneral + HOH -') H-sllicate day + NaOH H-Sllicate day + HOH -') Ab 0, H,Q + H, SIO,

NaOH + cO; (air) -') NaHCO, 2 NaHC03 -') Na,Co, I_I

Limitation of Alkali Soils for Plant Growth

Management of alkali SOils present dlfficu~les due to their physical. chemical and hydrological properties. which affecl the field preparation. Irrigation practICeS. dramage and choice of crops. Malar limrtatlons of alkali SOlis are

Extent and Nature of Salt-Affected Salls In India

Physical properties

Most alkali soil exhlbrt Impervious charactenslles WIth slow to ml InMratlon rates The surface honzon WIth the highest pH, ESP, high content of sodium carbonate and platy structure IS the Ilmrtlng honzon At about 1 m depth 3().6(l percent calaum carbonate concrellon 30 to 70 em thick layer IS Invanably fOund Roots have to wind their way through the nodules and, therefore, find less space for growth total nutnent reserve In this honzon IS accordingly low. The underground water In most of the alkali soils IS non-saline and non-sodle

I

Chemical and Nutritional properties

In alkali salls chemical environment IS unfavorable for piant growtli Crop failures on alk!ill 5011 resu~s largely from toxlcrty of sodium caibonate and blcamonate and qsmotlc effects of other sa~ present Soluble and exchangeable calCium and magnesium precipitate as calaum eamonate rendenng 5011 defiaent in these elements Availability of trace elements except molybdenum and boron decreases due to reduced solubility Weathenng under alkaline condItions resu!ts In the relea'se of high quantrtles of potassium, Silica and Iron

Hydrological properties

Alkali SOils have flat. very gently sloping surface and negllgible'lnfiHrabon ,ates In the surface honzon Surface 5011 reclamation through applleabon of amendments Improves Infiltrallon rates leading to reduced surface run-off losses and increased ground water recharge Drainage of excess water accumulating on surface IS accomplished through shallow ditches dug along the natural slope gradients In those areas where water table prevails Within 1 to 2m depths and IS not ubllsed nobceably for Imgabon, vertical drainage through a net walk of deep tubewells IS necessary. The phySiCO- chemiCal charactensbcs of a typical alkali 5011 are presented In Table-l

Table 1 PhyslCO-ChemlCal charac\enstlcs of a typICal alkali SOil from Etah (U P ) , .

Depth (em) ECe(dSm-l) pHs ESP lomc c:omposlbon( mell)

Ca Mg Na CO, HCO, SO,

0-16 13S4 102 88 06 16 2100 1510 260 210 16-27 1250 10 1 87 1.1 1.4 1900 1290 200 130

2T-64 460 9T 6T 05 06 450 320 100 30

64-81 192 96 78 10 15 190 40 130 10 81-100 188 94 24 05 15 160 40 90 10 108-127 235 91 31 0'5 05 210 70 100 1 0 127·148 140 86 22 1 3 14 130 20 60 10

Depth (em) Partlde sIZe analYSIS ('Yo) CaCe, (%) OM (%) CEC [emol(p+)kg.1] Sand Silt Clay

0-16 620 240 140 19 07 67 16-27 570 255 175 40 06 }3 27-64 450 220 330 38 06 15.9 64-81 380 350 270 27 05 139 81·106 340 340 320 12 a 05 129 108-127 395 330 270 238 05 120 127-148 650 180 170 250 05 80

Other Categories of Alkali Salls In the Indo Gangetic Plains

Some other categones of alkali soils dlifenng slightly from the above do eXist In different parts of the country They are bnefly descnbed below

Alkali soils with Shallow Calcic Horizon

They occasionally have a calCIC honzon wllhln 50 ern from the SOil surface The occurrence of a shallow calCIC honzon IS caused erther by removal of the top 5011 by excessive erosion or accumulation of dolomitiC matenal at reduced dep1hs due to Inadequate leaching The main characteristiCS, Ilmrtatlons and amellorallve requirements of these are similar to soils With a calac horizon at depths of 1 m or mere A shallow calCIC honzon reduces SOil depth for root spread and has low nutrient reserve and water storage capacity

29

Chemical Changes & Nutnent Transformation In SodldPoor Quality Water Irrigated SOils

/

J\1~all soil with a saline ground water , Also eXists in narrow bands In states of Punjab, Haryana and Uttar Pradesh In area having 500-700 mm

annual rainfall A shallow saline or SadlC ground water. when nse. to Within ,1m depth. aggravates the eXisting sodlc condlbons ' ,

Alkali Salls occurring In Black Soil Region (Deccan Plateau)

Due to high coefli"ent of swelling and shnnkage of montmonlcoMIC clays, black salls (vertisols) on drying develop deep cracks Introduction of canallmga~on has rendered them. either SodlC or saline At certa," places even Imgatlon With saline water has brought about such detenorallon

SOil Characteristics

5011 matnx colours vary from grey to very dark grey, dark greYish brown and very dark greYish brown In the surface honzons and black to dark grey and dark greYish brown in the subsurface 5011 texture remain mainly clay or clay loam wrth major parts remaining subangular blocky in structure With high s~cklness, plastlCltY,and coheSiveness remain workable only'w,thln a narrow range of mOisture content On drying these turn extremely hard rendering tillage impossible and so does excessive stickiness when wet Severe IImltabo" In alkali vertisols IS the extremely slow permeability and Infiltration Montmonlionltlc particles get deflocculated faster under high pH and high degree of sodium saturabon resultlng.1O dlsrntegratlon of soil aggregates and sealing of pores Under a build up of shallOW water table, high capillary conductiVity facilitates nse of water to the surface rendenng It excessively mOist, saline and unworkable High pH adversely affects solUbility and availability of I(on and trace elements caUSing serrous nutnlronal disorders Molybdenum, however, may become tOXIC due to Increased solubility at very high pH Phosphorus defiCiency IS unlikely because of enhanced solubility of sodium phosphate at high pH Unlike alkali SOils of the Indo-Gangetlc alluvial plains, pH and electncal conductance vary Irregularly Indicating different stages of alkallsatlon and sahnlsatlon These differences are assOCiated With nSlng water taple_ When the surface honzons have a hlgt'l pH and high salt content the magnitude of problem becomes more senous than when such situations arc confined to deeper honzons In the laHer a shallow surface SOil strate may remeln fit for cultivation while the deeper honzons tum unfit and threaten alkahsat,on of upper strata too In these "rcumstances an effective depth of SOil for root growth decreases accordingly

Alkali vertisols are associated With shallow water table and Impeded subsurface drainage Due to hlgM capillary conductiVity water may nse to the surface even from 5m depth. Prevention of SOil alkaJlSalron, therefore,

. necessitates keeping the water table under check In deep black Salls Because of very poor rnMratlon, surplus rain water escapes through natural drainages. eXisting within the plateau While provIsion of sub surface drainage IS necessary for amelioration, rts execution IS extremely difficult The factors contnbutlng to low hydrauliC conductrvrty of alkali vertisols are, excessive coheSIVeness, pore seahng by sodium saturated deflocculated clay, Irttle POroSity and lack of conlrnuous water conducting channels In the substratum The physlCO-Chemlcal

• charactenstlcs of an alkali vert,sol are gIVen In Table 2

Table 2 Physlco-chemlcal charactenstlcs of an alka" soli (vertisol) from dlstnct ShaJapur, M P

Depth pHs ECe Inole Compsitlon ( meJI) (em) (dS m-1) Ca Mg Na HC03 CI 504 0-13 83 35 51 51 260 63 230 20 13-31 84 17 42 10 7.5 92 60 20 31 --62 82 26 22 48 140 142 2.5 20 82· 94 • 94 16 21 49 7,8 102 50 40 94-126 91 65 61 88 588 870 Tr Tr

126 -158 87 24 29 5-1 178 88 1.0 05

Depth ESP Partlde sIZe (%) CaCa, (em) Sand Silt Cla~ (%)

0-13 52 150 500 345 80 13- 31 60 300 455 295 70 31..-62 65 30 560 420 128 62-94 73 4,0 525 435 212 94-126 51 70 460 470 214 126 -158 56 30 540 480 187

30

Extent and Nature of Salt-Affected Sol/$In IndIa

Saline Soils

Due to the presence of excess saHs saline sOlis remain flocculated and thelf hydraulic conductivity IS equal to or slightly more than that of slmlla!._~ol!-saline soils Poor plant growth In salln-e sOils resuHs from high osmo~c pressure 01 sOIl sol\l\lon caUSing \ow phYSiological availavlllly 01 waler 10 the planl, direct loxlc eHeets 01 indiVIdual Ions and complex mteradlon betweim sodium, calCium and magnesium leading to distUrbed equillbnum of these IOns m the plant's ability to absorb water and nutnents ,n reqUired amounts Charactens~es of atypical Inland saline soil of IGP are presented In table 3, In India saline SOils occur under t~ree broad groups namely, Inland, coastal and delatlc saline soils.

Table 3 Saline SOil from Kalayat, Haryana ,

Depth pHs ECe (dS m-) Ca+Mg Na CD3 CI ESP

(em) me r 0-15 7,8 617 87 516 2 580 7

t5-31 77 202 47 - --'47 15 137 8

31-68 76 104' 22 86 1 3 102 8

68-103 77 94 37 50 16 72 7

103-145 76 57 17 36 20 48 8

Inland Saline Soils of the Arid and Semi-arid Regl!!ns

Highly saline SOils ennched With neutral saijs are WIde spread in Ihe and to semi and parts of Haryana, Punjab and Rajasthan states These occur In regions wrth less than 550 mm mean annual ramfall Neutral salts abound m these and maximum salt accumulaton under exceSSIVely deSiccating condl~ons happens to be In the surface-honzon These have a shallow saline water table and often remain waterlogged or even submerged for some duraoon each year, Saline-Alkali Soils of the Indo-Gangetlc Alluvium

These are mostly confined to regions wrth around 550 mm mean annual rainfall", the form of a narrow band separating the alkali and saline SOils These have a preponderance of neutral salts but contain SIZeable quantJhes of sodium carbonates and bicarbonates These generatly have sandy to loam textural gradation and may have a cal",c or a petrocal",c horIZon In the substratum thereby resuijlng In reduced water Intake

Inland Saline Soils of the Sub-Humid Region

SIZeable area ,n the sub-humid parts of north Bihar has undergone seoondary salinlsatlon under the, rmpact of operating Continental and Anthropogenrc cycles Widespread in parts of East Champaran, West Champaran, Muzaffarpur,Saron and Saharsa dlstncts These are unique In haVing developed on dolomrtlc allUVium containing 23 to 40 percent calCium and magnesium camonates In fine powdery fonn Mhough neutral salts predomInate In these soils, some solis containIng SIZeable quantIties of sodIum carbonate and bIcarbonate present sallne-alkali nature

Inland Salt Affected Medium and Deep Black Soils (Vertisols)

The medium and deep black SOils (Vemsol) are extensive in part of Madhya Pradesh, Maharashtra,RaJasthan, Andhra Pradesh, GUJarat and Kamataka states All vemsols have the potential to turn saline, alkali or saline-alkali and all the three srtuatlon may eXist Within a small geographical area Sallnlsatlonl alkalisatlon processes are assoCiated With, nSlng water table SUbsequent to introduction of canal Imgallon, on vemsols MontmonlionrtJc (smectitic) clay minerology and high clay content (sometimes as high as 70 to 80 percent) Impart unfavourable phYSical charadenshes to these SOils The Inland vertisols inrtlally have deep water \able With low degree of mlnerallsahon

Medium to Deep Black Saline Soils of the Deltaic and Coastal Semi-arid Region

In the deltas of the Godavari and Krishna rivers and along the Saurashtra coast In the GUJarat slate saline vertisols With shallow water table prevailing mostly Within 1 meter depth occur These generally contain only neutral salts With traces of bicarbonates Wrth smectitic mineralogy and high clay content these pose problems Similar to the Inland saline vertisols The operatJng manne and delta cyles however cause salinlsatlon

Saline Micaceous Deltaic Alluvium of the Humid Region

The deep mlcaceous,fine textured SOils of the Ganges delta In the humid subtropical climatiC region are saline to varying degrees With a perpetual shallow saline water table These have neutral salts which owe thelf

31

Chemical Changes & Nutnenl Transformation In SodiclPoor auah~ Water Imgaled SOIls

, , ongln to saline substratum and saline water Innundatlons dunng manne cycles and also dUring the ongln of della Salt accumulation happens to be the maximum In the surface

/ ,Saline-Humic and Acid Sulphate Soils of Humid Tropical Regions

These occur along the Malabar coast, humus nch,dlstinctly sahne soils occuPYing marshy srtuat,ons and ,undergOing seasonal penodlc floodl~g and Innundatlon~

Saline Marsh of the Rann of Kutch

The great Rann of kutch cons~tute the vast sahne marsh and cOnlalns a vanety of sahne sOil types The process of accretion IS continuing and textural stratifications are Interspersed With bands of gypsum, calCium carbonate and hydrated Iron OXide accumulabon thus facllrtating IdentlficaMn of separate t"xonomlc Units

Extent of Salt Affected Solis In India

Systematic Survey Using Remote Sensing and Ground Truth

The first systematic sHempt to map salt affected soils (SAS) of entire countl)' was made In 1996 by NRSA In association with other Nallonal and State level organizations hke CSSRI, Kamal, NBSS & LUP, Nagpur; AIS & LUS, Deihl, and State Govemment AgenCies A total of 125 false colour composrte (FCC) pnnts of the Landsal TM satelille were used In mapping sail affected SOils al 1 250,000 scale The methodology consisted of, development of nation-Wide mapping legend, Interpretation of satellite data, ground truth collection, analYSIS of SOil samples, post-field interpretation and reconciliation and area estimation A common legend was evolved after extensive diSCUSSions With the collaborating partners engaged In either convenliOnal or remote sensing based SOil surveys Satellite Images were Interpreted for broad categonsatlon of different types of salt-affected SOils, sample areaS for field verlficalion were Idenlified and surveyed for SOil sampling and c1haractenzallon The sail affected SOils were claSSified aCleordlng to norms for pH, electrical conductiVIty (EC) and exchangeable sodium percentage (ESP) The salt affected 5011 boundaries drawn earlier were modified, wherever needed, and were transferred onto base maps prepared from SUlvey of India topographical sheets at 1.250,000 scale The dlstnbutlon and mapping legend of salt affected SOils of 15 states IS shown In 125 map sheets, whiclh are available With NRSA Hyderabad, The stateWide extent IS given In Table 4 It shows that maxlmUITl area of salt affeeled soils occur In GUjafat followed by UHar Pradesh, Maharashtra, West Bengal, Rajasthan, Tamil Nadu, Andhra Pradesh, Hal)'ana, Bihar, Punjab, Karnataka, Orissa, Madhya Pradesh, Andaman & Nlcobar Islands and Kerala Due to the limitation of small scale some vel)' small and Isolated patches 01 salt affected Salls occurnng in the states of Deihl and Himachal Pradesh could not be detected The sail affected SOils aCleounts for 67 27-lakh hectares eqUivalent to 2 1 per cent of the geographlcat area of the country 194 out of 584 dlStncts have salt affected Salls 4 dlStncts, 3 dlstnbuted In UHar Pradesh and 1 ,n West Bengal have more than 20 per cent of geographical area under these Salls Out of the total 67 27-lakh hectares of salt affected Salls, 2956 lakh hectares are saline and the rest 3771-lakh hectares are sodlc Out of the total 23 47-lakh hectares salt affected Salls In the IGP, 5 60-lakh hectares are ~ahne and 17.87-lakh hectares are sodlc

Table 4 Extent of salt-affected Salls India (ha)

State Saline SodlC Total

Andhra Pradesh 77598 196609 274207 Andaman & Nlcobar Island 77000 0 77000

Bihar 47301 105852 153153

GUjarat 1680570 541430 2222000

Hal)'ana 49157 183399 232556

Kamataka '1893 148136 150029

Kerala 20000 0 20000

Madhya Pradesh 0 139720 139720

Maharastra 184089 422670 606759

Orissa 147138 0 147138

Punjab 0 151717 151717

Rajasthan 195571 179371 374942

Tamil Nadu 13231 354784 368015

UHar. Pradesh 21989 1346971 1368960

West Bengal 441272 0 441272

TOIaI 2956809 37'70659 6727468

32

Extent and Nature of Salt-Affeded SOlis In India

The 67 27-lakh hectares area of salt affected solis reported by the NRSA and Associates (1996) did not give the spht up under sahne and sodlc classes This was reckoned by abstracting InfolTTlabon from the mapping legend, kind of soils, clay minerals, climatic condlbons and physiographic setting of vanous regions The mapping legend prefixed With letter F represents medium and deep black SOils, the lE!tters s, nand sn denote sahne, sodlc and sahne-sodlc respectively As per discussion on the threshold value of ESP for sodlc Salls In black SOils region the enllre mapping umts prefixed With letter F (I;llack SOils) were classed as sodlc Thus most of Ihe sail affected SOils oecumng In Pennlnsula India were sod,c ,n nalure Further, all the mapping umts denoting sahne-sodlC conditions in physlograpnlc regions A, B, E and H were classed under sodic Tne mapping umts of sail affected solis failing In phYSiographic regions C, D and G were classed under sahne. In Uttar Pradesh, sail affected Salls occumng In Agra and Malhura districts were 'classed as saline while the' others under sodlc In Bihar, as per the recent appraisal of ShalTTla and Bhargava (2002), the salt affected SOils falhng In Gandak command were classed as sodic

Bibliography

NRSA and ASSOCiates 1996 Mapping salt affected Salls of India, 1.250,000 mapsheets, Legend NRSA, Hyderabad

ShalTTla,R.C Rao. B R.M and Saxena, R K 2004 Sail affected Salls In Indla-current assessment In International Conference on Advances In Sod/C Land Rec/ama~on held 9-14 Februa"! ,2004 at Lucknow, India

33

Genesis of Saline and Sodic Soils in Canal Irrigated Area of Desert Ecosystem' ". " -

S.K. Singh ,DIVIsion of SOil ani! Crop Management Central Soil Salinity Research Institute, Kama/·132001 - .:

Introduction

Desert ecosystem extends from 22°30' to 32°05' N latitude and 68°05' to 70°45' E longitude, coveflng 387 million hectare land The region IS dlstnbuted In western Rajasthan (196 million hectare), adjoining northern and southern part of GUjarat (622 m!llIon heclare) and southwestern part of Haryana and Punjab (275 million hectare) Dune and Intrudes, belonging to late Pleistocene period (Kar, 1992 and 1999) account for 70 to 80% area of the region The renewed aeohan activities of late Holocene period has given birth to active barchans, sub COPPOlce, sand dunes and sand sheeting on pre·exlstmg landforms (Kar, 1992 and 1999) SOils of the area ranged from deep loam to clay loam on the One hand and localized small extent of calcareous and gypseous depreSSions on the other hand (Khan et al 2003) Low rainfall, very low available water capaClty, shorter growing period, frequent drought. severe erOSion, Inadequate available nitrogen, phosphorus and deep brackish ground water are the major constraints Pearl millet, moth, guar and Khanf pulses are the major crops The region, however, sustains on perennial vegetation of ProSOPIS cmnarana, Tecomefla undulata, and shrubs and grasses, which are rich resources at fodder for ammal offering a dependable source 01 livelihood

The area has been regarded hlstoncally marginal for human eXistence and the population pressure has been relatively low although they have always been an Important support and natural resource lor the eXistence 01 small rummant produclion system 01 the region Traditional systems 01 eXistence cereal cropping and pastoralISm ,n these areas of marg,nalproduc\'~'ty were 'IIell adapte<:! to the ptlys,cal enVIronment and ,\s constraints but they no longer adapted to the evolVing circumstances In which mtenslve explOItation of the limited resource base of land and natural vegetation 1$ an economic Imperative lor the local population

The central and state Governments after Independence have mvested heaVily In large scale Irngallon works to capture and manage surface flow from the perennial nvers Nallonal projects have been supplemented by IndiVidual farmers' Investment In dnll wells, which tap underground water supplies A vast area was brought under Ifngated agriculture Sand dunes were reclaimed Recent studies showed that the sand dunes reduced 10 226 ha In 1959-60 (Post-Irngabon era) from 3000ha In 1913·14 (Pre-Ifngabon era) In a case study on some area In S,rsa dlstnct of Haryana Land use has been changed dramatically Recent change IS hereby marked an increased cropped area, pushing the frontier of cereal cultivation Into dner and dner areas and poorer to poorer Salls while, at the same time drastically redUCing the area under fallows Even paddy IS being cultivated In the Inter-dunal areas The land use statistics 01 Hanumangarh dlstnct 01 Rajasthan shows tremendous shift of land use from 1985-86 to 1997-98 Area under pearl millet, Jowar, Khanf pulses,

'groundnut and sugarcane was declined by 0075, 749, 1294, 9455 and 26 17 %, while cultivation of wheat, barley, nee, gram, mustard and cotton has Increased by 4383, 1624, 11 85,2486, 1097 and 58 2 % dunng the penod (Ram and Chauhan, 2002)

However, sustamed productiVity through Ifflgallon development IS threatened by over explOitation and poor management of water applicabon and drainage leading to declining water <luality and depleted aquifers often resulting In salinity, SOil fertility loss and water logging Irngated agnculture Wlth low water and nutnent use efficiency (Dhlf, 2007) now shows 51gns of un·sustalnability and produclion constraints In some or other part 01 the command are. The mammoth degradation calls for Immediate amelJOralive acliOn for sustalnln9 the productiVity Flndln9 reasons for developm9 salinlty/sodlclty and causes for Increased seventy of erosion in the region IS the first milestone for evolving sustamable package of practices The present attempt highlights the extent and distribution of salt affected Salls In the Window area of 10920 km2 falling In the administrative setup 01 Sn·Ganganagar dlstnct of Rajasthan Of the total 57, 34 and 9 % area IS Irrigated With Indira Gandhi, Gang and Bhakhara canal, respectively Factors, teadlng to salinization and sedlficatlon are also analyzed

Extent and Distribution of Salt-Affected Area

Soils of the area are mapped In sixteen SOil senes assoclaliOns.(Table 1) Among the associations of 5011 senes, Dabla· Panlllwali On 96 10 km2 (0 9 % of the total area) In older allUVial plainS, Jamsar- Molasar on 38890 km2 (35% of the total area) In gYPslferrous older alluvial plains and J3ilsar loam -J3ilsar sand association In younger allUVial plains of Ghaggar on 952 km2 (869% of the total area) were affected Wlth varying degree of salinity and SOdlClty Salinity was marked at the depth of 45 to 60 em In Dabla·Panmwall senes assoclalion, concentrated In the subsurface mostly on the calcareous bentonite matnx A part of Jaltsar

Genesis of Saline and S(ldlc SOils In Canallmgated Area of Desert Ecosystem

loam _ Jallsar sand assOCIation showed' sahnlty-sodlc condillons at ihe surface, while tile subsurface was Impregnated with hIgh salt content in other part The sahne-sodle condrtlon was traced below the depth 40 to SO an tn sods Involving Jamsar-Molasar aSSoCiation The maximum salt accumulation was marked In the

• middle of gYPsle horiZon : !

Table 1 5011 senes aSSoCiation In the Irlvestigated area

S No SOil $Snes assoclatrons ProportJon Area (Km )

Sc>ils of older alluvial ptalns

1. Pannowah. Ganganagr 60AO 145390 (13.7)

2 Ganganagr PanOlweJI 70'30 86350 (7 8)

3 Ganganagar Lalgarh 6040 65260 (5 9)

'" LalgartL Ganganagar 7030 97690 (89)

5. Govlndpur Panmwall 60040 35430 (3 5)

6 Govindpur Ganganagr 6040 37640 (34)

7 Pannowali Govindpur 7030 97550 (88)

8 Ganganagar Govlndpur 6040 4550 (04)

9 Dabla Pannmah 7030 9610 (0 9)

10, Panniwah Lalgarfl 6040 9220 (0 8) SoilS of Younger alluvial ptatns

11. Jallsar loam Jallsar sand 7030 62930 (5 7)

12 Jallsar sand. Jaltsar loam 6040 32280 (299) Soils of older alluvial plains (Gypslferrous)

13 Jamsar: Molasar 7030 38S90 (3 5) Solis of inter dunes

14 Molasar Jamsar (hummockY, 20-40 % 7030 1034 eo (94) mtenslty)

15 Molasar. Jamsar (hummockY 40-60 % 6040 42330 (3 8) Intensity)

16 Dune complexes 2215.60 (201)

17 Settlemenl 5250 (05)

• Causes of Salinity

trrigation

A high water requlnng crops (Cotton-wheat) IS the main focus of the area (FIg 1) Area fallln9 near the canal head (Older allUVial plams and a part of younger allUVIal plains) receives good supply of canat water for "ngallon round the croppmg season The area located away (other part of younger allUVial plains) from the source used to get the water. At the npenlng stage of the crop water supply IS not property maintained and the farmers are forced to go for ground water Imgatlon, which IS hIghly sahne and sodle As a result of this kind of mIsmanagement of IrrigatIon, sahne-sadle condItions emerged In the area

Fig 1 Sahn.ty In well irngated cotton field In the beginning of the season

35

Chemlcai Changes & Nu\rient Transformation in SodlcJPoor Quality Water lnigal~d Soils

Diversity in the soil characteristics affects distribution of salts in the sods. Salts tlas leached from surface to subsurface in the soils , having loamy sand to sandy loam surface horizon afld accumulated on the impervious layer of calcareous bentonite and gypsum in Dabla-Panniwali and Jal)1sar- Molasar series, respectively (Fig.2). In contrast, loam to sandy clay loam texture at the surface in a part of Jaltsar loarn- Jaitsar sand association attributed to the accumuJafjon of salt jn first 40 em of the soils. With the persistent of the prevailing irrigation system from fairly long time soil profile for a part of Jaitsar loam- jaitsar sand association was salinizedlsodimized. The maximum salts were accumulated in the clayey sub-surface

Fig.2 Gypsiferrous soils

Salinity developed adjacent to the canal is attributed to the ground water. S~epage of water from canal is the main cause of genesis of this kind of salinity. Excess water. above the field capacity, percolates down to the soil profile and mix with highly saline ground water. On the demand of evapo-transpiration pull the mix water moves through capillary and appears on the surface This kind of area was not considered as the part of soil mapping unit and were shown separately as water logged feature.

Airborne salinillt

A part from irrigation, salt Is also deposited by the winds. Evaporation of the sea sprays from the coast; desiccated surface of Rann of Kutch and adjoining salt lake of Sambhar; inland lake of Lunkaransar and Didwana are the possible source. Dried salt particles from the surfaces of these are carried inland by prevailing winds. The persistent south-west monsoon, which blow through Rajasthan for half the year carry a large quantity of saline mud Bnd salt particles from the above sites, which are dropped when the velocity of winds decreased. The occasional rainfall and first irrigation of cropping season ~athe"s the salt and accumulates in the soil profile. Due to the persistent of drought conditions year after year a part of water logged area is completely dried and tf1at also become the hunting ground for westerly to pick up the salts (Fig. 3).

Fig.3 Dried water Jogged area

Genesis of sodiclty

GenesIs of sodicity may be exp1ained on account of exchange equilibria and solubility product. As the concentration of sodium increased in the soil sofution, it replaces calcium from the exchange complex. As pH of soils goes beyond 8.2 calcium precipitates as carbonates and moves down the soil profile as authegenic lime. Hydrolysis of the adsorbed sodium ions gives soil pH more than 9.0. This may the reason for higher soil pH of Dabla, Jaitsar and Jamsar series of the investigated area.

36

GenesIs of Salina and SadIe Soils In Canallmgated Area of Desert Ecosystem

summary and conclusions

The results of the present compilation indicated that prevailing Improper land use and Inadequate lin 3tlon management are the malar cause of the salinity In the Imgated part of the desert ecosystem Change of ~.nd use and adopting good practlce~ for Imgatlon management IS Imperative for' suslalnabllrty of agnculture In the canal command area of the desert ecosystem

Bibliography

Dhir R P 2007 Challenges of managlnQ sandy soils under canal liTIgation In, Thar Desert Journal of the , Indian Society of Soli SCience, 55 421-426. .

Kar, A. 1992 Geomorphology of the Thar Desert in Rajasthan In Geomorphological Facts of Rajasthan (Shanma, H Sand Shanma, M.L eds.J Kuldeep Publication, Ajmer, pp 175-212

Kar, A. 1999 QuatemalY period in Rajasthan Geomorphic process response to forclngand ImplicallOns foi terrain evolution In Geology of· Rajasthan-Status and Perspectives (Katana, P ed), Geology Department, M L Sukhadla Umverslty, pp 175-212

Khan, MA, Moharana, P C and Singh, S K. 200~ Integrated natural resources 'and enVIronment Impact assessment for sustainable development of Ganganagar dlstnct Rajasthan D,v,sion of Natural Resources and Envlronmen~ CAZRI Jodhpur, pp 111

Ram, B and Chauhan, J S 2002. Impact assessment of IGNP canal on land use in H~numangarh dlstnct, uSing remote sensing and GIS Indian Cartographer, 1~

37

-' Genesis, Taxonomy and Behavior of Sodic Vertisols in India

/ , S.K. Singh Division of 5011 and Crop Management Cenlral Soil Salimty Research Institute. Kamal -132001

Introduction "-

Vertisols are dark smecbte clays nch sOils (>30% clay) with characteristic of shnnklng and swelling This group of sOils m a dry state develops tYPical cracks. which are at least 1 em Wide reaching to a depth of 50 em or more Vertisols are often also called heavy crackmg clayey sOils. These owe thelf speCific properties to the presence of swelling clay-minerals. mainly montmonllonlte As a result 01 wetting and drying, expansion and contracbon of the clay minerals take place Contracbon leads to the fonmatlon of the Wide and deep cracks. The cracks close after r,lIn when the clay minerals swell. Dunng expansion of the clay mmerals high pressures are developed within 'these soils, causmg a charactenstic soil structure with wedge-shaped aggregates m the surface SOil and planar SOil blocks In the subsoil The slippage of one SOil block over the other leads to the formation of typical polished surfaces, "slickenSides" on the blocks ExpanSion and contractiOn also cause the lonmalion of micro-topographic features known as "gllgai", a dlslinc!Jve mlcro~relJef of knolls and basins 'that develops by mternal mass movements 10 the SOil and heaVing of the undertYlng matenaJ to the surface - .

Extent and DistributIon

Vertisols cover a total 01 about 340 mlllJl~n hectares Most Vertisols occur In the semi-and troPICS. mainly In Afnca (the Gezira and other parts of central Sudan, South Alnca, Ethiopia. and Tanzania), ASia (the Deccan plateau of India) and Australia The Extent 01 Vertisols and associated 50115 In India IS approximately 729 million hectares. compnslng 222 % of total geographical area 01 the country (Murthy et al 1982) Verbsols and associated soils are mainly connned between 8"45' to 2So ~ labtude and SO to 83 "E longitude In India, extensively occurnng In Madhya Pradesh, Maharashtra, GUJarat, Andhra Pradesh, Tamil Nadu and Rajasthan (Murthy et al 1982)

Main Production ConstraInts

Vertisols are difficult to work, they have very hard consistence when dry and very plastiC and sticky ('"heavy'") when wet Therelore the workability of the 5011 IS often limrted to very short peflods of medium (optimal) water status However, tillage operations can be performed m the dry season With heavy machmery Mechanical tillage' In the wet season causes senous sari compaction. Wet land IS Impassable Vertisols are Imperfectly to poorly drained. leaching of soluble weathenng products IS limited, the contents of available calCium and magnesium are high and pH IS above 7 ThiS IS due to the very low hydrauliC conducbvlty Once the 5011 has reached its field capaCity, pracllcally no water movement occurs Flooding can be a major problem In areas With higher rainfall Surface water may be drained by open drains Vertisols

• are chemically nch and are capable of sustaining contmuous cropping They do not necessanly reqUire a rest penod lor recovery. because the pedoturbatlon continuously bnngs subSOil to the surface However, the overall produc!Jvlty nonmally remains low, espeCially where no lmgatlon water IS available Nitrogen IS nonmally deficient as well as phosphorus Phosphate fixatJon (as tncalclum phosphate) may occur but IS not a major problem particularly In the Salls denved Irom sedimentary rocks Potassium contents are vanable and ns response IS expected In SOlis derIVed from basall and basa",c allUVia al Ihe elevated topography Secondary elements and mlcronutnents are often defiCient

, The problems 01 flooding. hard setting behaVior. very low hydraulic conductiVity, shorter penod lor farm operatIOn and shorter LGP (length of growmg perIOd) are very common These problems are magnified as the sodlficatlon of smectrtes takes place In the present chapter views on genesIs of sodlc Vertisols and assOCiated non sodlc Vertisols are discussed

Soil Fonming Factor.!

The claSSical SOil lonmlng lactors I e parent matenal, climate, topography, vegetation and time, established by Dockuchaev are stili the best elements to comprehend the lormatlon of Vertisols These lonmlng factors are Interdependent and highly vanable They Influence the properties of Vertisols in many ways The difference In the mtenslty of processes as conditioned by each 01 these factors Within and among the regions IS responSible for the global dIVersny In Vertisols Each of the factors among Ihem IS descnbed With the locus on the factor responsible for ,"duclng SOdlClty In Vertisols

Parent material

The parent materials must proVide. Iroill Inhentance of weathenng, a high content of clay With high surface area and generally a high base status The distinction between inhented and neo-formed clay

Genesis, Taxonomy and BehaViour of Soche Vertisols In India

mlnerals IS stili speculatve, espeCially In the case of sedimentary deposits If pnmary minerals have persisted, rt may pOSSible to suggest source of onglns of parent material that contnbuted to these sOils A high base s!lltus favors formallon and stability of clay, mInerals abundant "' Vertisols However, the base status may be relatIvely low In certain types of parent matenals (e 9 volcanIC tUff, granite, gneiss and SchistS) With time the base status may increase due to release of bases from mInerai weathenng and lor from external sources e g leaching from upland, flood waters, base nCh-nch water tables or aeolian depOSIts Weathenng of sodIum feldspar andlor base nCh waler tables are the cause for the develop")ent of ,SOdIC Vertisols In IndIa The vanatlon In the mInerai composItIon of Verosols denved from dIfferent parent matenal of Rajasthan IS shown In tableS 1 However, vanatlon In the chemIcal composItIon of clays in VertIsols of dIfferent parenl matenal of Rajasthan IS elUCidated IR table 2, .

Table 1 MInerai composItIon of sand fractIon (after SIngh et al 1999) VertIsols Ralasthan

SOil Series Landscape Parent malerial Dominant minerals

Kola SemI-hyperbolic BasaltiC allUVIa 01 Au En ° Aklera Concave BasaltIC allUVIa 01 Au Am En

Bhatewar' ConCave Schist (Feldspar) 0 PI MI

Taswana Convex SchIst (Feldspar) ° PI MI

Ol-olivlne, Au-AugIte, En-enstatite, Am-amphibolites, O-orthoclase, PI-plagioclase, Mi- microcllne,' Sodic Vertisols

Table 2 Chemical composItIOn of smeetnes In Vertisols (after Singh el al 2002~ of Rajasthan

SOil Senes Landscape Parent matenal SI02 AI20, Na20 K,O

("/0)

Kola Semi-hyperbolIc Basaltic allUVIa 5390 ,14,aO 080 o·eo

Aklera Concave, BasalllC allUVIa 57,20 1860 ·070 070'

Bhatewa" Concave Schist (Feldspar) 51-70 1460 1 90 280

Taswana Convex SchIst (Feldspart 5350 1340 220 440

Climate

Vertisols occur pnnclpally In the SOIls of hot marked allernabng wet and dry seasons, It may occur under a Wide range of cilmallc conditIOns With mean annual temperatures varying from 0 to "25, DC (crylC to hyperthermiC), With respect to mOisture regime, Vertisols differ In the amount of raInfall they receive In terms of annual preclprtatlon, the range from 250 to 3000 mm but most commonly 500 to 1500 mm PeriodiCity, duration, Int~nsity of rainfall events or other hydrological events ,such as .surface runoff, surface run-In, fluctuabon of groundwater table or flooding may Influence VertIsols formations Surface run-IO, fluctuation of base nch groundwater and floodIng are the factors InducIn!l sodl\:tty In Vertisols

Topography

Topographical POSItion Influences drainage condlbons and SOIl depth F'or instance, Vertisols that' Occur at higher elevations (Convex shape landscape) with better drainage conditions will have tendEmcy to produce hIgher content of kaOlinite and "on oxides, which WIll be eVIdent from higher chroma of SOIl matnx, lower catIon exchange capacIty and higher phosphorus sorptIon than In black VertIsols (Table 3) Free "on OXIde to clay rato, which IS higher at the elevated topography, governs the expression of soli colour (Singh ef al. 1995) Wider the ratIO, bnghter is the colour and V/oo-versa Bnghter colour of SOils suggests that bondIng between organic collOids and smectltes IS not strong enough, resultIng In redder hue and darker chroma. The underlYing topography of basall rock is the other factor that govems SOIl depth In basal~c region of India It was recorded dome and baSin shaped In Malwa region of Rajasthan The SOils were shallow on the dome segment and moderately deep to deep In the valley segment VertIsols that OCCur In depreSSIons (Concave ~hape landscape), nearly planner Or concave pos~lon would favor accumulatIon of Silica, thus promollng the orm~tlon of chemical equllibnum of smeclltes Such"solls likely have a high CEe and srnectlte"mlneralogy,

and lis colour WIll depend on free iron OXIde to clay ratIO It IS dar1(er If the ratio remained narrower than 0 085. ~thelWlse acqUired brighter colour (Singh et al 1995) Micro-topography may also cause for formatIon of sodlc

ertlsols by modifying dlstnbul<on of water across the landscape and faCilitate greater'preciplta~on of rain water for weathenng and smectltes formatIon (Table 3)

39

ChemIcal Changes & Nutrient Transformation In, SodlClPoor Quahty Water Imgated SOIls

/ . , ~able 3 Vernc properties on different landscape configurabon In Rajasthan (after Singh el al 2()()4)

SOIl Series Landscape Parent matenal Colour Cracks + Slickensides #

,Kola Semi-hyperbolic BasaltiC alluvia 10 YR 3/4 33150 Id nI 540

Aklera Concave BasaltiC alluvia 25Y312 42900 P 560

Bhatewa" Concave Schist (Feldspar), 10 YR 3/3 37944 P 450

Taswana Convex Schist (Feldspar) 10 YR 312 15840 Id I 185

• Sodlc Vertisols (After Singh at al), # smectite content glkg of clay, + volume cm31m', Id- Indistinct, p-Prominent, !-Intersecting, nI-non intersecting

Vegetation and Time

Vegetallon usually IS not cOnsidered an active factor on development of Vertisols In general Vertlsol~ that have a gllgal micro relief, generally xerophytic plants occur on mounds, while more mesophytlc vegetation occupies depressions (Wilding and Coulombe, 1996) At present time, most Vertisols are being Influenced by post cultural human activities, e g fire, agncultural practices and englneenng consiructlon Therefore It IS difficult to predict about the role of vegetation on development ot Vertisols Even though the parent matenals may have formed in older geological time penods, however, Vertisols have developed on recent times Some unconsolidated parent matenals may require only a few hundred years to develop because of high clay contents, while for consolidated parent matenals suffiCient time is needed for weathenng, clay fonmatlon and swell-shrink dynamiCS to develop Vertisols

Genesis of Sodie Vertisols

It IS discussed In light of the Vertosols,denved from feldspar nch carbonaceous schist (Bhatewar and associated senes) from Rajasthan under rain fed Situation ,Partial hydraulic decompOSition of feldspar has "'d' to the formation of mica! Illite and then to smectite under alkaline conditions Vermiculite (Fig 1) being Intermediate product of alteration subjected to rapid conversion to smectltes under poorly drained conditions and that vermiculite is mica derived unstable Intermediate, Release of sodium was the byproduct of weathering process As the concentration of sodium Increased In the 5011 solution, It replaces calCium from exchange complex and results In sodium dominated clay micelle Liberated calCium preCipitated as GaCO" when 5011 pH goes beyond 8,2 At thiS pH, higher concentration of Ca" and HeOi shift the solUbility product to Its nght for CaCO, precipitation Recently precIpitated lime In the subsurface endorsed the obselVatlons, However, landscape configuration further Induced the diversity among them The problem of sodlficatlon With extensive cracking and prominent slickensides was more acute under the close system (depreSSions, Bhatewar senes» as compared to the partoally open system in Vertisols of Taswana senes, This could have attributed to deep penelratlon of water vIs-a-vIs rapid weathenng of feldspar, for a higher release of sodium and a higher content of smectrtes (Table 3)

However, the above proceM does not explain the presence of Kaolinite In sodlc Verllsols, of Bhatewar, accounting to present day wanm semi and type of climate, not condUCive for feldspar to kaohnlte transformation Neutral to alkaline condition also does not favor the outline transformation. Therefore kaolinite formahon from orthoclase might have occurred In prepliocene geological penod:when the entire region might have expenenced comparatively higher rainfall and larger Ouctualions In temperature Dunng those peneds' parllal hydrolytiC decompOSition of feldspar had led to the fonmatlon of micaflillte, which had transformed to kaolinite In latter stage of weathenng Pal e/ al (1989) were also given similar kind of interpretation

~artlally altered orthoclase Mica In fine Silt , ____ ... illite In clay

In ,VIeW of smectlte-kaolimte transformahon, It IS pcstulated that dlOctahedrai was the first weathenng product of, orthoclase feldspar dunng humid period, which was ephemeral dunng tropical penod and had tra nsfonmed to kaolinite

Genesis of Non Sodie Vertisols

The fonmanon IS explained In light of Vertisols denved from basal! and basaltiC allUVium in Chambal and PalVan rover plainS on Malwa region of Rajasthan Clay specimen of Aklera and Patan senes of the region showed traces of kaolinite and their Silt and fine sand traction contained smaller quantitY of feldspar These

, wrth neutral pH condition discounted the InfluenCe of smectlte-kaollnte transformation Furthermore, absence of vermiculites (Fig 1) rules out the active process of transformation These conditions suggest that smectltes on SOils of basalt and basallic allUVium was dlr~ctly Inhented from parent material I! IS presumed that In the Initial stage of SOil formabon weathered matenal charged With smectltes from the basalt cap, resting on the

40

GenesIs. Taxonomy and BehaVIour of Sodle Ver1lsols In India

vlndhyan system (well exposed In Jhalarapatan near Jhalawar dlstnct of RaJ3sthan), was deposited on the lime basement. Occurrence of geogenlc lime nodules were already reported from these sOils (Singh al 8/ 2004) Smectltes thus contnbuted from basalt and basaltic alluvIum remained In their natural state under concave shape land configuratIon where pedo-environment and surrounding were In equlhbnum (Aklera series) Smectltes were sublected degradabcn on the associated senes on seml-hyperbolic and linear shape landscape configuration prominently observed in Kola senes. Dark brown colour and sphenoid's, replaced usual black 5011 colour and slickensides In Kola senes, and were the example of smectite degradation

• f

Sodlfleallon of Non-Sodlc Vertisols

This kind of sodlficabon generally reported in command areas of GUlarat, Maharashtra, Anahra Pradesh, Madhya Pradesh Bnd Tamil Nadu. Vertisols are generally eltiher moderately sUitable or not sUilable for Imgatlon because of high clay content and restricted draInage. On account of these, Vert,sols have tendency to sodlficatron under imgatlon The problem becomes severe under high RSC water Imgat.on The process of sodlfication IS stmple as descnbed under rainfed condition Difference IS only the source of sodium Imgallon water is the driving force for sodification In the present case Instead weathering of plagioclase under ralnted srtuatlon

Pedogenic Processes In Sodie and Non Sodlc Vertisols

Several authors have proposed different models for development of gllgal, slIckensides and cracks rn VertIsols First model, commonly known as haploldlzatlon by argllll-pedoturbation or pedoturballon or self mixing (Suol ., 8/ 1980) states that cracks are formed dUring dry season They extend to the depth of 1 meter or more While the cracks are open, surface soil matenals fall in to them by biological actovlt,es or as matertal transported by wind, water or gravity Upon rewettlng, the cracks close due to expansion of clay in the 5011 and space problem IS generated

rI.O A

Fig 1 Smectltes In non-sodlc and SodlC Vertisols from left (after Singh ef 8/ 2002)

ThiS results In sotl movln9 honzontally and vertrcally to accommodate tihe space of the Infined matenal The final resun IS weak honzonation, a homogenizatIon of whole sOil profile and a development of features at dIfferent morphological scales such as mlcroshear, dJscontlnUlhes stress cutans, pressure faces of the peds, slrckensldes and gllgal micro-topography However, according to wildIng and TeSSIer (1988) the self mulChIng model does not explain attnbutes like systematic depth function of organrc cat'oon, carbonates and salts (Table 5 ), the Increasing mean residence Irme of organic carbon With depth and the formation of albiC and Bt hanzon In VertIsols. These attributes should not eXIst In VertIsols formed prlmanly by the self mixing model due to lhe profile homogenlZa~on and tumover.

41

Chemical Changes & Nutnent T(ansfo(matlon In SodlclPoor Quahty Water lITIgated Solis.

Table 5 Distribution of organic carbon, CaCO, and salts In sodlc Vertisols of Bhatewar senes, Ralasthan /

$011 depth (em) 01'9 C (%) CaCO, (%) EC (1 2) dS m')

0-24 071 91 022

24-42 043 11 1 061

42-58 041 11 6 039

58-93 051 98 'Q 17

93-115 061 11 7 1 20

115-140 041 201 1 07

140-150+ 014 249 087

The second model WaS dlfferenllal loading (Gastavson,1975), which states thai 911gal In Vertisols, would result from a process whereby days move from areas of higher to lower confining pressure under plastiC VISCOUS flow (Paton, 1974) The model suggesls that the overburden loads exceed the shear strenglh of the unde~y,"g matenal and enable How to occur (Knight, 1980) ThiS model also falls to explain the formation of sllckens.des In Vertisols According 5011 mechanics model third one In succession, slickensides develop, whenever swelling pressure of sOil matenal in a confined system exceeds to shear slrenglh of salls at specified mOisture (Wilding, 1985) Dunng swelling, the SOIl IS subjected to vertical and lateral stress Vertical stress IS the function of 5011 water content and rainfall, whereas lateral stress IS the function of 5011 depth Shear strength IS the function of coheSion plus angle of Intemal fnctlon among the clay particles, CoheSion among the clay particles depends on bulk density, clay content, clay minerals and mOisture content (McConmork and Wilding, 1979) Angle fnctlons are related to the abundance, roughness and Inter locking skeletal grains (Wilding, 1985) Whenever lateral stress exceeds the shear strength of the Salls, failure occurs along grooved shear planes theoretically at 45° to the honzontal, -less }Ii the angle of Internal fnctlon Angle of Intemal fnctlon would relallvely be small for Vertisols because skeletal grains are Widely spaced and are not Inte~ocked. In practical, failure may range from 10 to 60 0 (Fig 2) fram honzontal

. Fig 2 Sllckensldes In Sadie Vertisols of Bhatewar senes In Rajasthan (after Singh 61 a/ 2004)

Structural Instability

Vertisols slakes under rapid wetllng followed by dispersion, tillS Induces surface sealing and a reduced rate at hydrauliC conductiVity, Infiltration, redlstnbutlon of water and evaporation from the soli surface Influence of these manifested as low subsurface recharge, compaction, massive coarse blocky structure, crust fonmabon and hard setting behaVior Impeded drainage reduced hydraulic conductivity and low rale evaporallon may Increase runoff and SOil erOSion, PhYSical condition of the Salls may not be favorable for seed genmlnatlon, development of seedling and fanm operations

High Swelling and Reduced Hydraulic Conductivity

_ Clay systems are essentially unaffected until Na reaches a threshold of about 7-20 % of the lotal cation sUlle (Shalnberg et al 1971) When the exchangeable sodium percentage (ESP) exceeds the threshold value, swelling Increases Significantly wllh an Increase, In ESP In contrast, small Increases In ESP tend 10 have a large effect on the hydrauliC conductiVity of the clay paste and the decrease starts from a value of zero

42

Genesis. Taxonomy and Behaviour of Sodlc Vertisols In India

ESP (Shalnberg and Calsennan, 1971) ThIs contradlctoon was explaIned In teoms of the domaIn theory. At low values 01 ESP, Na ions were adsoroed on the outer surfaces of the domains As ESP exceeded to threshold level that sodium starts to enter In to the space WIth In the domains, resuHing in macroscopic swelling Destruction of the domaIns was complete at ESP of around 50 % Therelore It can be concluded that Inltlslly, IncreasIng sodiu'!' results In the dIspersIon of the aggregates onto domaIns, whIch are small enough to be transported WIth the water and block the larger pores. resuillng In a reduced hydraulic conductivity (K) At hogher values of ESP, macroscop'c swellmg may contribute to a further reduell_on' in K. A hIgher crack volume, thlcl<er slIckensides WIth simIlar COLE values and a reduced hydrauliC conductlvijy in Sodlc VertIsols of Bhatewar as compared to non SodlC Vertosols of Aidera senes 01 Rajasthan under a comparable sItuatIon of, clay and smectite content (Table 6) endoosed the observations (SIngh et al. 2()()1, 2()Cl4) Exlenslve crackIng cutting the zone of slickensides In strongly alkaline sodic Vertisols 01 Puma Valley Maharashtra has also been reported (Pal et al. 2001) ,

OrigIn and denSIty of charge are Ihe other factors thai modlfymg the mfluence of sodIUm on Ihe exchange complex. Swellings in low charge smectites are comparahvely hIgher as compared to the VertIsols of high charge density For example octahedron from sodlc Vertisols of Bhatewar senes showed net poslllve charge, which countered the net negahve charge on tetrahedron (Singh et al 2002), resulting In hIgher d spaCIng (192 A, FIg, 1) Laller swells eaSIly as comparedJo the" counterparts haVIng d-spaang of 17 2 A

~

High Dispersion and Reduced Hydraulic ConducUvity

SodIClty In VertISOls leads to high dIspersion and a reduced hydraulIC COnductiVIty The effect of increasing sodIum on the amount of dlspeised clay is dIScussed In light of the data from Australian VertIsols (39 to 75 % clay) of Darling Downs in Queensland (Cook 1966, So and Cook 1992) Equation 1 shows very poor relatIonship between dIspersed clay and ESP. RelationshIP was' slgnoficant when dIspersed clay was regressed agaInst exchangeable sodium ecntent (Eq. 2). PredIctabIlity of dIspersed clay further Improved on the InclUSIon of clay conlent in the equation (Eq.3).

DIspersed clay DC= 0009 ESP"0.Cl43

DIspersed clay DC=O.29+0 023 ES

Dispersed clay DC=-O 21 +0 013·ES "0.0012· Clay

R'=0.21--Eq 1.

R'=O 77--Eq 2

R'=0.88- -Eq 3

Table 6 Influence of SodlClty In Vertisols of Rajasthan (alter SIngh el al. 20(4)

PropertIes

SlIcI<ensldes

Cracks

He (em hr')

COLE value

AWCm'm-'

Bhatewar senes

Mlcro-highs 61.0 em, tnterval between two adlacent mlcro-hlghs- 27 em

Mean WIdth 5 5 em; Spaang 111.62 depth 62 em and Volume 37944 em!,m'.

Tr- 0 06

018-019

0.38-039

Aklera senes

MIcro-hIgh 57 0 em, Interval between two adjacent micro-hIghs 45 em Mean WIdth 65 em; SpaCIng 120, depth 55 em and Volume 42900 em'lm'

010-0,11

017-0.18

0.22-0.25

Slmlla~y the relatIonshIp between sod,um and hydraulic conductiVIty IS Improved on Inclusion of bulk ~I sodium (ES) In place exchangeable sodIum percentage. Exchangeable sodIum accounts for 44 % vanablilty '~ hydraulic conductIVIty. A beller relatIonshIp IS reported If hydraulic conductIVIty is regressed agalnsl dIspersed clay (R2=0.56). Thus the effect of sodium on hydraulic conductiVIty IS medIated through dispersed clay MagneSIum is the other factor that also modified the Influence sodIum In VertIsols The effect 01 sodIum on dIspersIon and hydraulic conductlvijy can be exaceroated by the presence of exchangeable Mg (Bakker et al 1973) It is concluded from Bakker wor1{s, based on Australian experience that the aChon of Me IS obVIOUS untIl exchangeable sod,um percentage reaches a value 12, beyond whIch the influence of sodIum become domInant. DespIte the effect 01 magnesIum on dIspersion; ds Influence is often not observed In the field However, as Emerslon (1977) pOInted oul, Na-Mg-ciay dIsperse al a conSIderable lower water content than Na-Ca-ciay Therfore, soils WIth hIgh exchangeable Mg have potentIal lor dIspersIon when cull,vabon IS eamed out at hIgh water content Hence forth, use of ESP as a yard stIck across,lhe soils for sodlClty ~mehorntlon may be used with precautions Pal et al (2006) suggested thai characterizatIon of sodlc SOIls In

Herms of hydraulIC conductIVIty for 0-100 em depth may be one of the robusl optIons Instead of ESP IghpH

43

Chemical Changes & Nutrient Transformation In Sodle/foor Qualily Water Irrlgate~ SOils

, In mJ)<ed cation systems where both Na and Ca are present on the clay, the ratio of Na and Ca concentrations In the soli solution affects the ratio 'if the exchangeable Na end Ca according to the Gapon equabon (QUIrk and Murray 1991)

ENa/ECD. = KG ~ .JlNaJ/rCa Eq 4

ESR = KG" (SAR) --------- Eq.5,

. ~ Where, BNa and ECo is the fractions of the exchange complex occupied by those Ions, KG IS the Gapon

constant and the square braCkets Indicate concentrations (mmol dm") of the ions In soluMn. ESR and SAR are the exchangeable sodium' rallo and sodium adsorption rallo respectively. The reported values of KG range from 0.0072 to 0.020 (Richards, 1954; Bakker et al 1973, Shainberg and Letey, 1984), depending on the mineralogy of the clay. The Gapon equation shows that a small change In ESR contnbutes a large vanallon In SAR Therefore, a small increase in ESR or ESP (the two are similar at low values) results in a large Increase In the proportion of Na ions in the equilibrium sOil solution ThiS produces an Increase In the sOil pH, and values of 8, 5-9 5 are common and generally indicative of sodlc conditions in Vertisols

Available water capacity

Available water capacity Is greaHy retaoded In sodlc Vertisols A 12 fold increase in the Infiltrabon capaClCY of sodie Vertisols (72 % clay and ESP of 7 %) by application of gypsum @ 7 5 tlha (So and McKenZie, 1984) and a 14 fold increase in hydraulic conducbvrty by applicaton of 12 tlha gypsum (Love day, 1984) Indicated the adverse role of sodium on water dynamiCS However, a higher AWe in SodlC Vertisols of Bhatewar series tha~ their non SodlC counterpart of Aklera senes in Rajasthan (Table 5) indicated ESP based model for defining water dynamics In Vertisols IS not adequate.

High Strength

Surface waterlogging gives nse to high ,nn,al rates of evaporation and rapid drying of the surface sod and can result In the development of hard setting or surface crusbng to an extent d"pendlng on the sOil texture A linear relationship (MOR= ESP"33.27+66.9, R'~0.45) between ESP and the strength (MOR modulus of rapture) of two hard setting soils from Mendln, WA was observed (So and 'Aylmore, 1993), The slopes of this relationship indicate the sodium sensitivity to the soils, which increase With the net negative charge of the clay fraction (Rengasamy and Olsson, 1991). An important point of this relationship is that for a given soil, ESP IS a good indicator of Its hard-setting behavior Jhe effect of Increasing ESP on MOR is mediated through the effect of ESP on the dispersed clay. Hard setling of the surface sOil Invariably results In reduced seedling emergence

Difficult Soli Workability

Dry surface layers can constitute sunace mulch where water transport IS predominantly in the vapour form, _with the result thai the rate of subsequent drying IS reduced and the subSOil remains Wet and suscepbble to compaction and shearing .. The use of gypsum 10 suppress dispeJSlon results in greater sod hydraulic COnduclJvHy and a faster rate of water redlstnbution from the sunace to the subSOil Water-logging is prevented and timeliness of operation IS improved However, It will also result In an increased abllrty of the subSOil to supply and maintain the surface soil In a mOist and fnable condlbon These result In an Increased ease' of tillage, which can be manifested in one or more of the follOWing parameters: reduced fuel consumption, Increased velOCity of tractor, red~ced wheel Slip and greater depth of working Poor sOil productiVity ,

Assuming adequate nutntlon, soils productiVity is largely.determined by the probability of s~coessful seedling establishment; the depth Qf root development and the amount of water stored In the subSOil The effect of sodium on seedlmg establlshmenl has already been discussed However, for small grain crops which exhibit strong tillenng characlenstlcs, reduced establishment IS generally not a problem unless II results In very low plant derisilles Poor establishment IS a malar limitation to productiVity With single Iiller crops (summer crops) Sodlcicy may affecl root development when the subSOil pH IS high. Expenence With solubon cultures showed that root growth ceased at pH values of around 9, however, it is not clear if SOil pH values of 9-9 5 Will aCtually stop root growth. SodICICY, however, may affect root development indirectly through high SOil strength assoCiated With soil compactJon and reduced SOil water contents In the GwydlT, Valley Vertisols increased dlspeJSlon IS most strongly associated With increasing sad Icily (Yates and McGanty, 1984), and the survey by So and Onus (1984) showed thaI increaSing dlspeJSlon is largely responsible for the reduced productiVity of these SOils Abrol el al (1973) reported 1hat the use of gypsum on the highly sodlc SOils from India resulted In greatly Increased Yields of a vanety of crops:assoCiated With mcreased water infiltrallon rilles

44

Genesis, Ta)(onomy and BehaVIour of Sadie Vertisols In India

Placement of Sod Ie and Non Sadie Vertisols In 5011 'Taxonomy

The term Vertisols was adopted dunng 6"' congress of the Intematlonal SOCiety of Sari SCience In. 1956 for those salls, haVing swell-shrrnk potential (Dudal and Eswaran, 1988) Thereafter these have been recognized an many Intematlonal classification ':systems, e g, SOil Taxonomy (Soil Survey Staff, 1960,1975,1990,1992 and'1998), FAD-UNESCO (1974,1982, and 1988), CPSC French System (1967) and Referenbal pedologlque (Page and Glrad, 1992) Pnor to the adoption of the term Vertisols, these sorls'were names as regur and black cotton salls of IndIa (Knshna and Perumal, 1946,'SlmonSQn and Throp, 1950), black earth and cracking clays In Austraha (Hubble, 1984), dark clays In Afnca (Dudal, 1965) In India these salls were called by different names m'dlfferent part of the country, Kami' In UP, Mar In Bundelkhand, Kobar and,Kanhar In other parts of M P; Mar, Kahkasdar and Manyar In Maharashtra, Karlsal mannu In Tamllnadu, Kahl"mln and Bhal In GUlarat; Yen and Kan an Kamatka (Oulal and Eswaran, 1988) With the Introduction 01 SOil Taxonomy (Soil Survey Staff, 1975) the classlficalron begins based on SOil morphology Taxa were defined by selectrng the diagnostic characteristics, IndlcaMg Importan'! differential charactenstlcs with other sOil orders The diagnostic charactensues for Vertisols was 30 % or more clay In all hOrizons, 1 em Wide' cracks, open and close, perrodlcaJly and also had either one or more charactenstlcs like (a) Gllgal (b) slickensides between the depth 01025 to 1m (c) wedge shaped SOil structure (Soil Survey Staff, 1975) At sub order level Vertisols had four taxa (Soil 'Survey Staff, '1975 to 90) Tome, UdIC, UStlC and Xenc, depending upon number of days that SOil cracks remain open The categones at great group level were prrmarrly dependent on 5011 colour With exception of Tomc group The class differentIa was chromiC I e chroma value >1 5 In upper 30 em of the 5011 solum and peU,c i e, chroma <1,5 In upper 30 em af the salls (Soli Survey Staff, 1975 to 1990) French System of SOil classification lays emphaSIS on SOil genesIs With speCIal reference to parent matenal and drainage conditions French System has named the Salls as Vertisols and Para Vertisols These are further subdiVided at sub class level into topomorphlc (depreSSions) Vertisols With humid pedoclimale (CPSC, 1967) Ecological genellcal approach In RUSSian system of 5011 classification lays emphaSIS on the evolution of SOil properties and pedogeniC processes In the SOil solum, relating to the factors 015011 formation (Murthy et al 1982) The category, 5011 typeS In RUSSian System of SOil claSSification roughly corresponds to the order and suborder categones '" US, so" taxonomy,

Based on 5011 taxonomy (5011 Survey Staff, 1975) cntena, black SOils of IndIa were claSSified and follOWing conclUSions were drawn • Some of the pedons, normally deeper black Salls satisfied the dlagnosUc crltena" however, moderately

deep to shallow salts In most of the cases did not satisfy the requirement • Based on the chmatlc charactenstlcs, Vertisols 01 India could ,quahfy lor Usterts but vast difference was

noted In the penod of deSiccation, defiCit, 'moisture potential and available mOisture storage In these contexts, II Uniform copping system IS followed In vIew of the eXltmg family cntena In all the locations, failure In crop performance would be IneVitable

• In 4" ed,"on of Key to SOil taxonomy (SOil Survey Staff; 1 990), the colour limit of 5011 chroma became 2 rather 1 5 Based on the amendments In 4'" edItion black SOils of India were claSSified again However, the above framework falls to accommodate the charactenstlcs such as accumulation carbonate, gypsum, salts and sodlficatlon, which are Important lor ubhtanan pOint of view

• In 5'" ed~lon of Key to so" taxonomy (So" survey. Staff, 19(2) VertIsols contained Significant changes In SOIl taxonomy to resolve the above pending Issues (Commerma et al 1988) Many new categones were recognrzed for accommodating the diversities 01 Vertisols lor better Interpreta~ons, management and use, SOil colour at higher categoncal level was dEHlmphaslZed Definition of Vertisols remained Similar; however, a layer 01 2(; em thickness, shOWing intersecting sl,cJ<ensldes was added G"gaJ was not conSidered as the common leature of all Verbsols A vertic diagnostic honzon has been proposed for mcluslon In 5011 Taxonomy (Blokhuls et al 1991, Mennut et al 1991) but has not been accepted However, a honzon WIth slickensIdes (Sss) as recognized In the field as vertIc conditions has ~een accepted

• The Verbsol order in 5" edition of SOil taxonomy has 6 suborder, 23 great groups and 123 subgroups Sub order IS categonzed based on the number of days that 5011 cracks remain open but the question of regional varlablhty Within sub order IS yet to be resolved The great group categories have a morphogeniC bias by conSIdering properties such as salt (Salic, Natnc, CalCIC, Gypsic) accumulations, depth 01 saturation by water (EpI and Endo great group) Finally, 153 categories are distinguished at the great group levet In thiS ed,Uon of soil taxonomy Vanatlon In the status of SOil taxonomy remams unchanged till eighth edition of key to soil taxonomy

Unresolved Issues

The present claSSification system falls to claSSify shallow black SOIls or black Salls which do not have dlsbnct regular pattem of shckenSldes Or thickness of the shckenSldes are less than 25 em Although, these Salls behave Identically With respect to management In order to accommodate Vertisols of India In the present frameWOrk of taxonomy the definition Qf Vertlsol SOil order IS proposed as SOils which have a layer With an upper boundary WIthin 100 em of mineral 5011 surface that has eHher shckensldes close enough to Intersect or

45

Chemical Changes & Nutnent Transformation In SodldPoor Quality Water Imgated Salls

wedge shape aggregate along the" long axis tilted 10 to 60 0 from honzontal or sphenoid's, Also weighted' average of 3D % or more clay In the earth fraction either between the minerai sOli surface and a depth of 18 em or m Ap h'onzon whichever IS thicker and 30 % 'ormore clay In fine earth fraction of all horIZon between the depth of,18 cm and erther depth of 50'em or a hthlc or parallthlc contact, Dunpan or petrocatcic horizon, if shallower " .

Summary and Conclusions , Vertisols covering an area of 340 million hectare land In the world and 72 9 m,lI,on hectare area In

India have sinking feature of shckensldes, wedge shaped structure and penodlc craCking Base rich parent material and topography have Immense role for the development of Vertisols SOil mechaniCS failure model comparatively betler explamed the formalion of cracks, slickensides and gllgal than other proposed model such as differential loading and haplOldlzatlon Poor "ngatlon management and In srtu weathenng of feldspar lead to the sodlficatlon of Vertisols Sodlc Vertisols showed comparatively higher swellmg, thicker slickensides, reduced water retenbon, poor hydrauliC conductIVIty and difficult wor1<abll,ty The crltena of ESP as yand stick to claSSify the SOils may not be adequate because the change In the crystallography of smectite. from tectolds to plates Latter magnified the adverse Influence of exchangeable sodium on phYSical properties of SOils SOOlclty has been considered at subgroup level as d,fferenlla charactenstics for claSSification of SOils in Intematlonal system of SOil taxonomy

Bibliography

Abrol, I P Dargan, K S, and Bhumbla, D R 1973 Reclaiming alkali so,ls Central SOil Salinity Res Inst Bull No 2, Kamal, India I

Blokhuts, W A , Wilding, L P. and KOlstra, M J 1991. ClaSSificatIOn of vertic Intergrades, macro- marpholog,cal and mlcro-morphologlcal aspect In Charactenzatlon, claSSification and utllizalion of cold Andrsols and Vertisols Proceedmg 6'" International Sol/ Correlation Meei (VIISCOM) (J!<1 Kimble ed), pp 1-7 USDA-SCS National SOil Survey Center, Lincoln, N E

Buol, S W, Hole, f D and McCracken, R J 1980 SOil genesIs and claSSification, 2"" edition, The IOWA University Press Amenca IOWA

Dulal, R 1965 Dark Clay soils of tropical and subtropical regions, Agriculture D,VIs,on P.aper 83, FAO , Rome

Dulal, Rand Eswaran, H 1988 Drstrlbulion, properties and claSSification of Vertisols In Vertisols the" distribution, properbes, claSSification and ~anagement (L P Wilding and R. Puentes, eds), pp 1-22 Texas, A&M University Pnntmg center College station, TX·77843

FAO-UNESCO 1988 Sorl map of the world, reVised legend, ppl-19, World Sol/ ResoulWs, report No 60, Rome, Italy

Knight, M J 1980 Structural analYSIS and mechamcal onglns of gllga; at Boorook, Victoria Australia Geooerma 23, 245·283

Knshna, P G and Perumal, S 1948 Structure In black cotton sorls of the Nlzam Sagar prOject area , Hyderabad state Journal of the Indian society of SO/I SCience 6, 29-38'

Loveday, J 1984 Amendments for reclaiming sodlc sOlr~ In 'Soil Salinity under ImgatlOn' (Eds I Shalnberg and J 'Shalhevet) Ecological Service No 51 pp 220-37 (Springer Verlag Berlin)

Mermut, P R, Action, D f. and Tomocal, L 1991. A review 01 recent research on swelling clay SOils rn Canada In Characterlzabon, classlficalion and utilization of oold Aridisols and Vertisols Proceeding 6 Ur Infemallonal SOil Correia lion Meet (VIISCOM) (J M Kimble ed ), pp 1-7 USDA-SCS National SOil Survey Center, Lrncoln, N E

Murthy, R S , Bhanacha~ee, J C , Lande, R J and Profali, R M .1982 Distribution, characterlzallon and claSSification of Vertisols Transaction 12 Ih InfemaflOnal Congress Soli SCience, New Deihl, India 2,3-22

Pal, D K, Oespande, S B , Venu90pal, K Rand Kalbande, A R. 1989 Formation of d, and tno-octahedral smectltes as eVidence for paleOClimate .changes In southern and central peninsular India Geoderma 45,175-184

Pal, 0 K , Bhattacharya, T, Ray, S K, Chandran, P, SrIVastava, P., Ourge, S Land Bhuse, S R 2006 Slgmficance of SOil modifiers (Ca-Zeolites and Gypsum) m naturally degraded. Vertisols of penmsular India In redefinrng the sodlcsolls Geoderma 136210-228

Rengasamy, P , and Olsson, K A. 1991 SOdlClty and 5011 structure Austl3llan Journal of SOil Research 29. 935-52

Richards, L A 1954 DiagnOSIs and improvement of saline and alkali SOils (Ed) US D A Agncultural Handb 60 (Government Printer, Washington DC)

Shamberg, I , and Letey, J 1984 Response of Salls to saline and sodlc conditions Hllgarrlla 52, 1·57

46

GeneSIS, Taxonomy and BehaViour of Sadie Vertisols In India

Shalnberg, I , Bresler, E , and Klausner, Y 1971 Studies on NalCa montmonllonrte systems 1 The swelling pressure SOil SCience 111, 214-19 ,

Shalnberg, I, and Calserman, A 1971 Studies on NatCa montmonlloRite systems 2 The hydraulic' conductlvlly Soli SCience 111, 277-61

Slngl\ S K , Das, K , Shyampura, R L, Girl, J D , Singh R 5 and Sehgal, J 1995 GenesIs and taxonomy of black 50115 In Rajasthan Joumal of the Indian Soclely of SOil SCience 43 430-436

Singh, R S, Singh, 5 K, Jain, BLand Shyampura, R L 2001 Water retention, charactensliCS of some Verllsols of Rajasthan Joumal of the Indlsn Society of 5011 SCience 49 245-249

Singh, S K , Baser, BLand Shyampura, R L 2001 Vanability in hydrological Properties a! Vertisols denved from two parent Matenals Journal of the Indian Soclely of Soli SCIence 49 239-244

Singh, S K, Baser B,L, and Shyampura, R l 2002 Chemical composrtlon and charge behavior of smectltes In Vertisols of Rajasthan Joumalofthe Indian SOCIely of SOil SCience 50: 106-111.

Singh, S K, Baser B L , Shyampura R.L. & Pratap Naraln 2004 Variations in morphometnc properties of Verosols In Rajasthan, Joumal of the Indian So~tyof SOIf Sdeilce, 52 114-119

So, H B, and Cook, G D, 1993 The effect of salting and dispersion on the hydraulic conductIVIty of clay salls Calena Supplement 24, 55-64

SOIl SUivey Staff 1975 5011 Taxonomy, A basic system of 5011 claSSifiCation for making and interpreting SOIL sUlVey, USDA-SCAlWilly New YO'Ik,

SOit SUlVey Staff 1992 Key to SOil Taxonomy, 5" edillon, SMSS Technical Monograph No 19, USDA-SCS, US Govemment Pnntlng Office, Washington, D C

Wilding, L P. and Coulombe, C E 1996, ExpanSive Salls Dlstnbullon, morphology and genesIs In Proceeding NATO-ARW on clay swelling and expansIve soils, (P Baveye and M C Bnde, eds) Kluwer AcademiC, Dordrecht, Netherland

Wilding, L P. and Tlssier, D 1988 GenesIs of Vertisols, shnnk "-swell phenomena In Vertisols, their dlstnbutlon, properties, classlficabon and management (L P WildlO9 and R Puentes, eds), pp 55-61 Texas, A&M University Pnntlng Center College Stabon, TX-77843

47

Chemical Changes in Submerged Sodic Soils /

N.S. Pasrlcha Dlreclor (Retired) Potash Research inslrlule, Gurgaon, Haryana

Introduction

Paddy wetland sOils require special management skills and techniques lor continu~us stagnatIOn of water These management practices include leveling of land and construction' of levies for uniform lI"poundlng of water followed by plowing and harrowing called as puddling. Puddling also serves for Incorporabon of weeds, stubbles, green manunes and fertilizers and maintenance of 5-10 em'of standing water dunng 4 to 5 months of crop penod These specialized operations and secretion of oxyge'l from rice roots lead to the development of certain features peculiar to paddy SOils In the process of submergence, the 50.1 undergoes reduction, and turn dark grey. Iron, manganese, SIlica, phosphate become more soluble under these conditions The soluble SUbstances migrate to the SOil surface by dlffuslo'h and to the roots or the sub· soil by both diffUSion and mass flow When reduced Iron and manganese reach oxygenated SOil surface, the OXidized rhlZosphere of nce plants, or the zone of high potential below \he plow tayer, they' are OXidIZed and preCipilated as Fe" and Mn" OXide hydrates giving the surface a reddish brown colour a few mm thiCk, dark brown oxidized zone lies between reddish brown oxidIZed layer In the subsoil and the dark grey zone With reddish brown vertical stneaks along root channels

The follOWing changes are recorded dUring water logging or submergence of the 5011

I) Decrease In Redox Potential of the 5011 from about 500 mV In aerobiC state to -200 mV under anaerobiC condilions (Fig 1) Redox potential IS a measure of Intenstiy of reducllon condition ,n the SOil Salls that are fine In texture and nch In decomposable organic matter undergo rapid 'reduction, their redox potential IS low and negative Coarse textured Salls which are low. In organic matter, the redox potential value remainS high and POSitive On such soils, rt IS often difficult to keep standing water because of ample permeablhty Therefore, aeralion cannot be completely cut

II) Increase In pH of aCid SOils and a decrease In pH of calcareous and alkali SOils until Ihey converge to about 7 0 (Fig 2) Such a change In pH has Important practical implications relating nutnllon of nce which mclude release of phosphorus to so.1 solubon when pH of alkahne calcareous so.ls decreases on submergence Most of the P In such soils IS calCium bound Phosphate compounds of calCium become less stable as pH decreases resultmg In ItS solubility arid Incieased availability Simlla~y In aCid solis, most of the P IS "on- and aluminum bound On submergence, pH of aCid Salls Increases to near neutralIty. With Increase In pH, feme compounds of phosphorus are converted to less stable forms resulting In the release of phosphorus In 5011 solution

iii) loss of nitrates as gaseous nitrogen Within few days of submergence. Nitrates are highly stable In aerobiC SOils, but hlghty unstable under anaerobic condlbons Among the molecular and IOniC species

• that exist In more than one OXidation states, nitrates are the first to be affected due to submergence In the absence of free oxygen. facultallve organtsms In Ihe SOil slart uSing nitrates as source of oxygen for their respiration, In the process, NO, reduced to nitrogenous gaseous forms such as N20, NO and N, depending upon the Intensity of reduction condilions

2NO, + 10 H+ + B e' = N20T+ 5 H20 NO, +4H' +3e' = NOT +2H20 2ND,' + 12 H+ + 10 e' =, N,T + 6 H20

IV ) Accumulation of ammOnium in SOil Organic matter In the so.1 undergoes decompcsltlon, organtc-N is converted to amino form and then ammonia form However, the reaction stops at ammlntzatlon In submerged Salls Further process of nttrificalton does not take place because of lack of fnee oxygen as mtnficatlon IS an OXidatIOn process, Therefore under submerged conditions, N IS present mainly as NH4' N

nitrificatIon Organic N _, NH,_' N02- __ NO,

an'lmlr'llzabon oxidation

Reduction of manganic and ferne compounds to form more soluble divalent forms which are present mainly as blcarbonales, in concentration ranging from 5 to 100 mg/kg for Mn" and 5 to 600 mgt kg for Fe" Under arable conditions, manganese and Iron are present In SOil as Insoluble Mn (IV) and Fe (III) compounds On submergence, ferne and manganic forms are reduced to ferrous and manganous forms .

Chemical Changes In Submerged Sodle Solis

Reduction conditIOns In sOil on submergence are caused by accumulation of electrons In excesSive number Feme and manganic forms accept electrons and gel reduced to ferrous and manganous forms

Fe3+ -+ e = Fe2+

I Mn4+ '+ 2e = Mn2+

IV) Reduction of sulphate to sulphide As the reduction condrtlons co~tlnue, SOl'reduC!lon sets In However, reduction of sol' to H2S requires Intense reducllon condlilons and formation of H2S from sol' occur; only when alilhe NOi has been losl and all the femc and manganiC forms have been reduced to ferrous and manganous forms, respectly

v) Release of phosphates and Silica ,n soluble,lorm VI) Formation of CO2, 01'98nlc aCids, melhane, mercaplans, H2S, ethylene, hydrogen and resistant reSidues

of organic matter. The C02 partial pressure bulld:..u~ to 0 6 atm In 5011 solullon of submel'ge(j salls,

llwaler-Iogglng continues, follOWing addilional changes may take place

PreClpltallon of some minerals like hydraled magnetite, Fe,(OH). or Fe30. n H~O, which IS also called lerrosolenc hydroxide and we shall see laler that It IS an importanl source of Fe • In submerged SOils Hydrotnohte, FeS nH20, MacklnaWlte, FeS, Pynte FeS2, vlvianlte Fe3(PO')28H20, sidente, FeCO, and rhodochrOSite MnC03 When the SOils are drained for cuilivation 01 arable crops or when the SOils are emel'ged, oxygeri re-enters the SOil The redox polentlal Increases, pH of alkah SOil Increases and Ihat of aCid Salls decreases, ITon and manganese are OXidized chemically and blo-chemlcally and depoSIted as strains, concretions, ammonia IS OXidized to nitrate and sulphides to sulphate

Redox Potential

OXldalion reduction reactions are chemical changes In which atoms, molecules undergo electron transfer The entity that losses, electrons (the eleclron donor) is said to undel'9o oXldallon, and the electron acceptor, redudlon. thiS OXidation reduction reaction IS a conjugate process In which the electron donor IS OXidized and acceptor is reduced. The donor and acceptor constitute an oxidation-reducllon or redox couple In nature oxygen IS the most Important electron acceptor and hydrogen the most readily donor Thus most natural OXidation-reduction Involves addition of O2 or removal of H, reductions IS Just reverse Before further diSCUSSing about redox potential, It IS essenllal to know the OXidation number and OXidation state of the Ions present In the SOil These two terms are used synonymously In order to define the electnc charge on an Ion or alom With mono-atomic Ions, the OXidation number 15 merely the charge of the lon, but complex Ions and In molecules, the Situation IS not straight forward But there IS a clear cut distinction between OXidation number and OXidation state as suggested by quantum chemIstry, The ,use 01 lormal oXldalion number h~s been recommended as a convenient way for balanCIng redox equations Here we shall see that oXldallon numiler denotes the net apparent charge on an atom when all valence electrons hnklng two diSSimilar atoms are aSSigned to Ihe more electro-negative atom The OXidation number may be POSitive, zero or negative, It can be an Integral or a fraction e 9

CH, CH30H C,H2 CH,O. C co CO, -4 -2 -1 0 0 +2 '+4

NH,N2H. NH20H N2 N20 NO N02·· -3 -2 -1 0 +1 +2 +3

Mn MnO Mn30. Mn20, Mno, MnO. 0 +2 +8/3 +3 +4 +8

O'(ldatlon-reductlons are eleclron transfer Involvln9 changes In OXidation number of participating atoms

NO,' + 2H· + 2e = NO'- + H2O +5 +3

Mn20, + 6H· + 28 = 2Mn2+ + 3H,o +3 +2

Fe30. + 8H· + 2e = 3Fe2+ + 4H2O +8/3 +2

49

Chemical Changes &. Noutnent Transformation In Sodle/Poor Qualrty Water IrrIgated Soils

Oxidation-Reduction Potential

The driving force 01 a chemical reaebon IS the tendency of the free energy of the system to decrease until at equlhbnum, the free energies of the products equals those of the remalmng reactants In reversible OXidation-reduction eqUilibrium, the free energy change can be expressed In calories or In volts For a reaction such as. \

Ox+ne=Red

The free energy change In calones (~G) IS given by

~G = lIGo + RT in (Red)/(OX)

\

Where (Red) and (OX) denote actiVities of the reduced and OXidIZed species, GO IS the free energy at UM activity The tree energy change «lIG) can be converted to electncal energy uSing the equabon

~G = -nEF

E = -lIG/nF

Where E IS the voltage of the reaction, I' IS the Faraday constant In heat Units and n, the number of electrons /Ovolved In the reaction When E is measured against standard H electrode, H. (8-1)+e = ~ H, (1 aIm) whooe potenllalls laken as 0 al2SoC and .s denoted as Eh, then

Eh = Eo - RT/nF In (Red)/(OX)

Eh = Eo + RT/nF In (OX)/Redi I

Eo IS the potenllal of the couple when OXidized and reduced species are at unit actlvijy and is can slant for a system Eo IS quantitatJVe meaSure of the OXidiZing power of the redox couple

Effect of Change in pH

Changes In H+ Ion activity can directly affect the Eh value Or indirectly by affecting the lomc equrhbrla

Ox + !,"H-I- + ne = Red

Eh : RT/nF In (OX) (H+)m/(Red)

= Eo + 2303 RTlnF log (OX)(Red) + 2 303 RT/nF, m log H+

= t.o + 1303 Rl"lnF log (OX)J(Red) - 2 303 RTfnF mpH

When n= 1 'and T= 29B 16 K

= Eo + 0 0591 log (OX)/(Red) - 0 0591 mpH

Thus Eh depends not only on ratio of oxidant to reductant but also on pH becayse dE/dpH = 0 0591, The dE/dpH IS slope, the value of Which is 0,0591

pE concept

It has been suggestea to use the pE Instead of Eh In redox equations The common reagent In OXidation-reduction IS the electron and accordingly rt should be treated like other participating species Just as pH is a measure of proton actIVIty of a system, so IS the negallve log of the electron actIVIty (pE), a measure of electron acllvity. ConSider the SImple oXldaM-reductlon -

Ox + mH'" + ne = Red

Its eqUlllbnum constant K = (Red)/(OX) (H+)m (e)"

ParentheSIS denotes activities of the partiCipating speCIeS Taking log of both Sides

Log K = log (Red) -log (OX) -m log H+ -'n log e , or

- n log (e) = log K -log (Red) + log (OX) + m log H+

- log (el = lin log K - 1/n log (Red) • 1/n log (OX) + mfn log (H')

-log (e) = lin log K + lin log (OX)/(Red) - min pH+

-log (e) = 1/n log K-l/n log (Red)/(OX)-m/n pH ,

50

Chemical Changes in Submersed SOdic Soils

pE = 1/n log K - 1/n log (Red)/(OX) - mlri pH

When the actlvHles of all the reactants and resultants are at unit activity, then

pE = lin log K = pEo ,therefore,

pE = pE' -lin log (Red)/(OX) - min pH

This equation is similar too that 1M which rt h~s bee,n shown that besides acIJVlly of oxidant and reductant, the redox potential (Eh) IS also affected by the H Ion concentratlon/actlvlty or pH e g

OX + mHo + ne = Red

G = GO +RT In (Red)l(OX)(H")m

G = ·nEF, - nEF = -23 06 Eo, when 11= 1

-nEF = GO + RT In (Red)/(OX)(H+t

E = -Eo - RT InF In (Red)/OX) (H+)m

E "Eo + RT/nF In (OX)(H'jm I(Red)

Eh = Eo + 2 303 RT/nF log (OX)lRed) +2 303 RTlnF m lagH

Eh " Eo + 2 303 RT/nF log (OX)lRed) - 2.303 RT/nF mpH

If we dIVide thiS equation by 2 303 RT IF

Eh x F/2 303 RT = Eo x FI2.303 RT + 1/n log (OX)lRed) - min pH

At 29816 K, 2 303 RT/F = 00591

Eh I 0591 = Eo/0591 + lin log (OX)/(R.ed) - min pH

EhI.0591 and Eol 0591 can be deSignated as pE and pEa, respectively,

pE = pEa + lin log (OX)I(Red) - min pH

So pE can be simply calculated from Eh value

as pE = Eh/0591 and pEa = Eo/0591

In system of law electron activity (strongly OXidIZed system), pE IS large and positive, In reduCing systems, It IS small or negative Some of the Important redox systems are given In table along with -their standard free energies of formation

Yo MnO,c + 2H+ (aq) + e = Y, Mn 2+ aq + H,o; Eo = 1 2:29, pEa = 2080

Fe (OH)3s+ 3 H+ + e = Fe2'(aqt 3H,o; Eo = 1 057, pEa = 17.87

118 SO;' aq + 5/4 H+aq "te = 1/8 H,S aq +112 H, 0, Eo = .303, pEa" 5 12

51

Redox System Controlling Nand S Transformations in Sadie Soils jlnder Submerged Conditions

/ . N.S. Pasr/cha Dlreclor (Retired) Potash Research Inslilul~ of India, Gurgaon, Haryana _

./

Introduction

Salls managed for wetland paddy have special management techniques The management pracllces Include levehng of land, construction of levies and Impounding of water This 19 followed by puddling (plOWing and harroWing In standing water) and incorponatlon of weeds, stubbles, green manures and fertilIZers, mainlenance of 5-10 em of standing water during the 4 to 5 months of crop of growth, dnalnlng and drying of the fields at harvest and re-floodlng after an Interval which vanes from few weeks to as long as 9 months These operallo~s and secretion of oxygen by nce roots leads to the development of certain features peculiar to paddy salls "

The processes

Dunng submergence, the sOil undergoes reduction, and turns dark grey, '"O~, manganese, Silica, phosphate become soluble The soluble substances migrate by diffUSion to the sOil surfaee and by both diffUSion and mass flow to the roots and to the subSOIL When reduced Iron and manganese reach oxygenated sOil surface, the OXidIZed rhlzosphere of nce plants, or the zone of high potential beloW the plow layer, they are OXidized and preCipitated as Fe" and Mn" OXide hydrates giving the surface a reddish brown colour Between reddish brown oxidized layer a few mm thick, and dark brown OXidized zone I~ the SUbSOil, lies the dark grey zone With reddiSh brown vertical streaks along root channels ThIS IS the root-zone of nee

• 0'

Dunng water-logging or s~bmergence of the SOIl, the follOWing changes take place 1, Decrease In redo~ potential of the SOil from about 500 mV In aerobiC state up to -200 mV under

submerged SOil co~dltions 2 Increase rn pH of ~cld Salls and a decrease rn pH 01 calcareous and alkair Salls I)nlll they converge 10

about 7.0 3 Loss of nltrales as gaseous nitrogen Within few days of submergence

4 Accumulation 01 alllmonium In SOil 5 Reduction of manganic-and femc compounds to form more soluble divalent forms which are present

majnl~ as blcarbonate~, In concentration ranging from 5 10 100 mg kg" for Mn'o and 510 600 mg kg" for Fe +

6 Reducllon of sulphale Ie sulphide

7 Relea5e 01 phosphates and Silica In soluble form 8 Formallon of CO" organlc,aclds"methane, mercaptans, H,S, ethylene, hydrogen and resistant reSidue

of orgamc matter

If water-logging continues for longer penods, following additional Changes may also take place

PreCipitation of some mir1erals

Mlnenals like hydrated magnetle Fe3 (OH). or Fe30.4H,o, which IS also called {errosolenc hydroXide and we shall see later that rt IS an Important source 01 FeZ' in submerged Salls Hydrotnohte, FeS nH,O, MacklnaWlte, FeS, Pynte FeSz. VlVlanlte Fe, (PO.» 6H,o, sldente, FeCO, and rhodecrosrte MnCO, are also fermed

When the Salls are drained for cultrvaton of arable crops or when the 501ls are emerged, oxygen reenters the SOil The redox potential Increases, pH of alkali SOil ,ncreases and that of aCid Salls decreases, Iron and manganese are oxidized chemically and blo-chemlcally and depOSited as strains, concretions, ammOnium IS OXidized to nitrate and sulphides to sulphate

Nitrogen and Its Oxidation - Reeducation Reactions In Soil

Nitrogen and ItS oXldahon-reduclion products are abundant and Widespread I~ nature They are soluble In water and they are In a constant contact WIth atmO$phenc oxygen or electrons liberated from organic matter by the proc;ess of decomposltlonloxldatlon BeSides, the three main nitrogen tnansformatlonsnitrification and nitrogen fixation are catalyzed by enzymes Therefore, It may be pOSSible to apply thermodynamiCS to the quanlltallve study of mtrogen transforma"on in Salls and other surface media Because these reactions Involve electron transfeJS, they are best studied from stand pOint of electron activity

Redox System Controlling N & S Transfonnabons in Sodle SOlts under Submerged Condition

rather than that of free energy changes Just as acid base equIlibrium IS best studied from view POint of proton actIVIty (pH)

The NO·, -N, system I Thermodynamically, the stability of NO·3 In surface enVIronments and its persistence at extremely low

0, concentrabonS can be explained consldenng th,e folloWing equations

2 NO·3+12H'+10e = N, +6H,o

1/5 NO·3, 6/5 H' + e··1/10 N,+3/5H,O

e" 1/10 N,. 1/5 NO·,- 6/5H'

log." log eO +Iog 1/10 N, - log 1/5 NO·3 - log 6/SH' i

_ loge = -log eO -log 1/10 N, + log 1/5 NO·3 + log 6/5H'

p'" pEa +1/1 0F'N,.1/5 P NO·3 -6/5pH'-

pE = 21 06 + 1/10 PN, -1/5 P NO·3-6/5 pH

In the media, exposed to the atmosphere, NO·, - N, system should be in eqUIlibrium with 0, -H20 system for which p' = 1362 at a po, of 021 abmosphere and pH 70 ThiS equation reveals that the pE at which nllrate Will be Just detectable (10.7 moles L·2,n an aqueous system at pH 70 In egUilibnum With N2 at a partial pressure of 078 aim IS 11 27 At thiS P , the parllal pressure of 0, IS 10.10 " ThiS explains the stability of nitrate even at very low 0, concentration even In the presence of denllnfylng organisms Any loss of mtrate as N, that occurs In aerobiC salls must, therefore, be due to anaerobiC spots as shown by Greenwood (1962) and discussed by Broadbent and Clark (1965)

But at a pE of 5 63 (pH 7,0), the parllal pressure of N, In eqUIlibrium wllh 10.7 moles L·1 of NO, IS 10· .. 03 ThiS shows how rapidly nitrate IS converted to N, In anaerobiC media The high pE of NO·, -N, system and Its small decline With decrease in NO, concentrations explains why even small concentratIOn of OItrates slow the reductIon of flood solis and prevents bad smell from developmg In sewerages and swamps

The NO·, -N, system

Although nltnte IS an Intermediate product both In nltnficatlon and denitrification, It occurs In traces or not at all In aerobiC SOils. The absence of hlQh nIInte concentration In aerobiC Salls has been attributed to the rapidity of Its OXidation to nitrates by mtrobacter while its transitory eXistence In anaerobiC media IS ascribed to the activity of deOltnlymg bacteria But now II has become Increasingly clear that nitrite preseni In the, sailor added to the soil is rapidly converted to N. and N,O by reactions' which may be non-enzymatlc and are Independent by Achromobacler IJque'aClens and by bacterium mtnfieans even In the presence of oxygen In other words, nltnte IS unstable In aerated SOils a·nd water. ThermodynamiCS of NO"3 -N2 gas systems explain these observations

2NO'" 8H' .. 6e = N2+ 4H,O

113 NO,· + 4/3 H' +e = 1/6 N' + 213 H,O

p.·pEO+ 116 PN,-413 pH+ 116 pN,

In aerated media thiS system should be In eqUilibrium With 0,. H,O system of the abmosphere and should have a common p. which shows that the concentration of nltnte nitrogen In eqUilibrium w"h air and water al pH 7 IS less than 0 1 ppm and the stability of Mnte Increased wrth Increase in pH But II does nol explain the high concentrallon of nltnte occaSionally encountered in alkaline Salls and attnbuted to the Inhibition of nitrobacter, '

The NO·, -NzO system

Th N20 IS present In abmosphere In minute quantities In the a~Ir as a product of denltrlficatlon~ ~rrnodynamlCS of NO·, - N,O system shows that nitrate Will not decompose to ""rous OXide In aqueous

~e 18 In eqUllibnum With 0, but Will do so readily at polentlal (Eh=O 33 V or pE = 5 63) at Which oxygen Isappear frortl the SOIl In water. ..

2 NO:,· + 10H' + 8e = N,o +5H,O

53

Chemical Changes & Nutrient TransformatJOn In Sodu::fPoor Quality Water Imgated Salls

Yo NO, ." + 5/4 H+ + e = 1/8 N,O + 5/8 H,O /

pE"= 1886 + 1/8 PN,O = Y. pNO,- - 5/4 pH' / If this system IS In eqUilibnum With 0, -H20 system of the atmosphere, then the partial pressure of N20 in

equllibnum With 10" mole L" of nitrate at pH 7 0 IS 10-321. But as the 0' IS deleted, the pE falls 10 5 63, the partial pressure of N,O that Will be In eqUilibnum"Wlth 10" moles of iutrate at pH 7 a IS 10'· B4 Thus nitrate IS hl9hly stable With respect to air, but very unstable In the absence of 0," thus therrm:idynamrcally N,D IS the highly probable product of dlnltnficatlon of nitrate "\

The NO,- - NO system

NO,-+4H'+3e=NO+ 2 H20

1/3 NO,- + 4/3 H+ + e = 1/3 NO + 213 H,O

pE = pEo.+ 113 PNO - 113 NO,-4/3 pH

pE =1619+1/3PNO-1/3pN03-4/3pH

At pH 70 and pE of 13 63, NO,- I PNO = 10.20.31. ThiS rauo Indicates that nllrate IS stable With respect to N) In aerated media and they support the conclUSion that large loss of nitrogen from Salls as NO are unlikely except under unusual conditions

At pH 70 and a pE 5 63 (at Which O2 IS not detectable), the NO,' I PNO ratio is 10""" ThiS Indicates that In an anaerobic system, NO can be .evolved from nitrate reducbon But nrtrate IS much more unstable With respect to N,O So the N,O IS the more likely to be product of denrtntlfactlon than NO In anaerobiC media.

The"NO,' -NH4 system

N03' + 10 H' + 8 e = NH. + 3 H20

1/8 NO,' + 10/8 H+ + e" 1/8 NH. + 318 H20

p' = pEfl +1/8 pNH, - 5/4 pH - 118 pNO,

pE = 1491 + 1/8 pNH4 - 5/4 pH - 1/8 pNO,

At pE of 1363, NOiINH. = 105976

ThiS equation shows tremendous dnvlng force of the oxidation of ammonia to nitrate 'In aerobiC media, regardless of pH., ilt pE of 5 63 and pH 70, NOi' -' .NH.+ =10~2'" At potentials of. flooded SOils (pE = 1 to 3), the concentration of nitrate that can be in eqUlI,bnum with NH. IS inftnlteSlmalthermodynamlcally, the reduction of nitrate to ammonia IS pOSSible 10 anaerobic medra, but in anaerobic Salls, only a small fraction of N03' goes to NH. apparently because of the tremendous drIVIng force of competong denitrification reaction. Plants and bacteria reduce nitrate to ammOia With the help of powerful reductants such as NADH and NADPH produce~ by light or by anaerobiC respiration

Fixation of molecular N2 In the anaerobic solis

The follOWing equation shows the likely conversion of N2 to NH. In anaerobiC rhlzosphere of rice

N2 + 8H+ + 6 e " 2 NH.

1/6 2N2 -I- 4/3 H' -I- e = 1/3 NH.

pE = pE. -I- 1/3 P NH. - 1/6 PN, _ 4/3 pH

The 5ulphur system

Sulphur occurs In Salls and ~ther surface media In organic compounds and as sulphate, sulphide and elemental S The main transformations of S In 'nature are oXldatJon- reduction reactions InvolVing SUlphur In oxiatlon states of +8, 0 to -2 .

The 50."- H,S system

In anaerobiC SOils, lakes, ocean sediments and water, sulphate IS redu-ced to sulphKie by

Desulpho~/bno sp, which use sol' as an electron acceptor In their respiration process Since most anaerobiC

54

Redox System Controlling N & S Transformations In Sodle SOils under Submerged Condition

media have a pH of about 7 0, the sulphide fonned IS almost entirely In the form of H,S and HS' The equations for two equllibna are

SO/'+ 10H·" 8 e =4H,o + H,S I

1/8 sol' + 5/4 H' + e = 118 H,5 +112 H,O

pE = 5 12 + liB PH,S' - 514 pH - 118 P so."

" sol''; 9H',+ Be = HS' + 4H,O

1IB sol' + 91B H' + e = 1/8 HS' + 1I2H,0

pE = 4 26 + 1/8 pHS' - 9/8 pH - 1/8 pSO/'

I If lhese systems are In equlhbnum With air, then these equations can be combined With equation pE =

2063 - pH to give.

pSO." - PH,S = -124 08 - 2 pH

and psol' - pHS'" -131'36 -pH

These equations show Ihalsulphate 15 highly stable In the Sir at all natural pH values If sol'= 10-3 mole L", H,5 WIll be detectable (10" mole L-' ) at a pE of -3 26 at pH 70 Conversion of reported Eh values at which sulphate reduction has been observed In waterlogged Salls Yields values Corrected to pH 70 ranging from -254 to +351, waters gave higher values than mud

The H,S fonned reacts With Fe" Ions and WIth crystalline goethite to give FeS nH20 which gradually changes to makmaWlte and later to the pyntes found In the reduced SOils and sediments , The S-H,s and sol'· 5"systems

s'" + 2H' .. 2e = H,s

U S",.H' + e = Yo H,S

pE= 24+ Yo PH,S- pH, and

50l-+ 8H' + 8 e = 5" + 4H,O

1/8 sol'''H·.j. e =,1/8 5" .. Y, H,O

pE = 6 04 "118 pS" • pH - 1/8 pSO."

These equations mdlcate that In aerobiC media at pH 7 0, H,S should be readily OXidized to Sand then Sol, The oxidation of H,S to S IS both chemical and biological When suylphide beanng waters reach oxygenated water, H,S Is OXIdized mally by ihlObac,((us IhlOo",dans and deposited as sulphur

H,s + Y, 0,= H,O + S

The presence of sulphide In lake bottoms IS attributed to thiS reaction

Photosynthetic bactena, both green and purple use H' Ions and electrons from H,S for the photosynthetic reduction of CO, to carbohydrates In anaerobiC media

Co, + H,S - CH,O + S

The OXidation of elemental 5 in SOils IS enlirely biological and IS mediated by autrotrophlc thlobaoll/us, heterotophlc bactena and green and purple S·bactena The OXidation of pyntes is chemical In early stages and biochemical afier the pH has been reduced to SoH,S and sol' . S'

The In~lal pE values for transformations of S corrected to pH 7 0 are as follows sol'- H,s = ,2 to -4 , H,S - S = -2 to +1, and S-SO. = +3 to +5,5,

55

Transformation and Availability of N, P andK in Submerged Sodie Soil /

p,_D~y DIVISion of SOil and Crop Management 'Central SOIl Sal,nity Research Inst,tuta, Kamal-132001, Haryana

Introductron

Submerged 50,1 creates cond,IIons markedly d,fferent from thOS} of well-<lralned SOIl and has profound effect on the 5011 properties In a well drained 5011 there is usually enough oxygen available compared to waterlogged 50115 Aerated 50115 have charactenst,c redox potent"" In the range of +400 to +700

mV, whereas waterlogged sOils exhibit potenllal as low as -250 to -300 mV The demand of electron by facultative anaerobic organisms after disappearance of submerged 5011 oxygen result'ln reduction of several OXIdized components such as Fe", NO, and sol-. Although nce IS not toleranl to 'excess SOdlClty, It IS prefe~ntlally grown espeCially after mltlal reclamation by Prosopis-Leptocflloa based system In sod,c SOils Submerged paddy 50115 dIffers from the other 50115 because of several reasons like, puddling (plovvng: and harrovvng the water saturated SOil), maintenance of 5-10 em of standing water almost throughout the growing season vvth Intermittent draining, dralnmg and drying the field at the harvest and re-floodlng the 5011 before next crop These operatIons leads to the development of certain features peculiar to paddy SOIls meludmg Significant reduction in the root zone pH level due to submergence In case of sodlc 50115 DUring the penod of submergence, reducm9 conditions prevails and iron, manganese, Silica and phosphate becomes more soluble The Increase In conductance dUring the first few weeks of flooding IS due to release of Fe'- and Mn" from their Insoluble fORn, the accumulation of NH;', HCOi and R-Coo- and dissolution of CaC03 by CO, and orgamc aCids (In calcareous 50115) The decrease In conductance of calcareous Salls is caused by the fall In partlat pressure of Co, and the decompOSition of organic aCids

Nitrogen

Volume of research and attention received wo~dwlde gives N the p"me POSition among the ",Iant nutnents The green revolution m ASia dunng the 19705 and 19S0s owes much of Its success 10 fertlhzer Input particularly N Sodlc Salls are generally deficient in available nitrogen (N) due to poor organic matter content, less biological N2-fixatlon, slow transformation of NH,' -N to N03 -N, high volatilIZation loss and other losses of N High SOil pH coupled With poor phySical condillons also adversely affects the transformations and avaIlability of applied nitrogenous fertilizers In sodie SOils The defiCiency of thiS key nutnent IS further intenSIfied by Imbalanced use of fertIlizers ooupled With crop IntenSIfication A host of chemical and biochemical processes are Involved In the tumover of N In the SOil through vanous N transformallon processes SOil morga",o N, particularly NO, is readily soluble and IS lost in drainage or through leaching depending on 5011 condition and crop uptake In the extemal cycle operating between the SOIl and the atmosphere, gain In soli N occurs through biological N, fixation, N deposlllon or N fertilization while deplebon of SOil N occurs via NH3 volatilization from SOIl or floodwater and demtnfication Mmeral nitrogen In sorl is of course also removed by crop plants Finally, a part of plant N fixed by leguminOus crops IS returned to the SOil organic N pool. Transformation and availability of N m submerged Salls IS Important for follOWIng three reasons.

• N IS a key nutllent element for achieVing high Yield potentials of modem crop valletles

• Cost of prodUCtion of fertJllzer N IS getting higher day by day due Increase In crude pnca • Fertthzer N use efficiency IS qUite low In submerged solis due to their unique chemistry

• Na~ve or applied nitrogen under submerged oond,~on encounter SIX distinct transformation processes as detailed below

Mineralization and Immobilization 2 AmmonIa volatlhzatlon 3 Sorption and desorption

4 Urea hydrolYSIS 5 Nltnficatlon and denltnfrcabon 6. AmmOnium fixatlonwlthln the day lattice

Mineralization and Immobilization of Soli and Added N

SOil nitrogen IS in a state of dynamiCS with the process of mineralization and Immobilization forming a sort of Internal cycle WIthin 5011 and net mmerallzatlon-,mmob,llzallon turnover detenmlnes the 'mineral N reserves of the soli at certain pOint of bme Mineralization of orgamo-N In SOIl follows the steps

Protel~ Polypeplldes -+ Ammo aCids _AmmOnia _ Nitrate -+ Nitrite

,

Transformation and AvaIlabIlity of N, P and K In Submerged SadIe SOil"

N losses Mechanisms

The major pathways of N losses are leaching of NO,-, volatlhzatlon of NH, from sOil and crop tops, denitrification as NO,,,nd croR uptake

Leachmg , Nitrate IS assumed to be infinitely soluble In water and to move downwards at the same rate as the

water In which It dissolved, 1'10,- movement showed a strong relation with water movement, and accumulated NOi m oxidized mlzosph~r~ IS highly susceptible to leaching,

Volatilization NH, volalll,zation can be a pathway through which N is lost from SOil-plant system after the'

application of NH; containing or formmg fertlhzers and also from the senescmg plant. Soil factors (pH, CEC, PCo,., buffering capacity, SOil type, CaCO, conten~ o'9aOlc matter, soil mOisture), management factors' (depth of placement, time of apphcatlo~ and type of N camers) and' environmental factors (temperature and' Wind velOCity) may affect NH, volat,hzat,on AmmOnium fertilIZers' are particularty subjected to volatlhzatlon loss If (I) Ihey remain on the surface of a damp but ,drying calcareous SOil, and (II) lhe fertilizer anion fO!TT1S an Insoluble calCium sail Increase In volatlhzation losses of NH, was nollced with a decrease In solublilly of, reaction products of NH; -N sources With Ca compounds NH, volatlllZabon from different N camers In' calcareous SOil follows the order NH.F:> (NH')2S0. > (NH.),HPO. > NH.NO, > NH4CI > NH,I

Oemtnneatlon It IS the process of N-Ioss mechamsm mediated by mlcroorgamsms under anOXIc enVIronment

through which NO,' IS reduced to gaseous NO, an'd lost from SOil-plant system resulting In the reduction In fertilizer use effiCiency and causing concern for enVifonmen'i owing to Its (N20) contnbutlon In the depletion of stratosphenc ozone level

Phosphorus

Phosphorus IS one of the Immobile ,nutnents In the SOil It' occurs In the SOil In both organic and Inorgamc fOlms, the latter b_e~flg of greater: importance 10 mIneraI SOIls InorganIc P IS known to occur In three maIO categories, VIZ" apatlle which IS a discrete phase of P compounds, P sorbed on sulface of Fe, AI and Ca as soli constituents and P present ",!hIll matenlils of Fe and AI camrxmnds Sadie solis are nen In lotal and Olsen-P The content In reclaimed sodlc SOils, on the other hand, decreased due 10 Inactlvalion by added gypsum (soluble SOdium-phosphates are converted to less soluble Ca-phosphates) and higher sorption of' added P by SOIL Most of the Salls have the abllrty to retain soluble P against recovery by plants With the result that crop uptake of phosphorus rarely exceeds 20-25% in the firsl growing season ThiS is due to vanous types of reactIOns occumng In the soli such as adsorption, preClpltallon, chemical and blOIO(lIC81 transformations occurnng in the SOil that revert the added soluble Pinto vanous Insoluble forms The reversion rate, release and availability of Pare influenl::ed not only by contact pened between P and the SOil bul also by factors such as temperature and mOisture

Transformation of Pin Sodic Soil

Transformations 01 P 10 SOIl involve both Inorgamc and o'9amc reactions The most Important reactions In the InorgaOic P cycle Involve dissolution, preCipitation and sorptlon-desorptlon reaction ThiS can be diVided m two SOil systems, one In which Ca IS dominant controlling cation as IS the case of sod,c SOil and the other in which Fe and AI are controlling cations as IS the case of aCid SOil Reaction With Silicate Clays may also takes place wherein phosphate Ions may combine With clays directly by either replaCing OH group or forrnlng clay-Ca-phosphate linkage

In Sodie SOIls, P reactIons are maInly dIVIded In two types of reactIons, VIZ I reactIons WIth free CaCOJ and reversion Durmg reactions With free CaCO" phosphate Ions coming in contact With SOlid phase of CaCO, are precIpitated on the sulface of these free particles The Initial stage In thiS reaction may rather be a sulfaoe phenomenon which changed to preCJpltatlon of mass action type of reaction On the other hand dunng reversion reaction, Ca is regressed or reverted back to inactive forms Increased Ca actJVlty In most sodlc SOils coupled With high pH favours more Insoluble dl- and tn-calCium phosphates or to apatite fotms Expenences of CSSRI With barren sadie Salls showed that Ihese Salls generally contained high amounts of extractable PfhosPhorus and Ihat,there was a positive correlallon between soluble P stalus and the electncal conductiVity, a the SOil Presence of sodium carbonate In these salts resulted In the formation of sotuble sodiUm p~asPhates and hence a positive correlation between electncal conductiVity and soluble P status However, W en a SOil contains Significant amounts of sodium carbonate most of the SOil calCium IS In the calCium :;arbonate form and not available to the plants resulting In 90mpiete Cf9P failures even 10 presence of soluble

co ' After the dissolution of applied fertilizer In soli solution, the moving fronl of SOil solution thus fO!TT1ed mes In contact With 5011 matnx for the reSidential penod of SOil solution on a particular sulface area

57

Chemical Changes & Nutner'lt Transformation In SodlolPoor Quality Water lITIgated SOils

Gradually Ihe sOil solullon gels supersaturated With mixture of P compoonds which slowly preGlpllate _In the sOil matnx Fertilizer reaction products Inillally may be amorphous compounds possessing large surface area, faclors which favour high availability, With time they age and tend to move towards crystalline forms resulting In'a decrease in Ihelr surfaee area and solubility BeSides sOil pH and mOisture content, the nature of the

, precIpitating compound depends upon the kinds and amounts of callons and anions supplied by both the fertilizer and the sOil

SOIl submergence can bring abelut profound changes In phosphorus transformations The reView of physlco-ehemlcal changes that Influence the P chemistry In SOIl Showed an Increase In concentration of waler soluble and available P as a result of reduction, It IS Widely recognized that due to chemically reduced condillons, solubility and availability of phosphorus, assOCiated with Ifon increases appreciably Thus reaction products containing Iron assume speCial ,Significance under submerged condlbon- In calcareous 50115, the Increase In solubility of P IS aSSOCiated With decrease In Eh or an Increase In Fe2' suggesting the role of Fe3' bonded phosphate tn SOOIC SOils, the 'Increase In \he solu'oMy 0\ 1> IS a consequence 0\ cleerease In pH 0\ these SOils on flooding The phosphate.lons'released by these reactions and from decomposition of organic matter were thought to be resorbed by clay and hydrous OXides of AI In the anaerobiC zone or they may diffuse to ,OXidIZed zones and be re-preClPltated .In general, non-calcareous sediments adsorb and retain more P than calcareous lake sediments suggesting little .and temporary Increase In concentration of water soluble Inorganic phosphorus in acid clay SOil compared to calcareous SOil

Adsorption vis-a-vis P availability

Sorption elUCidates the remov,,1 of phosphate Ions from solullan by soil ccmponents Sorption Isotherm descnbes the relationship between amounts of P sorbed at a particular solullon P concentration Desorption IS the reverse phenomenon of sorption which describes the extraction of sorbed·P from solid phase to solubon phase Calcium carbon@te, clay and oxides and hydroXides of Fe .and AI.are the major sites of P adsorption m calcareous and acidic 601ls, respectively Although mechamsm by which P is removed from 5011 solution by solid phase IS not clearly understood, It IS agam thought to be a sorpllon process rather than precIpitation process Some researchers have endorsed P sorption to a gel complex consisting largely of hydrated Iron OXide In SOils exposed to free oxygen and active Fe", most likely as ferne-oxl·hydroxlde, but under anaerobiC conditions most of.lhe aellve Iron IS In Fe

2+ form, With some occurring as ferrous hy<lroxide

gel complex

AnaerobiC SOils have much more Iron In solubon'- approximately 50-100 mg r' compared io less ihan 1 mg ,-1 in aerobiC SOils as well as greater amount of Fe adsorbed on the exchange complex The OXidation state of Iron compounds apparently affects the phosphate eqUlI,bnum between solid and solution Phosphate co-preclpltated or occluded in feme-oxl-hydroxlde In an aerObiC SOil does not exchange With solution phosphate as readily as. In anaerobic SOIL The behaviour of phosphoriJs In submerged Salls IS markedly different from that In upland SOIL The occurrence of marked increase m avallal:ilhly of native and added phosphates In flooded Salls compared to well-drained SOils has been well established Therefore, 1M general, lowland nee shows conSiderably less response to phosphates than upland wheat crop grown on the same SOil ThiS IS commonly observed In allUVial solis of Punjab and Haryana where wetland nee·wheat IS the major cropping sequence followed,

Potassium

Potassium compnses an averagEl of 2 6% of the earth's crust, making It the seventh ,most abundant element and the fourth most abundant minerai nutnent in the lithosphere. The most abundant source of K in minerai Salls are the pnmary aluminOSIlicates, which include the K·feldspars, biotite and muscovite micas, and the secondary aluminOSIlicates, compnslng the hydrous micaS (1lhle) and conllnuum of thelf weatheflng ?ro<!lld,<>, <>1lCh .. <> t\\e ~ .. <,mICIl\lt'e<> I\\'e <e\d.,..."" =.},'q. 0.1 .. " \"~mj,'e ""_ QI S\O. an.d m. tef.<aI:>eIJJ:"" The substitution of AI" for SI4' Within thiS structure Imparts a reSidual negative chargelhat is neutralized by 1<';, lila' or Ca2

' Ions present In avaIlable vOids Ihe mIcas are prunary minerals of the 2. i ph~"osillcate Iliell? In the Silicate mmeral class, The structural differences between the 'various niica minerals are of great Significance In determining the ease of weathenng and K release characterlsllCs, For examples tn-octahedral micas, such as biotite, are much more eaSily weathered than the di-<lctahedral micaceous minerals, such as muscovite Micaceous minerals and thelf weathenng products are the most important source of plant available K' In a SOli system Chemlcar weathenng of mica Involves Imtlal proteolYSIS reaction at the lateral edges of the particles, resulting In frayed edges Subsequent weathenng proceeds zonally Inward towards the centre of the mica particle, With mterlayer expansIon aoeompanying the J( dissolution release reactiOns The release of K+ In thiS fashion and the resulting expansion of the clay minerai mteltayer eventually results In a senes of minerai transformallons The weathenng of mica Includes the transition through 5011 minerals, Illite or hydrous mica, which can be descnbed more Simply as K-depleted mica Further K depletion resulls In transition clay

. mlnera' and vermIculites and 'Smect~tes

56

Transformatlon and Avallatlllity of N. P and K In Submerged Sadie SoU

The native K status of salls depends on their parent matena! and the subsequent stage, of that material. Salls will be most weathered when rainfall exceeds evaporation to a much greater extent so that the excess water passes through the sOil carry.,"g whatever IS soluble With It Salls are expected to bedow '" available K SOil potassium is ,conSidered to e~st In solution, exchangeable and non-exchangeable (fixed and K) forms The amount of solutIon and exchangeable K IS usually a slT'all portron of total K, bulk of so,1 K ex,s!s In K beanng micas and feldspars A major portion of SOil K moves to the roots from the 5011 solullon through diffusion and mass flow However, the crop requirement for K IS often much larger than the SOil solution Kat any pOint of lime Thus, conllnuous renewal of K ,n the 5011 solulloo for adequate nounshment of plants (lunng crop growth IS obvious. SImilarly, the exchangeable K component has to be continuously replenished through the release of fixed K and the weathenng of K reserves such as micas and feldspars Hence, K availability to crops is a functIOn of the amount of different fonns of K In 5011, their rate of replenishment and the degree of leachmg .

K Equilibrium In Soil , The eqUlllbnum between solubon; exchangeable, non-exchangeable and moneral phases of K have a

profound influence on Ihe chemIstry of SOil K. SOIl mOI~ture has an Important role In K fixatIon and release behav,or Drying of SOil causes fixation of added K but can also release the potassium under some situations. The release of K depends upon the on,tlal available K status of the SOIl. The direction and rate of reactions determines the fate of applied K and release of non-exchangeable K A schema~c diagram relating the four forms of SOil K IS depicted as under

Minerai K <:==:> Non-exchangeable K <==> Exchangeable K ¢=::l SolutIon K

Consldenng the ease or dIfficulty With which plants can ~se different fomn of SOil K, the dlsbnctlons tend to fade and the adjacent forms tend to overlap Thus, K-IO the solutIOn IS conSidered as a form which IS In equlllbnum with but difficult to dlsbngulsh from exchangeable K and can be defined as the fraction that occupIes SItes In the SOil collOidal complex, SImilarly, fixed K IS K which occupies Internal positions Within clay sheets as well as hexagonal cavilles In minerals such as illites SOl" solution and exchangeable K are considered directly available to plants Non-exchangeable K, Which IS partially available to plants, can be spht Into two fractions 1 difficulty exchangeable (dIlute H2S04, Hel and HNO, extractable) and II fixed (extracted by strong aCids such as 6M H2S04 or Hel)

Crystalline Imperfections such as openings In the basal s\~c\ure cause the m,caceous layers to form Scrolls Properties of K-feldspars crystals whIch Influence the rate of their weathenng are Composition such as the Inclusion of Na in the'structure, crystal and particle size and the nature oftwonong and crystallization of several minerals Within a part,cle Mica appears more important than K feldspars In crop nutnllon, oWing to rapid weathenng However, due to much larger' amounts of K-feldspar, and the variations In the weathenng rate of feldspars and micas, feldspars can be of Significance on the K nutntlon of plants

Clay Mineralogy and K Availability

TransformatIon and availability of potassium under submerged conditions seems to be related to the m,neralogy of the soil, weathenng of K beanng minerals, K fIXation and K release charactenstlcs of K-beanng ~TlInerals, mOisture status and available K status of the SOil However, scanty Infomnabon IS avaIlable and there IS a need to study these aspects Simultaneously under submerged v,s-a-vls nonmal cond,t,ons to bnng out the clear Picture of K transfonnat,ons and Its availability under submerged cond,t,ons Changes In available K w,th time depend pnmanly on the mineralogy of clay fractIon under submerged conditIon In K fiXing minerals (Montmonlonlte) dommant Salls, available K decreases throughout the IncubatIon penod m all the SOil mOIsture conditions However. under contJOuous submergence after initial fixation there was release affixed K In K' releaSing mmeral (lilije) dominant Salls, although with high K saturation the available K did not decreased whereas It Increased m some cases Although potassium availability has been reported to Increase In flooded SOil due to reduction of Fe '3 to Fe" and exchange of the more soluble Fe·2 for K' and due to secondary effect of reductIOn of soli and displacement by the acbon of water through hydratIOn and hydrolYSIS. However, results ~f another study With vennleullte SOils suggest that plant available K would decrease after flooding of dry SOIl f hiS decrease was more pronounced With greater SOil drying In the fallow penod and after incorporation of ertlllZer-K, A drasbe decrease in available K WIth continues nee-wheat cropping for 3 years has also been

Cited In the literature

h Expenences at IRRI showed that high (Ca+Mg)/K ratio were related With K defiCiency In nee The yrthesls is that high (Ca+Mg)fK rabos result In stronger K adsorption to cabon eXChange Sites, wh,ch ~ uces K buffenng power and K diffuSion rates In the SOil Studies on non nce Salls have demonstrated that at~ny Salls have a preferential adsorption of K' over Ca" or Mg'2 and that thiS preference IS relatively greater pre~: K levels and WIth VenmieullllC or mICaceous components of the clay fractoon A Side effect of Increased ratio ~ntlal of K adsorpilon would be a Significant decrease In soluilon phase K and an Increasing (Ca+Mg)fK

there IS a h'gh preferential K adsorpllon o~ the eXChange sites of clay mmerals, the amount of K

59

ChemIcal Changes & Nutnent Transfonnatlon In Sodlc!Poor Qualrty Water Imgated Solis

desorblng inay then decline, resulting In reduced K uptake at high (Ca+Mg)/K rabos In their exchangeable forms The high concentration of bicarbonate amon In 50115 with pH 75 keeps the concentrations of all cation hig!) as well However, in an addic environment, such as th-e rhl~osphere of rice, HCO,- concentration Will be

,low, whIch may reduce K diffUSion rate to the root at high (Ca+Mg)/K ratios On the other hand, KINa rabo IS important for sod ICily tolarence Higher or preferenhal uptake of K IS said to off set the III effect of Na In sadie 5011 Thus a balance IS warranted regard 109 these ratios

Release and Uptake of K

The release of K and K uptake, in addlbon to presence of micaceous mmeral will depends upon the weathenng of minerals Potassium release by NaTPB and uptake of K by five crops was less In poorly constructed illite w~h broader loA peak as compared to soils With Illite high degree 'of crystality with sharp loA peak Although both Salls have dorm"ant clay minerai as Illite the release and uptake depended upon structure of Illite Thus, In 50115 denved from gramte matenals, exchangeable potassium was 10-20% of the exchangeable bases while in soils derived from quatemary red clay and latente, thiS figure was 3~% and 4-5%, respectIVely, The lomc composition of SOil solution dunng submergence differs from that under upland Salls The werk With aCIdiC paddy 50115 showed that the amount of K' Ions adsorbed by salls and their bonding energy Increases With nse 10 pH but decreases With electrolyte concentration The submerged 50115 are characterized by larger amount of exchangeable K and ~a compared With upland Salls, espeCially 10 cultivated layer

Potassium availability dunng the growth or nee has been studied by variOus wOrkers Expenences of TNAU showed thai the exchangeable K gradually decreased from pre-planting to heading and Increased thereafter. Some werkers have also 'recorded a general reduction In exchangeable K With crop age although the trend was not customary In allUVial, latente, red and black 50115 exchangeable and non-exchangeable K has also been reported Besldes,'the removal qf the charged.potasslum from different group of Salls by nee and contribution from non-exchangeable K has been suggested for submerged condition Such contribution was found to be comparatively less In black Salls as compared to other group of sorls In general, the release of non-exchangeable K was found to be more under submerged a5 campared 10 normal upland condJ\lons

Epilogue

Submerged SOI/S offer unique opportunity Vis-a-VIS liabIlity. Management aspect for nutntlon In

submerged SOil, beSides Integrated application should take Into account the follOWing facts availability of nrtrogen IS mamly oriented to the transfonnatlon processes, thai of phosphorus IS mainly gUided by reactions and mineralogy has major beanng on potassium availability. 'To counteract various loss mechanisms In sodle SOils, higher (25% higher than the recommended dose of N for nonnal 5011) should be applied Application of P becomes essenbal 10 reclaimed sodlc SOli Balance between CaiNa nd KINa rallos should be_ taken IOta conSideration for K application In sodlC 5011

60

Integrated Nutrient Management for Sustaining Crop Production on Alkali Soils and Sodic Water Irrigation

H.P. S. Yaduvanshl DIVISIon 01 Soil and Crop Management Central Soil Salmdy Research InstItute, Kamal-' 132001, Haryana

Introduction

In India, about 6.73 million ha, -are I;';ng banren or produce vel}' low and uneconomical Yields of vanous crops due to excessive accumulation of salts The popula~on of our country escalating at an alarming rate of around 22 % per annum IS expected to stabilIZe at 140 billion In the year 2040 AD The land for agnculture IS snnnking al1d except for sa~ affected 50115 there appear Irttle scope for ~s further expansion The fertll~y status of 24 million heclare of alkali SOils of Indo-Gangallc plains IS generally poor due to high pH. excess soluble and exchangeable Na, higher amounts of CaC03, negligible to low organiC matter content and adve,,;e SOil phYSical condrtlons A large number of manunalitertlllZer expenments conducted In the country have revealed that 5011

fertility ViS-a-VIS nutnent supplYing capacrty of most SOils have either already dealned or In the process of dedlmng due to mtenslVe farming cond~lOns. resulting In gradual loss of essential nutnents like. N. p. K. Zn, S etc from the I"OQt zone The integrated use of chemical fertilizers, organic manures Inaudlng green manure and recycling of croP reSidues. thus assume greater Significance of Improve ferullZer use effiCiency In alkali 50115

RIce-wheat IS the most Widespread cropping system In India which occupies nearly 10 million hectares area It contnbutes about 85 % of the total cereal producllon With present pace of development area under nce-wheat system 15 unlikely to expand and Will remain StatiC We therefore need to deVise means and ways to Increase nce and wheat producllon from available land resources and achieve self suffiCiency to feed our ever Increasing popu!atJon Utilization of salt affected arkah Salls and their proper management for nee-wheat system IS discussed here

Integrated Nutrient Management

The objectives of maximIZing Yields and fertilIZer use effiCiency. maintaining SOil producllvlty. proper enVIronment and ecological balance can be met by balanced use of Inorganic fertilIZers and organic sources of nutnerrts such ,,5 organic manures like FYM "nd compost, green manures and bio-felllllZers The crop Yield are higher when both chemical and organic source are used as compared to either chemical and organic sources added IndiVidually ThiS IS attnbuted to the proper nutnent supply as well as creaMn of better 5011 phYSical and biological conditions FertilIZers supply available fomns of nutnents readily to the plants on apphcatlon as opposed to orgamc manures whICh make avallatlle only a f",cllon of thelf total nutnents In the first few weeks after application

Efficient Use of Fertilizers

For alkah Salls, the main problem is high pH, high ESP. high amounts of calCium carbonate and poor phYSical conditions, limiting nulnent availability al1d ptl10nt growth Crop grown Crop productlOfl al1d fertilIZer use effiCiency In these 50115 can be Increased by use of amendments like gypsum On the other hand. the appropnate prescnpbon oll.IIlllze,,;, they must be given In nght quanlrty. at the nghttlme and place, frOm the nght source. and 10 the nght comblnabon are benefiCial for fertilIZer use effiCiency Different aspects of effiCient fertlhzer management are diSCUSses In thiS section

Nitrogen

Alkali SOils are very low 10 organIC maHer and avaIlable N Ihroughout the SOil profile Because of thIS. most crops suffer from Inadequate N supply Nrtrogen transfomnatlons are adversely affected by high pH and ~- .

Fertilizer Nitrogen Efficiency

Arkali soils redamation and effiCient management of fertilIZers did not get attention of the farmers before the Informabon of high Yielding vanelles mainly because of vel}' low economic retums from ,nd,genous vanebes Bul dUring Ihe last two decades, both farm'"'' and researchers have sought to Improve fertilIZer nrtrogen effiCiency =erous mlrogen use expenments have shown that the recovery of fertilizer nitrogen for nce normally ranges

20 to 40% In alkali soils Proper management of feruhzer N IS thus necessal}' for better N use efficiency ~cause of the adve,,;e physico-chemical conditions. the recovery can expected to be sbll lower In the _salt ffeeted soils An expenmentln alkah 50115 has shown that apphcatlon of Inorganic fertilIZe,,; alone, and Integrated -

Use of organic and Inorganic fertilIZers did not affecl NUE In nee but It Increased In wheat With reSidual effect of organic manures (Yaduvanshl 2003) In alkali Salls ammonia volat,l,zabon losses are a major constraint In IncreaSing N effiCiency High pH/alkalinity and high amount of caleum carbonate In""as.. volabllZat,on losses of

1

ChemIcal Changes & Nutnent TransformatIon In Sodle/Poor Quality Water Imgated SOIls

applied N In alkali ~oil Researchers observed that 32 to 52 % of the applied N was lost through volabllzabon In' alkali 50115 /

/ ,T)1e results of a expenmental Indicate that ammonium fertilizers were broadcasted directly on the SOIl

Without incorporation, NH, vol311lizabon losses ranged from 10 to 60 % of the fertilizer - N appbed Losses of ammonia were higher at the field mOisture range and In unreclalmed alkali SOils Another fietd stUdies showed ttiat ammonia volabllZabon losses decreased significantly with FYM or green manunng combined With urea - N application compared wrth urea - N application alone The losses of NH, volabllzabon from green manunng combined with urea - N were lower (13 4%) as compared to alone urea - N application (19 5%), the use of green manunng could be save 6 per cent fertilizer - N (Table 1), possibly because In the fornier, Mnfylng populalion could adequately OXidIZe the ammoniacal - N slowly mineralIZed from green manunng (Yaduvanshl 2001) Rao and Batra (1983) also reported lower losses from green manunng (56%) as compared to 'urea - N (30 %) under laboratory Incubation studies Yaduvansh, (2001) also reported that ammonia volatilization losses IS more up to 24 hoUis of urea application and sharply declined dunng the next 48 hours Significant decreases In ammonia losses were measured when add Ilion of second and third spirt urea - N application In compared to first urea - N basal applicatiOn The benefits viere allnbubed to reduce N losses through volabl,zat,on thereby Increasing the absorption of NH3 - N by plant at the bme of second and third spill applicallon

Table 1, Ammonia losses from reclaimed sodlC 5011 nee field In Integrated nutrient management system

Treatment combination Urea applrcatlOn TotalN Urea N pH

1st t" 3'" lost lost %

Control 1 23 1 23 856 N,20 849 821 676 2346 1955 849

N,20 P", 8 28 7,35 6 70 22,33 1861 848

N,20 P", 1<.2 8 14 724 665 2175 1813 845

N'20 P", K." 5 82 520 506 1608 1340 8 10

N,20 P", K." 673 574 528 1775 1479 815

N,oo P39 Kro 1212 1060 948 3220 1789 849

Mean 826 7.39 666

CD(P=005} 051, 091 1,19

Stage of Urea applrcalion 032

Amount of Fertilizer Nitrogen

SaH affected sorls rn the Indo-Gangelic alluvl2l plains have low organrc matter Surface and profiles soil samples analyzed In these saris and reported all of them to be containing less than 0 4 per eent organic carbon content Malonty of lhese Salls had less than 02 per cent organic carbon, These 50115 can be consrdered to be unIVersally deficrent In n~rogen and, therefore crops greatly respond 10 the applrcalion of nrtrogenous fertrllzers Many expenmenls conducted rn sail affected saris show the trends in responses of nee and wheal 10 applred N In reclaimed sod,c sorls These observation clearly suggesllhal both nee and wheal crops respond to much higher levels of N under sodrc sorl cond~lons than that commonly recommended (120 kg N Iha) under nonnal SOil condrtlons The applrcatron of 150 kg Nlha is, therefore, a common recommendatron for bolh nce and wheat grown rn inrual redarmed alkalr SOils The crop responses to hrgher levels of N may be attnbuted to low rnherent organic matter status of these smls, losses of N through volatilIZation anathe benefiCial effect of N In Increasing the abllrty of plant to tolerate' higher salinity or sOOlCIty

Method and Time of N Applicatlon

Nitrogen applrcalion should synchronise wdh the growlh stage at which plants have the maximum reqUIrement for thiS nmnent For gram production nee and wheat plants use nitrogen mosl effiClenUy when rt is applred al the maximum lillenng slage Rice plant use N around the panrcle Iniliallonljolntrng stage also Therefore, spirt appllcallon of N for wheal (1/2 at sOWIng, remarnlng 112 N rn two splits at at bllenng (21 days) and 42 days after sOWIng and for nee (half at transplanting + 1/4 at trllenng + 114 'at panicle Inlliallon) resulled maximum effiCiency Anotlher field expenmenls have shown that maximum Yields of nee and wheat were obtained when N was applied rn 3 equal spirts, as basal and al 3 and 6 weeks after transplanting/soWing (swarup 1994)

Phosphorus

Next to nItrOgen, P IS the most cntlcal nulnenl reqUired for effiCieni crop productiOn In normal salts But barnen alkalr sorls hav,e high amounts of avarlable (Olsen'S extractable) P and have been calegonzed as medrum

62

Integrated Nutnent Management for Sustaining Crop Production under Sodle Saris

to hIgh In avaIlable P status Due to hIgh pH and the presence of soluble calbonates and blcalbonates, sodium phosphates are formed In these sOils which are water soluble Sadie salls are reported to contain high amount of soluble phosphorus Research conducted at CSSRI has re ...... aled no response to added phosphorus on sod,c sOlis eany years after redamatlon However, other stud!es Indicate that sadie sOils are not always high In available phosphorus and significant Increase In Yields .of some ~rops IS obtained With application of P fertilizer When these soils were reclaimed by uSing amendments and growmg nce under submerged condl~ons Olsen's extractable P o! surfaee SOil decreased due to Its movement to lower sub-SOil layers, uptake by the crop and Increased immObilization (Chhabra et ai, 1981, Swarup, 1986, 1994) Long term field studies were conducted on a gypsum amended alkali 5011 (pH 9,2,ESP 32) With nce wheat and pearl millet cropping sequence and NPK fertilIZer use for 25 years (1974-75 to 1999-?000) The soun:es of N P and K were urea, Single superphosphate and munate of polash respecWely Phosphorus applied at a rate of 22 kg P Iha to e~her or both nee and wheat crop In rotation Significantly enhanced the grain Ylel;! of nee (Swarup and Singh 1989) when Olsen,S extractable P In 0-15 cm, SOil depth had oome the Inlballevel of 33 6 kglha to 127 kglha which IS very dose to Widely used cntlcal soil test value of 112 kg P Iha. Wheat responded to applied P when available P came down close to 8 7 kg Plha In 0-15 an 5011 depth and neany close to crrtlcallevel (11 6 kg Plha) In the lower depths (15-30 em) Application of N alone slgnlficanlly enhanced the grain Yield of pearl miliel but phosphorus applied eJlher or both crops had no effect on Yield though available P ded,ned to less than the artlcal_soll test value In 0-15 and 15-30 ern SOIl depths Further studies that crop responses to applied P were limrted to only levels I e 11 kg In the iMlal years of cropping and that 100 only to nce crop In a nce-wheat cropping sequence Application of 22 kg plha Significantly affected the nce and wheat Yield

Recent studies on Integrated nutnent management showed that contmuous use of fertilizer P, green manunng and FYM to crops Significant enhance the Yield of nce and wheat and Improve available P status of the alkali SOils (Yaduvanshl 2002) .

Potassium

Applicabon of K fertilIZer to either or both the crops had no effect On Yields of nee and wheat (Swarup and Singh, 1989, Swarup and Yaduvanshl 2000) Lack of crop responses to applied K In these SOils IS attnbuted to high available K status due to presence of K beanng minerals and II) large oontnbutlon of non-exchangeable K (97% ) towards total K uptake by plants and reduced the release of K from no~xchangeable reserves Studies conducted so far suggest that application of K fertilizer to nee-wheat system can be aVOided With out haVing any advelOe effect on crop productIVity and K fertility status "The Contnbutlon of the non-exchangeable K towards total potaSSium removal was about 94 9 % in the absence of applied K Which decreased 69 9 % With use of K The decreased was about 50 6 % wrth use of K combined use wrth organic manures (Yaduvanshl, 2002)

Zinc

High pH, low organic matter content and high calCium calbonate , Imbng the solubility of Zn In the calcareous alkali 50115 Most of the alkali Salls contain high amount of total Zn (40 to 100 mg Znlkg soli but the available Zn (DTPA extractable) IS qu~e often less than 06 ppm (Singh et ai, 1984) Rice crop raised In the Salls Inyanably suffelO due to defiCiency of Zn The defiCiency symptoms appear after 15 to 21 days of transplanting In the lonm of brown rusty spots on the third mature teaf The aflected plants show stunted growth, poor tillenng, delayed matunty and low grain Yield An applica~on IOta 20 kg of zinc sulphate IS suffiCient to get optimum Yields of crops

Incorporation of Organic Manures and Inorganic Fertilizers

In IntenSIVe cropping system and heavy use of chemical fertilizers have created an economic, environmental and eoologlcal problems and are adversely affecting the sustainable agncultural Organic manures play an Important role In the sustalnabllrty of a cropping system Conlinuous adoption of nee - wheat system may read to the emergence of other mlcronulnents defiCienCies espeCially that of Mn Wrth the apph~lon of FYM and green manunng crops has been pOSSible to prevent the occurrence of Zn and other mlcronutnents In nee grown on alkali soil However, applYing organic and green manures as a pnmary soun:e of plant nutnents may not support the susta,nabllrty coneept Therefore, integrated use of ' organic manures and chemical ferbllzers IS extremely Important for the long tell11 sustalnab~lty 01 nce -wheat and o!her cropping system.

On the baSIS of 25 years of researches of Long -Term Fertilizer Expenments project In India (Swarup 2000) and several other Long -Term SOIJ Fertility expenments conducted In Indo - Gangetic Plains on nee-wheat (Abrol et al 2000) rt was revealed that nce Yields In nee-wheat system declined In most expenments, whereas Wheat Yields remained more or less stable But whether or not !hIS stability In wheat Yields would conlinue In tutu"; remains to be seen However, the results of two oore projects under Imgated R,ee Research Program of IRRI showed dedimng trends in nce-wheat Yields Duxbury et al (2000) also showed that 8 out of 11 long-term nceWheat expenments that had run for more than 8 years resulted In a downward trend in nce Yields over time. ThiS contrasted WIth only 3 of 11 showing a downward trend In wheat Nutnenl.mbaiance crealed by continuous use 01

63

Chemical Changes & Nutnent Transformation In SodlcJPoor Quality Water lITIgated SOils

plant nutnents paTtlcUlany N alone or combmed With sutKlpbmal rates of other nutnents (espeCially P and Zn) has been the pnmary Cause of non-sustainable Yields In a nee-wheat cropping system on alkali sOils

Grej>O manunng has a long and chequered hIStory In IndIa In the IntenSIVe fanmng system, farmer may not be able to practice green manunng In a traditional manner by devoting an entire season to a green manure crop. A new green manunng techniques that does not replace a crop and demand even only one day for decomposlllon bme before transpJanbng nee was developed The green manures can easily be Introduced 10 the farmIng systems of low Intensity, however, fittIng In green. manure crops of 50 days duratIon In IntensIve croppong systems has not been easy and needs to be properly worl<ed out sa as to make green manunng a successful pracbee The green manures crops can be grown eaSIly dunng summer months Ie. afterthe wheat harvest and before transplantIng paddy In fifty days dhalncha green manuoe produeed about 42 t/ha dry matter and accumulate 90 kg N, 11 kg P and 90 kg K and gave a savIng of 60 kg Nand 11 kg P 1M (Yaduvanshl 2001) Another field studIes conducted by Swarup (1991) on a gypsum amended alkalI 50115 showed that Incorporation of 50-<laY-<lld 5esbanla canablna produced 385 Mglhlliyear of bIomass (dry weight) whIch In turn contnbuted 110 kg Nand 11 kg Plhalyear and enhaneed SIgnificantly the graIn YIeld of nee and wheat Ghal et al (1966) reported a decomposrtlon penod of 5--day for Sesbania species 10 a reclaImed sadlC 5011 as compared to a penod of 10-15 days normally practIced for non-alkall Salls However, the advantages of green manunng In alkalI sods were mooe when rt was decomposed tor one week under submerged condrtlons pnor to transplanting of nee (5warup, 1988b) Further, II new green manunng technIque that does not replace a crop and demands only one day decompOSItIon IJme belore Iransplantln9 nee developed (Ben & Meelu '9SI)

Reeent studIes on Integrated nutnent management showed that nce and wheat YIelds SIgnificantly Increased with Inlegrated use of green manunng Of FYM and 100 % recommended (120 N , 22 kg P and 42 kg Klha) as compared to 100% recommended InorganIC fertIlize", alone. The Yield of nee and wheat could be maIntained even at lower (50% recommended dose) of inorganic fertIlizer applicatIon (N60 P13 K21) when conluncbve use WIth FYM or Sesbanla green manunng The response of nee 10 the applicatIOn of 100% recommended treatment (120 kg N,26 kg P and 42 kg Klha) and lis combined use wrth green manunng or 10 tlha FYM and 150% recommended treatment (180 kg N, 39 kg P and 63 kg Klha) was 2 98,427,410 and 354 tlha, respectIvely. Further, the addrtlon of green manunng or 10 t FYMIha In combInation WIth 60 kg N, 13 kg P and 21 kg Klha ( 50% recommended dose) the nee mean yield (579 tlha) was at par WIth YIeld (551 tlha) obtaIned from the 100% NPK recommended treatment (120 kg N, 26 kg K and 42 kg Klha) ApplIcatIon of green manunng and 10 t FYMlha saved 60 kg Nand 13 kg PI1Ia as inorganIc ferllllzer In nee (Yaduvanshl, 2001a, 2003). These results SU99est that Integrated use '01 chemICal lellll.ze"" ot9amc rnanUI9S .nclud.ng 9,een manure and recyc\lIYil 'Of = reSIdues, assumes greater SIgnificance of Improve effiCIency of chemIcal fertIlize", In alkali SOIls, espeCIally dunng post reclamation penod

Sadie Water Use Condition

In many arid and seml-and regIons of the wortd SodIC groundwater is the maIO or only source of irrigation and lis use poses a threat to agnruftural production ApplIcatIon of gypsum as saIlor waler amendment IS commonly recommended to offset Ihe detenoratlng effects of that type of water Prolonged uses of sodlc water creates sodlclty I sallMy problems and Induee severe nutritional dlsorde",flmbalanees ,n the lITIgated SOIls and crops leading to reduced crop y'elds (Bajwa and Josan , 1989, Yadav, 1989, Mlnhas and Bajwa, 2001, Sharma and Mlnhas, 2004») With the mcreaslng paee of sodlc land reclamatIon programmes and WIth lhe greater use of marginal qualIty waters for Imgatlng nee-wheat 10 the country, the recyclIng of nutnents through crop residues management and IS gaming oenewed Importance for maintainIng 5011 fertIlity and crop produc!Jvity of these lands. Wheat straw 15 often burned or removed from the field after harvest despIte rts plaYing an Important role 10 maIntaIning sool productIVIty If returned to the SOil (Tanaka 1978) More than 100 mIllIon tons of nee straw IS esbmated to be produced annually In South-West ASia but only a small fractIon is poesently reincorporated Into the soil (Bla" et all 995). jmprovlng and sustenance of thIS croppIng system through Integrated use of Qrganlcs, crop reSIdues, Industry waste and chemical fertlilzers is therefore, VItal for conserving Ihe lertlhty of reclaImed alkah SOil and for strengthening food and nulntlonal secunty

In long -term field expenments Initiated to evaluate the effee! of N, p, K and Zn fertJhzer use alone and In combinatIOn WIth gypsum, farmyard manure (FYM) and pressmud on changes 10 SOil properties and Yields of nee and wheat under contInuOus use of sadlC imgatlon water (reSIdual sod,um carbonate (RSC) 8 5 meq 1", and sodIum adsorptIon ratIo (SAR) 88 (m molll) '12 at Bhal", Majra expenmental farm of Central SOIl Sahnlty Research Institute, Kamal, IndIa. Continuous use of fertilizer N alone (120 kg ha"j or in combinatJon WIth P and K Significantly Improved nee and wheat yIelds over control (no fertilizer) Phosphorus applied at the rate of 26 kg P ha" each to nee and wheat SIgnificantly Improved the YIelds and led to a conSIderable bUIld up In avaIlable SOIl P When N alone was applIed, avaIlable SOIl P and K declIned from the Inlllallevel of 14 8 and 275 kg ha" to 8 5 and 250 kg ha" raspec!JVely. potassIum apphed at a rate of 42 kg K ha' to both crops had no effect on YIelds Response of nce to Z,nc applicatIon occurred Since 1997 when DTPA extractable Zn declIned to 1 46 kg,ha" from the Inlllallevel of 1 99 kg ha' Farmyard manure 10 Mg ha-', gypsum 5 Mg ha' and pressmud 10 Mg ha' along WIth NPK fertilizer use SIgnIficantly enhaneed Yields over NPK treatment alone Conllnuous croPPIng WIth sodlc water and InorganIc fert!lIzer use for eIght yea", shghtly decreased the SOIl pH, and SAR from the Inrtlal value of

64

Integrated Nutrient Management for Sustaining Crop Production under Sodlc Solis

8 6 and 29 0 10 8 50 and 18 7 respec!rlely However, treatments InvolvIng the use of gypsum, "FYM and pressmud' slgnlficanUy decreased the soil pH and SAR over Inorganic fertilizer treatments and control Nitrogen, phosphorus and ZinC uptake were far less than additions made by fertilizer The actual SOil N balance was much lower than the ' expected balance Ihereby Indicating large losses of N from the SOil There was a negative potassium balance due' to greater namoval by the crops when compared to K addrtlons The results suggest that either gypsum or FYMlpnassmUd along with recommended dose of fertilizers must be used to sustain the prOductlVlly of nce -wheat system In areas haVIng SOdIC ground water for liTIgatIon (yaduvanshl and Swarup, 2003) , '

Bibliography

Abrol, I P, Bronson, K F , Duxbary, J M and Gupta,R K 2000, Long,-Tenn SOil Fertility Expenments In Rice -Wheat Cropping System Rice-Wheat Consortium Paper Senes 6

Bajwa M Sand Josan, AS, 1989, Effect of gypsum and sodJC "ngabon water on SOIl and crop Yields In a nee-wheat rota~on Agncultu/'fJ Water Managemenl16 53-61 Bla)(, G , Lelrog, R, Konboon, and Naklang, K 1995, Calbon and nulnenl pools In nce croppIng system In'

FragIle lives In fragile ecosystems Intematlonal RIce Research Institute (IRRI) Los Bonos, pp 161-172,

ChMbra, R, Abrol, I P and SIngh, M V 1981 Dynam,cs 01 phosphorus dunng reclalmatlon of sOdlc Salls SOil Sci 132 (5) 319-324, '

ouxbary, J M" Abrol, I p" Gupta, R K and Bronson, K 2000 AnalySIS of long tenn 5011 ferlllity expenmenis With nee - wheat rotabon In South ASIa In Abrol, I p, (2000) Long -Term 5011 Fertll"y Expenments In Rloo -Wheat CroPPing System RIce- Wheat Consortium Paper Senes 6

Mlnhas, P S. and BaJwa, M, S, 2001 Use and management 01 poor quality water In nee-wheat produ~on system Journal of ClOp Produc/Jon 4. 273-306

Rao D L N and Batra, L 1983 AmmOnia volablizatlon from applied n~rogen In alkali Salls Plant and SOil, 20 219-228

Sharma, 0 R. and Mlnhas, P S 2004 SOIl propertIes and Yields of upland crops as Influenced by long-tenn use of water haVing vanable reSIdual alkalInity, salinity and sOdiClty Joumal of the Indian Society of SOil SCience 1 100-104

Swarup, A 1994 ChemIStry 01 salt affected SOIls and fertility managemnet In' Sa/lmty Managflmflnl for' Sustainable Agncufture, Central SOIl Salimty Research Insbtute, Kamal pp 18-40

Swarup, A and SIngh, K N 1989 Effect of 12 - years nce wheal cropping and lerlllizer use on SOIl propertIes and crop YIelds in a sodlc SOIl Field ClOps Res 21 277-287

Swarup, A and Yaduvanshl,N P S (2000) Effects 01 Integrated nutrient management on SOil propertIes and yield of nee In alkali SOIls J Indian Soc SOli SCI 48' 279-282

Yadav J S P 1989 ''''gatlon Induced SOIl sa"mty and sodlclty Proceeding of World Food Day SympOSIUm on Envlronmflntai Problems Affecting Agnculture In the ASia and PaCific Region, FAO, Bangkok, ThaIland Pp 47-62

Yaduvanshl,N P S 2001.Ammoma volatIlizatIon losses from Integrated nutnenl managemenl In n," fields of ~Ikali SOIls J Indian Soc SOil SCI 49 276-280

Yaduvanshl, N P S 2001 a Effect of five years of nce-wheat croppIng and NPK fertlhzer use With and WIthout orgamc and green manures on SOIl properties and crop YIelds In a reclamabon sodlc SOIl J Indian Soc Soli SCI Vol 49(4),714-719 '

Yaduvanshl, N P S 2002 Phosphorus and potassIum 'budgeting for nee and wheal sequence under Integrated nUlnent management system In sadlC SOil TropICal Agnc Vol 79(4) 211-216 '

Yao'uvanshi, N P S 2003 Substitute of inorganic fertilizers With organic manures and Its effect on SOIl fertIlity in nee-wheat rota~on on reclamed sodlc SOil J Agnc Scl Camb Vol 140161-169

65

Management of Land Degradation in Arid and Semi-Arid Areas /

/

KhaJanchi Lal and Gajender Yadav D,vJslon~of sOil and Crop Management Central SOil Su/fnfly Research Institute, Kamal 1-32001, Haryana

Introduction \

World population has Increased from less than two thousand million to over SIX thousand million In the course of past century Until one hundred years ago, the increasing needs of expanding population for food, fuel, fiber and construction matenals were met from cultivating progressively laiger area of land Steep Increase In populatIOn dunng last cenlury has been supported mainly by Intensifying the use of most of the already cultivated land. In the course of the next twenty-five years another two thousand million people Will be added to the global populabon Most of these people Will live In the and and semland areas As a result, future demands on sOil and water resources In these areas Will far exceed those of the past The aim of thiS chapter IS to summanze past and present soil management pracllces for ecological and enVIronmental sustalnabllity with Intensified use of 5011 and water resources In Brld and semi-and areas It IS Intended to assist all those concerned with agncultural development and the environment to recognize the problems of 5011 degradatIon, compatlblhtles and incompatibilities of Increased agncultural production With protection of the environment Chapter also descnbes about management practices evolved under lower demograph,c pressure lri the past and have sustainable 5011 management systems, adapting both to the envlro-nment and to eXisting social and economic ClrGumstances

An understanding of the factors.determlnlng sustalnability of these systems and their breakdown under Increasing demographic pressure can make It possible to establish sound pnnclples of sustainable 5011 management. Such management aims not only to maintain or improve soH productivity, but also to avoid or rectify If necessary all forms of 5011 degradation so that damage to the enVIronment IS prevented The· ways In which these pnnclples may be applied to the development and implementation of more productive and sustaInable management systems are also discussed

The Problem

Population of the world has reached the level of one thousand million in more than one milhon years ThiS figure was reached In the middle of the last century It IS now increasing by approximately one thousand million every ten years Perhaps surpnslngly, In view of Thomas Malthus' prediction In 1798 that the world would shortly outgrow Its ability to feed Itself, the world continues to support ItS rapidly Increasing population (Figure 1) Two factors underlie the ability of the earth to support the enormous Increase In number of people now liVing the reSilience of Salls In response to Increasing demands made on them, and the Increasing knowledge of farmers and sCientists about how to manage productiVity and sustalnability of 50115 Probably the most Important advance In knowledge which has helped to sustain the huge growth In popula"on was the discovery of how to manufacture inorganic fertilizers Other advances In crop Improvement and pest management, Including the use of peslicides, have of course made a Significant contnbutlon Much of the debate about the sustainability of systems reqUlnng high Inputs of synthetiC chemicals has focused on the pOSSible damage,!o the health of those hVlng on the produce of those systems The health of the population supported by food grown under Intensive management systems IS, In fact, beHer than ever before achieved A s()ll management system that depends on la'lle inputs of mO'llanlc fertilizers may be sustainable when conSidered In Isolallon, but the sustainability of mineral and energy resources from which the fertilizers are made must also be taken Into account In addition, the enVIronmental effects of the movement of chemicals (from fertilizers and pesbCJdes) out of the SOil and Into the groundwater, and of by-products released Into the atmosphere, should also be conSidered Particular attention should be paid to the effects of these chemicals on the plant and animal populations, and the biodiversity of those populations The traditional system depended on the erosion of Silt from higher land, thus resulling In degradation of the upland areas

Management of Land Degradation In And and Semi-And Areas

1 II" t----:;-----;r7,.,.-,==::I~.- I •. , - r ' J.. r~·jA

- ---- --- ---'_ Fig 1 Projected growth of populatron VIS-~-VIS food and energy requrrement of world

I

Perhaps the biggest challenge facing farmers, ecgnomlsts and sOil sClen~sts today IS to develop suslarnable farming systems together with the polobcal and SOCID-economIC conditions In which they can be practiced, so that a much larger population may be supported by the sOils of these less fertile areas Many attempts 10 Introduce continuous arable cropping systems Into the and and sem,-ands have failed Often, Ihe maintenance of the nutntlonal status of the SOil has not been adequate Other causes of failure Include SOil degradation In one or more of the followrng ways phYSical degradation due to erOSion, compaction and crusling, chemlCllI degradation associated With nutrient mining and aCldlficatron, biological degradatron aSSoClated WIth lOSS of organic matler, and detenoratlon 01 drainage condilions causing water logging or salinization.

Degraded Land at Glance

Globally, 1,964 milioon ha of land has been facing human-Induced degradation (UNEP 1997) Of thiS, 1,643 milioon ha are subject to SOil erosion by water and Wind, 239 million ha to chemical deterioration. 68 million ha to compaction and 11 million ha to water logging In addltron, an estrmated 955 million ha 01 arable land on earth are affected by SOil salinity and/or sodlcrty (Szabolcs (992) In India alone, an esllmated 175 million ha land accounting for 53 % 01 geographical area of our country IS subject to vanous kinds of degradalion. Of this. an eslimated 150 million ha are sublected Wind and water erosion Extent of salt affected SOils on India IS 6 72 m ha (Saline 3 0 mha, Alkali 3 7 mha, NRSA & ASSOCiates 1996)

VVl'ule arable cropping has often been found to be non sustainabre, production of tree crops In these areas has presented relatively few problems wrth respect 10 sustalnabllity Although much remains to be done, the basic pnnclples of good SOil management are now well eslabllshed They should now be Widely known and understood, evaluated and adapted to SUit the speCific SOils and environmental, SOCial and economic condItions of different regions. The necessaoy pollCles must the'; be impleonented so that good SOil management may be practiced In such a way that It proVides a satlslactooy livelihood for the farmer and hiS or her family.

Principles of Good Soli Management

Good management always emphaSizes the use of sal' I~ such a way that ItS productlvlly IS maintained or preferably, enhaneed. This requirestha! the chemical and phYSical conditions of the SOil do not become less SUitable for plant growth than when oultrvatlon commenced Cultivation normally means that Ihe 5011 Will, In fact, deteriorate due both to nutnent removal With harvesllng of crops, and to phYSIcal damage to the SOil structure What IS essenbal IS that the detenoratlon should be reversible, by chemical additions to the SOil, mechanocal manlpulalron, or natural processes of fertllily restoralrDn under pasture Dr trees ThiS Imp Ires that the 5011 must be reSilient, I e after being subjected to the stresses Involved on crop productIon

'1::1 UllI.lOfIily...",J

6:J ...... "" byW1l<'r

D~l'fWlI>lI

Gl """' ......

Types of Land Degradation

67

Causabve factors

L:J ddnTtUlon

'EJ-,,'~n"'S

Chemical Changes & Nutnent Transformation In Sodlc/Poor Quality Water Irngated SOils

./ It musl have Ihe ability 10 return 10 its lonmer condition, or an improved condition (Greenland and

5zaboles, 1994)/Good soil management must not only serve the Immediate needs of the fanmer but should also be acceptable to the wider community This requires mamtalnlng and Improving 5011 productiVity, avoid 109 and rectifying SOil degradation, and aVOldmg enVIronmental damage

Maintaining and Improving Soil Productivity '. , If a 5011 IS to sustain the production of crops It must provide the nutnent requirements of the crop, a

conducive phYSical medium 10 which plant roots can grow adequately and absonb Water and nutrients SOil should be able to store sufficient water for meeting crop reqUirement and allow It to enter and move In the SOil to maintain the supply as It IS transpired by the crop and evaporates from the SOil It should provide a medium for soil organisms SO thai they can decompose organic matenals releaSing nutnents and assisting plants In transport of nutrients to plant roots Soil medium must support microbes to compete successfully With pathogens which might otherwise Infect roots and damage the plants and fonm the SOil organic compounds which Will have a favorable effect on other SOil properties

Soil Nutrients Management

A few SOils contain suffiCient nutnents to allow them to be mmed for many years Without Significant loss of Yield, but the maJonty of Salls can only be explorted for a few yealS before their ability to supply nutnents falls to a low level If Yields are to be maintained, and the SOils used to produce crops on a contlnumg baSIS, a method by which mtrogen, phosphorus, 'potassium and' other nutrients can be replaced has to be found Nitrogen IS a speCial case because It can be fixed from the air A great deal of efforts have been made to quantIfy and maxImIze the contnblltlons that, can be made tl? the mlrogen nutntlon of crops by natuTal nitrogen fixabon processes, and to find SOil management systems In which biological nitrogen fixation IS maximized LikeWise maintaining phosphorus, potassium and other nutrients normally requires the use of morganlc fertlllzelS

ManagIng Soil Physical Conditions

Salls under natural vegetation normally support an active population of 5011 micro-flora and fauna When the vegetation IS cleared to grow a crop, the 5011 IS exposed to the Impact of rain, people, animals and machines, treading and Inducmg compaction of the SOil Exposure and subsequent drymg of the SOil can also lead to surface crustmg ThiS reduces the rate al which water can enter the 5011 and cause water to run off the surface leading to SOil erOSion Therefore, managmg 5011 phYSical properties must aim to preserve the structure of the SOil where thiS IS already favourable or to create a favourable structure by SUitable tillage or other practices where such a structure does not eXist (FAO, 1993) Tillage IS also Important for weed contro~ and thiS IS often the most Significant reason for ploughing If the 501115 naturally well structured as IS often the case under forest canopy for long penod IS easy to seed A major advantage of zero- and minimum-tillage techniques IS that they can be used to leave a cover of crop reSidues on the SOil to protect It from the Impact of direct rainfall This prevents the dlspelSion of SOil matenal from aggregates, and maintains the Infiltrallon capacl~y of the 5011, SO mlnll'nlziog run-off and the consequent 5011 erOSion problems

In dner areas, the cover also protects 5011 from Wind erOSion Keeping a cover on 5011 JS now Widely recognIZed as the most Important factor In SOil conservation Wind erOSion IS best controlled by trees planted as Windbreaks, although crop reSidues can be equally effective If they persist on 5011 Water erOSion can be controlled by bundlng of fields or prOViSion of bamelS on waterShed scale The barner can be a Simple earth bund, constructed so that It Will lead water mto a grassed channel In order to aVOid guUy formation.

Managing Soil Organic Matter and Soil Biological Condition~

5011 organic matler IS extremely Important for productiVity, and particularly so for the poorer soils of and and semi-and areas Its dlTecl contnbutlons to nitrogen and sulphur nutnllon of crops, and ItS role In s_tablllzing 5011 aggregates and supportmg the 5011 biota responsible for creallng pores through which air and water move cannot be Ignored In addltron, 5011 organiC matter plays a major role In the retention of cationiC nutnents by dominant Salls of these areas which have clays composed of kaollnrte, and low activity Iron and alummlum OXides clays With only a weak ability to hold nutnent cations Furthermore, under aCid conditions, some of the organic compounds present In SOil fonm complexes With aluminium which would otherwISe be tOXIC to plants In addition to phYSical and chemical effects, organic matter prOVides substrate for supponng biological life In the 5011 Under natural vegetation the amount of organic matter 10 the 5011 tends to be established at a relabvely high level but under cultivation, addition IS usually much less than from the natural vegetation, and consequently the OM level tends to fall If good crops are grown and all reSidues returned to the 5011, the level established after croppmg may be different than under grassland

68

Management of Land Degradation In And and Semi-And Areas

Table 1. Changes In SOIJ properties (0-30 em) under different tree-crop combinations In 5 years

land use system Organic carbon (%) Available N (kg ha-')

Crop based system +007 +10

E~/yptus based +012 +21

AcaCia based +020 +31 f

Populus based +017 +25

A general principle of sustainable SOil management systems IS that return as much organic matenal as posSJble to arable upland SOils but It should be free from tOXIC contaminants, and the costs and problems of collecting and spreading should be SOCially and economically acceptable

Avoiding Erosion

ErOSion IS a natural process and IS difficult to eliminate _completely However, on cultivated land there IS a real nsk of accelerated erosion If the natural vegetatrve-cover of the soli IS compatible vvth the cultivation of large areas by machinery Trees used as Windbreaks to control SOIl erosion by the Wind are usually essential in dner areas of light textured Salls, as are contour bunds and channels deSigned to drain away runoff water in areas subject to erosion by water, Other techniques such as tied ndge cultivation and alternate StriP cropping can also be effectJve for erosion control

Avoiding and Rectifying Soil Degradation

The maJor, fonms of SOil degradation are displacement of SOil (water and Wind erOSion), and detenora\lOn of soil Without displacement, which usually Involves both chemical and phYSical properties Chemical degradation Include, loss of nutnents and organic matter, aCidification associated With removal of nutnents or misuse of fertilizers, Increased leaching by SOil exposure due to removal of vegetative cover, Increased temperatures and OXidation of the SOil organic matter due to exposure and cultivation, salinization and sodlcallon often associated vvth inappropnate I",gallon practices and Inadequate dralnage'and pollution from Improper managemenf of Industnal and mining wastes PhYSical degradation Involves crusllng, compaction and waler-Iogglng Other forms of degradation Include the problems of sallmzatlon and sodlcallon or alkal,n,zabon Sod,cat,on causes dispersion of the clai and inhibits water movement Into and through the SOil Whether or not the effects of SOil degradation can be eaSily corrected depends on the extent to which the problem has developed ThiS, In turn, may be controlled by good 5011 management Some SOils are more resistant to certain forms of degradation than others, and the ease for the" management (Figure 2)_

Process of Land Degradation

1 Vegetat on ~ ~ Water (""gatlon) i '

Over + t razing Fires Deforestation VYate[logglng _ Sallmty

1-1-----....j.I"'~vegetatlon Degra*atlon .... ~-l-I------li SOil Cultivation _'SOM Loss _t ErOSion Land Degradation

t---___ -*ertlhty .....s<II! Quality

comp~ct!'hty ,_jrQdlblltY,

Fig 2 SchematiC diagram of land degradation processes

69

Chemical Changes &: Nutnent TransfonnatlOn In SodldPoor Quality Water Imgated SOils

, ' Rectifying Chemical Degradation

/ Chemical degradation due to nutnent removal," crops cannot be avoided for the ma,onty of salls It

can, however, be readily corrected by use of fertilizers or manures, or both Another form of sOil degradation IS

associated Wlth the cultivation of salls which are poorly drained, or where the water table ~,S close to surface Salts and sometimes potentially tOXIC Ions such as boron may be earned',nto fields with Irrigation water Unless there is adequate drainage, and sufficient water is supplied to wash out excess salt and undesired Ions, salt Wlil accumulate and reach phytotoxIc levels This problem IS commonly found In areas where dams have been constructed, and areas below the dam which receive Imgatlon water, Th'e water stored behind dam IS also hkely to raise water tables In areas below,the dam In sahne groundwater'areas thiS may not only induce salinity but will make drainage of the area receiving lITIgation more difficult In addition to salinity, sodlcatlon can be a senous problem ThiS IS not necessanly associated With poor drainage, but anses when Imgatlon water With hogh content of sodium IS used, or when sea-water flooding occurs Sodium displaces other Ions In the exchange complex, and at about 15 percent of sodium saturation the clay Wlil disperse ThiS makes the SOil extremely difficult to manage for crop production as it becomes extremely sticky when wet, cloddy when dry, and the smaller clay particles Wlil tend to move down the SOil profile, II proceSs sometimes known as Internal erosion ThiS leads to extremely ,compact SUbSOil, In which water movement and root development are largely inhibited Many saline Salls are also alkaline due to the presence of sodium carbonate, but these do not show the features of SodlC Salls because soluble salts prevent dispersion of clay Management of sodlc Salls Involves addition of gypsum, which prOVides a concentration of calCium sulphate In ~the SOil solution sufficient to flocculate the clay, thus giving rise to a more eaSily manipulated structure, Tne calCium Will also gradually displace sodium from the exchange complex, so ellmlnatong the cause of the condition

Avoiding and Rectifying Physical Degradation

Deterioration of SOil structure IS the commonest form of physlca" degradation It Involves loss of stabll,ty of aggregates In surface Salls leading to crusting and compaction, and consequently poorer Infiltration rates, greater run-off, erosion and translocation of clay partJcles~to subsurface layers LOSS of porosity In the subsurface SOil layers leads to loss of water transmiSSion and storage capacity PhYSical degradation of SOIl IS most commonly found where heavy machinery IS used to clear and cultivate the SOil Pro~lems occur mostly," Salls of ontermedlate texture and low organoc matter content, particularly sandy and Silty loams Difficulties can be aVOided by usong no-till and mulch farming techmo,ues, and careful atient,an to re~tnc;t cultivation at limes when SOil IS too wet as wet cultivation readily damages the structure~ Maintaining a relatively high organic matter content can oncrease SOil aggregate stability, although even high organic matter ~olls are also subject to damage by wet cultivation

Practice of Good Soli Management

The pnnclples of good SOil management are unJVersally applicable The practices wh,cn embody those pnnClples vary qUite Widely accondlng to speCific SOil, climate and other environmental cond,lions Productive capacrty of Salls IS being degraded as a result of decreaSing organic matter, detenoratlng structural condillon, or declining nutnentlevels In maJonty of the humid trop'cs perennial crops systems, though all palm, rubber, cocoa, bananas and plantations ifave been grown for many years throughout the humid tropIcs The crops prOVide a cover for the SOil and usually return suffiCient reSidues to maintain a sallsfactory organic matter level In arable cropping systems, dominant Salls of the humid troPICS are often Simple to manage as far as thelf phYSical properties are concerned They have relatively stable aggregation and are free draining However, effiCient drainage and high ramfall means that they are often severely leached of nutnents, and are strongly aCid Hence, management of their chemical properties by caneful use of fertilizers and lime, combining tree crops With arable cropping systems IS Widely practiced These systems can be sustainable, depending on the effiCiency of the tree crop In recycling nutnents, 5011 organic matter and control of aodlty

In wetter parts of sub-humid trop'cs, plantation agriculture With perennials haS some limes been sustamable, whole the chemical condition of the SalliS usually better In the more humid areas where domonant Salls are usually phYSically weak, and therefore readily eroded, Alley !armlng, In which rows of trees are planted along the contour, and crops groWln between them, has been Widely promoted as a sustainable system for the sub-humid tropics In what must be regarded as a model system, rows of the fast growing legume Leucaena leucocephala are planted, and maIZe or cowpeas grown between the rows loPPing from the trees are used as a mulch to protect the SOil and prOVide nitrogen Although It IS Inevitable that the trees Will compete With the crop for water and nutnents, they, too have the potenllal to proVide an economiC retum Indeed, If thiS system IS to be accepted more widely then an economic return from the treeS'" addition to the If value In controllmg eroSion and bUilding SOil fertility must be an Important conSideration Indigenous agroforestry practices at present appear to offer a better baSIS for sustainable fanning 'systems for the semi-and trop'CS than alley farming, except on some larger farms where the alleys are of a size which allows mechanized cultivation between the tree rows Continuous arable fanning under no-till mulch conservation systems, and using fertilizers to maintain nutnent levels, IS certainly supenor to the plough-till system In terms

70

Management of Land Degradation 10 And and Semi-And Areas

ofproduc!lvity maintenance Although CtJrrent eV":lance Indicates that-Yu§lds decline under no-till systems, they do so more slowly than under plough-till systems It also appears that, at Intervals of several years, a break in cropping can rebuild sOil productivity II is not clear )IIhy this break should be necessary, but control of pests may be tile main reason For,the system as a whole to be sustainable, It reqUires that the 'fallow' crop offem some economic advantage, and a legume based pasture may be the best provided that livestock can be economically raised

Table Components of sustainable SOil management systems

Humid tropIcs ,Sub- Humid troprcs Semi-arid tropiCS Wetlands

Trees AVOid erOSion, Trees AVOid erOSion, Animals, transfer nutnents, TerraCing or recycle nutnents, mulch, recycle nutnents, prOVide manure bun ding, maintain OM, suppress mulch, malntam OM, retain water weeds suppress weeds Fertllzers mcrease Yield,

replace nutrfents Puddling minimIZe FertllZers Increase Yield, Fertllzers Increase draInage! control replace nutnents yield, replace nutnents _ 'Grassed contour striPS, weeds

hedgerows or bunds. control

Lime conlrol aCidity, Lime control aCidity; eroSion, prOVide animal feed Illigation replace Ca (and Mg) replace Ca (and Mg) supplement rainfall,

Raised beds control water on natural floods

Relay and '"tercroPPlng Green manure prOVide heavy clays mlmmlze soli exposure, nitrogen, maintain Ferthzers Increase control erosion organic matter! Tree WIndbreaks control yield, replace

minimize SOil exposure erosion by wmd nuillenls

TerraCing and conlour bundcng control erOSion, Contour bundlng Imgallon and dramage Surface drainage remove excess water control erOSion supplement rainfall, aVOid SOil remove excess

salinity and water-logging water

In the semi-and troPICS uncertain rainfall and long dry seasons make sustainable crop production difficult In the semi-and troPICS PastoralISm, rather than crop production, offers the greatest prospect of sustainabillty, ThiS ensures that the vegetation persiSts, and continues to prOVide the essential ground cover. In most parts of the and and semlalld the demand for food has meant that stocking rates have often exceeded sustainable hmlts! and arable cropping has continued to Invade traditional grazrng areas The extent to which fertility IS restored IS often limited Thrs has lead 10 falhng productiVity, sometimes partly arrested by the Inlroductlon of fertilizers to supplement the animal manure used on the crops In some ,"stances, shorter duration crop vanebes, e 9 sorghum, have helped to overcome water shortages by redUCing the length of trme tI1at the crop rS uSing water The demand for nutnents, however, is not reduced, Legumes nearly always reqUire an adequate level of SOil phosphorus, and so ferllllzer phosphorus has normally to be used together With a suitable legume, In order to maintain the productive capacdy of land In the and and semi-and a cropping system is required where the rate at which SOil fertility can be restored (under a rest crop) IS much Improved compared With the changes under native grassland Unfortunately, after many years of expenmentafion, there are only a few areas where cambrnatrons of grasses and legumes have been rdentlfied as sunable for sOil Improvement and grazing use

71

/ Nutrient Management for Sustaining Crop Production in Salt Affected Soils

/ Anand Swarup D,v,s,on of SOil SCience and Agncullural Chemlslry Indian Agncul/ural Research Insltlute, New Delhl- 110012

Introduction

Indian population Increasing at an alamung rate of around 1.9,% per annum IS proJected to reach the figure of 1 40 billion by 2025 AD To ensure food secunty for such a large ever IncreaSing population,. India needs to produce huge quantities of food grain, fodder and fuel There IS a little scope for bnnglng additional area under food crops because out of 182 2 m ha gross cropped area about 75 % has already been brought under cullivatlon of food crops Rather, area under food crops IS shnnklng due to diversion of, good fertile lands for non-agrtcultural purposes like urbanization, roads and Induslry However, we have about 6 73 million ha salt affected salls which are lYing barren or produce very low and uneconomical Yields of vanous crops due 10 excessive accumulation of salts This area IS expected to mcrease with spread of water-Ioggmg and salinity due to Increase in canal Irrigation without provIsion of drainage and Intensive exploitation of poor quality groundwater for agnculture In non-canal commands Based on sOil pH, exchangeable sodium percentage (ESP), concentrailon and nature of soluble salts and the reclamation procedure to be adopted, these saltaffected 50115 have been classified In two major categories VIZ. alkali (sodlc) soils and saline 50115 Nulnent constraints vls-a VIS management strategies for Improving and sustaining crop production and malntalOmg SOIl fertIlity are cntlcally discussed In the present chapter

Nutrient Management in Alkali Sl)tts

About 3 77 million hectares area IS severely affected by SOdlClty In the Indo-Gangetic plaIns Sodlc or alkali conditions alter availability of nulnents In Salls and generally cause either nutrient defiCiency or loxlclly 10

these Salls Fertility of these Salls WIth low nulnent reserves and thell altered avallabll~y IS confounded by the low supply of water and oxygen to roots In profiles With dispersive clays The mam problem IS of high pHIESP, high amount of calCium carbonate, very low amount of organic matter and poor phYSIcal cond,lions limiting nulnent availability and plant growth Crops grown on Ihese 50115 Invariably suffer nulntlonal disorders (N, Ca and Zn deficiency and Na loxlclty) resu~lng In low YIelds Crop production and fertl[fzer use effiCiency In tIlese SOils can be Increased by follOWing the reclamation technology involVing Integrated use of amendments preferably gypsum based on gypsum reqUirement of 5011, balanced and integrated use of chemical fertilIzers and orgamdgreen manures which help In maximizing and sustaining Yields, Improving SOil health and mput use effiCiency Rice based cropping systems like nce-wheat, nce-berseem and nce,mustard are recommended on these Salls

Organic Carbon and Nitrogen

Alkali 50115 are highly defiCient In organic matter which serves as storehouse of essenlial plant nutnents, especially available N Ihroughout the 5011 profile High exchangeable sodium (ESP >15), high pH (>85) and low biological actIVity, commonly assOCIated WIth above properties of these SOIls, are deterrent to the aCCUmulation of organic matter and ItS mineralization, Therefore, ItS effiCient management and maintenance assumes greater Significance (Swarup et ai, 2000) 10 salt affected 50115 Results have shown that long-term,balanced fertilizer use under nee-wheat system helps in mamlalmng the orgamc carbon status 01 these Salls Results further suggest that alkali 50115 have great potential for carbon sequestration (Lal and Swarup, 2004) Most crops grown on these Salls Invanably suffer from Inadequate N supply Moreover, "'trogen transfonnalions are also adversely affected by high p!-I and sodiC/ty, thereby affecting the effiCiency of applied N through dnhanced losses

Numerous experiments have shown that recovery of fertilizer nitrogen normally ranges from 30 to 40 % for nee In alkali SOils. Proper management of fertilizer N IS thus necessary for better N use effiCiency Recovery of N can be stili lower because of the adverse physlco-chemlcal condrtlons In alkali SOils Under such SItuations, "'trogen use-effiCIency can be Increased by Integrated use of organic and Inorganic sources ofN

Phosphorus

Unculilvated barren alkalI Salls contain high amounls of avallaole (Olsen's exlractable) P ThiS IS pnmanly due to the presence of sodium phosphates, whIch are water soluble Water-soluble P Increases With SOil pI:! In all the major bench-mark senes of alkali soils in the Indo-Gangetic plains, and strongly alkaline calcareous sodlc Salls have the bulk of 5011 P as Ca-P (54%) and reSidual inorganic fractions (28%) Olsen's extractable P of surface 5011 decrease due to Its move,ment 10 lower subSOIl layers, uptake by Ihe crop and

Nutnent Management for Sustalnmg Crop Production In Salt-Affected Solis

mcreased Immobilization when alkali sOils are reclaimed using amendments and 9rowln9 nee under submerged conditions ,

The cnllcal values of response of crops to apphed P vary greatly With the nature of the SOil (clay content), stage of Its reclamation, imllal SOil-test value, crop to be grown and the type of amendment used for reclamation Results of a long-tanm ferlility expenment conducted on a gypsum-amended alkali SOil (texture loam, pH 9 2, ESP 32) With nee-wheat and pearl millet-wheat cropping sequence and NPK fertilIZer use showed that phosphorus applied at a rate of 22 kg P ha-' to either or both nee and wheat crop In rotation Significantly Increased the grain yield of nee when Olsen's extractable P (0'15 ern SOil) had decreased from the Initial level of 33 6 kg h~" to 127 kg P ha", which IS very close to the Widely used cntlcal SOil-test value ~f 11 Z kg P ha" Though wheat responded to apptled P when available P level decreased to a tow of 87 kg ha , and pearl millet did not respond t? apphed P even at thiS level of cntlcal SOil-test value ,RICe and wheat responded to P apphcatlon In pynte-amended alkali clay-loam SOil (pH 93, ECe 3 42 dS m ,CEC 20 1 meq 100 g-' and ESP 46 7) testing low In available P (463 ppm) These studies Indicate that recommendations for P fertlhzallon in alkah salls should be based on SOil test Single superphosphate (SSP) IS" belter source of P than other phosphatic fertilizers because of high Na of alkah SOils and as It contains appreCiable amount of calCium sulphate Redent studies on Integrated nutnent management showed that continuous use of fertilizer P, green manunng and FYM to crops slgnlficantly:erihanced the yields of nce and wheat and Improved available P status of the gyp~um amended alkali Salls

Potassium

Alkah Salls of Indo-Gangetic plains generally oontaln very high amounts of available K Studies so far Indicate that Ihe crops do not respond to apphed K even 'after 20 years of nee -wheal anct pea~ millet-wheal cropping systems In alkali Salls Lack of crop response IS attnbuted to the presence of K-beanng minerals and their dlssolullon and large contnbutlon of non-exchangeable K (> 90%) towards total K uptake by the crops Potassium appllcallon Increased K uptake of plants and reduced the release of K from non-exchangeable reserves from 95 10 70 % The decrease was about 51 % With the use of K combined With organiC manures The quantity intensity (QII) relationship remained virtually unaltered after continuous cnapplng Due to low leaching, a large portion of applied K remained In the top 30 em SOIl

Micronutrients

Atkall Salls are suffiCient In lotal zinc but generally defiCient In ItS available fraction Onty 3 3 % of the total Zn IS attributed to the exchangeable, oomplexed, organically bound and occluded forms, which are conSidered to be available dunng crop growth Thus zinc defiCiency IS very common In nee and Its defiCiency symptoms appear in the ea~y growth stages (21-25 days), which delay matunty and reduce Yields Therefore Significant response of crops 10 its apphcatlOn IS observed on alkah soils Application of 9 kg Zn ha' (40 kg zinc SUlphate) eliminated Zn defiCiency In nae grown on alkali Salls treated with gypsum, pyrrtes, fanm-yard manure (FYM) and nee husk and raised the available Zn slatus of the SOil to a level which is adequate to meet the t reqUirement of 2-3subsequen crops With the application of FYM and Sesbanla green manure It was POSSible to prevent Ihe occurrence of Zn defiCiency In nce grown on alkali Salls Organic amendments like press mud, poultry manure and fanmyard manure could effectively supply ZinC to nce from native and applied sources In a saline sodle soil.

The alkali Salls are nch In total Fe and Mn but are generally poor In water-soluble plus exchangeable and redUCible fonms of Fe and Mn. There exists negative relationship between pH and Fe-Mn availability, SOluble Fe and Mn salts when applied to alkati soils are rendered unavailable because of rapid OXidation and, precIpitation, and their recovery by sOll-test methods IS very low, Thus higher addition of Fe and Mn salts IS, needed to correct the defiCienCies or to have benefiClal effect on crop growth Transformation of Fe and Mn In, alkah SOils IS very strongly Influenced by organic malter under submerged condillons, pH per se being relallvely less Important ThiS IS pnmanly because of Intensely reduced conditions (drop In redox potential) and enhanced PC02 created by organic matter under submerged condllions In nee culture Addition of FYM, nee husk and green manures had a marked effect '" Increasing the extractable Fe and Mn by 10 to 15 times" With corresponding decrease In reduClble forms Available Fe and Mn and nee yield Increased Significantly. When alkali Salls were flooded for 15 and 30 days before transplanting nce, the effects being more. pronounced at higher levels of ESP However, benefit of Iron application to rice could be realized In sodlc Salls only When rt was apphed along With Zn.

Adoption of nee-wheat system ·for more than two decades on gypsum-amended (ilkall Salls resulted In decline of the DTPA- extractable Mn.to a levet.of.27 ing kg", where wheat responded to manganese !UIPhate application at a rate of 50 to 100 kg ha'. Substantial leaching tosses of Mn occur fo"~wlng gypsum

Ppllcallon In alkali solis Fohar apphcabon of Mn gives betler results than salt application. Nutrients such as B and Mo are not likely to be limiting factors for plant nutnbon In atkall Salls, though at higher concentrations they could prove tOXIC However, once the alkah ,Salls are amended With gypsum/pyrites and leached, cancentrabons of these elements in solution drops to wrthln safe limits and remain nO'longer toxic to plants

73

Chemical Changes & Nutnent Transformation In $odlc:lPoor auallty Water Irngated Soils

/ Organic and Green Manures vis-a-vis Integrated Nutrient Management

'" Nutrient Imbalance created by continuous use of plant nutnents particularly N alone or combined with suboptimal rates or omisSion of other nutnents (especially P and Zn), is the pnmary cause of non- sustainable Yields in'alkall SOils Sesbama green manunng or the use of farmyard manure Improves the orgamc carbon

"and"N status of SOil and crops Yields especially when combined With gypsum, But the use of inorganic N fertilizer showed hardly any residual effect Long-tenn field_ studies conducted on a ~ypsum-amended alkali SOil showed that Incorporation of Sesbama aculeata at 50 days produced 3 85 Mg ha- year-' of dry biomass, which In tum contnbuted 110 kg Nand 11 kg P ha-' year' and Increased significantly the grain Yield of nce and wheat With average Increase being 1 48 and 067 Mg ha', respectively Even If half of thiS N IS available to the crops, a green-manure crop could substitute for 50 to 60 kg fertilizer N ha-' Application of 40 kg N ha' along With ~reen-manuring gave nce yield eqUivalent to 120 kg N ha" Without green- manunng thereby saving 60 kg N ha' , Green-manunng With Sesbanla significantly Increased the organic carbon and available nutnents '(N, P, K, Ca, Mg, S, Fe, Mn and Zn) and promoted uplake of these nutnents by nce and wheat crops The advantages"of Sesbama green manunng In highly detenoraled alkali SOils reclamabon included Increase In

crops Yields and N contribution "when It was decomposed for' one week under submerged conditions before transplanting of nce,

Recent studies on Integrated nutrient management showed thai rice and wheat Yields Significantly Increased With Integrated use of green manure or FYM and 100 % recommended Inorganic fertilizers (N12O 1'261<.. kg ha-') as compared to tOO % recommended Inorgamc fertilizers alone Yield of nce COUld, be maintained even b~ applYing lower doses I e" SO % of recommended dose of Inorgamc fertilizer apphcabon (Noo P" Kz, kg ha-') when used In coni unction With FYM (10 t ha") or green manunng Growing of In Situ green 'manure or application of 10 t FYM ha" saved not only 60 kg N_ and 13 kg P ha-I as Inorganic fertilizer In rice but also Improved ferilhty of 5011

Nutrient Management in Saline Soils

In India about 2 96 mil han hectares are lYing barren due to problems of watertogglng and SOil sallmty Out of these 1 146 million ha lie In vanous canal commands Saline Salls are Ihose Which have excessive amounts of soluble salts, (ECe>4 dSm-', pHs < 85 and ESP <15) These SOils predomlnanlly have a high concentratIOn of chlonde and sulphate of sodium, calCium and magnesium Many times these SOils have shallow water table representing brackish groundwater, which may be the major cause of salinity due to capillary rise under and and semiarid climatiC condlbons ProvIsion of adequate subsurface drainage to lower the depth of water table and to facilitale leaching of salts has long been recognized as fundamental to the reclamallon and management of sahne soils Dunng leaching of these SOils release of SOil nutnents espeCially N, P, K, Ca, Mg and Mn and their loss to Ihe ground water have been reported Moreover, the chOice of crops t" be grown In sahne SOils under reclamation IS also 0\ paramount Importance, Since different crops differ widely In their tolerance to sallmty

Nitrogen

Nitrogen IS the most IImltll'g nutnent for crop production In saline SOils as they are poor In N status and organic matter Volatlhzallon IS a malar N loss mechamsm that reduces the effiCiency of applied N Volat,l,zallon losses Increased With Increase In salinity VolatiliZation losses of N from nce fields Increase by about 100% when SOil sahmly (ECe) Increase from 4 to 8 dSm-' Appllcallon of N through ammonium sulphate shOwed highest amount of loss being '37.4 per cent at'soll sahnlty 01 6 dSm"', whIle fertilizer placed In SOil (UPP-urea in paper pack';J'and UB -urea briquette) reduced losses to about 5-6 % Results also showed that sulphur coated urea followed by urea b'nquelte were more effiCient than pnlled urea 'for nce Poor nltnficallon rates of NH:_- N at high 5011 salinity was chiefly responSible for _hlgher volatilizatIOn of N from saline SOil Apart from antagomsllc effects of high amounts of cr and sol' on the absorption of N03 in waterlogged saline soils, poor aeration and anaeroolc conditions may restnct the availability to and absorption of N by plants leading to low efficllency of applied ammomcal fertilizers Further, high concentration of salts inhibits Mnficatlon and results In ammomcal nitrogen accumUlation (Swar\lP, 1994) Due 'to these reasons, It IS belter to u-se N03-N fertilizer as compared to NH4-N In saline Salls, Plants face high water stress In saline environments which further reslncts the proper metabollsatlon of the absorbed nllrogen These factors along with higher leaching losses of NO, dunng reclamation of the sahne SOils results In low availability of N 10 the plants and therefore mtrogen reqUirement of crops IS higher In saline Salls than In normal Salls

Phosphorus

Available P status of saline SOils IS highly vanable Phosphorous avallabll~y does not show any regular lrend In relation to SOil salinity probably because of the vaned concentration of neutral soluble salts of Ca, M9 and Na in the expenmental 5011 These may displace exchangeable Ca and change the iOniC composition of the soil solullon thus Influenong the extraction of SOil phosphorus Availability of P increases up to a moderate level of salinity but thereafter It decreases Application of P Significantly enhanced the Yield of mustard, wheal aQd peart-millet"the effects beIMg more pronounced at high 5011 salinity Increase In sahmty

74

Nutnent Management far Sustaining Crop Producban In Salt-Affected Solis

decreased avarlable P concentration and uptake by the crops Absence of P in the drain water effluent and available P status of the sOil profile after crop harvest indicated very slow movement of P, the large portions being retained by the top sOil (30 em) thereby drastically reduce the chances of ground water pollution through ' phosphOf\lS fertilIZation. Avaltat:lIlity of fertilizer P In the sOil may be mod.fied by so.1 salinity due to higher preClprta~on of added soluble P I

potassium .r

Ava.lable K status of saline salls IS high InI~ally but after continuous leach 109 and cropping It declines to a level where crops respond to Its application Application of K fert.llzer In saline sOil IncreaSes crop Yields In several ways (.) by directly supplYing K, (II) by Improving tolerance of plants to Na uptake (III) by Improving water use effiClency, (IV) by Improving N use effiCiency Plants grown under high salinity may show K defiCIency due to antagonistic effect of Na and Ca on K ~bsorptlon and lor disturbed NaiK or CalK ratio Under such conditions, application of K fertilizer IS likely to Increase Yields Studies showed that application of K enhanced Yield of pean millet and wlle"t, and also reduced the contnbullon of non-e<changeable K towards K uptake by plants The contnbubon of non-exchangeable K towards total K uptake was 97 per cent In plots receiving no fertilizer K whereas K application at 2t and 42 ~kg ha-' reduced It to 83 and 71 per cent respectively Pearl millet was more exhaustive of K than Wheat. ThiS Implies that continuous cropPing With higher level of K along With Nand P would result In rapid deplebon of K reserves thereby rendenng the SOil poo"n K fertility

ThiS suggests that unless K fertility IS maintained, yield Will remall' at low levels rather Will show declining trend Presence of K In the drain effluent (3 2 to 8 2 mg K L-') and higher level of available K Into the lower SOil depths Indicated continuous release of natIVe and applied K from saline Salls, thereby contnbutlng towards higher K content of groundwater In the VICinity of saline areas K concentration and salInity of drainage effluent were lower dunng rainy season (July-5eptember) than In winter (November-March) and summer season (Apnl-June) Leaching losses of native and applied K were also confirmed In laboratory column expenment when a highly saline SOil (ECe 43 dS m-') was leached With good quality water (EC 03dS m-') maintaining a constant water head In the column

Micronulrients

In a micro plot field study effect of mlcronutnents namely, Fe, Mn and Zn and the" combmatlons was studied on Yields of wheat and availability of mlcronutrients In a reclaimed saline SOil With sub-surface drainage system (ECe 5 5 dSm-', organic carbon 0 36 per cent, DTPA extractable Zn 0 56 mg kg-', Fe 4 3 mg kg~'. and Mn 265 mg kg-" Results showed Significant mcreaSe In grain Yield follOWing Zn and Mn fertilization Highest Yield was obtained when both Zn and Mn were applied_ However, application of Fe had no effect on YIelds of crops grown After crop harvest recovery of added I'e, Mn and Zn was 25 t, 23 7 and 17 1 per cent, respectively

Nutrient Interactions and Balanced Fertilization

Nutnents InteractIOns play an ImportanIroie for sustaining crop production In saline SOils Studies on nutnent interactions showed that Nand K Interacted Significantly on wheat yield, N concentration, uptake and recovery HIgh dose of N alone had a depreSSing effect on Yield Application of K had Significant effect on Yield at all levels of applied N IncreaSing rates of Nand K enhanced Significantly Nand K concentration and uptake_ In fact, the much hrgher N and K uptake With the hrgher K rate Indicated that there might be a complementary uptake effect between Nand K It was concluded that K+ enhanced NH: assimilation In the plant and that K' dId not compele With NH' in the absorption process of the plants The recovery of Nand Nuse effiCiency mcreased With K application at all levels of applied N and more so at the highest K rate These results thus suggest the Importance of adequale K for effiCIent N use Interactions between nitrogen and phosphorus and between phosphorus and polasslum were sigmncanl However, increasing rales of P and K Significantly enhanced N concentration ,n grain and straw and uptake by pearl mIllet and wheal, the effect being more pronounced when both P and K were applied together The highest uptake of N by peart millet (122 kg ha') and wheat 159 kg ha-') was attained at the highest P and K rate In fact, the much higher N uptake WIth the highest P and K rate indicated that there might be a complementary uptake effect between N and P and Nand K ThIS IS pOSSibly because of a more balanced use of SOIl nul"ents In the presence of ~'i7suate phosphorus and potassium for efficlenl N use by crops In salme SOils Drain effluents did not have

4 and NO,-N, thereby indicating little danger of ground water pollution as a result of leaching of nitrates

Bibliography

Swarup, A. 1994 Chemislry of sail affected Salls and fertIlity management In Salinity Management .for Sustainable Agnculture, (Eds) S K Gupta, S. K Sharma and N K Tyagl PP 18-40 Central SOil Salinity Research Inslrtule, Kamal

Chemical Changes & Nutrient Transformation In SodlcJPoor' Quality Water Imgated SOils

, /

Swarup, A 1998 SOIl fertility problems and their management ,In Agricultural Salinity Management In India (Eds) N K Tyagl and P S Mlnhas pp, 145-156 Central SOil Salinity Research Institute, Kamal

Swarup, A/.j998 Emerging SOil fertility management Issues for s~stalnable Irngated crop production systems , 'In Long-Term SOil Fertility Management through Integrated Plant Nutnent Supply Eds A Swarup

et al pp 54-68 IISS, Bhopal

Swarup, A" Manna, M G and Singh, G B 2000 Impact of land use and management practices on organic carbon dynamiCS In 50115 of India, In Global climate change and Tropical Ecosystems pp 261-281, (Eds) R Lal, J M Kumble and B A Stewart GRG/LeWis Pl.lblisher,Bocc Raton, FL'(USA) ,

Lal, K and Swarup, A 2004 Effect of afforestallon and fertilizer use on functional pools of carbon In alkali 5011, In Extended summanes Intematlonal Conference on Sustainable Management of Sodic Lands, Lucknow, Feb 9-14,2004 pp 212-14

Swarup, A 2004 Chemistry of sodlc Salls and fertility management In Advances In Sodlc Land Reclamation Intematlonal Conference on Sustainable Management of Sodlc Lands, Lueknow, Feb 9-14, 2004 pp 27- 52

Swarup, A and Yaduvanshl, N P S 2004 Nutnent stress management for sustaining eroR production In saltaffected Salls Bulletin No 1/2004 CSSRI, Kamal.

76

Long-term Fertilizer Effects on Fertility of Soils and Productivity of Cropping systems

Ana(ld Swarup DIYlslon of SO/I SClf!lnce and Agncultural ChemIstry , Indian Agncullural Research Inshtute, New Defhl - 110012

Introduction

Indian agnculture IS passing through a cntlcal phase 10 thIS era of globalization and ItS complexity IS confounded WIth dire need of Increasmg crop production, sustainability and environmental quality Issues Answers to these questions can be sought by the long-term expenments which are valuable repoSItories of Informabon regandlng the sustainability of Inlenslve agrlcullure Many factors Influence the complex chemical, phYSical and biological processes which govern SOil fertility and productIVity Changes in fertility caused by imbalance use of fertilizer nutnents, aCidification, alkallnrty and declining 5011 organic maUer (SOM) may take several years 10 appear. These properties In tum can be Influenced by external factors such as atmospheric pollution, global climate changes or land use management practices Long-term expenments proVide Ihe best pOSSible means of studying changes In SOil properties, nument dynamiCS and processes and Idenllfymg emerging trends In nutrient Imbalances and their defiCienCIes to formulale future strategies for maintaining SOIl health In fact, agricultural sClentlsls have recognized Ihe SIIes of long-Iemn Ina Is as Invaluable tools In the study of agro-ecosystem dynamics But. the renewed emphaSIS on such stUdies has ansen from the growing notion that 'certam SOil processes are baSically of long-Ierm In nature and must be studied as such" In vIew of groWIng Importance of long-term expenments for addressmg current and future agricultural and environmental Issues Dawe et al (2000), Powlson et al (1998), Swanup (2001), Swarup and Wanlan (2000) and Swarup et al (t 998, 2000) made extensive efforts to reView and document available data on (I) Yield trend analYSIS, SOil properties and key sustaInable Indicators such as ,Organic carbon and pH under long-term experiments which can not be measured from short term stUdies and (II) Identified regional fertlhty constraints and opportunitIes to mcrease agncultural productiVity through mlegrated plant nutnent supply ( Swarup and Gaunt, t99B) These experiments have prOVided very valuable data which are highly relevant for farmers, sClen~sts and poliCY makers The outcome from these expenments IS discussed here as under

Effects of Long-tenn Fertilizer Use on Soil Health and Crop Productivity

The responses to fertIlizer nutnents were in the order of NPK>NP>N but the degree of response to indIVIdual nutrien!s vaned WIth the loeatlons The rate of response declined In some cases sharply WIthin a penod of few years whereas at some other Sites, the decline was slow and gradual The dechne was more when high y,elds were obtained continuously for a number of years with hIgh dose of NPI( fertilizers, causing a severe draIn of other essentIal plant nutnents from the SOIl which became limIting factors for crop productIOn

Continuous use of N alone resulted 10 reduced Yields of crops at all the centers except at COlmbatore, Ludhlana and Pantnagar and had deletenous effects on long, term fertility and sustainabillty, Indlca~ng that other major and micro nutnents were becomIng limitIng and adequate response to N could not be obtamed unless those factors limiting Yield were taken care of The decline ,n Yield With. N alone was mosl spectacular at Palampur, Ranchl and Bangalore. Incidentally, Ihese are also the aCid Salls where there were severe defiCIenCies of both P and K Localions havmg Verbsols or Vertic Ustrochrept type of soils such as at Jabalpur and COlmbatore, P deflclem:,~ IS 00 se~e'e that ","th"u~ Its appil<:atlon crop ~Ie\ds _'e e~\reme\y poor and the benefits of N and K application were not realized at all

R Super ImpoSlllon of lreatments al Panlnagar showed benefiCial effects of S, Zn and FYM application 1 esponse 10 Zn IS clearly eVIdent al Ludhlana also Thus the addition of Zn and S becomes essential afie, a ew cycles of IntenSive croppmg at most 01 the locatIons Thus next to N, P and K, the defiCiency of Zn and S :~ :so becoming the major yield limIting factor In most of mtenSlVe croppong systems and appropnate changes Ih rtJhzer use policy are needed for sustaining high productIVIty Up to a number of years the responses to coe ~reatment NPK +10/15 t FYM ha·1 were as good as NPK atone appllcabon at 100/150% However, Ire n

t nuous use 01 these trealments started shOWIng less response to NPK alone in comparison to NPK+FYM

we" ment after some years ThiS indicates Ihat some mlcro-nulrlenls or secondary nulnents like Zn and S qu::' ~~ecomlng YIeld hmillng factors These numents are prOVided by FYM beSides supplymg addilional 'e n es of NPK and ItS effect on the phYSIcal properties and biological condlilon of soli II has to be K.,~nlzed thai 15 t FYM of an average quality can add annually 75-100 kg N, 50-75 kg P20, and 170-200 kg locat

er hectare Farmyand manure thus helped In sustaIning the Yields of crops over the years at all the

Pan~ons and the results were spectacular In Alfisols at Palampur, Bangalore and Ranchl, In Molhsols at agar and In Vertisols at Jabalpur.

ChemIcal Changes & Nutnent TransfolTllation In SodlclPoor Quality Water Imgated SOIls

The effect of NPK+FYM treatment was most conspIcuoUS on maIze than on wheat In the malzewheat system at Palampur and Ludhlana In these cases the Improvement of physIcal condItIons of the sOIl and addrtlonal supply of nutnents (N, P, K, In and S) could have produced synergIstIC effects also Scheduling P"K"Zn and S applIcation to the more responsIve crops of the sequence should receIve attentIon As for Instance, In nce-wheat system application of P to wheat and that of K, Zn and 5 to nae IS mare beneficIal SImIlarly, applicatIon of Zn, 5 and FYM IS more beneficIal to maIze than wheat m maIze-wheat croppIng system However the residual effect of FYM was more,consplcuous m wheat at Palampur

, The residual and cumulatIve effect of FYM was also reflected In the enhanced productIon of SUbsequent

crops The elrect of NPK (100% optImal) + fanmyard manure (15 t ha') on crop YIelds m aCId SOIls (Ranch I and Palampur) was comparable to or often supenor to that of NPK + lIme IndIcating that to a certain extent the bene~ts of limIng were met by FYM which also has buffenng effect on SOIl aCIdIty cOrrectIon, as confirmed by changes m pH status a! Palampur and Ranchl Salls For attaining high y,eld potentIal liming has, to be a=mpanled WIth optImal doze of NPK In acid Salls of these two locations Recommended dose of NPK sustained hIgh productIVIty of cassava than FYM alone treatment m an aCId UIt,sol at Tnvandrum LIkeWise, NPK + FYM helped In sustaIned hIgh productiVIty of soybean and wheat over NPK or N+FYM treatment at Almora The results of the experiments at dIfferent tocatlons have clearly brought out the follOWing facts

• YIelds of crops decline WIth contInuous prolonged Imbalanced use of fertIlIZers

• Crops YIelds stagnate or decline WIth constant andlor sub-optImal Input levels

• Downward shift in the entire fertltlzer rasponse functIon at all levels of applIcations are indIcatIVe of lesser increase WIth same dose of plant nutnents and a need for applicatIon of higher fertIlizer doses to obtain same YIeld

• ApplicatIon of FYM over and above 100% of recommended NPK InVariably sustaIned hIgh productiVIty over the years

• Continuous croppIng WIthout adequate Inpuls decreases IndIgenous 5011 N, P and K supply

Conctusions

ImprOVIng and maintaIning SOIl fertIlity for enhanCIng and sustalnmg agricultural productIon IS of utmost Importanae for IndIa's food and nutritional secunty, Though IndIa is a food surplus natIon at present WIth about 218 mIl/Ion tones food graIns productIon per annum, ~ WIll reqUIre about 7-9 mll"on tonnes addItional food grams eaCh year If Ihe present riSing trend in populatIon persists ThIS challenge can be met by greater and more effiCIent use 01 fertilizers and organic sources The results from severat long term fertl/lzer expenments conducted m dIfferent agro-ecologlcal regIons mvolvlng dIversIfied croppIng systems and SOl' types have shOwn that imbalanced use of fertIlIZer partlcularty N alone had a deletenous effect on SOIl heatth and crop productIVIty DamagIng effects of appilcallDn of N alone In the absence of P and K fertIlizers vaned In different SOils In the order of Alfisols> VertIsols> Incepbsols > Moillsois In a penod of less than ten years crop productIVIty In N alone plots came to almost zero In Alfisols IntegratIng organic manure (FYM @ 10-15 Mg ha' WIth 100% recommended NPK fertIlIZer doses not only sustaIned hIgh productIVIty but also mamtalned fertIlity In most of the Intensive croppIng systems and SOIl types, The results further revealed that sOit type IS one of the most Important faclor affectmg fertilizer use effiCIency and crop YIelds Therefore, sustained efforts are neeoed to ITnprove and mamtam th15 most Important natural resource base - the SOil. through JudIcious integration of mmeral fertIlizers, organIc and green manures, crop reSIdues and blo-fertlllzers so that It nounshes IntenSive croPPIng Without being IrreversIbly darT)aged In the process

Bibliography

Dawe, D, Doberman, A, Maya, P, Abdulrachman, S, SIngh, BIJay, Lal, P L, LIn, B" Panaullah, G" Sanam, o , Singh, Y , Swarup, A , Tan, P 5 and Zhen, Q-X 2000 FIeld crops Res 66-175-1930

SWarup, A 2001 Lessons from Long-Term FertIlity Expenments, IndIan InstItute of SOIl SCIence, Bhopal,

Swarup, A and Ganeshmurthy, A N 1998 FM News 43(7)' 37-50 Swarup, A and Gaunt, John L 1998 Long-Tenm 5011 FertIlity Management through tntegrated Plant Nulnent

Supply pp 326-332 (Eds) Swarup et al IndIan InstItute of 5011 Science, Bhopal

Swarup, A and Wanjan, R H 2000 Crop'Productlv~y and Sustalnablilty In Three decades of All IndIa Coordmated Research PrC>ject on LTFE to study changes in SOIl Quality, pp 59 IndIan Insbtute of SOIl Science, Bhopal

Swarup, A Reddy, D and Prasad, R N, 1998 long-Term 5011 FertIlity Management through Integrated Plant , Nutnent Supply (Eds ) pp 333 ~ IndIan InstItute of SOIl SCIence, Bhopal

Swamp, A Manna, M C anel Smgh, G B 2000 In Global ClImate Change and TropIcal Ecosystems (Eds) R. lal et 81 pp 266-282 Adv, SOIl SCI (2000)

78

Input Use and Resource Conservation for Barley Production in Degraded Soils

A. s. I<harub Directorote oflMJeat Research, PBNo 158, Kama~132001. Haryana

Introduction

In India barley h~s been traditionally considered as poor man's and poor 5011 crop because of Its lo~ Input requirement and better adaptability to harsh enVIronments, like drought, salinity I alkalinity and marginal lands Area under the crop IS mainly concentrated In the states of UP. Punjab. Rajasthan. Haryana. M P and Bihar ,n plains and Himachal Pradesh. UHranchal and Jammu & Kashmir In the hills It IS mainly used as cattle feed and Industrial raw matenal'iii Ihese slales. In hillS. ba~ey IS Ihe main staple food crop In the tnbal areas and also utilized In preparation of the local beverages In addition to cattle feed, In the mc;ldern time It IS more popularly being preferred as mediCinal food ,." unnary as well as diabetes problems Ba~ey occupied nearly 06 m ha area prodUCing nearly 12m tones grain, With a per hectare productiVity of 2 0 tones Despite area reduction ,n ba~ey cuttlvatlon, productiVity gains through research efforts on vanetal development and' production technology were also lagging, Ba~ey·(HciIT1eum vulgare) IS a fast growing, cool season, annual grain crop that can be used as forage or as a cover crop to Improve SOil quality ThiS Old World plant has many valuable features Barley seed IS readily available and IS relatively cheap The plant has a deep. fibrous root system, a deSirable feature for erosion control and SOil quality Improvement Barley qUickly produces large volumes of biomass for Improving the 5011 organic mailer content 1\ provides weed and Insect suppression by helping to break pest life cycles Barley IS drought tolerant and can· be used In ram-fed agnculture Barley can be grown on many SOil types Including well drained, fertile loams and lighter clay SOils tt tolerates loamy to heavy soils but will not do well In waterlogged Salls It has very good heat and drought tolerance, making It a valuable plant for semland areas Barley IS also the most salt-tolerant among cereal crops It grows at 5011 pH between 5 0 and 6 3 It thnves In cool, dry conditions, Benefits of barley excellent for· erosion control by proViding a lasbng crop reSidue, very good for taking up and stonng excess nitrogen, Increasing organic matter and Improving SOIl structure, and suppressing weed growth, good for attracting benefiCial msects tolerates heat, moderate drought, and saline Salls, good feed source for all classes of IlVeslock, offenng good production, numlional quality, and palatability, SUitable for cool seasons, higher elevations, winter production at low elevatIOn Sites, Promising in tenns of vigor, rapid cover establishment, weed suppreSSion, low plant heoght, and lack of flowenng

Ba~ey IS useful as a reservOir of nutrients for the follOWing crop In rotations Barley's extensive rool system also helps to minimize leaching of nrtrates Into aqUifers, Improving walershed water quality The N taken up by the plant Will become available for the follOWing crop, resulting In less fertilizer costs for the fanner Incorporating barley Into the SOIl also Improves SOil 'health" by Improving 5011 structure, enhanCing SOil tilth and water infiltratIOn Although Its roots can reach as far as 6 ft down, most farmers Wilt see 5011 Improvement In the top 5011 layer The organIC matter additions, as the residues decompose, Will also encourage the formation of a nch, benefiCial microbial SOil Use of conservation tillage has been increasing over the past several years In different crops By maintaining crop reSidue on lhe SOil surface, conservation tillage may change the 5011 phYSical environment and resuiling higher productiVity and quality A very limited work on tillage has been reported In barley, Input use effiClency In. new ba~ey vaneties also Influenced by seed & spaClng, water, nutrients elc There IS stagnallon in productivity of barley in India due to decrease in effective nulnenl supply, organic matter status, Imbalanced use of other Inputs and less potential of eXisting genotypes Growing of barley in poorl saline Salls is also one of major cause of low productiVity -Integrated application of nutnents has manifold benefiClal effects Including storehouse of nutnents, Improve 5011 health, activate and Increase m,croblal populabon Nulnent management strategy may be based on prinCiples of eea fnendly, effiCient, balanced ferblizaMn and based on optimization" of nutnent supplies from all souroes, Inorganic as well as organic Enhanced productiVity of feed, malt and dual purpose ba~ey based on prinCiples of eco fnendly, effiCient and balanced Input use IS the broad objectives The Immediate objectives are to mcrease productiVity of feed and man barley by optimum Inpul use and to enhance malt and feed quality The slleCIfic objective IS to mOdify eXisting nutnent management systern, and improvement In soli management for sustainable Intensificabon of production system or in other words to enhance the productiVity and SUstalnabllity of fanmng systems through a better understanding of the pnnClples and practice of conservation agnculture,

Work done In India and abroad on tillage technology and Input use

Resource Conservation I Tillage

Foth (1974) reported that ploughing deeper than 4-6 In not reqUired but ploughing to 12 In gave a more uniform dlstnbulion of P and K In the top 16 In of soil Drew and Saker (1978) reported markedly higher ~noenlrabons of phosphate and K in the upper 5 em ofthe SOIl In direct dnillng, but at depths between 10 and

ern, the concentrations of K and particularly phosphate were lower than Wlth ploughing Root weight and

Chemical Changes & Nutnent Transformation In Sadie/Poor Quality Water Imgated SOils

, /

length per umt SOil volume In the upper 5 cm were also greater With dlrec! dniling than With ploughing Dudas and Pelikan (1916) studied the effect of cuilivation techniques and fertilizer apphcatlon on the malting quahty of barley greYIn In monoculture It showed that variety 'Diamant' was more sensItive to environmental conditions than 'Valtlcky' however 'Valtlcky' grain was supenor when produced by traditional methods but Without nutnent addition, the Improvement obtained With minimal til age Rll<on ,(19BO) reported 10% hllJher grain Yield In direct dniling than conventional mouldboard ploughing In winter wheat, but differed little for barley Concentration of nulnenls and more roots we're found In the surface SOil after direct dniling Themen and Grant (2004) conducted expenment on effect of tillage on malting quahty In barley and resulted that percent malt extract (MEX) was significantly affected by tillage, whereas malt enzyme levels (alpha amylase, AA) and enzyme acllvdy (dlastatlc power, DP) were n6t Genotype and enVIronment affected all three malting quahly traits, as well less fertilizer was required to obtain a target yield under ZT compared With that required under CT Rashid et al (1987) reported that the use of mouldboard ploughing and shallow tine cultivation led to decrease In SOil salinity and contents of Na , CI and sulfate dunng the wmter crop DUring the summer crop, shallow cuilNallon 'Has less effectN. than ploughIng

Webster and Nyborg (1986) sludled five tillage opllons In combination With two amendmenls and two crops on two Solonetzlc sites and continued for 6 yr Simulated deep plOWing Significantly (P _ 0 05) reduced SAR values for the 0- to 15-em depth (Ap horizon) to favorable levels With few exception For the other four tillage treatments (slmulateed normal tillage, Simulated shallow plOWing, chiselling and chlsellmg plus Simulated shallow plOWing), the non amended subplots had undeSirably high SAR values In the 16 to 23 range There was a trend for gypsum to lower SAR values of the 0- to 15-cm depth In masl cases to the 10 to 15 range and was usually more effective than lime There was a negative correlallon (P =001) between SAR and SOil aggregates < 6 mm In diameter and a positive correlallon (P=O 01) between SAR and SOil clods In the 25-to 76-mm size Simulated deep plOWing produced higher Yields of alfalfa and barley than"the"other four tillage treatmenls (P=O 05) The chiselling treatmenl produced the highest Yields of barley at thiS slle Gomma (1995) reported that 5011 bulk denSity was lowest and sol/ porosity hlghesl With subsOiling + mouldboard ploughing SOil salinity was generally lower With the subsOlling trealments Weed conlrol was most effective With a comblnaton of subsoiling + mouldboard ploughing Grain, Yield was highesl With mouldboard ploughing 10 either depth With or Without subsOlhng

RC Dalal (1990) In a long-term cultivation and cropping In vertsols up to 70 years resulted In reduced orgamc malter conlent, lower biological acllvlty (less mlnerallsable N), less aggreg"tlon and Increased exchangeable sodium percentage When continuously tilled SOil was brought under no-tillage, aggregation Increased and exchangeable sodium percentage declined In the surface layer (0-0 1 m) Chlonde contents and NaCI eqUivalent salts (0-1 2 m) In 5011 under no-liliage were reduced to almost one-tenth of the lilled SOil, resulting In better control of secondary salinity and subsoil salinity WIth no-tillage practice In vertisols Furthermore, no-tillage With crop reSidue retention and fertilizer application substantially Increased SOil organic malter and mlnerallsable N, even In a fine-textured vertlsol Sharma (1998) In a tnal With wheat grown on an alkaline 5011 reported that breaking the crust formed after Ihe lsllmgalion or after the 1st and 2nd Itrlgallons Wllh a hand-hoe under optimum mOisture condilions showed to mcrease rool growth and penetration, tillenng and ear length and gave belter grain Yields of 364 and 3 98 tlha, resp, compared With 3 10 t Without crust breaking Water use effiCiency In the 3 treatments was 79, 84 and 70 kg gralns/ em water per ha, respectively,

Anonymous (2008) evalualed the perfOimance of four vanelies, two each of 6-row (RD 2035 and RD 2552) and 2-row (DWRUB 52 and RD 2668) In three tillage systems (zero, reduced and ccnventlonal tillage) at Durgapura, ludhlana, and Kamal under AICW&BIP It was revealed from pooled data that there was no slgnlficanl difference 10 Yield In different tillage opllons, however, the highest Yield was obtained in convenllonal tillage followed by reduced and zero tillage Three vaneties (RD 2035, RD 2552 and DWRUB 52) were at par In different tillage options and Significantly supenor to RD 2668 The interaction effect was not Significant. Both 6-row vanetles were at par In different tillage opllons bul among 2-row vanetles, DWRUB 52 was superior In all tillage options Although eathead/m' were more In low Yielding vanety RD 2668 but more grams! ear in other high Yielding vanetles resulted In more grain Yleld_ The heclohtre weight was not affected by tillage options but It IS higher In DWRUB 52 as compared to other vanelles The percentage of bold grains were found to be higher In zero tillage as compared to conventional, conveISely, the thin grains were less In zero tillage and more In conventional Protein contenl was found to be more under reduced tillage and 2-row vanetles were supenor under reduced and conventional whereas all vaneties were at par under zero tillage ludhlana and Durgapura gave higher proleln % as compared 10 Kamal, At ludhiana, zero tillage gave the highesl Yield whereas al Duragpura and Kamal, conventional practice had an edge over zero tillage

Malhi at 8/ (1988) reported that zero IllIage consistently resulted In reduced tillage cosls In reduced barley Yield It IS indicated that zero ~lIage on the average was less economical than conventional IIIIage long-term e~ects; such as erosion control, changes In SOil structure and nutrients, or the Indirect consequences of Increased herbiCide use were not conSidered In the economic analYSIS

80

Inpul Use

Nutrient

Input Use and Resource Conservation for Barley Production In D~graded §OIls

Nulnent use effiCIency (NUE) refers to the prOportion of applied nutnent .. that are taken up by the crop In an ideal wortd, 100% of Ihe nutnents applied \youid be used by Ihe crop, but In the real wortd, much smaller proportion .. are typical The NUE IS dependent upon the nutnenl source, lime of apphcabon, methods of application and the specific nutrienl biological and chemical Interactions With Ihe SOil Higher NUEs Improves crop productivrty, enhances economic returns and mmlmizes envlronmental,mpacls Dudas (t991) sludled Ihe effect of Increased nitrogen doses on prolem content m the grain 01 spnng barley grown In monocullure and found a Significant Increase In gram proleln contenl as the N dose Increased The new variety KM1192 showed the besl response 10 N dose In lenns of protein conlent The relallve effect 01 the v-anous factors on proteIn content was as tollows' N dose 1862%, genotype 17 10%, cultivation technique 5801% and Interaction effects 627% Chauhan and Ram (1993) grown wheal on partially reclaimed sail al Kumarganj ,n Silty loam (pH 9 0, ECe 5 2 dsJm) soIl and showed Ihat no N + P, 60 kg N + 30 kg P, 120 kg N + (i() kg P or 160 kg N + 90 kg P produced grain Yields of 1 25,2 00, 2 50 and 2 00 tlha, respectively ,N and P uptake Were highest In ,treatments given 120 kg Nand 90 kg P, respectively, whereas NP use effiCiency was hlghesl where 60 kg N + 30 kg P was applied Grain protein; N, P, K, Mg and Na contents generally increased With N + P rate, but Ca content was unaffected Chauhan et al (1991) reported that applYing 120 and 180 kg N gave higher grain Yields than 60 kg, but there were no differences In Yield between the higher rates Grain Yield Increased Wllh up to 60 kg Plha N fertilizer Increased N, P, K, Ca and Mg contents and decreased Na contenl P applrcabon Increased N. P, Ca and Mg and decreased Na conlent Nand P uplake Increased With Nand P applications. and decreased WIth sallnrty Horst et al camed out investigation under greehouse conditIons, to study the effect of foliar application Wllh mlcronutnents to conrect the nutnents Imbalance caused by sal! slress conditions ,Resulls indicated that root dry weight and nulnent uptake of were negatively affected by high NaCI concentrations Application of mlcronutrlents showed posl~ve effects on growth and nutrient uptake ellher before or after the salinization lreatment It might be concluded Ihat foliar application of mlcronutrients could Induce tolerance to salinity Papaslylianou (1990) reported that stubble burning gave the lowes! Yield SOil OM and N were unaffected by treatments, while there were Inconsistent effects on P and K It was concluded that no general recommendations for stubble management can be made, and management should be adapled to SUlI prevailing conditions ' .

Anonymous (2006) studied Integrated nutnenl supply In malt and fe'i1d barley to Increase productiVity on sustainable manner The tlial was conducted With seven nutnenltreatments In two vanetles one each of maM (DWRUB 52) arid feed (RD 2552) barley at Durgapura, Hlsar, Ludhlana, Karnal The nulnent treatments were t 100% Inorganic fertilizes (IF), 2 75% IF +5t FYM ha", 3 50% IF+ 51 FYM ha'.', 4 75% IF +5 t FYM ha" +Blofertllizer, 5 50% IF+ 5 t FYM ha" + Blofertllizer, 6. 100% Ihrough FYM+Blofertllizer, 7, Absolute control II was revealed thai the hlghesl Yield was,observed on 'the 'treatment where 100% Inorgaflic fertiliser Was applied It was closely followed by 75% inorganic fertiliser appllcahon + 5 t FYM tha and both were sta~s"cal/y al par 100% orgaflic ferbllser appllcallon gave 15% less yield as compared to 100% inorganic nutrient supply Both Ihe vanelies (OWRUB 52 and RO 2552) were al par In Yield under all the lreatments of nutnents application Tlliers/m2 were found to be more un<!er Inorganic and Integrated use of ferolisers as compare to organic nutnent supply' whereas 1000 grain wt was higher under 100% organic fertiliser application The vanety 'OWRUB 52' was supenor to 'RO 2552' In hec!olJtre weight and bold grain proportion The bold grains were found to be more under Integrated nutrient supply Bolh the vanelles and nulnenl combinations were al par In prolem content but centres differs Durgapura gave the hlghesl protein content ~ollowed by Ludhlana, Zn and Fe content were found be more In malt barl~y as compared to feed ba~ey,

owever. there was no speCific lrend In nulnenl combinations

lITigation

1m Chauhan el al (1991) studied the effects of Irngatlon With saline water (2 2,60 or 12 0 dS m") and + ~~tlon at crown roollOillatlon (CRI) + flowermg. CRI + IllIenng + flowering + mllk-npe slage or, CRI + tillenng BI I h ntlng + flowenng + milk + douph slages on Yield and minerai nutntlon of wheat on sandy loam soil at gaC p~n, Agra Salinity at 12 dS m' reduced grain and straw Yields by >25 and 30%, resp , 4 or 6 ImgaMns M;e 8 and 34% higher grain Yields" resp, Inngatlon Wlth'saline water Increased Na content N, P, K, Ca and 1m ~nlents were nol affected by sallmty atS a dS m" bul were reduced al12,O dS m". IncreaSing number of In:a~ns ,Increased K and Na contents and decreased Nand P conlents Nand P uptake Increased With Wheat ed ~mgatlon frequency and decreased WIth salinity Singh and Saxeena (1979) In pol tnals With barley, COnduct an pea grawn in 3 SOils and Imgated With 12 waters of different quality haVing EC [elec!ncal grain/s IVlly] values In the range 05-6 dS m" and SAR [sodium adscrpllon ral1o] value .. In Ihe range 10-50, EC an~~;~ported that yields of all crops were decreased wilh mcreases In EC and SAR values The higher and cia s " values produced Ihe smallesl reduction In Yields of crops on sandy SOil, followed by loam SOil a sand: I 0 I. the reducIJon was smallest In barley, folloWed by wheat and pea Singh (1989) did field Inals on and lenlll~am soil at New Delhi, wheat cv Kalyari Sona, Brasslca luncea cv, Pusa Kalyani, barley cv Ratna

c:v Pusa-4 were given 1 pre-soWing ,mgatlon of good qua lily waler and Irngated after sOWIng wllh

61

Chemical Changes & Nutnenl Transformation In SodlcJPoor Quality Water lITIgated Salls

, , / - ,

saline water giving sodium adsolptlon rallos of (a) 0 9, (b) 5 8 or (c) 9 5 Wheat grain Yield was 4 57 and 4 34 t ha" for (a) and (c)j resp; corresponding barley grain Yields were 372 and 339 t B ,Iuncea seed Yield was 139 and 0,93 t ha' for (a) and (c), resp, corresponding len~1 Yields were 2.00 and 061 t Water use efficiency of wheat increased while that of barley, mustard and lentils decreased With increaSing salinity AgalW3l (1993) reported use of brackish water by spnnkler and dnp ImgatlOn recoroed conSiderably lower salt accumulation In the SOil profile Con~nuous use of saline or sodlc water for 8-10 yealS In south western Haryana on loamy sand SOil gave wheat Yield of 30004000 kg per heCtare, ~ - \

Seed and Its Germination

Seed gerrmnatlOn IS one of the most senous problems affecting crop stand and, ultimately, productiVity In saline and alkaline SOils The objective of thiS study was to assess and compare the effect of a presoaking seed treatment on seedling charactenstlcs (seed germination percentage, root and shoot length, root shoot ratio) and amylase a~vlty With soaked and unsoaked seeds of wheat (var UP 262) under salt stress condlllens a 35 (Control), 4, B, 12 and 16 dSm-l (Roy and Snvaslava, 1999) The resu~s'tndlcaled that seed gerrmna~on percentage, root and shoot length, root shoot ratio and amylase activity were Significantly reduced when salt concentrations were Increased, Presoalong seed treatments With chemicals such as sodium benzoate (50 ppm), calcium chlonde (100 ppm), and ascorPlc aCid (50 ppm) Increased seed gerrmnatlon, root ,and shoot length, root shoot ratio and amylase activity In seven-day-old wheat seedlings under five salt concentrations levels Amylase activity Indicating that presoaked seed treatment was effective In alleViating the adverse effect of salt stress Mallek (1998) stUdied the effects of sallmty on seed gerrmnatlon for several cereal vanetles (10 vanetles of durum Wheat, 5 vanetles of bread wheat, 6 vanelles of barley and 4 vanetles of tntlcale) grown 10 Tumsla. Six salt concentrations were used (NaCI 0 to 153 mM), covenng the Wide salt water concentrailon range The effects of NaCI on gerrmnailon were evaluated by two cntena radicle emergence from seed and leaf emergence ,from the coleopille tiP The results claSSify the different vanetles according to their salt tolerance germination as well as plantiet emergence can be conSidered ,as Indicators of sail slress tolerance for cereals al the firsl slages of development

Genotypes

Hamf and DaVies (1998) compared the relative salt tolerance of differentially salt-tolerant cultlvars of wheal, rye and barley grown al varying concentrations of NaCI 10 solution culture dunng germlnailon Increasing concentrailon 01 NaCI (60-150 mM) reduced the percentage of seed gelmlnatlng The Itnes of Hordeum sa"vum were generally less sensitive to the NaCI-lnduced reduction in respect of the character than Tntlcum aestlvum) or Secale cereale Bolle and Wells (1979) on non-lITIgated saline Salls 10 S Alberta reported that 6-row bartey outYlelded' 2-rovibarley, which out yielded wheat and oats The reduction In number of earslha on saline soil compared With adjacent non-saline plots was less In 6-row barley than In the other cereals More grains/ear were maintained on 6-row barley than on the other cereals under salinity stress, but the av grain wt was not differentially affected Although sallmty reduced germination of wheat mOre than that of other cereals, adequate stands were established and gennlnahon was not a major factor except when salinity stress was combined With sl>nng drought Under drought candillens on non-sallne 50.1, 6-row barley did not malntatn ItS Yield advantage over the other cereals There was a positive Interaction between osmotic and drought stress Ral (1979) In tnals during wtnter wrth 11 cv each 01 wheat and barley, Irngatlon with saline water of 4-12 mmho/em found no adverse effect on germtnatlon, growth and gratn Yields in the 1st year, but Irriga~on With >6 mmhos/cm decreased gerrmna~on and Yields of many cv in the 2nd year. In the 2nd year, saline water increased germination In wheat cv Sonallka, grain and straw Yields In cv HD 1955 and HD 2009 and grain Yields In cv S307 Among barley cv , Amber was most tolerant of salinity for all characters and can be grown With saline water of less than or equal to 6 mmho/em for a longer penod Dut! (19S8) showed reductlon,tn grain Yield under saline condllions was due to the decrease in number of the filled grains/plant and 10oo1)raln wt Salinity decreased leaf water potential (LWP) and the more lolerant cultlvars maintaIned a higher lWP

Nair and Khulbe '(1990) tested10 wheal and 6 barley cultlvars for response to SOil sallmty regimes of 0-16 mmho/cm Barley showed greatest resistance to salt stress Germination was reduced ,by 7% at 8 mho/cm in barley compared with 28% in wheat Both crops showed a substantial yield reduction at 12 mmho/em, but barley stili out yielded wheat by up to 50% Significant interactions between salinity level and cullivar were observed In wheat but not In barley Cv Sonallka Yielded less than HP1102, Wl711, WH186 'lnd WH202 which showed some salt tolerance, It IS suggested that the salt tolerance of barley IS linked to Its ablilty 00 resist the efflux of potassium Ions from the plant The Impilcabons of these findings for breeding salt tolerant wheat and barley cultlvars are discussed,

Anonymous (2005) studied the performance of test entry was evaluated against checks at three nitrogen levels (90,120,150 kg/hal in 2004-05 The effect of nitrogen was not Significant ,The entry and the best check were at par In Yield at all N levels and supenor to other checks On an average the highest Yield of 265 q/ha was recorded In best check KRL 99, Anonymous (2003) evaluated the performance of test entry was against checks 'at three nitrogen levels (30,60,90 kg/hal In 2002-03 and observed.that barley entry NOB

82

Input Use and Resource Conservabon for Barley Production In Degraded SOils

1173 gave highest Yield which was at par With best barley check RD 2552 Among wheat genotypes the test entry KRl 35 was supenor to wheat checks

Barley for Marginal and ProblemaUc Soils

The potential of barley for problematiC Salls needs better explOitation as there IS a lot of area under such Salls In country. In U P alone there IS more than 12 lakh hectares under saline - sadie Salls -Similarly there are reports from Haryana also about the Increasing problem of sali"'tY'in Rohtak\Hlsar and adrOl",ng areas In order to meet the demand for such areas the research worn In thiS field needs more systematic efforts, by way of germplasm evaluation and Improvement With proper screening The field screening for, salinity tolerance IS some times not reliable, ba~ically because of the sod heterogenertyJ patches and nonrepetitive performance To have more effiCient evaluation, we may have to look for the In vitro ~~reen'"9 for sallnlty- alkalinity tolerance to supplement the research efforts Also the dlfferenbal screening fo~'salmllY and alkalinity Will help In better genolypes development for each type of stress, whrch so far has been taken up together Efficrent rnput management rn these ~reas should be future research prrontles tn case of barley Improvement for saline alkaline Salls condlbons several vanelles have been developed rn country under the' AICW&BIP In Rarasthan, Bllara 2, developed In early seventres has been a popular vanety for saline sorls Srmilarly In UP, vanetles Irke Azad (KI2S) and K141-were developed for cultrvatron rn sat,ne-alkallne Salls of NEP Zone Includrng Bihar and West Bengal These vanetres though, were haVing tolerance. to sallnltyalkalrnrty, but were lacking the resistance to prominent drseases as well as were not able to bear the better managemenl The recently developed vanelles Irke RD2552 and NOB1173 are having high level of tolerance to leaf blrghts, rusts along wrth the better yield levels (Venma et 81 , 2007)

Table 1. Recently released barley vanetres for cultrvatron under saline-alkaline saris

ObJectives Vanety Year Productron Condrlron Area of Adaptatron

Saline/Sadie Ol88 Salls

1997 Irrrgated (TS & l S) NWPZ

RD 2552 1999 Imgated (TS) NWPZ, NEPZ

NOB1173 2004 Imgated (TS) NWPZ, NEPZ

NBarley-l(NDB- 209) 1999 Irngated (TS) Uttar Pradesh

NBarley-3(NDB 1020) 2001 Irrrgated (TS & LSI Uttar Pradesh

Source Research Bulletrn No 23, DWR, Kamal

Barley as Green Fodder for Dry Areas

Bartey has been tradrtionally used as a grarn crop for human consumptron and animal feed rn India It IS grown dunng the Winter season (Rabr) rn the northern plains as well as In northern hrlls, mostly under ralnfed or Irmrted irrrgatron condition on poor to marginal Salls In the recent years It has been observed that because of severe drought In the dner parts of northern plainS (RaJasthan, Southern Haryana, Soulh West Punjab and Western UP) there is an acute shortage of green fodder In the months of Novernber to January Since both berseem (TlTfol.um spp) and sugarcane top are mostly used as green fodder In northern India .n addliron to oats (Avena sal.va) ana all these require frequent rrngatlon, they can't be grown under water scarcity condition Barley can be utrllzed as a source of green fodder In such conditions The crop can be given One cut between at 50-55 days after sOWIng for green fodder and the regenerated crop can be utrlrzed for grain purposes Since both the 'green fodder and grarn can be utrllzed for anrmal fodderl feed purposes, the crop can be advantageous over oats, because of liS dual utilization as well as less water requirement as It needs only two to three iITigairons The mulb-Iocatronal experrments taken up under AICW & BIP (Barley Network) dunng Rabi 2006-07 and 2007-08, The results have Indrcated that two vanetles (RD2035 and RD2552) of barley can be used as dual purpose barley wrth good Yield of the green fodder (between 200 to 220 qlha) and the gra.n y.etd (25 to 28q/ha) from regenerated crop. (Anonymous, 2008)

Research Prlolitiesnssues

I, Efficrent mput management in problemallC areas 2 Use of resource conservation technrques for malt and feed barley under poor/salme Salls Yield, maltrng

quality, Irngatlon and nutnents

3 Integratec;t nutrient management in relation to malUng qualrty and yreld for malt and feed barley 4 Seed and spaCIng for malt barley genotypes

5. Input management for dual purpose baney for dry areas - seed, Irrigation and nutrrents 6 Improvement in nutrrllonal qualrty of feed, fodder and malt barley

83

Chemical Changes & Nutnent TransformatIOn In SodlclPoor Quality Water Irrigated So!ls

Bibliography , Annonymous, 2003. Annual progress report of barley network Directorate of Wheat Research. Kamal. India Anonymous' 2005 Annual progress report of barley networli Directorate of Wheat Research. Kamal India

o i . Anonymous 2008 Annual progress report of barley network Directorate of Wheat Research. Kamal. India Bole J B and Wells S A 1979 Dryland soil salimty, effect on the Yield and Yield components 01 6-row barley,

2-row barley, wheat. and oats Canadian Journal of SOil SCience 59 I, 11-17, Chauhan R P S, Pathak D C a~d Chauhan'C P S 1991 Nitrogen and phosphorus ",qUlrefTIents and lITIgation

schedule of wheat Irngated With saline waler {,ertlllserNews 1991,36 6,11-18 Chauhan R P S and Ram S 1993 Response of wheat to different fertility levels under partially reclaimed salt

affected SOil Fertiliser News 1993, 38 5, 51-52 ' Dalal, R C 1990 Changes In the properties of vertisols under different tillage and crop reSidue managemenl

Transactions 14th Intemational Congress of Soil SCience, Kyoto, Japan, August 1990, Vol VI 1990, 16-21

Drew, M C Saker, l R 1978 Dlstnbulion of nulnents and roots In a Silt loam Journal of the SCience of Food-and-Agncullure. 1978,29.3,201-206, '

Dudas, F. and Pelikan, M 1976 The effect of cultivation techmques and fertilizer application on the malting quatlty of barley grown In monoculture Rostllnna-Vyroba 1976, 22 2, 189-202

Dudas F 1991 Effect of Increased nitrogen doses on protein content In the gram of spnng barley grown In monoculture, Acta Unlversllalls Agnculturae, Facullas Agronom,ca 39. 1-2,89-96

Dutt S K 1988 SOIl salimty effects on the process of gram filling 10 barley (Hordeum vulgare l) vanetles Indian Journal of Plant Physiology 1988, 31 2, 222-27.

Foth H 1974 Effect of plow depth and lertlli~er rate on Yields of com, barley, soybeans and alfalfa and on SOil tests Research Report, Agncultural Expenment Station, Michigan State University, No 241, 6pp,

Gomma M R 1995 Evaluation of vanous degrees of soil tillage on wheat yield, assOCiated weeds and some SOil properties Annals of Agncultural SCience 1995, 33' 4. 1211-1224

Hamf M and Dav,es M S 199B Effects of salt on seed gerrmnallon In contrasting cereal cultlvars Pakistan Journal of Biological SCiences 1(4) 260-282.

Malhi S S; Mumey G; 0 Sullivan P A and HarkerK N 1988 An economic companson of barley production under zero and conventionalliliage SOil and Tillage Research 1988, 11. 2. 159-166,

Mallek MaaleJ E, Boulasnem F and Ben Salem M 1998, Effect of salimty on the gennlnatlon of seeds of cereals cuilivated ,n TuniSia Cahlers Agncultures 1998,7 2, 153-156

Naif K P P and Khulbe N C 1990 Differential response of wheat and barley genotypes to substrate-Induced salinity under North Indian condllions Expenmental Agnculture 26,2,221-225

Papastyllanou I. 1990 Effect of stubble management on barley Yields and SOil nutnents In a continuous barley cropping system In Cyprus Technical Bullettn. Cyprus Agncultural Research inslltute 1990, No 114 pl0

Rashid N M A, AI-Oman S M, Abdul Salam N M and Yasln SH 1987 The effect of conventional and reduced '1IIIage on the dlstributlOns of salt and nutnents 'In reclaimed sol/ Journal of Agnculture and Water Resources Research, 6 I, 1-22_

Roy N K and Srivastava A K 1999 Effect of presoaking seed treaiment on gemllnatlcn and amylase acbvlty of wheat (Tnticum aaslivum) under salt stress _conditions RACHIS (ICARD-!\) Barley and Wheat NewslaHer (1999) v 18(no, 2) p 46-51

Shanna D p, 1988 Effect of surface Crust breaking on growth Md yield of bread wheal (Tnttcum aestivum) In alkali SOils Indlan-Joumal-of-Agncullu/1lI-Sciences 1988,58 9,699-701 .

Singh A K 1989 Effect of salme water on yield and water use effiCiency of crops Annals of Agncultural Research 1989.10 1,39-48' -

Singh Goverdhan and Saxena G S 1979 Comparative study on the effect of quality of Irngahon water on the Yield of barley, wheat and pea grown In 50115 of different texture Indian Journal of Agncultural Research 13 4, 199-02

Themen, M C and Grant, C A 1998 Effect of tillage management on yield perfonnance In barley. Can J Plant SCI 78 301-03

Venna, R P S, Kharub A S, Shanma R K .. Randhir Singh and B Mlshra 2007 Jau Anusandhan - parampank se vayasaYlk Upyog kl Aur DWR. Kamal Research Bunetln - 23 p 36

Webster GRand Nyborg M 1966 Effects of tillage and amendments on Yields and selected SOil properties of two Solonetzlc SOils, Canadian Joumal of SOil SCience 1986,66 3,455-470

84

Modelling Solute Transp-ort in Alkali Soils

M.J. KaJedllonl<ar . . . DIVIS/O(I of ImgaiKJn and Dminage Engmeerlng I

Central SOil Salmdy Resaarch Insbtute, Kamal-132001 Haryana

Introduction

In the and and semi-and regions of India the use of poor quality ground waters IS In the range of 32 to 84 perrent of the total ground water use (Mlnhas and Gupta, 1992, Gupta et al 1994) .In such brackish water areas an average extent of saline, sodlc and saline sodic waters are approximately 20, 37 and 43 per cent respeavely (Yadav and Kumar, 1995) Highly alkali ground walers pose a senous threat to crop produaon In about 25 and 21 percent of total area of Punjab and Haryana states, respectIVely, which slates contnbute mainly to India's food grain production These alkali ground waters resources are commonly used In conjunction With can~1 water In parts of Indo-Gangetlc plains (In the states of Punjab, Haryana, Uttar Pradesh and RaJasthan) to grow nce and wheat crops In the areas WIthout canal water supply, ground .waters With low to medium residual alkahnrty (residual sodium carbonate) and divalent callan ratio less than a 25, are of senous concem as use of such groundwaters may lead to the rapid development of alkali sOIl Then, amendment may become necessary (Gupta et ai, 1994) Thus, continued use of alkali waters for Imgatlon In a closed system may detenorate the sOil and water resources of the region and affect the sustalnabllrty of crop production In the long run

The sodlfica"on of 5011 as a resuH of alkali water imgallon has been the subject of several studies, which related the changes In sOil With vanous indices of Imgation waters Exchangeable sodium percentage (ESP) IS generally used to Judge the Intenslly of sodlficatJon The ESP development affects the sOil phYSical properties, adversely Singh et al (1977) observed for 139 sOil samples collected from Bhabnda dlstncts of Punlab that development of ESP was better related With concentration of CO," + HCOi Ions, followed by reSidual sodium calbonate (RSC) and sodium adsorpbon ratio (SAR) of the Imgallon water The regression coeffiCients (r) were 06, 054 and a 45 respectively The low values of regression coeffiCient Indicate that the sodlficatlon process IS not completely descnbed by the IndIVIdual vanables Sharma and Mandai (1981) reported that root zone ESP IS better correlated WIth the adjusted sodium adsorption ratio (adJ SAR) wrth r =0 857 than RSC With r =0 598 Barwa et al (1983) reported s"mlar results BaJWB et al (1983, 1986),~ BaJwa and Josan (1989 a and b), and BaJwa et al (1992) conducted senes of expenments to evaluale the long term effects of alkali water use In wheat based rotatIOns like wheat-nee, wheat- millet and wheat -cotton The results Indicated that sodlficatlon occurred In upper sOil layers SOil pH and ESP Increased With Increase In RSC and SAR of Imgallon water The rate of sodlficatlon was smaller If high RSC and high SAR waters contained Ca" Ions In a quanlJty more than 2 mmokll The Increase In ESP and pH under nee' wheat rotation was larger at higher levels of reSidual alkallnrty because the quantity of applied Imgatlon water was larger than for other wheal-based rotations Thus, long term effects of alkali water use were Judged mainly In terms of ESP and pH developments In the Salls

Solute transport IS strongly affected by the cation exchange and preCipitation! dlssolurtlon processes that occur In SOil The present study IS aimed at determination of whether we understand the complicated chemical Interactions involved In solute transport In case of uSing alkali water for ImgatJon as IS done In the Indo-Gangetlc plains of the north -west india For thiS aim, expenments that have been conducted In the field are Simulated USln9 the UNSATCHEM code that has been developed by S,munek, et al (1996,1995) As thiS code IS able to account for many of the processes that occur In sailne and sodlC soils, It also reqUires the speCification of many model parameters. A good agreement between model and expenment is an Indication that the main processes have been Idenllfied and that the chOice of parameter values for the UNSATCHEM code was accurate Often, several paramete~ need 10 be estimated as they have not been measured or speCified In expenmental studies Hence, In a seCOnd phase analytical solutions are used which are only able to capture ,; few main phenomena A good agreement With these so/ullon5 and the UNSATCHEM results Increases our confidence In our understanding of the processes that occur In the~field The gained understandlO9 enables us to predict developments for different Jmga~on management strategies.

Calibration and Validation of UNSATCHEM Model

The UNSATCHEM code requires Input that IS partly general (e g chemical solublilly products) and partly ~1Ie speCific, such as SOil, meteorological and imgatlon management data The data sets that are deSCribed In T IS lecture concern two expenments that have been coducted at different places In the Indo -Gangetic pla,"s

he mOdel IS first calibrated With data of Paonia et al (1990) These expenmen!s conSider the reduction of ESP ~:cre~ses by mIXing the SOli With gypsum Secondly, the calibrated model IS applied to the field data of alkali water D~enments on Summer moong crop Mgna radlata L Wilczek) by Dhallwal(1992) Only where reported by D ~11Wa1 (1992), slle-speCl~C Input data have been adapted 10 comply With the conditions of hiS expenments.

unng catlbratlon, exact values of some parameters were not or not well known Hence, It IS pOSSible that different parameters sets prOVide an equally good descnptlon of the experimental data Therefore ~understandlng about the

Che~T1Ical Changes & Nutrient Transformation In SodlC:/Poor Quality Water Imgated Salls

/ transport phenomena was tested by further simplifications such that the transport equaUon, admit analytical approximations and by checking whether the latler support the results of the numencal slmulaUons

/ Alkali water use with gypsum amendment for bare soli: a column study experiment

The filSt study used has been conducted by Paonia et al (t 990) In laterally confined and vertically conllnuous soli columns Their aim was to study the development of ESP that results from the application of a 100em layer of sodlc water for imgation purposes These results were compared With the ESP development In case thiS irngallon IS applied to a soli treated with gypsum, \

The 5011 columns required for thiS study were prepared USing a bulk surface sample (0-15 em) of a sandy loam 5011 collected from SOil Research FalT11 of Haryana Agncullural UnivelSlty In Hisar, India The 5011 dass IS sandy loam It contains by weight p8% sand, 16% 5111, 16 % day, the catlO~ exchange capacity IS 120 mmoldl<g, pH" IS 6 1 and EG12 IS a 3 dS/m Initially, the SOil profile was not sodlc The SOil was alrdned and passed through a 2 mm sieve Then the SOil was spread to a thickness of 30 em In a 120 em deep trench Botlomless metalliC drums of 56 em inner diameter and 90 em height were placed on top of thiS layer In tlie trench and filled wrth the same SOil 111120 em below the drum's nm, leaVing the top 20 em of the drums to apply the Imgatlon water, The 30 om sOil layer below the drum provides continUity the soH within the drums The bulk densrty in the drum was 1500 kg/m3 The soil was stabilised by penodlcalleachlng With good quality canal and with rainwater for about one year, Layerwse, dissolved and exchangeable concentrations of different Ions were measured Immediately before the expenment

Artlficlallmgallon water was prepared uSIng sodium bicarbonate and calcium chlonde salts The imgatlon water had 20 mmolcll total electrolyte concentration, 14 mmolc/l residual sOd,um carbonate (RSC) ,and 139 mmolc°511''' sodium adsorpbon rabo (SAR)' Two situations were Investigated. I,e, Tl the application of a cumulative Imgabon water layer of 100 ern to the SOIl in the columns and T2 a similar application after filSt mil(lng 297 grams of gypsum « e , eq ",valent to the RSG of the cumulabve Imgallon water) With the (J..l0 em SOil layer The irrigallOn water was added in Increments of 10 em, where each event took place after disappearance of the preceding Input of water from the 5011 surface The alkali water quality parametelS are given In Table 1

Table 1 Alkali water quality paramelelS In gypsum column study expenment

Water Ca Mg Na K SO, GI EG SAR RSC ALK type

(mmolcll) (dS/m) (mmolcO 'n° 5) (mmolcll) A12 200 096 1690 015 095 209 2 00 1390 14 00 1696

Input data

The Input files for the UNSATCHEM for thiS expenment were prepared on the baSIS of the available data that ~re prOVided by Pooma et al (1990) The UNSATCHEM subroutines related to transient water flow and chemical transport were used but as the SOil columns were not under a crop, the opllons for noot growth and water extraction were not reqUired Neither were the heat transport or the CO, production! and transport options used due to lack of data, Time dependent atmosphenc and solute boundary conddlons were selected for the top boundary, Ie, for the SOil surface Pondlng of Imgabon water waS allowed Without surface runoff Free drainage was assumed at lower boundary A constant soil temperature of 25 degree CelSIUS and a dlsperslvrty of 5 em were assumed, The dlspelSlvl!y value was based on values commonly found for slightly aggregated SOils and on the value detemmned ,n the Dhaliwal (1992) expenment As the SOil solution might not flow slowly enough to eqUllibnum, 'the kinetiC option for a rate limited calcite preClpltatlon,lMls used for both the treatments by taking the calcte area as equal to lxl0-7 m'/m3

,

SOil evaporation from the column was conSidered An average 5011 evaporation rate of a 05 cmIday was calculated from meteorological data of H,sar (Kumar et ai, 1995) and emplncal relabons given by Singh ~9B3J CO, concentration or flux data were not available from the onglnal expenment The Co, concentration (em em ) was assumed to Increase from a 00033 at the SOil surface to 0,04 at 14,00 em'depth and below As 5011 In the column was submerged, anaerobiC conditions may develop, for which reason such a larger CO, concentration was conSidered more appropriate The Co, concentration was Ume Invanant for each ~arllcular depth The Gapen selectiVity coeffiCient (KG) for Na-Ca 'exchange for this SOil was taken to be a 27 molc"l5n~5 Paonia et al , (1990) gave a range of KG values of a 25 to 0 35 for the 50115 of this region and proposed a value of a 25 for thiS particular column study, USing the selecUvlty coeffiCient as a calibration parameter, the value of a 27 was selected bX tnal and error Gonsldenng potassium, a selecUvity coefficient (KG) for K-Ca exchange was laken as 027 mole ',f" which suggests that K and Na behave Similarly, Hence, the Kerr selecUvlty coeffiCient for Na-K exchange IS unity for the systems containing a high excess of Na Ions In companson to K Ions In the equllibnum solullon (Bolt at al , 1976) For the Simulations pertaining to T2, all paramete"l whlch were use<l dunng cahbrabon Simulations of T1 remained unchanged, except that gypsum was present In the top soli of treatment T2

86

MO<Ielbng Solute Transport In Alkali SOils

Their results were presented by Paonia et al (1990) In terms 01 ESP profiles Other details such as the dISSOlVed and adsorbed concentrabons 01 different Ion SpecIeS and the quanhty of calCIte preClplla~on were not provided by Pooma el al (1990) The preliminary calculallons revealed a large discrepancy between expenmental and simulated ESP profiles If calCIte predpilabon at equllibnum was assumed, In that case, ESP values became aboUt two ~es larger than observed values In the top deCimetres 01 the sad colum"!, The method used by Pooma et aJ. (1990) to Simulate their expenment suggests ~ dlsbnct non-eqUlllbnum due to Imperfect mIXing Their agreement between data and simulation was~very good, though Hence, assuming slow precipitation klnebes In UNSATCHEM simulations, the data ol!reatmentTl were fitted (F'9, la)

The calCite surface area was the only parameter adapted for decreaSing the rate of preCipitation We obselVe that the level 01 ESP-values-corresponds well With the measured values Howeve,; the steep gradient found at small depths was not well reproduoed by the model A further adaptaliol\ was not attempted 11\ VieW of the results of treatment T2 The parameter values used dunng calibration were tested with treatment T2 11\ which gypsum was applied to the upper 10 em SOil In seml-8nd and and areas of India, large quanbbes of gypsum are applied dunng alkali SOil ~reclamallon or in case of alkali water use In agricuHure to reverse or decrease sodlficabon The results 01 these calculallons are shoWl1 in F'9 lb We obselVe that In thiS case the model resuijs reveal larger ESP gradients at shallow depth, whereas the measured data do not Again the values for slmulabons and measurements show good general agreement These ESP values were sigmficantly reduced compareel With Fig' ta due to gypsum application, as is the intention of uSing gypsum

~ :t ="" '"".,-w " " " " , " " o I I

o 20 40 60 60

ll1pttr (em]

(a)

1=:::1 6

~ ~ i+--"-"+' _' _' _" -+----1-1 --.;

o 20 40 60 so Depth (trl)

(b)

FIQ 1 (a) Callbrabon (treatmentl) and (b) validation (treatment 2) of UNSATCHEM for gypsum column study expenment

Development of an analytical model for SO. transport

The soli onglnally, did not contain apPreCIable sulphate concentrations Due to gypsum dlssolubon, SUlphate IS dlsplaoed dDWl1stream and'the UNSATCHEM simulabons reveal an almost UT)retarded transport Hence, we analytcally determined the SO. breakthrough CUlVe for a final concentration of eo= 3 13 mmoldl as found numencally and other parameters as defined In the prevIous section For the Simplified initial and boundary C01Jd~lons gIVen by

c= c; C=Co

z>O z =0

t=o t>O

(t) (2)

for a semi infin~e colUmn, the concentrabon dlstnbutlon can be found analytically by solVIng the transport equation gIVen by

87

Chemical Changes & ,Nutnent Transformation In Sodrc:IPoor Quality Water Imgsted Saris

(3)

The parameter R In equation (3) IS the retarda~on factor, which for sulphate IS assumed to be equal to unity (unretarded transport) In that case, Integra~on of (3) sub,ect to equallons (1 )-(2) Yields ,

- 1 1 ' 2 C = -erfc(x)+-exp(-;;/ ).exp(x.+ 0) .erfc(x+ 0)

2 2 (4)

where we have defined

- c-c c=--',

Co - C,

z-vt V.t x= a=--2..J D.t ' JD.i (5)

The breakthrough curve found by thiS solullon, shows good agreement WIth the numerically found curve with UNSATCHEM.Flg 2.

c a 09

~ 06 807 6 06 ~ 05 g: 04 g 03 .~ 02

I'-analytical I I'-unsatchem I

~ a 1 I f. is a -I-[dJ= __ ~ ___ ~ ___ ~ __ --,

a 2 4 6

Pore volume

Fig 2 Break through curves for SO, at 65 em

ThiS shows that sulphate Indeed displaces through the SOil WIthout slQmficant chemlCailnteractlons, as was suggested by the numencal results Furthermore, the good agreement suggests that non- uniform flow and transport effects are limited and may be accounted for by appropnately chOOSing the value of the dlsperslVlty (/o=DNJ If thiS were not the case, rt would be much more oompllcated to deal Wlth non -uniform flow effects analytically, whereas UNSATCHEM at present does not allow for such campllcallons A further Improvement In the agreement between sulphate breakthrough curves by adjusting the dlsperslvlty was possible but not attempted

Alkali water Irrigation experiment: a field study

A field study was conducted' by (Dhaliwal, 1992) to Investigate the effect of alkali water imgallon on salt accumulation, plant root denSity and Yield of summer Moong crop grown on a loamy sand 5011 The expenmental field was prepared by repeated plOWing and planking at proper mOisture candlllons to get fine seedbed, The field was divided Into different plots, eac!l measunng 1.5m x 1.5m, and separated by 30 em bunds The plots were lined wrth polyethylene sheet to a depth of 30 em at boundanes to Impede lateral movement of water and salts

Input data

The Input files were prepared by making best use of field data given by Dhaliwal (1992) The sub madels for translenl water How, chemical solute transport, and water extraction from root zone were used In the simulations The opllons for root growth, heat lransport, CO, productiOn and Its lransport were not oonsJdered due to lack of reqUired data

The crop was sown on 16" Apnl 1989 and was Imgated WIth two types of water that differed with regard to Imgatlon water quality (Table 2) The treatment wllh RSC equal to 5 t a was used for cal.bratlon of UNSATCHEM The treatment With RSC equal to 7 90 was Simulated Without further adaptallon of parameters (and

88

Modelling Solute Transport in Alkali SOils

IS henceforth called vahdatlon), The total amounl of rainfall during the crop growth penod was 4 5 ern The rainfall events were Incorpomted With SIX Imgatron events The Imgabon amount corresponds to a layer of 7 em rn each event Class A pan evapombon data from March 1989 to June 1989 were analysed 10 determine the sOil ' evaporatron, plant transpiration and potential evapotransp,ratron (Feddes, et al , 1974, Singh, 1983). Appropnate trme dependent atmosphenc and solute boundary condrtlOns were selected for the top boundary where pondlng of water was allowed wrthoul surface runoff The water table In the area was deep enough (approximately at 10 m) to assume free drainage at lower boundary. The eanal water quality parameters that are given In Table 2 were assigned to rainfall water There was suffierent trrne between successive rnfittration events to allow the SOil solulron to reach equllibnum condition Hence, eqUllrbnum was assumed for calerte preCIpitation The Simulations for the crop pened ooncemed a layer of 120 em depth of sari whereas the major cheml",,1 changes occur In the root zone

Table 2 Imgatlon water qualrty parameters In alkali water use expenments ~

Water Ca Mg Na K' SO. CI EC SAR RSC ALK type (mmoldl) (dS/m). (mmoleo 'nos) (mmoi';)

GWI 090 060 990 010 070 420 1 07 1143 510 660

GW2 070 070 1120 010 070 2.70 1 11 1338 790 930

CW 150 0.80 040 010 095 035 020 037 000 150

The sCiI class was loamy sand With average catIOn exchange capaerty varying a$ a funcbon of depth from 30 to 62 mmolelkg Initially, the SOil profile was not sodlc The dissolved and exchangeable concentrations of different Ions In vanous sOIl layers were measured The Inrtlal calClte content was 1 percent by mass The Gapon selectlvrty coeffiClent (KG) for Na-Ca exchange was taken as 0 35 mol,-O'no5 and was detenmmed by tnal and error dunng cahbrabon ThiS value is well Within the range gIVen by Pooma et al (1990) Both the expenmental s~es are located rn Indo-Gangetlc pia 105, However, they are separated spabally by hundreds of kllometres and they are different With regard to e g 5011 texture Hence, H was conSidered reasonable to assume slightly different Ko values Similarly as for the earlier expenment by Poonla el ai, (1990) the exchange coeffiCient for K-Ca exchange was taken equal to 035 mOlc-0

511-0 5 Hence, sodium, which IS In excess In companson to potaSSium, IS assumed to behave similarly 10 K.

The field data Indicated that 82 to 93 percent of total roots were In top 0-30 em sari layer Hence 80 percent of rool water uptake was assumed frOm to occur In Ihls layer and the remaining 20 percent frOm the 30-100 em sOil layer Field data related to the C02 ooncenlratlon were nol available The CO, concentration (em' em' ') was assumed to mcrease linearly ,f",m 0 00033 at the sOrlsurface to 0022 at 30 CIT depth It reduced to 0 0025 (at 32 em) In view of the decrease In root densrty and remained constant up to 50CIT Below, a constant concentration of 0 0008 em' em" was assumed oonsldenng some trapped arr In sub layers, In thiS case also, a ~me Invanant CO, concentration was prescnbed The senSitiVity to water and salinity stress was defined by the emplneal parameters h;o : -2000 em and h", (osmobc): -1 e+20 ern (Van Dam and Aslam, 1997) The parameter h50 represents the pressure head at which water extractron rate IS reduced by 50 percent The constant 5011 temperature of 25 degree CelSIUS and the dlsperslvlty of 10 ern were assumed Molecular diffuSion was neglected For Slmulatmg the !realment vvth Imgallon waler With RSC =790, all parameters which were used for the eallbrabon for the RSC = 5 10 case remained unchanged, and only the Imgallon water quahty was adjusted

Expenmentally detenmlned profiles of ECe, SAR, dissolved Na and ESP were available for two treatments that differed vvth regard to the RSC values of the Imgatlon water (510 and 790, respectively) Initially both SAP. and ESP were smalllhroughout \he SOil profile Due to all<all waler use, beth properlles Increase as a function of time The agreement for both SAR and ESP between experimentally observed and Simulated profiles IS shown In Fig 3 The SAR conSiders the concentraVons of malar dissolved Ions like Ca, Mg, K and Na Of these, potassium IS hardly relevant In View of the small concentrations both Inrtlally In SOil and In the Imgatlon water The ESP development IS important, as It is the parameter that IS used for claSSifying sodlClty The results for the treatment With RSC= 5 10 (callbralron) 'are shown In Fig. 3a and 3b, The good agreement was obtained for SAR and ESP by adJusting' the dlspenvrty and Gapon coeffierent KG A Similarly good fit was obtained for the ECe and ~SSOlved Na profiles (not shown) Again Without further adjustment In parameter values, Simulated profiles for the

atment With RSC =790 were determined The results shown In Fig 3c and 3d indicate a good agreement With the meaSUred profiles. ThiS prOVides confidence In the assumpbons that were made for the calibration Simulation

89

Chemical Changes & Nutnent Transformation In $od1c:JPoor Quah\y Water Irngated SOl1s

o 20 40 60 80 100 ..r 120

Depth (em)

(a)

0..20 ~ Ot-==~==~~~~~~~~~~

o 20

a: 50

40 60

Depth(cm)

00 100 120

(b)

~ O+-~·~··~~~~~=r~~~--~~~ o 20

11.;50

40 60

Depth (em)

00 100 120

©

~ O+-~~~~=r~~~~--~--~----~ o 20 40 60 00 100 120

Depth{cm)

(d)

1·····.:]

Fig 3. (a) and (b) Calibration (RSC = 510), (c) and (d) Validabon (RSC" 7 90) of UNSATCHEM for alkali water imgaUon

The profiles of the IndiVidual cabons e;jl', Mi', and Na' and K' as a funcfion of depth Were available for the Imbal (at day z.eno) and final srtua~ons (after termination of the experiment at 106 . days) from UNSATCHEM slillulation output Both the Ihltlal and the final profiles of Ca", Mi', and Na' are shown In Fig 4 This figlJre Indicates that slgmficant changes in Na were found throughout the profile, but predominantly In the topsell Accordlngly,.Ca changed throughout the profile I;lS rt exchanged With Na The most profound changes for Ca were found In the topsoil because at that place Ca was displaced from the adsorp~on complex by the Invading Na as well as by Mg (whose adsoJbed quanbty Increased in upper few cenbmetres) The Na, K, and Mg concentrabons in solution close to the SOil surface approached the concentration found In Imgabon water The changes WIth regard to K at the exchange complex as well as In solution were minor

The changes In composibon of 5011 soluUon and exchange complex reveal a chromatography process in which a front that exchanges Ca In favour of the Inoornlng Na, a dominant Ion In imgation water, moved to larger depths In the topsoil, where CaiNa exchange has come almost to eqUilibrium, Ca exchanged In favour of the incoming Mg This front moved slowly Consequently, It seems reasonable to approximate thiS srtuation by considenng two separate fronts, ie, a CaiNa exchange front followed by a CalMg exchange front Closer consideration of the numencal results of UNSATCHEM calculatiOns revealed that Mg did not partiCipate In precIpitation reactions that form the Insoluble dolomite CaMg{CQ,)2 Both carbonates and bicarbonates react mainly ,WIth calcium It'alls introduced ilia ImgabOll wate, or that is desol1:>ed from the exchange complex In the

90

Modelling Solute 'Transport In AlkalI Salls

topSOIl This observabon SUpports our simplification to assume that bOth Na and Mg partICipate only In exci1ange processes

45

40

35

C)30 ~ 25

~2O E 15

10

...... ,

5 - .. ..,

-

'- .. __ . O~--+---~~~~~--~~

20 40 60

Depth (ern)

eo 100 120

---' Ca(m)

- _: - Ca(!) , -,Mg(m)

-, - - - .Mg(!)

---Na(,")

----Na(1)

K(ln) ----K(f)

Fig 4 Changes In adsOibed concentrabons at sOil exchange complex (based on callbrabon output) ,

Development of an analytical model for Ca, Mg and Na transport

To ascertain whether these slmpllficabons capture the main phenomena In the complicated transient flow and reactive transport problem under field condlbons. the srtuabon of Fig 4 was approXimated analytically uSing the baSIC theory provided by Bolt (1981) The CalNa exchange front IS a case of unfavourable exchange, as the e><<;hange complex prefelS resident Ca to the 'I1C5lml!19!'1a ThIS can be seen from the Gapoii exchange equabon

, .

,

rNa _ Ka.cNa ,rCa - (CCatMg/ 2) (6)

Where y refers io the adsorbed quanbly and c IS the concentration Examples of the Gapon equabon have been shown by among others Bolt (1981). which Indicates that the cabon exchange complex IS dominated by dIValent cabons In case of relabvely small hacbons of monovalent caban compared with divalent cabons In solUbon For the case,that Na displaces Ca, Bolt (1981) shows that the different dissolved and'adsorbed Na roncentrabons that lie In the range between Inlbal (5011) and final (Imgabon water) Na concentrations move with different veloCIties Consequently, a diSpersed front develops even In the absence of pone scale dispersion tn fact as can be inferred from the examples prOVIded by Bolt (1981) and Van der Zee (1990), after a relallvely short pened the major spreading IS due to the nonlinearly of exchange rather than due to pere scale dispersion The depth where we find a partlcuJar conoantrallon c can be deterrnlned from the transport equallDn (3) after Integranon For thiS purpose, Une Gapon equallon IS first wntten In temns of Na concentrahons and adsorbed quanbbes, Ie YCo>Mg = Q""/Na Wlth Q the cabon exchange capaCity; and ec..Mg = C - CNa, where' C IS the total concentrallon. We have neglected the small quantlbes 01 K present In the SOil and Imgatlon water Next, the Gapen equation IS rewntten In temns of dissolved and adsorbed hacbons, by the substrtutlOns I = CNJC and N = WO, As discussed at length by Bott (1981), the retardabon factor R In equabon (3) IS given by R = 1 + Ro, dN/df, where dNldf IS the denvatlve 01 the nomnallsed Gapon equallon With regard to I Therefore, setting In equalion (3) D=O as we neglect pore scale dispersion, we find that a particular concentration of Na (equal to CO) has moved to the depth

vi z(c·) - ------

[1 + (RD.dfV(f*)/ df)] (7)

'Where the denvabVe dNlclf conoams the denvabve of the nomnahsed Gapen exchange equation at each f>=C'/C With c· Within the range 01 Inrnat and finat concentrallons The nomnallsed exchange equallon IS found by Inserting I=c,IC and N,"l1/Q for the cation i under conslderabon In Gapen equallon The distribution ratio IS given by Flo =QleC The normalised exchange Isotherm was evaluated WithOUt distinguishing between Ca and Mg (assuming these divalent cabons behave Similarly wrth respect to exchange by Na) The total concentration was D 0107 N, which resulted In a Ro value 0133 8 The retardabon factor, R lor tlne range 01 r:: values was determmed

91

Chemical Changes & Nutnent Transformation In SodrdPoor Quality Water Imgated Salls

, to range from 291' to 36 90 The total concentrabon of Imgallon water was assumed to be somewhat smaller than 'the actual conc"mtranon (Table 2) to accommodate for the effect of calCite preClp,tatlOn (Shama, 1994).

/ , ,In the expenments, approximately 46 5 ern of water was added dunng the crop panod of 106 days The

average Darcy veloCity was therefore 044 cmJday \Mth an average volumetnc water fraction of 0 207, the pore velOCIty equals to 2 12 cmJday In equabon (7), the transient flow character of the expenment and UNSATCHEM slmulabons IS Ignoned The'denvabve dNldf IS given oy , •

dN K,(l- j)"' +O.5,K.f.(l- Jf" = dJ • (1- Jm+ K,J.(I- f) ")2

(8)

Besldes'a front lor Na. that Invades the SOil, also a MglCa exchange front where the adsorption complex releases calCium and Mg IS adsorbed, IS shown In Fig 4 In case of Mg/Ca exchange, the Gapen equaton as used aoove IS not appropnate Instead, the Kerr equabon should De used (Bolt, 1981), Which dictates that the molar ratoo at the cabon exchange complex IS equal to molar raba In the 5011 solution

rMg -K cMg - . YCa Cea

(9)

For this case, the equabon (7) IS applicable If the retardabon factor for the Incoming Mg concentratoons IS gl'(9n by

(10)

The dlstnbution rabo IS as before, but the exchange Isotherm denvabve has to be replaced by the difference between final and Inlbal adsorbed Mg diVided by the difference between ,the final and Inlbal Mg concentrallons In solullon Final stands for Imgatoon water and Inmal stands for adsorbed and dissolved Mg in SOil at the moment that the experiment starts EspeCially at early bmes, the front for Mg/Ca exchange IS dominated by dlSpe~lon and Inlbal and final s~uabons can be connected almost WIth a straight line For larger limes the Mg front moves as prescnbed by equabon 4 because Ca/Mg exchange IS almast hnear. All concentratons between initial and final Mg concentrabon move Wlth same velOCIty and the retardabon factor R for Mg has a single value For the present expenment, the retarda~on factor IS large and the front has hardly moved Into the 5011 profile For thiS reason, we calculated a mean Mg'retardabon factor of about 123, and connected' the final concentmbon of adsorbed and dissolved Mg at the soil surface Wlth the Inrnal concentrabon and d,ssolved'amount of Mg at a depth of v 11123 For thiS calculabon, we assumed a linear partobonlng of Ca and Mg according to their concentrabons In Imgatlon water, In agreement Wlth equaVon (9)

The Ca, Mg and Na fronts developed uSing the analytical approXimations and UNSATCHEM calculalions are shown In Fig 5 for companson The expenmentally determined adsorbed concentraVoh of Na In the field IS also plotted As Ca. Mg and Na predominantly occupied the soil exchange complex, the adsorlbea Ca concentrabons at different shallow depths were calculated for the analytical treatise by deducting the sum of adsorbed Na and Mg from the cabon exchange capaaty of the SOil For the numencal approach, UNSATCHEM prOVides all concentrations and adsorlbad quantrnes of the cations Involved, so no addiliOnal assumpbons were needed •

The numencally obtained results agree well WIth the expenmentally determined cation profiles The analytical solullon, which IS very Simplified, reqUires .few parameteos that have to be determined and eaSily evaluated, agrees well Wlth both the UNSATCHEM and the expenmental results This imphes that the main processes, which were accounted for analytically, have Deen Idenbfied well cabon exchange IS the dominant process, WIth a minor role for calate precl~bon The calion chromatography process concerns two different phases, ie, a fast front where Na replaces Ca at the exchange complex followed by a slow front that Involves Ca desorption by Mg These fronts can be modelled as If they occur separately Moreover. If long- term calculabons are needed to assess changes over many yeaos to predict e 9 changes at the phreabc ground water, analytical predictions may De accurate enough whereas they are much easier and faster to co,ncJuct than Simulations Wlth UNSATCHEM

92

45

~ 40 o Q 35 E

.s 30 c

,0

~ 25

.. 20 g 8 15 'C

.e 10

~ 5 <

o - 20

Modelling Solute Tra'1sport In Alkali SOils

----

40 60 SO 100 120

Depth (em)

- - - Ga(unsatchem) ---Ca (analytical) ••••• 'Mg(unsatchemj

--Mg (analytical) , - • - • Na (unsatchem)

/ ---Na(analytlcal) , . 'Na(~eld)

Fig 5 Companson of UNSATCHEM, analylJcal and field results

Summary and Conclusions

A good agreement of the presented analyIJcal solutions With the expenmental and UNSATCHEM results developed a confidence In our understanding of the processes that occur In the field under alkali condition The analyIJcal solutions consider movements of m8jor IOns, ...m1Ch are Involved In alkali solute trarlsport arid may be used for future predlcllons about 5011 and groundwater quality In alkali enVIronments potassium was riot a slgnlficarlt Ion In case of alkali solute transport As CO, and HCO, lOriS are involved In pre(Olprtatlon -dlssolubon react\Ons, predlct\O('.S about \hel' mO'lemenls b~ means of a('.al~lcal solu\lorlS ma~ be more compllcatOO,

Bibliography

BaJwa, M S, Hlra, G S \ and Singh, NT 1983 Effect of sodium and bicarbonate Imgabon waters on sodium accumulation and on maIZe and wheat Yields In northem India Im9 SCI 4191-99

BaJwa, M S, Hlra, G.S and Singh, NT 1986 Effect of sustained saline Imgabon on SOil salinity and crop Yields IITIg SCI 727-34

BaJwa, M Sand Josan, A 5, 1989 a Effect of gypsum and SodlC Imgabon water on soil and crop Yields In nee...meat rotation Agnc Water Manage, 16 53-ti1

BaJwa, M Sand Josan, A 5, 1989 b Predlcllon of sustained SodlC IITIgabon effects on SOil sodium saturation and aop Yields Agnc Water Manage, 16 217·228

BaJwa, M 5 Chaudhary, 0 P and Josan, AS, 1992 Effect of continuous Imgatlon With sadlC and saline SodlC waters on 5011 properties and crop Yields under cotton-...meat rotation In northwestern IndIa Agnc Water Manage, 22 341;-358,

Bo~, G H 1976 Transport and accumulation of soluble salt components In Developments In Soil sCience 5A SOil Chemistry A BaSIC elements (Eds 1 Bol~ G.H and Bruggenwelt, ElseVIer SClenhfic Publishing Company, Amsterdam 126-140

Bolt, G H, Bruggenwert, M G M and Kamphorst, A 1976 Adsorphon of cations by 5011 In Developments In SOil SCience 5A SOIl Chemistry A BaSIC elements (Eds) Bolt, G Hand Bruggenwert, ElseVier SCientific Publishing Company, Amsterdam 54-90

Dhaliwal, S S 1992, Effects of brackish water Imgahon and straw mulching on salt accumulahon and Yield of Summer moong Mana radlata L Wlczek), Unpublished M Sc ThesIs Submitted to Department of SOil SCience, Punjab Agncultural Umverslly, Ludhlana, India, pp105

Feddes, R A Bresler, E and Neuman, S P 1974, Field test of a modified numencal model for water uptake by root systems Water Resour, Res, 10(6) 1199-1206

GuPta, Raj K, Singh, NT and Sethi, M 1994 Ground water quality for IITIgabon In India, Tech Bull No 19, Central 5011 Salinity Research Inslltute, Kamal, India, pp13

KUmar, S Jhornr, R K and Slyag, R K Technical document on meteorological data for Hissr (1984-94), Inde: Dutch Operanonal Research Project, Department of SOIl SCiences, CCS, Haryana Agncultural

M Umverslty, Hlsar, India, pp82 Inhas, P S, and Gupta, R K 1992 Quality of Imgabon water- assessment and management, ICAR, New Deihl,

pp123

93

Chemical Changes & Nutnent TranSformatJon In SochcJPoor QualJty water lnigaled SOils

/ /

Poema, 5 R , Singh, M and Pal, R 1990 Predicting sodlficabon of sOIl upon Imgatlon with high residual sodium camonate water In the presence and absence of gypsum, J Indian Soc 5011 SCI 38713-718.

Sharma, D R. and Mandai. R C 1981 Case study on the sadIe hazard of Irrigation waters J Indian Soc SOil Sa , ,29 270-273.

Sharma, M K, Paonia,S R, Gupta, R K and Slyag, R S 1994 Sodlcdy of Imgatlon waters In relatlo~ to preClprtabon I dissolution of CaCe, J Ind,an Soc SOil Sa 422244-247

Simunek, J Suarez, D L, and Serna, M 1996 The UNSATCHEM software pa~age for simulatmg the one dimensIonal vanably saturated water How, heat transport, camon diOXIde pnoductlon and transport, and muJllcomponent solute transport WIth maror Ion equllibnum and klnebc chemlstl)l. Version 2, Research Report No. 141, U S Salrnlty Laboratol)l, ARS, USDA, Riverside, Calrfomla pp186.

Singh, 0 P 1983 Clrmate of Kamal Bull No 8. C S SRI, Kamal, India, pp68 Singh, B, Rana, D.S and BarW3, M S 1977 Salrnlty and sodium hazards of underground Imgallon waters of

8habnda drstnct (Punjab) Indian J Ecol 4.32-41. Van Dam J C and Aslam M 1997. SOil salinity In relation to Imgabon water quality, SOil type and farmer

management I I M I , Lahore, PakIstan, pp34 Van Der Zee. SEA T M , 1990 Analytical travelrng wave solullons for transport WIth nonlinear and noneqUlllbnum

adsorption Water Resour Res , 26(10) 2563-2578 Yadav, H.D and Kumar, V 1995 Management of sodle water m Ilglll textured SOIls Proc Nabonal Semmar on

Reclamabon and Management of Waterlogged Saline SOlfs Apnl5-8, 1994 at CSSRI, Kamal, 221)-241

94

Management of Saline Soils through Subsurface Drainage

M.J. Ka/edhonkar and S.I<. Gupta· I DIVfSfOn of {mgatfOn and Dramage Engmeenng & PC Undo Central sOIl Sa/ml/y Research InstlMe, Kama/- 132001

Introduction

lITIgatIon Induced waterloggIng and sOIl -salonlty/alkallnlty problems are generaTiy observed In imgation commands of large Irngatlon projects In many states of IndIa These problems adversely affect productoon and productIVIty as well as threaten the sustalnablilty of Irrogated agrIculture About 85 mIllIon hectares (m hal land was affected by sahnlty and alkahnlty In the past (Songh, 1996) and now, area under salt affected 50115 In the CQuntry IS 6 73 m ha as p~r revIsed estImate The allUVIal SQlls of Indo-GangetIc plaIns of north-west IndIa are very deep and the topography IS flat onterspersed With Indus-Ganges nver system The clImate IS semI-and to and Waterlogging and secondary_ SalIniZation problems are extending steadily over the years In vanous liTigation baSins of these plalns- -Aboul 07 to 10m ha seml-arid part of Punjab, Haryana. north-westem Rajasthan and weslern Uttar Pradesh IS affected by these problems and affected area IS increasing alarmingly (IPTRID, 1993) It IS also observed that large areas in Gangellc plain of north India suffer from cntlcal and semH:ntlcal waterlogging On the baSIS of post-monsoon water level data of year 2000, areas of cntlcal and seml-entlcal waterlogging In western, central and eastem Gangetic plains are gIven In

Table 1

Table 1. Extent of water-logged areas In the Gangetic Plains

S Part of Indo- Number of waler RepOOed Walerlogged "r"a No Gangetic level mOnltonng area (m hal

plain stations Cnllcal S ub-cnbcal

1 Eastem 1730 750 1 57 254 2 Central 898 453 073 093 3 Westem 1169 808 098 122

Total 3797 2011 328 469

(Source Dr D Rai, G W D , U P_, 2003) \

The Table 1 Indicates that entlcal and seml-cntlcal waterlogged areas. In the GangetIc plains of Uttar Pradesh, are 3 3 and 4 6 m ha, respectively WaterloggIng IS called as entlcal, if water table fluctuates between 0-2 m below the ground surface. II IS trealed as seml-cntlcal, If fluctuates between 2-3 m below ground surface It IS also reported that percent of area faCIng watenogglng problem vanes from 35% In 1995 to 43% In 2000 In SadlC land domonated dlstnets of Uttar Pradesh These data suggest that problem of waterloggIng IS of senous nalure

Waterlogging and 5011 sahnrty problems are -also reported In Irngabon commands In slales of Maharashtra, Kamata~a, Andhra Pradesh, Madhya Pradesh and GUlarst due to heavy nature of SOIls. which have low permeablhty values These problems are also reported In non-command areas Of these states due to cultivation of sugar cane crop With 11ft Irrigation schemes ThIS paper descnbes the detailed infoimatlon on drainage invesllgatlons, deSign entena. envelope matenal and installation of subsurface drainage system

Drainage Investigations

The reclamation and management of waterlogged salt-affected lands basically InVOlves prOVISIon of drainage for remollal of excess water and salts from the crop root zone. Drainage reqUirements and measures, however, greatly vary depending upon several factors such as soli, geo-hydrologlcal and climatic condilions, Imgatlon and cropping practices and natural drainage Drainage Investigations are mainly COnducted to understand different dimenSions of a problem for searching a SUitable solution However, inVestIgations are generally problem speCIfic It is always better to plan With minImum data obtaIned through best available means for a speCIfic site InformatIon on hydraulIC conducbvlty, dralnable porOSity, InfiltratIOn charactensbcs. SOIl sahnlty, SOIl alkalinity, depth of Impermeable layer, aqUifer parall1eters. groundwater fluct~atlons, groundwater quality, fresh water supplies, surface draInage network and allallabillty of outlets, etc IS a pre-requIsite for planning the drainage of waterlogged saline and alkali SOils In additIon to abovementioned information, knowledge on drainage reqUirements of dIfferent crops and entenon for draln-ag-e desIgn IS also required Informahon generated through drainage mvestlgabons IS utilized effectIvely to deSign a drainage system, which would satisfy the limits related to drainage cntena Execution of dr<lInage plan In

Chemical Changes & Nutnent Transformation In SadlclPoor Quality Water Imgated SOils

/

the field IS mainly Comes under Installation actIVIty The CSSRI has carned out drainage Invesllgatlons and designed subsurface drainage systems for waterlogged saline Salls at different places In Haryana Kamra and Rao (1992))lave discussed different aspects of drainage i~vesbgations The same aspects are discussed In details In this lecture With reference to waterlogged saline as well as waterlogged alkali SOils

The pre-<lrainage Investlgabons can be conducted at three levels VIZ the reconnaissance, the semldetailed and detailed surveys of the area The recm;nalssance survey helps In deterrmnlng the technical and economiC feasibility of a proposed project Available aenal photographs, maps (geological, topographical, SOil and land uso), reports related With surface water, groundwater, climate, cropping pattem and Yields and logs of shallow and deep tube wells are useful In the preliminary survey The maps should cover the whole of watershed baSin In which the area under conSideration IS located ThiS can serve a baSIS for water balance stUdies It IS always better to VISit a project area to collect the information on seasonal fluctuations of water table, Intensity of drainage problem, crops grown,_water management practices, phYSical boundanes, surface water bodies, sources of "rlgatlon water and natural drainage outlets Reconnaissance survey proVides the Information on the necessity of drainage, enables a tentative layout of main drainS and_the outlet, and helps taking a deCISion on drainage scheme to be adopted It also suggests the future programme, intensity of surveys and studies needed In the seml-detalled study phase Semi-detailed stUdies correspond to the level

.of feaSibility studies, which enable to deCide the opbmal plan, for execubon. A detailed survey Involves the collection of all relevant field data that allows an effective deSign of the drainage system Detailed Invesllgatlons related to topography, groundwater conditions, SOil salinity, 5011 alkalinity, SOIl hydrological characteristics and leaching behaViour of SOils are reqUired to develop understanding about the extent of the problem, and for determining the parameters required for the deSign of subsurface drainage system,

Topographical map

A topographical map on an approximate scale of 1 3,000 or 1 4,000 and contours at Interval of about 20 em are SUitable for understanding localIZed slope In drainage area The lowest POint In the area IS selected for outlet. Contour map helps In prepanng tentabve layout The main line may be located In the dlrecton of general slope, while the laterals may be located across the general slope

Groundwater conditions

Water table behaViour In drainage area needs to be studied on the baSIS of Water level data during pre and post-monsoon penod Water level contour map IS necessary to·understand dlrecton of groundwater flow It also helps to assess whether Interceptor drain IS necessary and to deCide the directions of main and lateral lines

Groundwater composition

Water samples are generally collected at watertable level from the drainage area at Interval of 30 or .40 m The samples are analyzed to know chemical composition Chemical properties such as electncal conductiVity (EC), sodium adsorption ratIo (SAR) and reslc1uaJ sodium carDonate (RSC) of groundwater are u!!ed 10 assess the nature of groundwater It can be saline, SodlC or sallne-sodlc Generally, groundwater close to unlined canaliS of good quality due to seepage The groundwater composition Indicates the threat of salinisallon or alkalisatlon In case of net upward flux In drainage area Secondly, It helps In deCiding the disposal ophon or reuse pOSSibility of drainage effluent from drainage system. Of course drainage water quality IS Influenced by groundwater composItion proVided the SOil mass below drain contnbutes to drain flow greatly as compared to SOil mass above the drain

Soil hydrological characteristics

Hydraulic conductiVity and infiltration charactensbcs of Salls In a drainage area are determined by field tests The honzontal hydraulic conducllvlty IS determined uSing 'auger hole method' for below watertable condrtlon and by 'Inverse auger hole method' for above waterUlble condition ConSiderable vanallon In hydrauliC conductiVity values is generally observed The values are statistically analyzed and the value at 50%

,log probability level IS selected for deSign of drainage system The infiltration rate IS determined uSing failing head Infillrometer nngs The 50% log probability value for infiltratIOn rate of the Salls is determined It IS useful In calculations related to drainage coeffiCient

Dralnage.criteria

}he agncultural drainage critena,ls defined as the state to which the on9lnal waterlogging on or In the SOil IS to be reduced by a drainage system so that the maximum agncultural benefit of the system IS attained Jn the 1910 definition of drainage, ~removal of excess wate~ indicates that land drainage IS an action by man, who must know how much excess water should be removed. Hence, when deSigning a system for a particular area, the dramage engineer must use certain cntena to determine whether or not water IS In excess A groundwater balance of the drainage area IS the most aecurate tool to calculate the volume of the water to ~e

96

Management of Saline SOils through Subsurface Drainage

d~med Before the water balance of the area can be made, number of the surveys must be undertaken to ~pare hydrogeological and topographiC maps. Further all surface and subsurface water Inflows and outflows

~U51 be measured and es~mated PreCIpitation and ~elevan! evapotransplralion data must be analyzed and hydraulic properties of the sOil should be COllected Dral'1"ga engineer, beSides agricultural drainage cntena, should also employ technical drainage crltena (rela~ng to minimization of the cost of Installation and operation of system while malntamlng the agncultural cntena). enVIronmental en!ena (rela~ng to the minimIZation of the enVIronmental damage), and economic drainage crrtena (relating to the maxlm,zat,pn of the nel benefits, Ie the difference between benems and costs and damages) ,

Orainage coefficient

Drainage coeffiCient IS the most Important parameter that deCides the lateral drain spacing. size of the laterals and collectors and capaCIty of the pump to dispose off the drainage 'effluent The drain spaCIng IS less In cases where drainage coeffiCient IS more as c9mpared to a case where drainage coeffiCient is less As such, the cost of the systel1'l depends largely up'on thiS parameter Therefore, the ~eed to select an appropnate value for thiS parameter has always been emphaSized The drainage coeffiCient for some of the Sites in India has been observed to be In the range of 1-5 mm(Table 2) It Would be appropnate to mention that the drainage coeffiCients based on rainfall are much less-,n India as compared to the recommendalions emerging from USA or other countnes It IS due to the fact that rainfall In India IS received only dunng the monsoon season that too In a few storms As such, runoff IS much more under the rainfall pattern in India Moreover, under the Imgated conditions of arid and semi-arid regions, the main fun~on of the drainage IS to help In leaching of the salts than to Improve aerabon Since excess salls In the root zone are crdlca' to the redamatlon process than improvement~ In the aeration The emerging 'gUidelines of subsurface drainage coeffiCient reveal that a drainage coefficient of 1-3 mm day-' would be suffiCient to reclaim waterlogged saline lands (Table 3)

Table 2 Subsurface drainage coeffiCients from different locations (as observed from test fields)

Srte Annual rainfall (mm)

Chambar (Rajasthan) 850 Sampla (Haryana) 600 Hlsar (Haryana) 400 Dabhou (Gu,arat) 800 Mundlana (Haryana) 500 Kallanakhas (Haryana)" ~500 Mura, (Gu,arat) 500 , Vanabon In the range of 600-1400 mm ~ Source Gupta and Gupta (1997)

Recommended Rate & (mm day")

30 2.5 20 40 50 68 28

Table 3. GUidelines on drainage coeffiCIent for subsurface drainage

Climatic condition And

Semi-arid

Sub-humid

Range (mm day-')

1-2

1-3 2-5

Optimum value (mm day")

1

2 3

Range (mm day")

25-35 20-30 1 ? -25 30-50 50- -50-70 20-40

In case of subsurface drainage deSign based on non-steady state condillons, the drainage crltenon IS baSed on time to lower the water table from a pre.{jeCided anginal to the final level UsuaJiy the anginal water table IS conSidered at the SOil surface 'whlle the fim"llevel IS taken as 30 em below the SOil surface As per the eari,er recommendation, the capaCity of the drainage system should be suffiCient to lower the water table by 30 em In 2 days bme Recent studies have revealed that the lime could be Increased to at least 2 5 days As ~ a result, the drain spaCing could be larger resulting In lower fnvestments on the drainage system

Estimating drainage coefficient for subsurface drainage project at Hisar

A procedure to deCide the drainage cntena IS explained here With the help of data of drafnage at Hlsar to reclaim waterlogged sahne SOils RalnfaJi data of Hisar station for monsoon months (say, July, August and September) are analyzed for determlhlng " 2, 3 and 4 day(s) duration maximum rainfall for different ~tum penods The results of analySIS of 30 years (1950 to 79) rainfall data for the months of July, August and

eptember are presented In Table 4

97

ChemlG31 Changes & Nutnent Transformation In SodldPoor Quality Water Irngated Salls

/ Table 4 Rainfall of different durations and return periods at Hlsar ,

Rainfall depth, mm Duration (days) -------------

1 2 3 4

5 63 87 99 103

Return penods, years 10 83' 113 \, 129 133

20 108 138 153 163

It can be observad that most likely dura~on and depth (on 10-year return penod baSIS) for Hlsar IS 3 days and 129 mm, respectively It IS assumed that 80% of amount of such storm may reach to ground water. It means that 103 mm of effective rainfall Will give nse of 103 em of water by consldenng dralnable POroSity of o 1 It may Increase the watertable level from 150 em below ground surface to 50 em below ground surface The water level stili remains safe for crops tolerant to waterlogging Thus, It eliminates need of rapid removal of water,

Drainage system is required to remove the recharge contributions of rainwater and deep percolation losses from the applied Irngatlon water For thiS purpose, the recharge from rainstorms of July, August and September have been considered The average annual rainfall for these months at Hlsar is about' 336 mm, For Hisar area, the contnbutlon to groundwater has been assumed to be 20% of the total rainfall of the period, The expected deep percolation losses from ImgatlOn applications of 132 mm of canal water for same months are taken at 35% Wth these assumptions the recharge from rainfall and deep percolallon losses would be 672 and 46 2 mm Neglecting subsurface Inflow and capillary rise from watertable during dry periods, the drainage coeffiCient would be 1,26 mm/day Ie 1 5 mm/day ThiS drainage coeffiCient IS usad In deSign of subsurface drainage system

Design of Subsurface Drainage System

Depth of laterals: Depth and spaCing of laterals should be planned according to agricultural drainage criteria The drain depth IS also deCided by the selected constru~on method, the available machinery and drain speclfica~ons Drains need to be ,"stallad at depths, where chances of damage due to agncultural operallohs are less In order to deCide the drain depth, Information on depth to water table for proper aeration In the root zone, the cost of drainage system With due conSideration of relation between the drain depth and spacing, presence of unstable or Impermeable layers, SOil texture and strata permeablhty, land topography, minimum SOil grade and outlet cond,uons ~In case a SOil layer With high hydrauhc conduCllVity IS avallCible at a reasonable depth, rt IS adVisable to lay pipelines In the more permeable layer To protect the PIPes against damage due to passage of heavy machinery, the minimum drain depths have been recommended which vary from one SOil type to,another (Table 5)

Table 5 M,nimum SOil cover reqUired for pipe drains

SOil type Minerai Deep peat and muck Organic '

M,nimum SOil cover (em)

60 120 75

In loamy, sandy and Silt loam Salls, opbmum Yield of crops can be obtained With an average seasonal depth to water table In the 60-80 CIT) depth range, For clay loam and clay SOils thiS range could be 80-100 em ~ For annual crops or tree plants, a deeper depth to water table IS preferable In arable cropping, for most crops, adaphlc envllonment of the root zone would be qUite condUCive to produce optimum crop Yield when the annual average water table depth IS at or around 100 em To achieve thiS depth to water table at the mid-pOint of the two laterals, depending upon the SOil type and hydrauhc charactens~cs, drain depth should be kept In the range of 125-150 om The general gUidelines tor drain depths are given In Table 6 Apparen~y, these recommendations take care 01 minimum soli cover reqUired against breakage of pipes, . - '

Tabie 6 GUidelines on drain depth

Olitlet cond~lans Gravity

Pumpad

Depth of the drainS 09-12 12-18

98

Opbmum depth (m) 1 1 15

Management of Sahne SOils through Subsurface Drainage

In CSSRI expenments at Sampla and Mundlana, lateral drains were Installed at 1 75 m deep The watertable remained In the depth range of 1.4 to 16m for most of the winter and summer months As a result resallmsallon problems remained negligible At Hlsar farm Salls are slightly heavy However, salts can be leached down With available effeClive rainfall and Irngabiln supply Therefore, the same depth of 1 75 m was adopted tor Hlsar system also ThiS depth IS a moderate depth and problems during Installation would be limited Generally drains should not be laid less than 15m depth from ground surface Otherwise drains get damaged due to agricultural operations ThiS condition IS applicable for saline as well as alkali salls

I •

spacing of lateral 'drai(\s: AssumIng the steady state draInage c~tena. and depth of laterals, spacIng betWeen the laterals can be computed uSing Hooghout's tormula

where

-' 8kdH 4-4kH' q~ 8'

t q = draIn dIscharge (mid) or unIt flow rate through plane (m'fd) k = hydraulic conductiVity of the SOil (mid) d = depth to Impervious layer (m) H = heIght of watertable at midway between the drainS (m) S = drain spacing (m) r

EquatIon (1) can be wntlen as

(1)

(2)

If drainS. are located on the imperviOUs layer (I e. d=O), the first term of Equation (2) becomes neglIgible In case of d »H, the second term of Equation (2) becomes negligIble If d»H, an Imaginary ImpelVlous layer above real one can be assumed The Imaginary layer decreases the thIckness of layer through which water flows towards the drainS It IS assumed that such Imaginary ImpelVlous layer eXIsts at eqUivalent depth (de) Hence Equation (2) becomes

where

K, = Hydraulic conducbvlty of the layer above draIn level (mid) Ko = Hydraulic conductiVIty of the layer below drain level (mid)

(3)

The Equation (3) can be solved through rteralton However, nomographs are also available, whIch value of de can be read eaSily In case of Hlsar proJect, the depth of ImpervIOUS layer was taken as 4 5 m as In some profiles the SOil changed from loamy sand to Silt loam In the depth range of 45 to 5 mUsing hydraulic conductIVIty, eqUIvalent depth, hydraulic head midway between drains and drainage coeffiCient as 05 mlday, 266 m, 075 m and 00015 mlday, respectIvely, spacing between the drains was determined as 77 9 m. For field installatIOn 75m was adopted

WhIle these equatIons can be used to design a drainage system for sIte-speCifIC condlttons, desIgn gUidelines have been prepared on the baSIS of field experimentations (Table 7) Apparently, It IS clear that lateral drain spacing would be more In a light than a heavy textured SOil Similar gUidelines on minimum grade lor pipelines are reproduced m Table B In deCiding the lateral spacing, beSIdes these gUidelines some other factors may also playa VItal role For an example, the Haryana farmers prefer to have drams on their farm boundanes After the land consolidation, the famns have been laid In a regular reCtangular shape of 60 m x 67 m. Therefore, the drain spacing is either 60 or 67 m d~pendln,g on the direction of drains,

Table 7 GUidelines on lateral drain spacing

SOli texture ught

Med,um

_Heavy Including vert,sols

SpaCIng of drains (m)

100-150

50-100 30-50

99

Chemical Changes & Nutnent Transformation In SodlclPoor Quality Water Irrigated SOils

Table 8 Minimum grade for pipe drains /

,Drain SIze (mm) ," 100

125 150

Grade (%)

010 007

'005 "" I ~

Envelope material, A drain envelope IS THE porous matenal placed around a perloraled pIpe draIn 'to perform dIfferent functions such as filter, hydraulic, mechanIcal and bedding functions Filter prevents or limits the movement 01 SOIl particles Into dramplpe, where they may settle and eventually clog the dramplpe Hydraulic functIon provIdes a porous medIum of relatively high permeability around the pipe to reduce entrance resistance at or near the draIn openrngs Mechanical function proVIdes passive mechanIcal support to'the pipe in order to prevent excess deflection and damage to the pipe due to SOil load Bedding function, which IS only accomplished by use of a gravel envelope, provIdes a stable base to support the pIpe In order to vertICal dISplacement due to soil load dunng and after constructton

SoIl$ that do not require drain envelope There is posSIbility that certain 50115 do not reqUIre the envelope for filtrabon function but there may be certain hydraulic or Installation condItIons, which necessitate the use of envelope The SOils do not require ftltenng envelopes are'

• Heavy clay SOils (clay Salls With clay percentage> 60% and hydraulic conductiVIty < 0 1 mid) • Clay SOils In humid regions With clay percentage exceeding 25-30% • Salls With a plastiCity Index greater than 15 • SOils WIth coeffiCIent of umfonmty (Cu» 12 and coarse SOils WIth 90% of particle sizes larger than

maximum drainpipe perfora~on Width

Soils that require a drain envelope In case of new subsurface drainage project,. beSides the deSIgn of subsurface drainage system one important quesbon comes to deSigner's mind is whether a drain envelope will be needed for drainage system, which is being planned As dram envelopes add extra cost to a prolect, ,d IS an Important decslon, If an envelope IS neceSSity, but drains are Installed Without envelope, the pOSSibility of system failure remains high

Sedimentation and clogging of the dram results If

• The openmgs of the drainpipe are too large and bridging of SOil particles does not take place • The SOil itself IS unstable under prevalent water flow gradients and drain envelope does not adequately

protect openings/perforations of the drain • Once the partIcles ana In the dram, the grade of the drain and water veloCIty In the dram is not suffiCient to

flush the particles out of the drain

Types of envelope material

• •

•

Based on the matenal used.the following types of envelopes can be dlstrngulsned

Granular envelopes Organrc envelopes

Fabnc envelope~

Gravel or sand gravel combinations Organic matenals such as peat or top SOil, burldlng paper, hay straw, cloth burlap, com cobs, leather, wood chiPS, Wire corr or coconut fibre, * . woven and non-woven matenals

Required thickness of the selected envelope

Once the above factors have been conSidered, an Idea might have been formed about which type of envelope IS deSIrable Now material thiCkness should be conSidered The required thickness of the envelope could playa role In the selection of the type of the matenal (synthetiC thin or voluminous or granular natural matenal) To create the most favourable hydrauliC conditIon at sOII-envelope Interlace the 10'OOst poSSible

• gradient (I e < hydraulic failure gradient) is desirable It means that gradient at sOII-envelope rnterface (Ienv) should be less than HFG, The thickness of the envelope needs ,to be Increased unless thiS condll>on IS satisfied

Design of gravel envelope at Hlsar proJect

The first step In selecting SUitable gravel filter is to determine gradation CUNes for base matenal and filter matenal On the baSIS of deSign cotena developed by \l S Bureau of Reclamation and U S Army Corps

100

Management of Sahne Salis through Subsurface Drainage

of Engineers, limits are established, which should be mel by a filter matenal for a specific base matenal (WInger and Ryan, 1970, USB R , 1978) The limits are summanzed as

50% size of filter "121056 (4)

50% sIZe of base

15% fine size of filler /

"12t040 (5) 15% fine size of base

If the filter and base matenal are more or less unlfonmly graded Without a lack or excess of certain particle Sizes, a fitter slability ralio of less than 5 IS generally safe, thus;

15% fine size of filter " 5 f (6)

85% fine size of base

In case of Hisar proJect, 50115 of the fanm being to light textured, rt was proposed to use gravel envelope around the perforated PVC pipes to eliminate the sedimentation and choking problems The requITe<l gravel sizes and gradallon for these SOils have been walked out as per the U S Soil Conservation SaMOO recommendations A' 5 to 7 5 cm thick uMiformly graded gravel envelope With gravel size ranging from a 25 to 20 mm all around the pipes was recommended for these SOils. For some laler~ls 60-mesh, nylon filter was also used

Layout

The layout of subsurface drainage system IS adjusted to utilize the natural slope and 10 minimIZe earthwork against slope. Collectors are generally laid along the natural slope and laterals are laid across the general slope The details of position of lateral, gravel envelope, collector and main dram, Junction holes etc are worked out to decide theIT exact locations At Hisar prolect, the slope of laterals was 0 15% and slope of collectors was varying from 01% to 0 15% to keep earthwolk minimum The Juncbon holes serve the purpose of Inspectron manholes and sediment lrap.

Sizes of lateral, colleetor~a"d main drain

Though drainage Coofficlent,for Hlsar prOlect was calculated as.1'S· mmlday, It could lise up to 30 mmlday when watertable reaches to 0 5 m depth below ground level The areas that can be dialned With different slopes and different diameters of pipes can be computed With a capaCity hmrtatlon of 60% for pipeS less than 100 mm in diameter and 75% for pipes for more than 100 mm diameter (due to Silt depOSition, pipe deflecllon, etc) With fOllOWing Equations (7) and (8) The results of calculations are presented In Table 9

Q" 'l'A= 20 "10"d'S"1 05

Q=q'A = 25'10.·d'.'·1 05

Q = drainage volume Im'/d) A = dramable' area (m ) q = drainage coeffiCient (mid) d = Intemal diameter of the pipe (m) I = slope of lateral line (m/m)

If d " " 100 mm Ifd> 100 mm

Table 9 CapaCIty of corrugated pipe lateral dram '(~ICulatlons from Hlsar project)

Intemal Q dla (mm)

75 100 125

01

627 1352

Drainage Max Length at 75 m area spaCing between_laterals (m'/day) (ha) (m)

Slope (%) 015 01 015 01 015

765 2.1 25 278 339 164 8 45 55 599 730

(7) (8)

3067 3740 102 125 1359 1659 4986 6085 166 203 2212 2699 150

-------~~~~~~~----~~--~~---------

101

Chemical Changes & Nutnent Transformation In SodldPoor Quality Water Imgated Solis

/ Drainage Sump

/

, -'

/ f.fter taking Into consideration the expected discharge from collector drains, the construction of sump IS proposed In case of pumped outlet In case of Hlsar proJect, a sump of 4 m diameter and 4 5 m depth below ground level was constructed. The sump was bnck masonry open well With adequate steel relliforcement It was constructed by Sinking well technique. ./ \

Evaporation pond \

In case of Gangetic Plain River network IS qUite good and drain water can be eaSily disposed Probably evaporation pond IS not necessity In those areas The Hlsar farm has no' natural outlel An .evaporatlon pond of 1 ha surface area (100 m"100 m), 2 m depth, and 2 m high embankment was constructed as pumped outlet for storage, evaporation or pOSSible ,reuse of dlllinage water (Kamra et ai, 2000, Kaledhonkar and Kamra, 2004).

Installation of Subsurface Drainage System

The Installation of subsurface drainage system ends WIth construction of outlet In absence natural ouUet, pumped outlet IS constructed The installation of collectors and laterals follows·the construclion of outlet Excavation of trenches, lYing of lateral pipes along With filter matenal and Immediate back filling of trenches are done to 'aVOid any problem In event of rainfall Proper slopes of collectors and laterals are reqUired for gravity flow of water. Manholes' (RCC pipe 25m length and 0 6 m diameter) can tie Installed and collectors and laterals are connected to manholes at 20-30 em above their bottom levels so that manholes act as sediment trap Installation could be conSidered as successful when all the laterals and collectors start funclionlng In case of suffiCient rainfall or Irrigation

Summary

A drainage investigation to deCide drainage cntena IS the first and most important step In the planning of any subsurface 'dr9.1nage system HydrauliC conductIVIty, dralnable porOSity, infiltration characteristics, depth to Impermeable layer, aqUifer parameters, groundwater fluctuations and quality, drainage coeffiCient, topography, availability of ouVet, etc are Important factors whi<;h influence the deSign and layout of subsurface drainage system greatly The collectors and laterals should'be planned taking advantage of natural slopes and Installed as per proposed slopes DeSign of subsurface drainage system for waterlogged saline Salls IS easier as compared to waterlogged alkali SOils. In case of design for alkali SOils, the hydraulic conducbvlty value might, be taken on higher Side considenng expected Improvement In 5011 properties WIth time because of reclamation The operallOn of subsurface drainage system enhances the process of leaching. The SSD controls water table, sallmty and Improves the crop Yields by' proViding better conditions at root zone for growth of crops .

Bibliography

CSSRI,2004 Reclamation and Management of Salt-Affected Salls Central SOil Salinity Research Institute, Kamal 160p ,

IPTRID, 1993 India Proposal for TechnoloQY Research In ImgatlOri and Drainage, World Bank, Washington DC,113p .

Kaledhonkar, M J, and Kamra, S K 2004 Water and salt balance of an evaporation pond constructed for management of subsurface drainage system effluent In' Prcc at Intematlonal Conference on Emerging Technologies In Agncultural and Food Engineering, liT, Kharagpur, Dec 14-17,2004, pp 289-296

Kamra, S K and Rao, K V G K 1992 Drainage Invesbgatlons and enterla for drainage deSign Better farming In salt affected SOils CSSRI Bulletin No 18 32p

Rao, K V G K , Gupta, R K and Kamra, S K 1987 Reclamation of Waterlogged HlghSAR Saline Salls a feaSibility report for CIRB farm, Hlsar, CSSRI, Kamal, 21p

Sharma, R C , Rao, B R M and Saxena, R K 2004 Salt affected 50115 In India-current Assessment In Advances In Sodlc Land Reclamation Proc International Conference on Sustainable Management of Sodlc Lands, Feb. 9-14, 2004, Lucknow, India, 1-26

Singh, N T 1996 Land degradation and remedial measures WIth reference to sallmty, alkalinity, waterlogging and aCidity. In. Natural Resources Management for Sustainable Agnculture and EnVIronment (Deb. D L Ed) Angkor Publication, New Deihl, pp 442.

U,S B R ,1978 Drainage Manual U S Govt Pnntlng Office, Washington, 286 p Wnger, R J and Ryan, W.F 1970 Gravel envelopes for pipe drains deSign Trans ASAE 14(3) Amencan

. SOCiety of Agncultural Engineers, St Joseph,471-479

,

102

Management Strategies for Sustainable Crop Production in Saline Vertisols

R. L. Meena', R. K. Yadav' and Khajanchl Lat' f AICRP (S SW) and 2 D,v,s,on of SOIl and Crop Management Cenlml SOIl SalInity Research Inslllllie. Kamal.132001, HafYBna

Introduction

In the course of the present century, the world population has Increased from less than two thousand mllhon to over Six and a half thousand million Until one hundred years ago, the expanding population's Increasing needs for food, fuel, fibre and construction matenals were met from the land by cul~vatlng progressively larger areas The -much greater Incniase In populallon dUring thiS century has been supported mainly by Intensifying the use of much of the land that IS already cul~vated In the next 25 years a further 200 million people Will be added to global population and most of thiS growth will take place In the trop'CS As a' result, Ihe demands which Will be placed on Ihe 5011 and water resourc;es of the troPICS will far exceed those of the past In the arid 'and semi and regions where low rainfall coupled With uncertainty of Its occurrence has been the limiting factor In the crop production The salt affected Salls are an Important ecological entity In India and It IS estimated that nearly 6 73 m ha IS affected With thiS menace The problem being dynamiC m nature, the extent keeps on changing The extent of Vertisols covers a total of about 340 million hectares Most Vertisols occur In the semi-and trOPICS, mainly In Gezlla and other parts of central Sudan, South Afnca, Ethiopia, and Tanzania In Afnca, the Deccan plateau of India ,In ASia and Australia The Extent of Vertisols and associated Salls In India IS approximately 72 g million hectares, compnslng 22 2 % of total geographical area of the country Verosols and associated Salls are mainly confined between 8°45' to 26° N latitude and 60 to 83 0 E longitude In India, extenSively occurnng In Madhya Pradesh, Maharashtra, GUjarat, Andhra Pradesh, Tamil Nadu and Rajasthan Vertisols are imperfectly to poorly drained, leaching of soluble weathering products IS limited, the contents of available calCium and magnesium are high and pH IS above 7, This is due to the very low hydraulic conductiVity As a result of 5011 degradation, there have been negative effects such as decrease In farm production due to abandoned farm lands, decline In resource prodU~Vlty, and cut back In resources use Similarly at the regional level there have been displacement of labour from agnculture, Widening of income disparities and adverse effect on the sustalnability of agnculture based sectors_ For belter management of land and water resources would not only tackle dynamic nature of 5011 salinity but also Increase the productiVity of the Salls

The Problem

For agncu~ural purposes, the Salls that contain exceSSive concentrallons of soluble salts or exchangeable sodium or both are referred to as problem Salls These salts seriously hamper crop growth and Yields Imgation IS one of the most Important Inputs -to agncultural production system espeCially In and and seml-and areas However, oWing to changes in natural hydrologiC balance after Introduction of ImgallOn, most of these areas expenence nse In water table This nse In water table leads to water-logging and consequently sallnlsatlon whiCh, In tum, seriously hampers crop production The reclamation and management of salt· affected SOils has become Important and urgent due to ever mcreaslng pressure on land resources to meet food requllements of increaSing populatIOn and also to mlligate the penis of lITIgated agnculture In many Imgatic>n project command areas In addition, since salt-affected 50115 commonly ~ur In productive Irrigated lands, thell reclama~on and strategies to prevent further prollfera~on IS of paramount Importance Sallaffected SOils cover an area of about 6 73 million ha In India, almost half of It l,es In canal command areas Five states, namely, Haryana, PunlaD, Ralasthan, GUjarat and Andhra Pradesh accounts for ~8 per' cent of total salt affected Salls of the country, Based on pH, exchangeable sodium, quantum and nature of salts, these SOils have been claSSified in three groups They are alkali, saline and saline-alkali

Saline Vertisols

S Among 11 soil orders (Andlsols, Alfisols, Andlsols, Entlsols, Histosols, Inceptlsols, Molhsols, OXlsols, pOdosols, Ultlsols, Vertisols), Vertisols form an Important 5011 group These Salls can be defined as clay SOils

:Ith high shnnk-swell potential that has Wide, deep cracks when dry Most of these Salls have distinct wet and ry penods throughout the year SOils With high content of swelling clays, deep, Wide cracks develop dunng

dry periods SOils With 30% or more clay to a depth of 50 ern and shrinking/swelling properties Vertisols and aSSOCiated Salls are generally very deep (150-200 cm), fine textured With clay content ranging from 45-68% a~ montrnonllonlte as the dominant clay mineraL The SOils exhibit high shnnk-swell potential and develop WI e craCks of 4-6 cm extendmg up to 100 ern depth The water holding capacity IS high but permeability IS :mP8rfect to poor These SOils are calcareous In nature (2 to 12% CaC03) The salinity status In the cultivable and vanes Widely tram EC 05 dS m-' In monsoon to 50 dS m-' In summer The saline VertJsols In GUlarat occurs In Bara tract which expenences a tropical climate The annual rainfall ranges from 275-1484 mm With an average of 737 mm The onset of monsoon IS errallc which normally affects crop seeding operallons,

Chemical Change,s & Nutnent Transformation In SodrcJPoor Quality Water Irrigated SOlis

, germinations and seedling establishment Cotton IS, the dominant crop grown In the 'khanf followed by sorghum and pearlmillet. Pigeon pea IS also grown In some area Mostly ramted khanf crops are grown In thIS area In the' rabl season the land IS either kept fallow or some fodder sorghum IS grown on the residual mmsture" . , , Soli Salinity

The Vertisols have low permeability, Salls haVing comparable sallnlty'affect the crop growth m a greater magnitude as compared to the light textured Salls As these Salls can sustain the deep rooted crops and are'havmg fine capillary pores, salt concentrations even at a conSiderable depth affect the crop growth and contnbute to surface sahnlty through capillary nse The salinity of su'rface Salls vanes from 046-21 dS m". The salinity of the sub-SOil of Bara tract ranges from 04-159 dS m" ThiS transient salinity fluctuates With depth and also changes With season and rainfall. Even In the absence of contribution of ground water" the excess use of water may also help the sub-SOil salinity to come to the surface layer.

Severity of Salinity

The light textured Salls With sallnlly of more than 4 dSlm are claSSified as salme SOIl In the heavy textured Salls I e Vertnsols and associated Salls, because of their low permeability the salinity of >2 dS m" IS detnmental for crop production In the area It was found that ,39 6 % of surface 50115 are free from salinity « 2dS m"), 49 3% 50115 are saline (2-4 dS m") and only 11 1% SOils are having salinity greater than 4 0 dS m·'. Whereas 10% of the sub-SOils are havlll9 salinity less than 2 dS m" , 15% between2-4 dS m" and 75 % greater than 4 dS m" ThiS pattem of salinity bUild, up may be because of prevIOus contmuous contact With saline or brackish water due to the proximity 10 the sea The sub-soil salts are very difficult to leach down further because of the presence of high saline groundwater table Though shallow rooted ralnted crops are not affected by Ihe sub-so" salinity, deep rooted crops like cotton and arhar are affected because of poor contnbullon of SOil mOisture from lower profile

Causes of Origin of Salts

The pOSSible sources of excess salt In SOlis are given below 1) High salt depOSits Inhented by the SOil from the onglnal parent matenal during SOil forming process. 2) Salls contained In Irrigation water applied or in the water lost In conveyance through I("9atl\,n dlstnbubon5

system, 3) Salt may come through upward movement (capillary action) of shallow brackish ground water,

4) High sub-SOil water table thus poor drainage conditions, 5) Back water flow or intruSion of sea water In coastal area,

6) Seepage from canals and farm-Imgabon systems due to inJudiCIOUS use of water, and

7} High cropping Inlenslty and' replacemenl of low 10 h!g~, waler reqUlfmg crops caUSing 9raoual "se waler table nse

, The Concept of Sustalnability and Non-Sustalnabllity

,All forms of production systems eXist today, from nomadiC herding to continuous. intenSive monocrop systems Their dlstnbubon is determmed by so" and dlmate condlbons, and by SOCial and economic factors In very'general tenms, as one moves from dner to wetter areas, pastures and animals become less Important, and trees more so Population denSity IS greatest where 50115 are most fertile, and management systems the most Intense Most producbon systems have evolved so that they are sustamable In terms of the enVIronmental conditions prevallm9 at the tlme-,"cludlng the level of demographic Pressure Given that demographiC pressure has Increased dramatically over the past century, and Will continue to do so for the next half century. sustalnablhty In relation to agncu~ure and 5011 management must be defined to ,"elude the need for Increases In demand to be mel FAO (1991) has gIVen the follOWIng definrtlon 'A sustainable agncuttura! system is one which Involves the management and conselVa~on of the natural resource base, and the orientation of technological and institutional change in such a manner as to ensure the a!tamment and conllnued satisfaction of human needs for present and future generations Such sustainable development cons elVes land, water, plant and a!llmal genetic resources, and IS economically Viable and SOCially acceptable (FAO, 1991)'

Definitions of Agncultural Sustalnablhly 'It means survival"

A subSistence farmer

'Low Input. no Input, organiC farming' An envlrof)meniaitsi

'LIVing' on Interest and not capital"

104

Management Strategies for Sustainable Crop Production In Saline Vertisols

An economIst 'The successful management of resources for agnculture to satisfy

changing human needs, while maintaining or enhancing the quality olthe enVIronment a~d conserving natural resources'

FAD Research and Technology Paper No 4 Sustamable Agncultural Production. ImplIcatIons for InternatIonal Agncultural

Researc/1, TAC/CGIAR, 1989

Agnculture has evolved through vanous stages of shilling cultlvabon Into semi-permanent systems, and to systems of conbnuous cultivation All of these systems are being practiced In different parts of the wol1d at the present time All of them can be sustainable, and all can fall, dependmg on the biophYSical and socio-economlc conditions in which they are practiced Indications of success or fSilure are given by changes In per caput food crop producbon In different regions Declining In !he productIvity of soils .Ieads to the expansion of cultivation onto marginal Salls Vllithln a stable political and social enVIronment, farmers Will always slnve to evolve a system that IS suffiCiently productive to support their Immediate social group, for the present and foreseeable future Where maJkets eXIst. they wll! _also strive to Increase production to provide economic benefits for themselves and their families Difficulties anse, however, as a result of changing SOCIal, economic and political circumstances Of greatest slgmficance among these has been the mcreaslng demands on the land as populations have grown, leading to conflicts over both land and water supplies ProductiVity Will only nse In favorable SOCial and economic Circumstances, and It IS the role of governments to establish such Circumstances In the follOWing sections, the pnnClples on which sustainable land management practices must be based are deSCribed

Establishing Sound Principles of Good Soli Management

Good 5011 management has always reqUired that the 5011 be used In such a way that ItS productiVity IS maintained or preferably, enhanced ThiS reqUJres that the chemical and phYSical condition of the SOil does not become less SUitable for plant growth than when cultivation commences Cultivation normally means thafthe 5011 WIll, In fact, deteriorate due both to nutrient removal when harvesting crops, and to phYSical damage to the SOil structure What IS essential IS that the detenoratlon IS reversible, by chemical additions to the SOil, mechamcal manipulation, or natural processes of fertility restoration under pasture or trees ThiS Implies that the soli must be resilient, I e after being subjected to the stresses Involved In crop production, It must have the ability to return to ItS former condition, or an Improved condition (Greenland and Szabolcs, 1994). The land must produce on a secure baSIS, the natural resources must be protected, and the management system must be economically Viable and SOCially acce~table However It must also be recognized that land cannot be managed sustalnably unless the SOil, whiCh IS a component.of the land, IS properly managed. ThiS requlles maintaining and Improving SOil productiVity, aVOiding and rectifying SOIl degradation, and aVOiding enVIronmental damage

Maintaining and Improving Soil Productivity

If a soli IS to sustain the prOduction of crops It must 1 PrOVide the nutnent reqUirements of the crop,

2 ProVide a phYSical medium

• In which the plant roots can grow adequately so that water and nulnents can be absorbed,

• Which stores sufficient water for the crop, and

• Which allows water to enter and move In the 5011 to maintain the water supply as It IS transpired by the crop and evaporates from the 5011;

3 ProVide a medium In which SOil organisms are able to

• • • •

Decompose organic matenals, releaSing nulnents to the plants,

AsSiSt the transport of nutnents to plant roots,

Compete successfully With pathogens which might othelWise infect roots and damage the plants, and

Form the SOil organic compounds which Will have a favourable effect on other 5011 properties

Management Strategies for Vertisols

The vertisols are charactensed by heavy textured and domination of shnnk -swell type day minerals, which create unfavourable SOil phYSical condillons for crop growth. It is proposed to further strengthen ~searCh In relation to preventive, ameliorative measures and evaluation of different tree species of fodder,

el and fruits for such conditions, and management of Salls

Chemical Changes & Nutnent Transformation In Sadie/Poor Quality Water Imgated Solis

land Configuration and Tillage Practices

Alternate ridges and furrows are the most commonly used layouts In the Vertisols and associated 50115 of ~ndla The ndges are of 35 em high and.75-100 a;n wide depending upon the space requirement of the crops In saline salls the plot size elln be kept small and well levelled to facIlitate proper leaching and unllonn Imgation The ability to cover large areas rapidly IS essential In Vertisols and associated sOils I.e more so in saline and sodlc sol/s because of very nalTOw workable mOisture range, If the bIlage IS attempted when the sOil IS too wet, It IS dIfficult to run the machines and, It also destroys the 51JII, structure badly ,If tillage IS attempted when the SOIl is too dry, It requIres more draft The brg clods folTIled hamper the seed germrnatlon For deriving max,mum advantage, the sol would have to be pnmarily tilled early rn the dry season II would help In both reducing the evaporabon by cutting up capillanes and conserve ,mOisture and thus reduce the sallmty bUild up In the SOIl '

Sultablo Crops

Usually the Vertisols are best SUited for the graminaceous crops such as nee, sugarcane, grasses etc because of the" extensIve root system which can Withstand the damage caused by crackIng However, because of the presence of hIgh sub-surface soil saJrMy and prevaIling ground water table WIth hIgh salrnrty, crops With high waler reqUirement are not recommended The graIn millets as well as fodder mrllets can be successfully grown WithOUt Imganon In a nOlTIlal monsoon year or with one or two Irngatlons In defiCIt rarnfall years Cotton and pIgeon pea are best and extenSIvely grown on VertIsols because of thell deep root system, both under "ligated and rain fed conditions These crops call mine both mOisture and nutnents from deeper layers of the soli In an average normal rarnfall year 80 percent potential Yield of cctlon and pIgeon pea can be obtained from these 50115 Without Imgatlon, In the rabi season, crops like dunum wheat, OIlseed crops like mustard, saff/ower and dill can be grown With lImited Imgation and lor Imgabon of canal water In conJuncbon Wltl'I saline ground water These crops can be successfully grown In the saline black Salls With salllllty range 01 ,4-5 Os m" (Gururala Rao et al ,2oo1a) Expenment on farmers' field revealed that durum wheat Yields upto '2,5-3,0 t ha-' With 3 supplemental IITlgabOns In these sol/s Vegetable crops such as chilli, bnnla! and tomalo can be culbvated With fair success These crops need well draIned salls because of thelf rntolerance to water ,logging conditIons and can be grown In the month of Sept/Oct after Withdrawal of effectIve monsoon Among frUIt crops sapola, aonla, bel, ber, and pomegranate hold promise in Ihese Salls For highly salIne SOIls cultivation of salt tolerant and economically important crops like SaJvedora perslce can be grown rn the salInity range of 1~ dS m" .. Salt tolerant forage grasses like Dichanlhium annulatum, Ae/uropus lagopoldes and Eragrostls speCIes can be successfully grown up to salinity of 14 B dS m" (Gururala Rao et ar., 2001b),

Blo-Sallne Agriculture

tn areas With poor resource endowment sltuabons, the farmers are not In a posItIon to adopt chemIcal amelIorative measures Under such SItuatIons, one of the optIons IS to go ,n for salt tolerant plant types It IS proposed to strengthen the crop breeding programme, explodation of natural resourceS (vegetaliOn) and screening 01 halophytes of economIC use

So~ln9

SOWIng IS the most difficult operation In agnculture The narrow Wolklng moisture range and crust fOlTIlatlon, which are unique to Vertisols and aSSOCIaled Salls, cause hindrance to Uniform ge"",nallon of seeds, In the sahne conditions, the 'germinatIOn of seed IS further reduced. In the khanf season If proper germmatlon of seeds IS not achIeved after first two showers, the success of achIeVing the same Is dImInIshed In these sol/s because of temporary water logging associated With rains The first monsoon showers reduce the salt on the top few em of the Salls and close the cracks which cause the temporary waterlogging of 3-7 days by'successlve rains Moreover the uncertainty of lalns alsCl contnbutes tCl the delay and poor gelTIlinalion Co~on 13 sensllive at germlnalion stage (Salwa et ai, 1992) but can be grown If proper gelTIllnabon IS ensured by the pre-soWing gelTIlrnatlon With good qualltv water In most parts of the Vertisols and assocJated 50115 area, pre-soWing IrrigatIon IS done because the land IS not free for cU~lvatlon at Ideal SOIl mOisture condition and hence the farmer has to Imgale the tand for getting proper lillh for sOWIng and u",form gelTIlinatlon In salIne and sadie SOil pre-sowrng Irngatlon not only reduces the Inibal salIne ccnditlon but also negates the effects Cl! crusting In case of post sowing Ifngabon, the gelTIllnabon and seedling establishment al'8 to be followed by hoeIng Which proVides the effect of soil mulch and reduce the excess SOil mOisture loss In the Vernsols of Central India, pallewa (pre-soWing Imgatlon) or Irrigation Immediate after dry sOWIng of wheat IS essentIal for proper gelTIllnatlon and seedlrng establIshment of wheat.

106

Man.agement Strategies for Sustainable Crop Producbon In Sahne Vertisols

Water Management

Soli and groundwater sltuabons In the area emphasIZe the need for deficd water management with supplemental Imgatlon In the khanf season and _inlmmum Irngatlon fonn canal water dunng rabl season Scheduling of IrngallOn.ls very difficult rn the V~rtlsols and associated salls partlcula~y when the 5011 IS affected by varyrng degree of salinization Cracking and surface sealing affect the water use effiCiency I the area where there IS a substanbal sub-surface salinity and high saline ground water problem there cannot be any Imgabon for the purpose of leachrng the salt ITherefore, the prevenloon of further nse of sallmty_level IS of strategic importance Moreover leaching reqUirement concept does not apply to Vertisols due to lack of unlfonllity In water movement in the SOils to effecl leaching, In these SOils the scheduling should be planned and framed In such a way that the net depth of SOil penetrated by water does not exceed 60-70 cm which IS well Within the root zone

Options of Conjunctive Use

As such the ground water needs suffiCient dilution before Its use for agnculture purpose Construcllon of tube wells In these areas should be made in such a way that the water GOuld be blended In the channels In an appropnate proportion to get the deSired quality at the outlel As the use of saline water In long tenn may lead to detenorabon of the SOil structure, constant monltonng of water quahty and sallmty status of 5011 IS needed The chOice of the crops should be made on the baSIS of salt tolerance and low water requirement Experiments conducted on the use of saline water and conjunctive use of waters on saline black Salls indicate that low water reqUlnng crops such as mustard, saffiower and dill may be IdeaJ opllons for these areas Two good quality water Irngatlons of 5 em each along With one saline water (4 0 dS m·') are sufficrent to raise these crops successfully In general cultivation of low water reqUiring salt tolerant crops, better mOisture conservation practices needs to be adopted

Table f B(lstlng and potential (lrngated) Yields of different crops, In the Vertisols area

Crops B(lsbng Yields (kg ha·')

Paddy 877 VVheat 601 Sorghum 919

Pea~ millet 917 Pigeon pea 585 Castor 1925 Cotton 615

PrOjected Yield potential (kg ha·')

3900 2400 2500

2600 150

2315 2000

Source In. Nayak et ai, (2004) CSSRI Status Paper 1

Bibliography

BaJwa, M, S , Chaudhary 0, p, and Josan A S 1992. Effect of conlonuous Imgatlon With SodlC and saline sadie water on soil properties and crop Yield under cotton-wheat system in north-westem India Agricultural Water Management 22 345-56

FAO 1991. FAOlNetherlands Conference on Agnculture and EnVIronment S-Hertogenbosch, The Netherlands, 15-19 Apn11g91,

Greenland, 0 J and Szabolcs, I (eds) 1994 , SOIl ReSIlience and Sustainable Land Use CAB International Wallingford, U K.

Gurura]a Rao G , Nayak A K and Chlnchmalatpure A R 2001a Conjunctive use of sahne and su!face water for culbvabon of some arable crops on salt affected black Salls With high saline ground water table Journal of IndIan SocIety of Coastal Agncultural research 19 (1&2) 103-109

GururaJa Rao G., Nayak A K Chlnchmalatpure A Rand V Ravlndra Babu 2001 b Growth and Yield of some forage grasses on salt affected black Salls Journal of Maharashtra Agncultural University 26(2) 195-97

Nayak A K, Anil R Chlnchmalatpure, M K. nhandelwal, G GururaJa Rao and N K. Tyagl 2004 SOil and water resources and management optIOns for the Bara tract under Sardar Sarovar Canal Command A Cnbcal Appraisal CSSRI Slatus Paper 112004, Central Soli Salinity Research Inslltute, Regional Research Statlon,Bbharuch 392 012, PP 20

107

/ Crop Tolerance to Waterlogging and Soil Salinity

/ /_

D. P. Sharma . D,vIsIon of SOil and Crop Management Central SOIl Sa/lfilty Research Institute. Kama/-132 001

liitroduction , \

Plants differ widely In tolerance to different kinds of abiotic and biotic stresses, and their comparauve tolerance IS evaluated based on four cntena Ie germlnauon. survrval, absolute growth or Yield and relative growth or Yield Large numbers of Investigations on differential response of crops and their vanetles have been reported at germination stage and attempts were made to extrapolate the tolerance limit for final performance More than often such attempts may be frustratrng because tolerance charactenstrcs differ from one growth stage to another Plant survival has been used as a cntenon by ecologists but without Yield, plant survival alone has little value to the farmer On the other hand, It can be useful cntenon for plant breeders Absolute plant growth or Yield IS of greatest Interest to the farmers However, thiS cntenon does not permrt companson between crops because yields of different crops are not comparable The relatrve growth or yield IS defined as the Yield on saline and waterlogged salls as a fraction of the Yield on a non-saline/waterlogged sorl under Similar environment and nutntlonal conditions The main difficulty with this method IS to deCide the level of Yield reductron at which different plants can be compared LIke a researcher companng salt tolerance at 10 peraent Yield reduction may essentially end up differently than other who compares at 50 percent Yield reductron Nevertheless, thiS cntenon IS favored wo~d over and IS Widely used for relative comparrson In addition to these four crrterra, attempts have also been made to evolve a crrtenon based on metabolic parameters The sodium and potassium contents In plant tissues and particularly their ratios have been found to be SUitable parameters to Judge the relalrve tolerance of crops. ThiS lecture summanzes the effects of stress due to surface water stagnation, high water table and excess salts In the root zone on plant growth

Surface Water Stagnation Stress

Unplanned Implementation of developmental and Irngatron projects is causing surface stagnatron of ralnlimgatron water on croplands and nSIng water table In Imgatlon commands because of unrealistiC drainage deSign systems and therr Inadequate maintenance Problem IS even more severe In alkali lands under reclamation. where water contrnues to stand on land surface for longer duration than normal lands Hrgh sodium concentrauons and high pH Impart adverse sorl phYSical properties leading to poor aIr-water relalionshlps Application of gypsum (CaSO.2H20 and continuous cropping for 2-3 years Improve surface layers, but subSOil layers continue to conduct poor water penetration, low water storage and movement (Sharma, 1986) Most of crops not adapted to wet-land conditions are severely affected when water stagnates even for a short pened The extent of damage or Yield reduction depends upon the crop and Its growth stage, duralion of water stagnation/flooding, type of SOil and prevailing agro~llmalic conditions In alkali Salls where the problem of water stagnalron IS more acute after rrngalron or rams. one can Cite only a few expenmental

• eVidences that have been gathered to quantify the yield loss (Shamna & Swarup, 1966, 1989b).

Several field expenments have been conducted at CSSRI, Karnal to evaluate the effect of water stagnation on growth of different crops Salls of eJ(perrmental site were Inrtlally highly sodlc but after addilron of

'gypsum and contrnuous nee-wheat cropping, pH and ESP of the Salls decreased to 8.7 and 24, respeclrvely in 0"30 em depth· 5011 Different crops were cultivated With therr recommended package and practices Water stagnation treatments were Imposed at different growth stages and different penods The data on nutnents composition of roots and above ground plant parts and ODR "alues In SOil reveal that In general water stagnatron for more than one day IS harmful to "anous crops (Table 1) It has also been observed that the adverse effects of water stagnation are relatively more when water stagnation occurs at the early growth stages Water stagnation decreased ODR and reduced Ion uptake, espeCially of N, p, K, Zn and Cu, and increased the absorption 01 Na, Fe and Mn Generally ODR depletion IS higher and the lower values persist for longer under water stagnation resullrng In lower Yield (Fig 1) Mainly poor aeration and Imbalance ,n the nutnent uptake causes Yield reduction but several other factors like reduced root growth, lomc Imbalance andlor nutnen! stress might also contnbute to decline In Yield

Nitrogen defiCiency trrggered by flooding IS conSidered as an Important cause of low Yields (Swarup and Sharma, 1993). StudJes have also shown that rncreaslng the rate of top-dressed urea-N (50-75%) after water stagnatron helps In alleViating the adverse effects of temporary water stagnation Supplementing N also promot uptake of N, p, K, Zn Since, such a strategy cannot be adopted on large scale, it cannot be recommended as a long-term solulron of the problem The results of thesa studies clearly indicated that to -ensure optrmum yield of crops In partrally reclaImed sodlc SOils excess Irrrgation water must be drained Within one day of Imgatlon or rains An Integrated drainage system would be the most cost-effective and eeo-frrendly solution of the problem

Crop Tolerance to Waterlogging and SOil Sahnlty

Table 1 Response of vanous crops to short-tenn water stagnatIon

DuratIon of water Grain yield (Mg/ha) stagnabon (days) Wheat Barley Mustard P mlliet Sunflower PIgeon pea

0 4.41 365 143 222 186 1.41 1 370 352 131 208 162 / 135 2 363 339 120 I.B9 150 122 4 313 318 112 174 138 1.16 6 2.35 275 102 163 129 1.11

CO(p=005) 028 028 022 012 006 013

Growth stages J

VegetatIve 322 1.11 190 151 1 17 Flowering 337 132 198 155 134 CD (p = 0,05). NS 0.14' -010 004 010

'vegetatIve Barley-25_days after sowIng (DAS), Mustard-3D DAS, Sunflower-50 DAS, PIgeon pea-35 DAS, Peari-mil/et-25 DAS Flowenng Bariey-ilS DAS, Mustard-{lO DAS, Sunflower -80 DAS, PIgeon pea-7S DAS, Pearl-millet-50 DAS (Source: Sharma & Swamp, 1988, Sharma & Swamp, 1989b, Singh et al , 2002, 2003, Thakur et al. 2003; Sharma et al , 2005)

IX; ", 'Q',20 ,o'"~ .

o 2 4 S '8, 10 Days atterwater stagnation

12

, . ''','''' '

Fig 1. Oxygen diffusion rates In different water stagnation treatments

A review of the available data on the Yield of various crops as a function of water stagnation was made The appncation of the Maas and Hoffman mOdel Yielded the threshold anti slope values as reported In Table 2 It may be seen Ihat in most cases Ihe threshold is less Ihan 1 day and dechne In Yield from 4 5% 10 23% for each additional day of waler stagnation

High Waler Table Stress

Since the 5011 IS the living ~medlum for plant roots, ItS environment rn tenn of salt and water neglmes, aeraboo, temperature and tilth determine crop growth AlthOugh, the depth of water table has no direct effect on crop growth, but Indirectly It effects crop growth by InfluenCing the sari edaphlc ervlronment and often crop ~Ields are affected With high water table For many crops and Salls, It IS desirable to have water table at least h Glow 80 em However, shallow water table may not always be a curse, particularly when It IS free from sahnlty liZard, as IS the case In most humid regions Water table contributes substantially towards the crop evapo-

~an5Plratlon On the other hand, shallow water table causes the hazard of 5011 sahnlzation, espeCIally where e ground water IS brackish and potential evaporative demand IS high The gradual and Irreversible

Sallnrzaton of Salls may have been the process responsible for destructron of once thnvlng agrrcultural C1vlhzatrons Presence of water table at 5011 surface or nearlwrthln root zone, replaces air from SOil pores

109

ChemIcal Changes & Nutrient TransformatIon In Sodlc:lPoor Quality Water Imgated SOIls

leading ,to'O, defiCiency Oxygen defiCiency affects root growth and nutrients uptake by groWing plants The opllmum depth of water table for vanous crops In non-saline areas IS given In table 3

/ .' I ;rable 2 Water stagnation tolerance of vanous crops at different locations In India

,Crop Water s1agnaboll tolerance mdlces " Threshold (days) -' Slope ('!o) DINs5Q (days)

Deihl Hisar

Kamal

Ludhlana

Pigeon pea Cowpea Pigeon pea Wheat Baney Mustard Pearl millet Wheat

16 232 38 08 66 84 05 92 60 00 70 72 10 44 122 05 68 7,9 00 53 94 19 92 7.3

Table 3 Optimum depth of water table for vanous crops In non-saline areas

Crop Rice Wheat Barley Sugarcane Cowpea

Depth of water table (em) 530 60 90 60 75

Crop Soybean Gram Maize Cotton Pearl millet

Depth of water table (em) 125 90 120 125 125

Water table affects 0, supply to the groWing plants and nutnent uptake, For an example, oxygen content of a heavy SOil at depth of 23 em was sharply reduced as the water table was raised from 90 to 30 em depth and the ootton Yield and nutnent uptake were decreased acoordlngly (Ta~le 4)

I

Table 4 Water table depths and SOil air 0, oonten~ yield and nutrients uptake of ootton

Water table depth (em)

O,at23 em (%) Cotton Yield (g)

30 60 90

1.6 83

132

Source' Meek et al (1980)

57 108 157

Excess Salts In Root Zone Stress

Soil Salinity and Plant Growth

Nutnent uptake by 5 plants (mg)

N P K 724

1414 2292

85 120 156

1091 2069 3174

. Excess salinity affects crop growth In three ways I e first and most Importent IS Increase In salts ooncentratlon causing low avalla~llIty of SOil water to plants even though the SOil may appear qUite mOist ThiS IS because the osmotic pressure of the SOil solution Increases With the Increase In salt concentration and the plants are unable to extract water as readily as they can from a relatively non-saline SOil In addition to the osmotic effect of salts In the SOil solution, at high ooncentratlon, absorptIOn of an individual Ion may prove tOXIC to the plants BeSides, preferential absorption of one Ion may also retard the absorption of other essenual plant nutnents necessary for nonmal grow1h of plants It IS believed that the adverse effects are usually due to cumulative effects of these factors although one or other may be dominating under specific conditions In many cases salinity problem occurs along With the problem of aikallMy It IS particularly true In the case of saline-alkali Salls Maybe therefore, crop se/ectlon In such cases ought to be made on the baSIS of tolerance to SOil salinity than alkalinity. The Yield reductions due to excessive salts oould be ascnbed to the follOWing three factors, which may influence plants Singly or In oombinatlOn

• General osmobc effect regulabng osmotic pressure of the medium • Imbalance In the uptake of Ions • Toxic eHects of accul)1ulatlon of certain causative Ions on specific plants

110

Crop Tolerance to Waterlogging and 5011 Sahnlty

Since crops differ In their tolerance to salinity, selection of crops and cropping sequences for saline salls assumes significance In overall management of saline solis and more so particularly for selection of first crop Since complete reclamation IS not attained in the inlbal years, tolerant or semi-tolerant crops that can withstand antecedent salinity levels are preferred (Table 5)

I

Table 5 Crop groups based on response to salt stress

Senslbve Group ReSistant Group Highly senslbve Medium sensitive Medium tolerant Highly tolerant

Lenbl Radish Spinach Barley

Mash Cowpea. Sugarcane Rice (transplanted)

Chickpea Broad bean Indian mustard Cotton

Beans Vetch Rice (direct sowing) Sugar beet

Peas Cabbage Wheat Turnip

CalTot Cauliflower Pearl millet Tobacco

Onion Cucumber Oats Safflower

Lemon Gourds Alfalfa Taramlra

Orange Tomato Blue panic grass Kamal grass

Grape Sweet potato Para grass Date palm

Peach Sorghum Rhodes grass Ber

Plum Minor millets Sudan grass MesqUita

Pear Maize Guava Casuanna

Apple Clover, berseem Pomegranate Tamanx

AcaCia Salvadora

In and and semi-and regions of northwest India, the recommended croppmg sequences for saline salls are pearl rmllet-barley, pearl millet-wheat, pearl millet-mustard, sorghum-wheat or barley, sorghummustard, cluster bean-wheat or barley and cotton-wheat or barley Pearl millet-wheat. pearl millet-barley, pearl millet-mustard, 'sorghum (fodder)-wheat and sorghum (fodder)-mustard cropping sequences are more remunerabve Cotton based cropping sequences are not benefiCial because Winter crops foliowIMg cotton sufler In water scarCity areas, mustard could replace wheat In cropping sequence as Its water requirement IS low than wheat

Maas and Hoffman (1977) prepared a comprehenSive table listing ECI , slope and ECo for many crops With the pieceWise linear model Such comprehenSive data for Indian condlbons IS lacking Gupta (1992) collated the eXisting Informabon on thiS subject and determined Eel, slope and ECo for several crops and sOIVcllmabc conditions (Table 6)

Based on a reView of experimental eVidence Gupta and Yadav (1986) reported cntical limits of Sa hOlly of the irrigation water at which Yield declines by 10, 25 and 50 percent of opbmum Yield that IS expected with use of fresh water The relative crop tolerance of 3 major crops wheat, barley and mustard )0 sallnJIy of 0-30 em 5011 depth IS depicted In Figures 2. Such data could be made use of In working out tolerance of a crop to soli saltnrty proVided leaching fracltons could be properly esllmated.

111

Chemical Changes & Nutrient Transformation In Sadie/Poor Quality Water Irrigated SOilS

Table 6 Crop tolerance to sOil sallmty for working out leaching requirement /

Sites / Soil type Crop CntlCal EC (dS m-') Slope ('!O) ECso (dS m")

Sampla" Sandy loam Wheat 40 290 5.7 Mustard 60 150 93 Barley '70 190 96

Kamal Sandy loam Mung bean 18 20.7' 3.3 Mustard 38 69 11.0 Sorghum 22 106 69

Agra Sandy loam Wheat 82 198 10.7 Mustard 61 20.7 85 Berseem 35 125 75 Tomato 1 3 6.5 90

Dharwad Black clay Wheat 23 205 47 Safflower 2.8 20.7 5.2 Sorghum (w) 2.1 39 149 ltailian millet 61 500 71

Indore Black clay Berseem 23 205 47 Safflower 28 207 52 Sorghum (w) 2 1 39 149 Italian millet 61 500 71 Satana 1.1 2.2 23.9

Indore Slack clay Berseem 2.0 11 2 65 Safflower 2.8 50 128 Maize 05 79 68

fig 2 Relatlons,hip between SOil salinity and wh~aL ba~ey and mustard Yield on farmers field

Blbllog raphy

Gupta, I C. and Yadav, J S P 1986 Crop tolerance to saline Imganon J Indian Soc. SO/I SCI. 34 279-86 Gupta, S K and Gupta, I.C 1987 Management of Salma Soils and Water. Oxfcrd and ISH Pub Co New

Deihl 339 p. Gupta, S K and Sharma, S K 1990. Response of crops to high exchangeable sodium percentage Img SCI

11 173-9 Gupta, S K, Singh, R K and Pandey, R S 1992 Surface drainage reqUirement of crops Application of a pieceWise linear model for evaluatmg submergence tolerance ImgatIDn & Drainage systems 6249-261 Maas, E V and Hoffman, G J. 1977 Crop salt tolerant Current assessment J Img Drain Ow. ASCE, 103

(IR) 115-34 Sharma, 0 P 1986 Effect of gypsum application on long-term changes in soil properties and crop growth In

. sodle Salls under field conditions J Agron Crop SCI , 156 166-172 Sharma, 0 P and Swarup, A 19S8. Effect of short-term flOoding on growth, Yield and minerai composilion of

wheat In a sO\Jicsoll under field conditions. Planf & SOIl, 107.137-143

112

Crop Tolerance to Waterlogging and SOil Sahnlty

Sharma, D. P and Swarup, A 1989a Effect of short-term waterlogging on growth, Yield and nutrient compOSition of wheat in alkaline soils J Agnl SCI (Camb), 112 191-197

Sharma, D P and Swarup, A 1989b Response of pearl millet to short-term flooding In a moderately Sod'C 5011 under field condition J Agnl Sci (Gamb.), 113331-337

Sharma, D P, Singh, M P., Gupta, S K and Sha';"a, N L 2005 Response of pigeon pea to short-term water stagnabon In a moderately SodlC field sOil J Indian Soc SOil SCI , 53 243-248

Singh, M P., Sharma, D P, Gupta, S K. and Sharma, N L 2002 Effect oftlms and duration of water stagnabon on growth, Yield and minerai compoSItion of sunflower In a gypsum amended alkali SOil CUff Agric, 26'23-29. I ..

Si:1gh, M p, Sharma, D P, Gupta, S K and Sharma, N L 2003 Response of sunflower to top-dressed N after short-term water stagnation In a gypsum amended alkali SOil J Waler Mgml .. 11 60-67

Swamp, A and Sharma, D P 1993 Influence of top-dressed nrtrogen In allevlaling the adverse effects of flooding on growth and Yield of wheat In l! sodlc SOil Field Crop Res., 35.93-100

Thakur, N. K , Gupta, S K, Sharma, D P, Swamp, A and Panda: S N 2003 A comparative assessment of tolerance of three rabl crops to water stagnation on SOil surface' J Indian Soc 5011 SCI, 51.554-556

113

Microbiological Properties of ,Soils in Relation to Sal(Stress ,. Lalita Batra/ DIvIsion of SOIl and Crop Management Central So/{ Salinity Reseearch Institute, Kamal- 132001, Haryana

Introduction

Salt affected salls occur wo~dWlde and are estimated to occupy about 952 million hectares area, of which sodldsolonetz salls constitute 581, m ha In India, they mainly occur In the alluvial Salls of central and Penlsular India and are estimated at about 377m ha The high pH and exchangeable sodium,. and presence of soluble carbonates and bicarbonates in sodlc Salls and ,high ,amounts of ,soluble, salts In 296m' ha saline _'s, no! only ad.",rsely affe..'t /i'IB rmyslco-ctremlcsl properties Bna lertility ollhese sl1lt I1ffectea soils, lind their ability to support plant growth, but also profoundly mnuence the 5011 biological condltlon-dlverslty of microbial species, their numbers and activities in SOil The Important miCfoblologlcal attnbutes of 'healthy' SOil Include cycling of nutnents, decomPOSitIOn of wastes and residues, pathogens destruction, toxic metal inactivatIOn and detOXification of pollutant compounds ale A biologically degraded 5011 on the contrary IS one In Which there IS a decline In 5011 organic and biomass carbon and decrease In the diversity and actiVItY of 5011 flora and fauna Researchers worldWide have concentrated largely on the physlco-chemlcal degradation of solis caused by SOil sodlficabon and SaliniZation or both because such effects are apparent and readily measurable The biological degradallon of salt affected Salls has not been suffiCiently appreciated because such effects are difficult to measure bEllng qUite subHe In therr effects, It was only Itom the beginning of seventies of the 20~ century, that increasing attention was paid to Ihe mlCfOblologlcal attnbutes, and biological activities of salt affected Salls, effects on nutnent transfonmatlons, biological fixation etc In the present paper the most Significant achievements of our 30 years research along WIth only Ihe mosl pertment related wof'o{ of other researchers on the most Important microbiological properties 10 relation to salinity and SOdlCltlty stress and effects of ImgaliOn wllh poor quality Water are discussed and enumerated below

Microbial Diversity in Salt Affected SOlis

In an alkali SOil lying barren for 60 years (pH 103), showed the presence 01 vanous Rhizobia VIZ Rhizobium leguminosarum (host plant, Egyptian clover), R. melifoti from Indian dover, Rhizobium spp (Sesbama spp), BradyrhlzoblUm sp (Cluster bean) and showed the absence of RhizobIUm legummosarum (pea, lenbl, black gram), Bradyrhizoblum sp, (Cowpea, Clcer) B Japomcum (soyabean) Occurrence of root nodules of tree legumes like AcaCia, teueaena, perennial Sesbama, Pongaml8, Alblzzla, ProSOPIS and Dalbergla demonstrated the presence Of tree Rhizobium In salt affected Salls A very good nodulation In a three years old stand of C, eqUlS8!1fotla Was nobced In normal SOil at Karnal (Haryana) and 811<8.11 SOil (pH 10 2 to 105) at Gudha (Haryana) Whereas, only 32% plants were found nodulated In saline Salls (ECe 285 to 42.0) of Sampla (Hatyana), which shOV;ed the presence of Frankla '" salt affected SOils Allhough, Ihe nodules were smaller In size In alkali and sal me Salls as compared to nonmal SOil Other bactenal speCies like Azotobacter, Tiobacillus, Nltrosomanas Could be Isolated from alkali solis Bluegreen algae or Cyanobactena are particularly tolerant to alkalimty and proliferate at very high pH of 100 to 105 The Mycohrlllzal spore counts of highly alkali Salls were very low but roots of grasses like Sporobolus margma/us showed the colonlzabon of their roots Hence, there IS a considerable microbial diversity In salt affected Salls With a represenIBtlOn of all major groups

Microbial Numbers

V\lnen the SOil extract used In bactenologlcal media was prepared Itom saline-alkali SOil (pH, 105, ECe 37 dS m-l, ESP 800) approximately 1 5 tJmes morE! bactena were recovered than an extract from nonsaline 5011 was used Media pH of 10 0, 105 and 11 0 decreased numbers only 19, 46 and 76% compared to neutral pH, thus shOWing the hlQh pH favonng the growth of alkahphilic bactena Dilution plating of SOil samples from a banren saline SOil (EC,I~ 7 or ECe 508 dS m-l) of Gudha fanm In Haryana could show total bactena and Actlnomycetes count up to 10' and 10', respectively whereas, a fungal count was 10' only and no Azotobacter

Biological Activity of Salt Affected 501111

Biological actIVIty In the,fonm of CO, evolubon, dehydrogenase and urease activity were detenmlned In salt affected Salls DHA reduced drastll:ally With the increase In salinity and alkalinity In highly saline Salls (ECa 67 0 dS m''l. the DHA was not deteetable, but in SOils under a halophyte, Saudla mantlma (ECe 46 0 dS m-'), DHA was 4 5 ~g g-' SOil Whereas, I~ barren alkali Salls of Gudha and Sarswati Forest range In Haryana (pH, vaned from 101 to 105), DHA wa~ In the range of a 44 to 47 I1g g_' soil Dehydrogenase actiVity at different salinity levels In the fields of sall~e SOils of Sampla, Haryana decreased With the Increase In sallmty ,

MIcrobIological PropertIes of Soils In Relation to SaltStress

At ECe 40 8 dS m-' , the'-~ecrease,in DHA was 87% compared 'io-IS dS m-' 'Total organic i:: also decreased Wlth Increase In salinity (Batra at a", 1997),

Effect Sodlc and Saline Water Irrigation

Microbial biological properties of salls after 2 years of cropping were observed to be Significantly affected due to sodlc water Imga~on In forage crops grown In Iyslmeters, Quollent (69%), microbial biomass mtrogen (27%), microbial biomass _phosphOrus (39%), aCidic phosphatase '(9%), SOil r.splrabo" (18%), SpeCific metabolic quotient by (75%) and percent microbial biomass Cltotal organic carbon were Significantly reduced at RSC 12 compared to goad quality water Ifngatlon (Table I), However, pH, mcreased from 82 to 86, EC, Increased-from 015 to 030 dS m" at RSC 12 compared to good quality water imgatJon (Batra, unpublished data)

In an another pot house study, while observing the effect of saline water ImgatlOn on some microbiological properties of a vertlsoll under Neem crop when Imgated Wlth saline water, urease actiVity decreased from 18 to 1,60 m mol NH3g" 5011, 'aCid-phosphatase decreased from 68 8 to 278 pk"t gO' 5011 Whereas, there was Imtlal mcrease 10 alkali phosphatafrom 141,4 to 246,0 pkat g" SOil while, It decreased further from 248 0 at RSC 4 to 1858 pkat g" 5011 (Table 2) -The results showed that 5011 enzymes of vertlsol 5011 decreased With Increase In sahnlty The decrease was more pronounced with aCid phosphataseJhan other enzymes Mlc~oblologlcal proper\les affected more due to vanatlon In sahnlty as compared to chemical properties (Batra, 2001-02)

Effect of Crops

AmelioratIon of hIghly deteriorated ~tkalJ SOil ws compared dunng 1989-92 USing two reclamatIon technologies, namely Karnal grass (Laptochloa fusea) as a first crop in the absence of any amendment (Biological reclama~on) under field condl~ons at Gudha, ,n Haryana SOil properties were compared between treatments where a) crops grown WithOut gypsum and b) crops grown with gypsum, After 10 months of treatments, the microbial activity of'the alkali Salls -expressed as dehydrogenase actiVity was Significantly greater where SOil reclama~on was Inrtlated by growing Kamal grass as first crop compared With treatments 1M whIch reclamabon was started by adding gypsum (Batra al ai, 1997) as shown In Table 3 However the difference between these two sets of treatments was less malked after three years of continuous cropping After three years dehydrogenase activity was highest where Kamal grass was grown as a forge crop for two years and It was lowest where the SOil was reclaimed by adding gypsum at 14 t ha" (50% G R) followed by nce crop Thus the results of Kumar et 81 (1994) and Batra al 81 (1997) revealed that Kamal grass can be ubllzed for the recJamabon of atkall Salls when grown without gypsum appllcabon, BIological reclamatJon was relatively faster in the initial years Where reciamatJon WS Initiated With Kamal grass as a first crop In the absence of gypsum as an amendment '

In a field experiment In alkali soil (pH varied from 9 0 to 92 In 0-15 em 5011 depth), the effect of SadlC water Imga~on was studied on microbiological prOperties, continuously for 2, 4, 5 and 6 years under different cropping sequences, The expenment was Indlated In 1993 at Bhalnl-manra CSSRI, expenmental farm, Kalthal With four crop sequences ViZ 1) nce-mustard, 2) nce-wheat, 3) nce-berseem, and 4) Jowarwheat Crops were Imgated With two types of water 1) Canal water, and 2) sodlc water IEC 1 55 dS m-l, RSC 825 meq L-1 and SAR (105 mmol L-1) 'I.1J In 0-15 em 5011 depth, 5011 resplfabon (CO, evolutIOn) was signlfican~y greater under nce-berseem at all penodlc Intervals compared to other three sequences The mean soJ! resplfabon for all the three years was 107%,42% and 16% greater for nCiNJerseem, nce-mustard, and nce- wheat, respecbvely, compared to the lowest value of Jowar-wheat At 2 and 5 years of Imposing treatments, nee- berseem showed greater dehydrogenase activity compared to other croPPing sequences A non-Significant difference In microbial biomass was observed at all.penodlC Intervals However, the speCific metabOlic quobent (C02IMBC) was slgnlfican~y greater under nce- berseem compared to other three cropping sequences, Microbial biomass mtrogen was also greater under nee-berseem at 4 and 5 years of Imposing treatments After 5 years pH dropped Significantly under nee- wheat and nce- berseem compared to ,ncemustard and lowar - wheat treatments Organic C and mlragen were significantly greater under nee- berseem treatment compared to other treatments Higher SOil resp"a~on, metaboliC quotient and microbial biomass, nitrogen under rice-berseem treatment may be because of higher bUildup of organic C and nitrogen In thiS treatment (Batra, 2003) .Imgabon Wlth sodlc water did not have any adverse effect on microbiological and' chemical properties of SOil, when Imgated continuously up to 6 years With the water of thiS sodlclty level (Batra, 2004-05)

Effect of Manures

In order to evaluate the benefiCial effect of organlcl green manures on SOil heaHh, green manures microbiological properties were studied for nee-wheat system In an alkali soil (pH 9 3) Irrigated With SadlC Water (RSC 10 meq L"; EC 2 7 dS m") After 27 months of Imposing treatments, SOIl respiration and microbial biomass mtrogen were Significantly greater under green manunng compared Wlth fannyard manure and

115

Chemical Changes & Nutrient Transfannatfon In SadlciPoor Quality Water Imgated Solis

;

Inorganic mtrogen alone Similarly, speCific metabolic quotient (q C02) , % microbial biomass mlrogen in total 'N (% MBN! TN) and dehydrogenase acllvrtyl microbial biomass C (OHAI MBC) were Significantly greater under green manure and FYM tr9lltment compared WIth inorganic fertlll~er alone The results thus clearty Indicate the need for introdUCing organic manures along With inorganic fertilizers to malntaln the health of an alkali soli (Batra, 2005)

, Table 1. 5011 microbial properties after 2 years In good quality and SodlC water Imgated forage crops

Treatment MBN flush MBP SOil Specific %MBC,\ DHA ACIdiC (mg kg-') flush resplrallon metabolic -in ' (~g TPF g-') phOSPhatase

Img kg- (mg C-l00g" quotient (q !TOC (mg PNP ) SOil) CO,) Kg.')

Crops Oat 596 26 645 478 218 1152 491 PelS Ian clover 623 1.9 574 183 304 927 471 ,Oat + Persian 57,1 14 535 028 288 1067 429 clover

'Water quality

Good quality 68B 26 649 4B7 172 844 503 RSC4 596 22 56.9 1 32 327 1097 447 RSC6 604 14 590 145 287 1168 449 RSC12 502 16 530 152 293 10S 7 456 CV(%) 0.1 9.7 41 24,6 12,6 17 1 8 CD 5% Crops 6.4 024 1,2 039 041 147 068

Water quality 210 019 24 056 034 176 084

MBC!TOC = Microbial biomass CI Total Organic C, Batra, (unpublished data)

Table 2 Microbiological and chemical properties of saline water imgated vert,so,l under neem crop

Water Urease Acid Alkali pH EC Avail Avail Mlnerallzable OC Total (ECdS (~mol phosphatase phosphatase (1.2) (1,2) P K N (ppm) .(%) N m-') NH3g' Im9 PNP kg- ImgPNP kg- (dS (kg (kg (NH4+ NO,) (%)

, hr') ) ) m") ha") ha")

Tap 16 3006 1414 87 045 29 3179 219 065 0061 Water 4 16 356 2480 84 150 35 2945 192 067 060

8 14 290 2400 83 331 45 2945 145 069 060 (36~)

12 12 230 1858 83 315 6,1 2856 135 061 0.60 ,(11%) (60%)

009 076" 17 NS 25 NS NS CO(P = o 05}

052 18.0 197 73 7 1 98 17 CV, (%)

Source Batra, 2001-02

116

Microbiological Properties of SOils In Relation to Salt Stress

rable 3 MIcrobIologIcal properties of alkali sOIl (0-15 em) after three years of groWIng Kamal grass and gypsum applicatIon

I Treatments DHA (~g TPF g") MBC (mg kg")

After 10 After '

K1F K1D

K2F K2D

Mean KG

SG RG

DG

Mean SE

Months 3 years

435 122 9 57 a 96 9 536 136 5 438 118.3

495 1187 264 112.1

3~6 1030 205 776 26,7 91,5

266 961 34 41

166 55 11525

1490 1788 1617

I 2033 2142 2142.

194 3 2065 121

DHAMBC

074 077 , 092 066 077 055

0.46 0,36

047

047

/

MBC in Total C (%)

45 46

'33 36 40 46

55 56

47 '51

Imbal 4 5 567 0 06 2 3

Inbal pH - 106, EC - 2. 5 dS m~', ESP - 95, DC - 0 25%, AvaIlable NPK - 20,39 and 420 kg ha", K1F & K2F Kamal grass, SG, Sorghum, RG, RIce, DG, Dhalncha All grown for three years wIth (50% G R) followed by winter covers SourCe Batra af al (1997)

Bibliography

Kumar Ashok, Batra Lalilta and Chhabra R 1994, Forage YI8Id of sorghum and Wlryter Clovers WIth biologIcal and chemical reclamatIon of a hIghly alkaline sOIl Expll Agncullure, 30 343-48

Batra lalita, and Manna, M C 1997. Dehydrogenase acbvlty and microbIal bIomass' carbon In salt- affected SOIls of semi-and and arId regIons, And 5011 Res Rehab 11 295-03

Batra lalita, Kumar A, Manna, M C and Chhabra R .1997 MicrobIological and chemIcai' amelioratIon of alkalI SOIl by Kamal grass and gypsum application. ExpU Agncullure, 33 389-97

Batra LalIta 2001-02 MIcrobial bIomass and enzymatic actiVitIes of salt affected SOIls CSSRI,Annual report, p 19

Batra lalIta. 2002-03. MIcrobial biomass and enzymatic actlVlbes of salt affected sOIls. CSSRI, Annual report, p 19

Batra Lalita 2008 Effect of organic and Inorganic manures on microbIological and chemIcal properties of a~ alkal, SOil when Imgated WIth sodle water (UnpublIshed)

117

Technologi~s 'for Efficient Use of Sodic Water in Sustainable Crop Production

/ D,RSharma DIVISIon of SOI/S and Grop Management Central Soli SalInity Research InstItute, Kamal (Haryan,a)

Introduction

An~clpated global shortage of fresh water supply to agnculture sector In 21'~ century IS likely to Increase the utilization of relatively pOor quality water fOr Irngatlon Poor quality groundwater occur extensively (32-84%) In and and semi-and parts of India and Its Indiscriminate use poses serious threat to sustainability of natural resources and enVironment Water quality r~searches over, ,past few decades have enabled development of technological op~ons to cope up With the problems of saline and sodlc water use, Possibilities have now emerged to safely use the water otherwise deSignated unfit 'The§e options pnmanly consist of I) sele~on of crops, croppIng patterns and crop vanebes that produce satisfactory Yields under the eXisting or predicted conditions of sodlclty II) appropnate imgatron scheduling and conjunctive use optrons With canal water, rain water rT)anagement and leaching strategIes to maintain a high. level of SOil mOisture and low level of salts and exchangeable sodium In the rhlZosphere and III) use of land management pra~ces to Increase the Uniformity of water dlstnbutlon, Infiltration and salt leaching beSIdes the optrmal use of chemical amendments Including trme and mode of their application With JudiCIOUS use of organrc matenals and chemical fertilizerS

Consistent efforts made at different" research centers In the ,country to deVise, the ways for, safe ublrzatlon of sodle water In agneulture have resulted In fair understanding of baSIC pnnclples of sOI~water-planl 'systems Based on understanding developed for preventing deterioration of SOil to levels which limit crop produCbvlty, speCialized sari, crop and Imgatlon management practrces are advocated Some such management measures for controlling the bUild up of ESP and maintaining the PhYSical and chemical properties of sodlc water irngated Salls are discussed below

Land Levelling and Rain Water Conservation

Proper land levelling' and prolllsion Of 30-40 ern high bunds for retaln!ng rainwater are essenbal prerequISItes for managing sadie water Imgated land Surface soil should be I'rot""cted agaInst beatJng of raindrops, This can be achieved by plougtllng of fields In between rarns which Increases Intake of rainwater and controls unproductive losses of'water through weeds and evaporation These practIces also promote unrform salt leaching and self-reclamation through natrve CaC03 dlssolubon '

• Crop Selection

The gUiding pnnclpie for ctioosmg the nght kind of crops and cropping pattems SUitable for particular SodlC water IS to selec! only those crops whose SodlCrty tolerance limits are lower than the SOIl SodlClty (ESP) expetted "t6 budd With use of that water Under average condltrons of water use, the eXpected root,zone SodlClty can be approximated by 1 5 x SARlw In fallow- wheat, 2 0 , SARlw In millet- wheat and 3 Q x SAR,w In nee-wheat croPPing sequences, Thus, based on the expected ESP to be developed, the SUitable crops can be chosen from the list of SoolClty tolerant crops given In table 1 & 2 Since use of sodlc water requires repeated application of gypsum, It IS adVisable to select only tolerant and semi tolerant crops and their varieties haVing low water requirement such as barley, wheat, mustard, oat, pea~;nillet and sorghum etc The chOice of promISing cultlvare can be made from the list given In table 4 The other gUidelines pertrnent to selecting trops SUitable for sodlc waters are

• Fields should be kept fallow dunng khanf In low rainfall areas « 400 mm) where good quality water IS not available However. only tolerant and semi·tolerant crops like barley, wheat and mustard should be grown dUring rabl

• Jower-wheat, guar-wheat, pearl millet-wheat and cotton·wheat rota~ons can be suceesfully grown In areas haVing rainfall ,. 400 mm/annum prOVided that sOWIng of khanf crops IS done With rain or gooo quahty water and only 2 to 3 sodle water Imgallons can be apphed to khanf crops

• In nce-wheat beJt of allUVial plaIns haVing rainfall 2600 mm, nee-wheat, nee-mustard. sorghum· mustard, and dhalnacha (GM)-wheat rotations can be sucessfully practiced With gypsum apphcatlon

• Sodlc water should not be used for summer crops In the months of Apnl to June

Taole 1

ESP

10-15

16-20 20-25 25-30

30-50

50-60 60-71

Technologies for Efficient Use of Sodlc Water In Sustainable Crop Production

Relative tolerance to SodlClty of salls

Crops

Saffiower, Mash, Peas, Lenlll, Pigeon-pea, Urd-oean; Banana

Bengal gram, Soybean, Papaya, MaIZe, CitruS Groundnu!, CowPea" Onion, Pearl-mlllet.,Guava, Bel, Grapes Linseed, Garlic, Guar, palmaresa, Lemon'wass, Sorghum, Cotto~ /

'Mustard, wreat, Sunflower, Ber, Ka,rcmda, Phalsa, Vetlver, Sorghum, Berseem Barley, Sesbama, Paragrass, Rhoades grass Rice, Sugarbea!, Kamal grass r

Usa of Amend~ents

Sodle water can be safely and economically, used,after treallng with ,calCium carrying amendments 'like gypsum Agricultural grade gypsum and aCidic PYrite can effectJvely neutralize RSC of SodlC water by adding! them either to sailor In water through specially deSigned gypsum beds The quanllty of gypsum 0-' pyrite to be applied depends on the'RSC of water, extent of soil detenorallon and water reqUirement of Intended crops and cropping system Hbwever,' follOWing gUidelines ca'n: be of' additional help In deciding the need and quanbty of amendment required for uSe sltuabons -

, ,

• Generally gypsum IS not needed on well-dralned light textured Salls In fallow-wheat rotation, however, applicallon of gypsum @ 25% - 100% GR of water boosts crop Yields ( Manchanda at aI, (985) In double cropping Yadav et al 1991 reported that add Ilion of gypsum @ 50% GR of a loamy, sand 5011 was sufficient to grow even the sensitive khanf crops like pearl-millet, moongbean, urdbean, cowpea, clusterbean In' areas receIVIng 600 mm rainfall

• In relatively high rainfall regions (> 600 mm), arinual gypsum application eqUivalent to 50% GR of water was sufficlent'to, sustain 6-,9 _Mg Iha of paddy and wheat Yields (Shanma & Mlnhas 2001) in SOils where pHs did not exceed 9 0

• Occasional application of gypsum @ 1-2 tonslha before rainy season In heavy textured SOils IS also recommended to offset Infiltration problems a"slng With use of high SAR saline water, (SAR~20)_

Table 2 ESP tolerance of crops In alkali SOils and Irrigated wltli alkali waters

Crop

~otton

Pearl millet

SOil under reclamallon ESP,- Slope

,-.136 26

Rice 24'4' 0'9

Wheat 161 21

• Threshold ESP, •• ESP for 75 % Yield

ESP,s-

"

232 521 280

Melihod and Time of Gypsum Application In Soli

",Ikall water imgatlon

ESP, Slope

149 13 61 13

201 16 162 19

ESP,s

341 253 357

294

It IS easier to apply gypsum In 5011 than through water"Requlred quantity of powdered gypsum should be broadcasted on previously leveled field and mixed With cultivator or dlsklng In shallow depth of IDem The best bme for application of gypsum IS after harvest of rabl crops, preferably In Mayor June, If SOme rains are received OthelWlse, ItS applicallon should be postponed till the first good monsoon showers,are received GYPsum can be applied In the standing water also The 5011 should be subsequently ploughed upon attal~lng proper sOIl mOisture condition Gypsum applied after harvest of rabl crops Will also help In conSiderable Improvement of the 5011 pnor to the onset of' kha"f season PYrIte has also been used for amending the deleteriOUs effects of high, RSC waters Pynte application once before sowing of wheat IS better than Its spilt application With all ""gabons or mixing With IITIgalion water (Cha~han elal 1986)

Gypsum Bed

Another way to reclaim sodlc water IS passing It through speCially deSigned chamber filled With gYPsum dods The gypsum chamber 15 a bnck-cement-concrete chamber Size of chamber depends on tUbewel1 discharge and RSC of water ThiS chamber IS connected to water fall box on one Side and to water channel on the other Side A net of "on bars covered With wire net (2 mm~2 mm) IS fitted at a height of 10 cm from the bottom of the bed Fanmers can also convert waterfall chamber of their tube wells Into gypsum chamber With little modifICations SodlC water nowmg from below dissolves gypsum placed In chamber and

119

Chemical Changes & Nutnenl Transformation in Sodle/Poor Quality> Water Imgaled SorlS

, reclaims It RSC of water from tube well discharge of 61 sec" decreased from 5 '5 to 1.9 me I' by passing It through a chamber of size 2 0 xl 5 xl 0 m In thiS method

• / However, thiS method is not SUitable for reclaiming very. high RSC, wa~er (> 12 me I") because the Size of the chamber reqUired to fill the huge quanb\y of gypsum needed to neutralize such high RSC becomes too large It has also been observed that the gypsum bed water quality Improvement techntque does not dissolve> 8 me r' of Ca The response of crops to the application of eqUivalent amounts of gypsum, either by passing the water (RSC 9 me r') through gypsum beds where the thickness of bed was maintained at 7 and .15 em, or the 5011 application of gypsum is presented 10 Table 3 Though crops under both the rotations (paddy-whea~ sorghum-mustard) responded to the application of gypsum In Glther of the methods, overall response of crops was sl>ghUy more In case of SodlC water whICh was ameliorated (3-5 me r') after passing through gypsum beds Thus, It seems that gypsum bed techntque can help /0 effiCient uWlzalion of ,gypsum

Table 3 Average (1993-2003) paddy-wheat and mustard-sorghum Yields (Mg/ha) and 5011 properties· With gypsum applied 10 SOil or passI09 SodlC water Ihrough gypsum beds '

Treatment Paddy Wleat pH ESP Mustard Sorghum pHs ESP Control (T,) 3 DB 261;1 96 66 227 1 lB 95 61 Gypsum through beds 3.3 meqll (T 2) 397 373 80 19 306 198 80 25 5.2 meq/l (T,) 424 3.93 80 18 318 213 80 24 EqUivalent SOil application As In T2(T.) 431 371 82 20 286 1 92 80 26 As in T3(T5) 452 389 81 20 300 205 8 1 24 LSO( p=005) 04l 046 038 024

• At the harvest of rabl (2002-03) crops (AICRP SalinG Water 2002)

IrrlgaUon Management

Convenbonal practice of baSin ""gatlon should be adopted With emphaSIS to mlmmlZe the quantity of applied alkali Irr>gatlon water because detenoratlon of SOil directly depends on It The 'alkali hazard' IS reduced conSiderably, if thiS water IS used altemabvely Or mixed With canal water BeSides redUCing the gypsum requirement of 5011, conjunctive use of alkali and canal water also helps In bnr>glng more area under protectIVe Imgabon and 'also In controlling nsa in ground. water table and assoCiated problems Canal water· should preferably be applied dunng Initial stages'lnclucllr>g pre-SOWing Imgalton to boost establishment of crops Studies have sown that when sadie water was used In cydlc mode With canal water, Yield of both the paddy and wheat crops were maintained equal to thaI Wllh canal water except In Ihe CW-2SW mode (Table 4)

Nutrient Management

Fertilizer.Applicatlon

Since sodlc water use cause "se In 5011 pH leading to higher mlrogen losses through volatllizabon and denltnficatlon, extra mtrogen has to be added to meet the requirement of the crops Similarly, the availability. of zinc and Iron also becomes low due to thelf preClprtabon as hydroXides and carbonates Some benefiCial tipS for fertilIZer management With sodic water use are

• Application of 25% extra n>trogen as compared '10 the normal conditions • Zinc sulphate @25 kg, ha should be added, par\Jcula~)' to the rabl crop ., P, K and other limiting nulnents should be apphed on 5011 test baSIS • Sadie water at some Sites IS nch In nutnents hKe N, P and S, and the doses of the nutnents should be

adlusted accordingly as per thelf composllion In such water

Addition of OrganiC Materials

Addition of orgamc materials IS observed to Improve sodlc Salls ihroUgh mobilization of Inherent Ca" from CaCO, and other minerals by organic aCids and increased pCe, In soils" SolubllZed Ca2

' replaces Na' from the exchange complex on SOil However, some disagreement on short-term effects of organic m~tter on dispefSJon of scdlc SOil partldes in SOils undergOing sodlcatlon eXIsts In literature (Gupta Bt' el 1984) Nevertheless, majonty of the available reports s~1I suggest overall beneficial poslWe role of organic manures in Improving SOil properties and crop y,elds Response of organic sources also vanes WIth the nature of orgamcmatter added' Sekhon and Balwa (1993) recorded effecllveness of different organic matenals In order

120

Technologies for Efficient Use of Sodle Water In Sustainable Crop Production

of paddy straw> green manure> FYM Moreover, with mobilization of Ca2• dUling decomposition of orgamc

",atena/s, the quantity of gypsum required for controlling the harmful effects of sodlc water Imgatlon can be considerably decreased.

I Table 4 Effect of cycliC use of sodlc and canal waters on 5011 properties and crop Yields ,

water quality/mOde adJ SAR" pH ESP RIR ,/ Average Yield (Mg/ha)

Rice Wheat

Canal water (CIN) 03 82 4 100 678 543 SOdIC water (SIN) 22.0 97 46 14 417 308

2CW-1SW e.9 as 13 72 667 522 1 CW-1SW

I 12.6 9.2 16 59 630 572

1 CW-2SW 16.5 93 22 34 572 485

Water quality ECw(dSm") Ca~ Ca+Mg RSC SAR adj SAR (meqll)--

CW '025 16 21 Oil 03 04

SW 135 04 0.9 10 1 135 267 Bajwa and Josan (1989), after 828 and 434 em of IrTigatlOn and rainwater, respectively,

Water Quality Guidelines

Based on field experience and results from different saline and~ SodlC water use expenments, CSSRI, Karnal In consultation With SCientist from HAU, Hlsar and PAU, Ludhlana has prepared some gUidelines for effiCient utilization of given poor quality water These gUidelines emphaSize on long- term Influence of water quality on crop prOduction, 5011 conditions and farm management With assumption that all rainwater received In field IS be,"g conserved for leach,"g and desaliniZing upper root zone

Table 5 Sodlc (alkali) water with RSC > 2 5 meq L-' and ECiw < 4 OdSm-' SOil texture Upper limits 01 Remariks

(% clay) SAR RSC

Fine (>30)

Moderately (20-30)

fine

Moderately coarse (10-20)

Coarse «10)

(m mol L-') ,/2 meq L-'

10 25-35

10 35-50

15 50-75

20 75-100

Special Considerations

Limits pertain to khanf fallow - rabl crop rotation when annual ra,"fall is 350 -550 mm

When water has Na < 75%, Ca+Mg >25% or rainfall > 55Omm, the upper limit 01 RSC becomes safe For double cropping, RSC neutralization With gypsum IS essential based on quan~ty of water used dunng rabl season_ Grow low water reqUlnng crops dunng khanl

• Gypsum application IS necessary for sensitive crops II sahne waler (SAR " 20 and / or Mg Ca ratio> 3 and nch In Silica) Induces water stagnabon '" rainy season

• FallOWing In rainy season under high salinity, SAR ,. 20 water use conditions IS helpful for low rainfall areas

• Fertlllzauon With additional phosphorus IS benefiCial espeCially when C1 SO. ratio In waters IS > 2 0 • Canal water should be used preferably at ea~y growth stages Including pre sOWIng Imgatlon In

conjunctive use mode • Putt,"g 20% extra seed rate and a qUick post-soWing Irrigation (within 2-3 days) Will help 'n better

germination • Saline water Imgatlon Just before onset of monsoon lowers SOil salinity and raises antecedent 5011

moisture to leach more salt With rains when EC,w < ECe of 0-45 em SOil at harvest of rabl crops • Use of organic materials In sahne enVironment Improves crop Yields • Accumulation of B, F, NO., Fe, 51, Se and heavy metals beyond critical limits With ""gatlon IS tOXIC

Expert adVice pnor to use of such water IS essential • For Salls haVing (I) shallow water table (Within 1.5 m '" khanf ) and (II) hard sub-SOil layers. the next

lower EClwlaltemate mode of ""gatlon (canaVsaline ) IS apphcable

121

ChemIcal Changes & Nutnent Transformallon In SodldPoor aU~IJty Water Jrngated Solis

/

Teldural cnlena should be applicable for all sOIl layers down to at least 15m depth In areas where ground water table reaches Within 15m at any time of the year or a hard subsoil layer IS present 1fT the root zone, the 1111'1115 of the next finer textural etass should be used

; , Biblography

Aggarwal, M C and Khanna, S S. 1983 Efficient sOil and water management 1fT Haryana Bull HAU. Hlsar. p 118 \

AICRP-Sallne water, 2002 Annual Progress Reports All IndIa Co-Ordmates\Research Project on Management of Salt-Affected Solis and Use of Salme Waler m Agncullure, CSS~I, Kamal

CGWB, 1997 Inland ground water salimty In India GOI, Ministry of Water Resources, Central Ground Water Board, Fandabad 62p

Manchanda, H R , Sharma, S K and Singh, J P 1985 Effect of Increasing levels of RSC In Imgatlon water on exchangeable sodIum pencentage of a sandy loam soil and crop Yields Journal of Indian Soclsty Of Soli SCIence, 33 366-371

Mlnhas, P S 1996 Saline water management for Irrigation In India Agncultural Waler Management. 30 1-24

Mmhas, P S., Sharma, DR and Chauhan, C.P S 2004 Management of salme and alkali waters for ""gatlon In Advances of SodlC Land RecommendatIon p121-162 InternatIonal Conference on Sustamable management of SadlC Lands, LUcknow Feb, 9-14. 2004

Raghu 8abu, M , P R K Prasad, G V Subbalah, M Khan and P S Mlnhas (1999) Subsurface Fresh Water Sklmmmg System; Improved Doruvu Technology, Bulletm No 1199, 19p Central Soil Salinity Research Insbtute, Kamal

Sharma, DR and Mmhas, P S 2001 Response ot nee-wheat to alkali water Imgatlon and gypsum application J IndIan Soc SOIl SCI. Vol 49 pp 324-327

Shekhon, M Sand 8ajwa 1993 Effect of Incorporabon of OM and gypsum in controlling sodlc Irngatlon effects on 5011 pnopertles under nce - wheat maIZe system Agnc Water Manage 24 15-25

Singh, SO, Gupta, J P and Singh, P 1978 Watereconom(and saline water use bydnp ImgatJon Agll)l1 ./ 70 946-951

Yadav, H D, Kumar, V, Singh, Sand Yadav, 0 P 1991. Effect of gypsum on some khanf crops In sodlc salls Journal of Research (HAU), 22 170-173

122

Technologies for Efficient Use of Saline Water for Sustainable Crop Production

D.R.Sharma DIvIsion of Salls and Crop Managemenl f Central SOil Salmlty Research Institute. Kamal-132 001. Haryana

Introduction

Availability of fresh water supplies to agnculture sector In future IS likely to re<Juce world over and partlcula~y in the Asian countries due to population pressure. improved living stand~rds and inter-sector competition The esbmates for India show that reduction could be 10 to 12 % by 2025 In the back drop of thiS gnm scenano. agriculture sector Will be left with no alternabve than to use poor quailty ",ater for Its Irrigation requirement The ground water surveys In India. Indicate that different states use poor quality water In the range of 32 to 84% of the total ground water development Many more areas with good quality acqUifers are endangered With contamination as a consequence of excessive Wlthdrawl of ground w~!er Groundwater of arid regions IS largely saline and In semi-and regions It IS sadie 10 nature I

Indiscnmlnate use of poor quality water for IITIgabon detenorates productiVity of .oils through sailnlIY. sodlclty and tOXIC effects In addlbon to~reduced productiVity. It detenorates the quality of produce and also limits Ihe chOice of cultivable crops Nevertheless. concerted efforts at AICRP-Saline Waler and other centers In different agro-climabc zones of the country have resulted In valuable concepts and VI~ble technologies for the sustamable inrigation With poor quality water (Mmhas, 1996) PosSibilities have emerged for sustaming Imgallon With water othelWlse deSignated unfit. by selection of appropnate crors, Improved water management and maintenance of SOil siructure/pemneability Technological and polley options for alleViating brackish water hazards and maximIZing producl1vlty are outlined here .

Classification of Irrigation Water

Irngatlon water IS claSSified based on electncal conductiVity (EC). sodium adsprptlon ration (SAR) and reSidual sodium carbonate (RSC) However. from management POint of View. the gro~ndwater In different agro-ecologlcal regions can be grouped Inlo three classes 16. (a) good. (b) saline lind (c) alkall/sodlc Depending on the degree of restnction. each of the two poor quality water classes has been further grouped Into three homogenous subgroups (Table-1)

Poor Quality Ground water Resources

No systematic attempts have been made so far In the country to amve at the estimate of poor~quallty, ground water resources However. some predlcl10ns about use of poor quality water I~ vanous states are given In Table 2 The CGWB (1990) approximated that the total area underlam With the saline ground water (EC>4 dS m-') IS 193438 km' with the annual replen/shable recharge of 11765 million m3 Y(', leaVing aSide minor patches ~

Table1 ClaSSification of poor quality ground water

Water Quality ECIW (dS m") SAR,w (mmor')11, RSC (meq r') a Good <2 <10 <25 b Saline I Margmally saline 24 < 10 <25 II Saline >4 < 10 <25 III Hlgh-SAR saline >4 > 10 <25 c Alkali waters I Marginal alkali <4 <10 254.0 II Alkali <4 <10 '>40 III Highly alkali variable >10 >40

Management Technologies for Saline Water Use

It has been established that the success With poor quality water Irngabon can only be achleved~ If' factors such as rainfall, climate, water table, and water quality, Salls and crops are Integrated With appropriate crop and Irngallon management practices. The available management options mainly Include the' lITIgation, crop, chemical and other cultural practices but there seems to be no Single management measure to control saliOity and sodlclty of Inrigated SOil. but several practices Interact and should be conSidered In an Integrated manner. Some of management options have been deSCribed as under

Chemical Changes & NUtrient Transformation In SodlcJPoor Quality Water Irrigated SOils

, Table 2 Use af Poar quality groundwater (M ha-m Y(') in states of India (Minhas 6181 , 2004)

.-state ~/ utihzable Net Groundwater (%) Poor quahty Krn2 Sahne >4dSm"

groundwater draft development water use groundwater area Punjab 1.47 1,67 98 O,6B 3058 Haryana 086 072 76 047 11436 UP. 631 2.98 42 142 ,1362 Rajasthan 095 0.77 73 065 i41036 Bihar 206 082 36 NA NA'

.w. Bengal 1.77 063 32 NA NA ,

Deihl 001 001 120 NA 140 GUJarat 156 085 49 026 24300 Kamataka 1,24 045 33 017 880:4 Tamllnadu 202 140 63 NA 3300 M P. 266 073 25 020 NA Mharashtra 2.29 088 35 NA NA A P. 270 0.78 26 025 NA India 3263 1350 37 193438

Crops Management

Seml-Ioleranl 10 lolerant crops like mustards, wheat, cotton elc as well as Ihose wllh low waler requirement are recommended for cul~vatlon Wlth salme water use, while crops like nce, sugarcane and berseem, which requITe hberal water use, should be avoided Mon~opping IS recommended for maintaining salt balances In low rainfall «40 em) areas Salt tolerance limits of cereals"oll seeds, vegetables, and puJses developed for different ecological regions of India are available In Table-3 FolloWlng are some of the speCific recommendations related to crop selection and management.

Growth stages

Gerrmnatlon and early seedhng establishment are the most cribcal stages followed by the phase changes from vegetative to reprodu~ve i e. heading and fiowenng to fruit setting So, Imgatlon Wlth saline water should be aVOided dUring Initial growth stages.

Crop Cultivars

In additIOn to Inter-genenc vanations, crop cu~lva~ also vary In their tolerance to sallmty Such ciJltivars (Tabla 3) have been identified on their rating lor high Yield potential, salt tolerance and stability under saline envIronments

Table 3 PromiSing Cultlvars for saline and alkaline enVIronments

Crop

W1eat P millet Mustard Cotton

Safflower Sorghum Barley

Saline environment Raj 2325, Raj 2560, Ral 3077, Wi-l157 MH269, 331, 427. HHB-60 CS416, CS330, -1, Pusa BoJd DHY 286, CPO 404, G 17060, GA, JK276-10-5. GDH 9 HUS 305, A-l, Bhlma SPV-475 , 881,678, 659, CSH 11 Ratna, RL345. RD103, 137, K169

Cropping Sequences

Alkali enVIronment KRL 1-4, KRL 19, Raj 3077, Hl10n MH 269, 280, 427, HHB 392 CS15, CS52, Varuna, DlRA 336, CS 54

'HY6, Sarvottam, LRA 5166

ManJira, APRR3, A300 SPV475. 1010, C5H 1,11,14 DL4, 106, 120, DHS 12

The recommended cropping sequences for saline sOils 'are pearl millet - barley pearl millet - wheat, pearl millet - mustard, ,sorghum - wheat or barley, sorghum - mustard, cluster bean - wheat or barley and cotton - wheat or barley The pearl m!lIet - wheat, pearl millet - barley. pearJ millet- mustard, sorghum (fodder) - wheat and sorghum (fodder) - mustard croPPing sequences are more remunerative In saline SOils Cotton b~sed_ cropping sequeoCes are,not benefiCial because the yield of winter crops that follow cotton are usually low In saline areas, mustard could replace wheal In the cropping sequence Since lis water requirement IS low compared to wheat

124

Technologies for Eflident Use of Saline Water for Sustainable Crop Production

Table 4 Salinlty.hmits of ImgaUon watern for agncultural crops

Crops SOIl Texture Pel'VlOus crop EClw (dS/m) for Yield ('!o) 90 75

VVheat Silty clay loam Sorghum 34 70 Sandy loam BaJra 66 104 Loamy saneI' Fallow 83

/ 117

Barley Sandy loam Fallow 72 113 Rice Silly clay loam Rice 22 39 MaIZe Slay loam Wheat 22 4,7 Pearl-millet Sandy loam Wheat 5.4 90 Italian-millet Sand Sunflower 2.4 46 Sorghum I Sandy loam Mustard 70 112 Sorghum Fodder Sandy loam Berseem 52 10.2 Mustard Sandy loam Sorghum 66 88 Safliower Silly clay loam Maize 33 68· SunRower Sandy loam Mustard 35. 72 Groundnut Sand Italian-millet 18 31 Soyabean Slityclay loam Mustard, 20 3 1 Pigeon Pea Sandy loam Onion 13 23 Clus\erbean Sandy loam Vanable 3.2 45 Cowpea Loamy sand Vanable 82 13.1 Berseem Sandy loam Sorghum 25 32 Omon Sandy loam Pigeonpea 18 23 Potato Sandy loam Okra 2.1 43 Tomato Sand Vanable 24 4,1 Okra Sandy loam Potato 27 56 Chnl,es Sand Vanable' 1'8 29 BrinJal Sand Vanable 23 4,1 Fenugreek Sandy loam Potato 31 48 Bitter gourd Sand Vanable 20 3.4 Bottle gourd Sand Vanable 32 45

Ionic Compositions Ellects

Chlondes, being more tOXIC tend to reduce saline water tolerance limits of crops by 1 2 - 1 5 limes as compared to sulphate nch waters (Manchanda, 1998) Similarly"more salts tend to accumulate In Salls When Imgated With high SAR water and thus tend t« reduce the limits of saline water use,

Tree Species

In condluons where crop production With saline water use IS neither feaSible nor economical, there such water can be used to raISe tree spec,,~s espeClaUy on lands those are already degraded The preferred chOice of species should be Azadlrachta mdlca, Acac/8 nilotlca, A tolllllS, A fameslana, Cassia Slamea, Euca!IJYPlus tarell3COmls, Feroma Ilmoma, .ProsOplS julmora, P Clnerana, PlllJac8llobl{lm dulctJ: Salvadora perslca, S oleoldes, Tamanx elc,

MediCinal Plants

Some mediCinal plants like Isahgol (Plantag ovala), Aloe and Kalmeg have also been found promlsmg aJternatlve to arable crops under saline Irnga(lon conditions

Irrigation and Leaching Management

Salt accumulate gradually In the root-zone 01 plants With each salme IrngallOn and vilimalely reach detnmental levels causing reduction in crop Yields If leaching does not take place However, proper Imgatlon and leaching practices can prevent excessive accumulation of salts '" the root ZO!1e The follOWing practices can be helpful.

• Arid areas need 15 to 20 percent more ITngabon water for leaching of salts

125

•

•

•

•

•

•

•

• •

•

•

•

•

Chemical Changes &: Nutnent Transformation In SadlclPoor Quality Water Imgated Salls

, Frequent light ';mgabons of saline water to maximIZe the benefits should aim 10 minimize the total water applIed /' Conventional Imgation practJces with no extra leaching are usually sufficient for monsoon type chmate areas' receIVIng > 400 mm rainfall ' Heavy pre-soWing sa hne water Imgabon should be apphed In sub-nonmal rainfall years so as to leach the salts accumulated dunng rabl season -' \ Mlcro-imgation systems Irke dnp and sprinkler hold promise for enhancing saline water use effiCiency espeCially In high value crops because of their betler control on saH and water dlsinbUtlons (Table-5) Pre-emergence sprinkler irrigation of saline water results in betler establishment of crops because of low concentrabon of soluble salts ,n seedbed during gennlnatron ' Some of the Indigenous altematlves to dnps on micro scale are the use of pitchers and speCially designed earthen pots but their large scale feaSibility remains untested Dunng rabl season sub surface drainage system can be used to reduce the Ir"gatlon reqUirement by indUCing crop water use from shallow water-table through cOntrolled drainage In rabl crops In saline water-logged Salls Suitable options lor conjunctrve use of saline and canal water should be explOited First option is blending two supplIes in such proportions that the sahnlty atlalned after mixing IS Within the penmisslble lImits of crop tolerance MIxing of canal and tube well supplies also helps In Increasing the stream sIZe and thereby application unifonmlty of Imgabon espeCially In sandy Salls On demand separate application of two quality water can be done practiced In different fields, seasons or crop growth stages so that higher salinity water IS aVOided at senSitive growth stages/crops Better quality water should be used for pre-sowing Imgatlon and at ea~y crop growth stages as germinatIOn and seedling stages are most senSItive Thereaiter a switch over to poor quality water can be made when crops can tolerate higher salinity. In the seasonal cycliC use, fresh water IS used for senSItive cropslinitlal stages of tolerant crops to leach the salts accumulated due to saline IrTlganon to previously grown tolerant crops CycliC uses, e Irngatlng With waters 01 different qualities separately offers both operational and perfonmance advantages 'over mixing. Improved "Dorouv" system With specrally desIgned sub-surface water harvesting syStem can Irngate up to 3-5 ha by skimming of fresh water floating over seawater in coastal sandy Salls (Raghu Babu, 1999)

Nutrient Management

Fertilizers

• Additional doses of nitrogenous ferbllzers are recommended to compensate for volablizatlon losses occumng under saline environments

• Soils Irngated With chloride rrch waters respond to higher phosphate application, because the chlonde icins reduce availability' of 5011 phosphorus to plants The reqUirement of the crop for phosphonc fertilizers IS, therefore, enhanoad and nearly 50 per cent more phosphorus than the recommended dose under normal conditions should be added, prOVided the soil tests low In available P

• For sulphate nch waters, no additional application of phosphate fertilizers 15 reqUired and the dose recommended under normal condlbons may be applied. ,

• for micro-nutrients such as ZinC, the recommended doses based 'on 5011 test values should be applied • Fanmyard manure' (FYM), FYM and other organrc matenals have not only the nutntlve value. bui play an

important'role In slructJural Irriprovements, which further influences leaching of salts and reduce their accumulation' in the root zone The other advantages of these matenals In saline water Imgaled SOils are In tenns of reducing the volatilization losses and enhanCing nitrogen-use effiCiency and the retention of nutnents In organrc forms for longer periods also guards against therr ieactllng and other losses. Therefore, the addition of FYM and other organic/green manure should be m"de 10 the maximum pOSSible extent

Cultural Practices

• OWIng to reduced genmlnatlon, there IS olten a poor crop stand In fields Irngated With saline water Thus to ensure betler populatJons follOWing measures are suggested

• Reduce Interflntra row spaces and use 20-30% extra seed than under nonmal conditions Dry seeding and keeping the surface 5011 mOist through spnnkler! post-SOWing salme Imgatlon helps In betler eslabllshment of crops.

126

Technologies !or EffiCient Use Qf Saline Water for Sustainable Crop ProducIJon

• Modifications In seedbed e g. sOWIng near the bottom of the furrows on both sides of the ndges and applying migatlon In alternate row and to seed on the north-east side of the ndges, IS recommended For the larger seeded crops, the seeds can be planted In the furrows ,

• The furrow Img"tlon and bed planbng system (FIRB) has been found better than convenbonal planting In cotton lpearl millet -wheat rotabons Adoption of'measures for better Intake of rainwater (bllage to open up sOil) and Its conservabon In sOil via checking .unp!oducbve evaporabon losses (SOIVStr'aW mulching) IS recommended dunng monsoon season) ./

Table 5 Yield and water use efficiency under different "ngabon methods

Crop Average Yield (Mg ha' ) for Imgatlon method Surface method Spnnkler method

CW SW CW SW Wheat (1976-79) /

Barley(1980-82) Cotton(1980-82) Peal millet (1976-78)

400 (97) 1 362 (63) 369 (107) 354(97) 351 (147) 232 (98) 346 (159) 259 (117) 2 30 ~·171 226 134 238 207 Dnp Method

Suriace Subsuriaoe Raddlsh (Ee" 6 5 dS m·' ) 157 (175) 236 (26 2) Potato (4 dS m·') 30 5 (93 5) 208 (76 5) Tomato (10 dS m·' ) 594 439 Tomato (4 dS m-') 42 6 369 (8d5m") 280 245

254

Furrow 99(8.7)

192(536)

• Figure In parenthesIs denote water use effiCiency ( Kg/ha-cm). Source AICRP (2002)

Guidelines for using saline Irrigation water

A Saline Water (RSC < 2 5 meq/l)

SOil texture Crop tolerance Upper limits of EC,w (dS/m) In rainfall regions

.150

(% clay) 350 350-550 550-750 mm Fine (> 30) '5 10 10 1 5

ST 1.5 20 30 T 20 30 45

Moderately Fine S 15 20 25 (20-30) 5T 2.0 3.0 4.5

T 40 60 80 Moderately Coarse S 20 25 30 (10-20) ST 40 60 80 ,

T 60 60 100 Coarse 5 30 30 « 10) ST 60 75 90

T 80 100 125

S, ST and T denote senSitive, semi-tolerant and tolerant crops

Bibliography

Aggarwal, M C and Khanna, S S 1983 EffiCient sOil and water management In Haryana Bull HAU, Hlsar, p 118

AICRP-Sallne water, 2002 Annual Progress Reports All India Co-Ordmates Research Prolect on Management of Salt-Affected SOils and Use of Salme Waler In AgnculluffJ, CSSRI, Kamal

Ba)W8, M Sand Josan. AS 1989 Prediction of sustained sodlc lITIgation effects on sOil sodium saturalion and crop YJelds Agncultural Wat .. f Management. 16 227-228

CG'Ml, 1997. Inland ground watsr sallmly in India GOI, Ministry 01 Water Resources, Central Ground Water Board, Fandabad 62p.

127

Chemical Changes &. Nutnent Transformation in SodlclPoor Quality Water Imgated SOils

/ Chauhan, R P S , Chauhan, CPS and Singh, V P 1986 Use of pyntes in minimizing the adverse effects of

sodlC waters, Indian Journal of Agncultural SCience, 56 717-721 / ,

ManCh.a~da, H R, Sharma, S K. and Singh, J P 1985 Effect of Incneaslng level~ of ' residual sodium carbonate In ImgabOn waters on exchangeable sodium percentage of a sandy loam 5011 and crop Yields Journal of Indian Society of SOil SCience, 33. 366-371. '

Mlnhas, P S, 1996 Saline water management for Imgallon)n India Agncullural Water Menagement, 30 1-24

Minhas, P S , Shanna, 0 R and Chauhan, CPS 2004 Management of saline and alkali waters for Irngatlon In Advances of Sadie land Reccmmendallon p121-162 InternatIOnal Conference on Sustainable management of Sodlc Lands held at Luckiiiiw, Feb, 9-14, 2004

Raghu Babu, M, P R K Prasad, G V Subbalah, M. Khan and P $, Mlnhas (1999) SUbsurface Fresh Water Skimming System, Improved Doruvu Technology. Bulletin No 1/99, 19p Central SOil Salinity Research Insbtute, Kamal

Sharma, 0 Rand Mlnhas, P S 2001 Response of nce-wheai to alkali water lr11gabon and gypsum application J indian Soc $oli SCI Vol. 49, pp 324-327

Shekhon, M.S and BaJwa 1993 Effct of Inccrporabon of matenals and gypsum In ccntroiling SodlC "ngatlon effect~ on 5011 properties under nce - wheat maize system Agnc, Water Manage ~4 15-25

Singh', S,O., Gupta, J P and SlOg, P 1978 Water eccnomy and sahne waler use by drip "ngallon Agron J 70: 948-951

Yadav, H D, Kumar, V, Singh, S. and Yadav, 0 P 1991 Effect of gypsum on some khanf crops In SodlC soils Journal of Research (HAU), 22 170-173

128

Recycling of Saline Drainage Effluents for Crop,Production

D. p.Sharma DivIsion of SOil and Crop Management f Central SOil Sallmty ResearclJ Instltute,l<:ama/-1320Ql

IntroducOon

Imgabon and drainage play very cnbcal role [n meebng the food requirement of ever increasing populabon of the wo~d on sustainable basts More than one third of the global food is harvested from 260 m ha [mgated lands, which IS only One sixth of the tOtal cu~lvated area There are several concems about the sustainability of imgation and drainage Projects because of qual[ty problems for d[sposal of drainage water, i'toCtIllmf at' ,m1U' ~;ro'.nl"''i' &1f &W encoun('et1'Jd a'ue ro Imgal'ron-Ina'ucea' sairnrt'y ana' water (ogg[ng out drainage IS a vital component of agncultural pioductlon system In humid regions, agncultural drainage IS required to remove_excess soil water ,from plant root zone Drainage IS ent[cal in controlling salinity and water logging of Imgated agnculture In order to enhance the net benefits of drainage system, more attention Will have to be given to the management of drain~ge water, Dra[nage water reuse and Its d[sposal are comparabvely new areas of management but cons[derable eXperience exits In saline imgated agncuHure that can be used in making deciSions However, It must be reoognlZeQ that each drainage sHe is and Will be unIque Vanous strategies have been proposed to use drainage water for Imgabon (Rhoades, 1984, 1987, Boumans ef ai, 1986, Sharma ef 81, 1994, 2001, 2oo5a, b, Sharma and Rao, 1998; Sharma and Tyagl, 2004, Yadav at al 2007) Selection of a particular strategy depends upon the qU<lltty of drainage water, soil type, crops to be Imgated and the agraclimatiC' conditions Saline drainage water reuse might be more pracbcal in areas where non-saline water IS ava[lable dunng ea~y growing season but lim[ted in supply to meet the crop water requirement fer entire imgation season Reuse of saltne'dra[nage water ntay ,be useful for Crop production ir and and semi-and regions where underground water Is of poor qualIty B:nd supply of fresh water [s not sufficient to meet Imgatton reqUirement of entire area Th[S lecture Illustrates the polElnbal of drainage water for imgatlon along With management strategies for arid and semi-artd regions

Scarcity of Water Resources

Fresh water supply, an essential ingredient for the economic development of society IS Just not enough to meet the reqUirement of all sectors Of'lconomy Presently, agnculture being the major user consumes 69% good quality water resources of the COUhtry, but estimates suggest that more water will be needed fer the groWIng demands of municipaltbes, [nduslr1es and energy generabon These sectors Will requIre about 22% (23 4 m ha-m year') of the total water resou~ (105 m ha-m year') by 2025 AD In India consumpbve use far outweighs non-oonsumpltve uses (Induslnal and domesbc uses) but non-consumpbve use IS also on the Increase, Populabon Will not stabilIZe by 2()25, and would canbnue to grow and so Will the water demand Under these CIrcumstances, the Mure water demands can be met only through judicious plann[ng giVing due pnonty to water conservabon, recycling and reuse of low qualtty water,

Management of Waterlogged Saline SOlis

Bas[cally management of waterlogged saltna so[ls involves lowenng of water table below roct zone and leach[ng of excess salts leaching [s essenUally the d[splacement of saline SOIl solut[on With good q ualtty water or WIth water of lower salt concentrabon Salts displaced dunng leaching need to be removed by subsurface honzontal drainage system If the natural drainage of SOil [s impaIred Subsurface drainage has proved successful In rehabilitabon and conservabon of imgat~ lands in and and semI-and regions (Rao at III, 1988, Sharma and GuPta, 2006) However, drainage systems produce poor qualtty drainage water and d[sposal of such water [s a sertnLlS ,nrntllw.t> .I~ ~t:ICe t:tI ,MlU'lI1 ~ This prcC!em has Imposed F85tm:!IOtIS on the reciamallol> o! potenbally producbve wate~ogged saltne area using subsurface drainage system In order to enhance net benefits of drainage system, more attention shouid be given to'the management and 0' [sposal of drainage water

VOlume of Drainage Water

Subsurlace retum flow of ra[nfall and Imgattan water draIned through crop root zone IS draInage water A pornon of this return flow percolates into the ground water storage zone and the rest moves laterally along the hydraul[c gradient The SUbsurf'lce return flow In a shallow groundwater system [S Intercepted and COllected by the subsurface drainage In the area at a partIcular reqUired depth The quantity of water from the subsurface drainage [S lim [ted and avallat,le only when water table IS above the drains, However, the volume of retum flow (drainage water) depends on the drain depth and spacing, depth and methods of Irngatlon, leaching requIrements, so[1 hydrological charactenst[cs, Intensity and duration of rain, type of crops and Seepage from the adJo[ntng areas For aX~mple, the average discharge rates from the draIns Installed [n,a 10 ha area of sandy loam saline so[1 at 1,75111 depth With spaCIng of 25, 50 and 75 m was 37, 11 and 09 mm day" dUring [mgatlon season (October to February), whereas dunng monsoon season discharge was 8.1, 2 2

Chemical Changes & Nutnent Transformation In SodlcJPoor Quality Water Irrigated Solis

, , and 1.7 mm day", respectively The range of drainage coeffiCient obsel\led at a'few Illaces In the eountry IS reported In table 1

./ . Table .1., Subsurface drainage coeffiCients observed In test plots at dlfferenllocatlons

Srte Rainfall (mm) Rate (mm rJay" ) Recommended ranlle (mm day" ) Chambal (Rajasthan) 850 30 25-35\ Sampla (Haryana) 600 25 20-30 • Hlsar (Haryana) 400 20 15-2S Dabhou (Gujrat) 800 40 30-S0

I Mundlana (Haryana) SOO SO SO--. Kallnkhas (Haryana) SOO 68 50-70

Muraj (Haryana) 500 28 20-40

A conSensus is now emerging that drainage rates in the range of 1-S mm could serve the purpose In monSOon type chmate In arid "nd semi-and areas where reclamallon IS more critical than aeration Depending on actual drainage discl1arge rale and quality 01 drainage water In lIle project area, the management opMns are decided

Drainage Water Quality Issues

The quality of drainage dlscl1arge depends on the nature and amount of salts present In the 5011 profile and the sahnity of underground water. The salt content In the drainage water IS vanable according to the Imllal salinity conditions of SOil and ground water and gradually Improves With bme Mean composlbon of drainage water In some drainage projects IS reported In table 2 The drainage water has only traces of Iron, manganese, Zinc and boron At Sampla, absence of phosphorus, NH: and NO, - N Indicated little danger of groundwater pollubon as a result of nitrate and phosphorus leacl1lng. But Installabon of drainage systems may cause cI1anges in the assoCiated ecosystem These changes may be either benefiCial or adverse However, potential adverse water quality Impacts are associated With drainage in some countnes Concentrations of salts, nutlients and other crop related chemicals In drainage discharge vary With bme and discharge rat~ Use of fertilIZers and pesbcldes In intensive agricu~ural production has somebmes led to damage to downstream ecosystems Drainage planners therefore need to analyze effluent for nutnents and pesbcides. The nutnents most concern are

.N and P Natural trace elements from the sOil Itself may be harmful to the ecosystem at many a bmes In 'addltlon to agncultural cI1emicals and trace elements, drainage water from "rig'ated areas frequently contains salts The Impacts of salts on downstream users need to be eVllluated Some so,ls are abundant In trace elements, and these could leach to the dralnllge system Small amounts of trace elements such as, Cd, Hg~ Pb, B, Cr and Se are harmful to aquatic species because of biological magnlficallon. The enVIronmental consequences of disposing drainage water from San JoaqUin Valley Into the 470 ha Kesterson Reservoir (a closed baSin) are well known .

Table 2. Drainage effluent quality at different locabons In India

Station . EC (dS m') Stalion Kamal (Haryana) OS-De Loonkaransar (Rajasthan) Hlsar (Haryana) 40-80 SegWa (Gularat) Gohana (Haryana) 32-58 UpperKnshna (Kamatka) Sampla (Haryana) 80-27.0 Konanki (AP) Mundlana (Har) 41-64 Lakhuwali (Rajasthan) Chambal (Raj) 20-50 Pollacl1l Udumalpet(TN)

Rausa of Drainage Water for Irrigation

EC (dS m') 35-65 20-S7 06-1S 13-24 45-7.4 30-3S

With the Increasing disposal problem of sahne drainage water and expanding demands on high quality water for other purposes, reuse of saline drainage water for crop producbon has gained recogmbon Results of vanous studIes (Rhoades et al 1989, Sharma et aI1989, 1995, Yadav a/ a/ 2007) have Indicated a potential for reuse of saline drainage water for crop producbon Vanous strategies can be adopted t<;> use sucl1 water for Imgabon In fresh water scarce and and semi-and regions haVing poor quality groundwater In such sltuallons the reuse of saline drainage water may be useful for crop production Some feaSible alternatives are discussed In the follOWIng secbons

130

Recycling of Saline Drainage Effluents for Crop Produdlon

Use of Blended Drainage Water for trrigatlon

Highly saline drainage water can not be reused dlrectJy for crop production Blending Involves mixing water of two different quall~es to obtain water that is SUitable for Imga~on Salinity attained after mixing should be WIthin the pennlsslble limits, based on SOil type, crops to be grown and climate of the area To use the blending strategy, a controlled way of mixing the water supplies must eXist

Blended drainage water reuse was studied at Sampla (Haryana) where a subsurface drainage sr,stem was installed at a depth of 1 75 m, Blended drainage water of different sallnibes (0 5, 6, 9, 12 and 16 dS m' ) was used for all and only for post-plant Imgabons of wheat The results are'summarized In table 3 Considering 'the yield obtained WIth the use of canal water as the potential (100%), the mean relative yields of wheat,Wlth use of blended drainage waler of EC 6, g, 12 and 188 dS m" were 95 8, gO 3, 637 and 778%, respectively Pooled data were used to work out response of wheat to saline drainage water quality (05 to 188 dS m") WIth piecewise linear regression AnalYSIS Indicated that compara~vely higher salinity Imgatlon water (up to 9 dS m") could be used for 90% wheat Yield In the SOils Which have subsurface drainage system (Fig 1)

, I

100

~ 80

" ~ 60

• ~ 40

~ '" 20

0

I I I I I I Ry ' 100 '1,82 (EC .. -4,0)

+-Threstlold \ , I

4 8 12 Ie 20 24 28

ECIw

(dSm")

Fig 1 Relative Yield of wheat WIth different salinity water Imgatlon

Mean relawe Yield of succeeding pearl-millet and sorghum fodder decreased sl9nlficanlly only on plots where higher salinity water (> 12 dS m") was applied to prevIous wheat cnop Mean relabve green forage Yield of sorghum In 12 and 188 dS m" treatments was 60,3 and 70 4% In comparison to 86 3 and 77 3 % in pea~-millet, respectively Indlca~ng that sorghum IS less tolerant than pearl-Millet These' results are consistent WIth the concept that both san, senSitive and san tolerant crops can be grown In rotation If non-saline water IS used for ImgaMg the succeeding crops

Table 3 Relative grain Yield of wheat WIth blended drainage water use for post-sowing Imgatlon and succeeding pea~-millet and sorghum crops

EC (dSlm) of lrTigabon water Wheat Pea~ millet Sorghum fodder a 5 (Canal water) 100 100 100 Blended drainage water 60 958 980 961 90 903 941 901 120 837 883 803 168 77,S 773 704

Cyclic or Rotational Use of Drainage Water

Cydic use, also known as sequential applica~on or rotational mode IS a technique which faCilitates conJunclive use of fresh and saline drainage effluent In thiS mode, canal water is replaced WIth saline drainage water In a predicted sequenoelcycle, An advantage of the cydlc strategy is that steady state salinity conditions are never reached In SOil profile Rhoades a/ al (1992) have also advocated seasonal cydlc use, called 'Dual Rota~()n', strategy where non-saline water is used for salt sensitive cropslinltlal stage of tolerant crops to leach out the accumulated salts from sally water imgallon to previously grown tolerant crops ThiS strategy may work beller in and Climates With very low rainfall, however, It naturally occurs under the monsoon Climate Expenments by Shanna e/ ai" (1994), where combined use of saline drainage water (ECm 105-150 12 dS m") and canal water were used in pearl-millet/sorghum - wheat retail on support the SUitability of cyclic use strategy where canal water was used for pre-plant Imgalion P millet and sorghum received no Imgabon except the monsoon rains dunng the growth period (Table 4),

131

Chemical Change. & Nutrient Tran.'onnotlon In SodlclPoor Quality Water lITIgated SOils

Table 4 Effect 01 cYclic modes of post-plant imgatons on mean relaUve (%) yields 01 wheat and succeeding pea~millet and sorghum crops

./

Mede 01 water applicaton Wheat Pea~ millet Sorghum fodder 4CW 100 . 100 lop CW: OW (sHemata) 94.4 970 918 OW, CW(altemate) 91.3 95,5 9111 2CW+2DW 943 964 "928 2DW+2CW 882 949 91 1 lCW+3DW 636' 919 872 4DW 737 650 767

. CW = Canal water, OW = Drainage water

Management of Shallow Water Table

A potential soluton for reducing drainage volumes IS to promote exploltabon of water from sMllow water table for meeting a part 01 crop water requirement Subsurface drainage over a pened of ume leads to improvement In the Quality of sub-soli water In drained field Upper few centmeters of subsOil water had very little salinity, and plants can be allowed to use It by manlpulatng the drainage system operation Thus plants Wlil meet part of their evapotranspiration needs directly from soli water. Rao at at (1992) observed that 1.0 m shallow saline (3 0 to 55 dSm") waler table maintained WIth proViSion 01 sub-surface drainage system faCilitated achievement ot potential yields of crops even when surface water application was reduced to 50% Salinity bUild up was negligible and Ihe salls accumulated were leached in the subsequent monsoon season These resulls indicate that drainage system should be operated IntensIVely dunng 5011 reclamation stages and less intenSively Just 10 meet the annual leaching requirements In the later stages as It can be a useful strategy In optimiZing the produCU\I~ of land and water

Management Practices for the Use of Saline Drainage waters

Many SUitable management praCUoes should be conSidered while using saline drainage water for imgation Rigid approach WIll not be pracbcal, since most management deCisions are subjeCWe and innumerable aXlsMg combmabons hold promise Management pracllces adopted for optimal crop producllon must aim at preventing the build up of salinity, sodiC/ty and tOXIC IOns In the root zone The following practces are suggested for avoiding the detenorabon of SOil producllVlty, control of san balance in SOil-water system and minimiZing the damaging effects of salinity on crop growth

Orainage Water Availability

Availability of drainage water basad on drain discharge In different seasons should be determined to estimate the volume of disposable drair>age water A s~stem for collection, redlslnbuUon and a networ1< for blending of drainage waler should be developed to aVOid the need for storage. Quanbty of water from subsurface drainage remains limited and available only when the water table IS above the drains However, the volume ot retum flow (drainage water) depends on the dmin depth and spacing, depth and metheds of Imgabon, leaching reqUirements, SOil hydrological charactensbcs, IntenSity and durabon of rain, type of crops and seepage from the adlOlmng areas Example of average discharge rates from drainS installed In a 10 ha area 01 sandy loam saline 5011 at 1 75 m depth with spaCing of 25, 50 and 75 m IS gIVen In table 5

Table 5 Mean seasonal cumulative drain discharge (mm) at Sa",!pla (Haryana)

Season Drain Spacing (m) 25 50 75

Monsoon (July to September) 730 198 150 Daily average (mmfday) 81 22 1.7 Wnter (October to February) 512 158 141 Dally average (mmfday) 37 1 1 09

Drainage Water Analysis

Standard water sampling and analYSIS techmques for quality 01 drainage water should be used to evaluate Its reuse potentJal Most important water Quality parameters are EC, SAR, B and presence of Other tOXlC elements

132

Recydmg of Salina Dramage Effluents for Crop Produdlon

Crop Substitution

Most agncultural crops differ sl9n1ficsntly In their tolerance to concentration of soluble salts In the root zone. It IS desirabre to choose cropstvanebes that ean produce satisfactory Yields under·excess soluble salts ooncentrabons In root zane sOIl solution The difference between the tolerance of the least and the most sensrtlve crop crops may be 8-10 fold Wide range of tolerance allows for greater use of marginal quality water EXtent In

Increase of tolerance limits wdl<perrmt greater use of such water, thereby ieduclng the need for leaching and dramage Semi-tolerant to toleranr crops With 10..: water requirement hke mustard, baney and pear1:millet<elc should be grown under such oondlMns Expenments at Sampla Indicated that high sahnlty drainage water can be used for post-plant Im~atlOn for mustard Without any substanbal loss In Yield Grain Yield was more when It was Imgated With 8 dS m- sahnlty water than With canal water (Table 6)

Table 6 Effect of drainage water salinity on relative (%) Yields of musiard

Ec.. (dS m-' ) I 1" year 2 year 3 year I Mean 05 100 100 100 100 8 - -1007 1201 1167 1125 15 941 904 680

Pre-Sowing Irrigation

Pened of gennlnaban and seedhng emergence IS the most sensllive to sallnrty A failure at thiS stage leads to poor stand and a considerable Yield decrease. Pre-sowing IrngallOn With hiQh sahnlty water Will resuR In very poor gennlnallon It IS possible to neduce the nsk of high sahnrty dunng the germlnabon stage by pre-sOWIng canallmgabon

Adequals Subsurface Drainage , Use of saline drainage water adds salts to soli wrth each 'mgatlon and salts may gradually accumulate

In the root zone over the years" no leaching takes place Adequate <subsurface drainage IS esserrllal to facllrtate the leaching of accumulated salts from the root zone dunng the monsoon pened Results Indicated that under subsurface drainage system cnticalllmrts of saline water Imgabon for different d~rees of Yield reducbon In crops Will be higher than those prescribed in the Irterature

Alternate Area/Area Switching . - I

Project area 'should be dIVIded In different sectors for sustafnable1use of saline drainage water for Imgabon Depending upon the avallablJrty of drainage water, different sectors shOUld be selected for Imgabon With drainage water/canal water Imgate the selected sector with saline drainage water lor 3-4 years and than SWitch to next sector ThiS practice Will prevent the salt accumulabon In the lower layers If the volume of drainage water IS surplus In the project area, Its use in the adjOining area should be conSidered If the elevation al which the water is avaiJable IS higher than the place where It is needed, cost of lifting Will make the reuse unfeaSible

Grain Quality

In addllion to management aspects In reuse of drainage effluent, some conslderaban should also be given to the effects of saline drainage water 011 grain quahty and toxIC IOn accumulation

Salt Build-Up in Profile

While uSing saline drainage effluent for Imgabon, salts concentrate In SOil salullon due to evapotranspiration and accumulate In soli profile But If the sa~ accumulation does not exceed threshold hmlt of crop satt tolerance In the root zone, the crops will grow normally, Soil salinity mon~ored in different studies Indicated that 5011 profile salinity Increased With Increasing sahnrty of Imgabc," water (Sharma and Rao, 1998) Further observations Indicated that salt build up did not take place '" profile over the years because much of the salts added dunf'9 sahne Imgation are leached out of SOil profile With monsoon rains (Fig 2) ThiS downward leaclJlf'9 of salts reduced sallnrty levels Within acx:eptable ',mlls for good germlnallon of nex! wheat crop leaching 01 soluble salts under prevailing condlbons was brought about by rainwater and a good water pre-plant Imgabon However, if monsoon rainfall IS not sufficlenL salts ,n profile should be leached down With <a heavy (7-10 em) canal water pre-plant ImgaUon

Sahnlty profiles measured before and after the monsoon rains were used to develop a relation between salt removal and rainwater depth Relalions Indicate that 80% of salts accumulated With 6, 9, and 12 dS m" sahnlty water Imgatlon csn be removed by 051,076 and 0 92 m of rain water per meter depth of SOil Average annual rainfall of 637 mm In Sampla ana pre-SOWIng Imgatlons With canal water was enough far keeping root zone sahnlty In acx:eptable limits DynamiCS of soil sahnlty In crop root zone of subsurface drainage system areas

133

Chemical Changes & Nutrtent Transformabon In 50dlcIPoor Quality Water Irrigated SOils

, ,.-

IS such that long- term salt accumulabon does not occur and sOil salinity remains within crops salt tolerance limits Even i(some salts accumulate In subsoil layers after 5-6 years, Imgabon With canal water for one or two years IS ~uffident to prevent any salt accumulabon '

Long-Tenn Effects on Soli Properties

Studies have suggesbad that Imgabon water conialnlng salt concentfabons exceeding convenbonal SUitability standards can be used successfully on ma!'y crops for at least 6-7 'yea", '!"_thou~ !oss· In yield, However, unoertainty still eXIsts about therr long-barm effects c

,.>

... ,~,

·'r '.':

~ \ , , \

<c>

,. Fig "2~S"'oi::-1 s-a""lin-,ty:-p-ro-';fi::-le""'(;-a:-) a-:t-wh-:--Ce-at'""s"'OWI---:n"Cg-:, ("'b)""a"'tLwh7"Cea"CCt"'h"'a-rve-'st,...,J(C) after monsoon

Long-term effects on soil Include 5011 dispersion, crusbng, reduced water infiltrabon capaCity and accumulation of toxic elements' Magnitude of these effects Will depend on quality of drainage water used. Effects high salinity effluents Irrigation on some SOil properties In Sampla drainage prOject area were monttored for SIX years Since the SAR of saline drainage water was more (123 - 170) than that of canal water (0 7), Its use increased so" SAR. (Sharma and Rae, 1998) Leaching of salts by monsoon 'rains reduced SAR. and the remaining SAR. values did not cause any alkali hazard to the succeeding crops Similarly, after monsoon rains no Significant adverse effects were observed on saturated hydraulic conductivtty and water dispersible day Slight decrease In hydraulic conducbVlly after monsoon leaching IS not a problem dunng IITlgabon season because negatIVe effects of high SAR drainage water can be offset by lis high salinity Only slight variation in wabar dispersible clay after 6 yealS, of Imgabon with drainage water indicates r)lintmum structural detenorabon In Salls Although, no potenbal adverse effects were observed In \!1~ studies at Sampla farm, cautJon of careful evaluabon of SpeCIfic condrttons should be taken before resorting to reuse of drainage water

Conclusions

• • •

•

•

Fresh water supply is just not enough to meet the Imgatlon requirements. ~Imgabon With saline drainage water for sa~ tolerant crops is a Viable option to minimize disposal Drainage wat<;!r of varying salinity can be successfully used for Irrrgabon of Winter crops either directly or In conjunction with canal water by blending or '" cycliC use. The exbant of salt leaching and crop

, establishment depends on total monsoon rains and adequate subsurface drainage Use of drainage water not only Permits expansion of Imgated area but also reduce drainage disposal and assoCiated environmental problems In and and seml-and regions where good quality water IS not available in adequate quanlrttes Disposal of unusable saline drainage water by an out fall drain towards sea should be seen as the last interstaba water management option to solve exCess water problem The Idea may gain momentum when large- scale drainage projects are commissioned In northwestem states of India

Bibliography

Boumans, J H, Van Hoom, J W, Kruseman, G P Tanwar, B S 1988. Water table control, reuse and disposal, of drainage water In Haryana, AgncuUural Water Management, 14,537-545

Rao, K V G K, Sharma, D p, and Oosbarbaan, R J 1992 Sub-irrigabon by groundwabar management With oontrolled subsurface drainage In serni-and areas Pnoc Int Con' Suppf6mentary fmgatlon and Drought Water Management, 3(S6) 71-79, Sept 27-Oct.2, Valanzano, Ban (Italy), 1992.

134

Recycling of Saline Drainage Effluents for Crop Production

Rhoades, J D', Kandlah, A.- and Mishall, AM. 1992. Use of saline water tor crop production frogatlon ana Drainage Paper 48, FAO, Rome, Italy, pp 133 I

Sharma 0 P , Singh, K N, Rao, K V and Kumbhana P S, 1991. lrogatlon of wheat with saline wafer on sandy loam sOil Agricultural Water Manageroenti 19 223-33.

Sharma, D P, Rao, K V G K, Singh, KN , Kumbhana, P S, 1993 'Management of subsurface saline drainage water fndian Farming, 43 15-19

Sharma, D P, Rao, K V G K , SIOgh, K Nand Kumbhana, P S 1994 Conjunctive use of saline and non-saline Imgabon waters In semi -and regions frogatlOn SCIence, 15 25-33

Sharma, 0 P and Rao; K V G K 1996 Strategy for iong-term use 'of saline dralnage,water for Imgatlcm In semiarid regiOns. Sad & Tillage RElsearch, 48 287-295

Sharma, D P, Singh, K Nand Kumbhare, P S 2001 Reuse of drainage water for crop production Journal of/he Indian Society 0' 5011 SCience, 49,463-486

Sharma, D P and Tyagl, N K. 2004. On farm management of saline drainage water In and and seml·and regions Irrigation and Dramage, 5~·~-;:'103.

Sharma; D P, Singh, K.,N and Kumbhare, P. S. 2oo5a ,Response of sunflower to conJunc!J've use of saline drainage water and non-saline canal water Imgation Archives of Agronomy and 5'01/ SClBnce,'51·91. 100

Sharma, D P "Singh, K 'N and Kumbhare, P. S 2005b Response of wheat to conjunctive use of saline drainage water and non-saline canal water In semi-and region. AgrochlrillC<l, 49' 1-12

Sharma, D. P and Gupta, S K 2006 Subsurface drainage for reverSing degradation of waterlogged saline lands Land Degradabon & Development, 17605-014 -

Yadav, R K, Singh, S P, Lal, D and Ashok Kumar 2007 Fodder production and SOIl health With conjuncbve use of saline and good quality water In Ustlpsamments of a semi-and region Land Dagrad Develop 16 153-162 ' .

135

, /

Implication, of Fluoride Rich Irrigation Watereon Agriculture an(! Public Health /

D.S. Bunde/a and Kaplla Shekhawat DIvIsIon of Imgatlon & Dramags Engmesnng Central SOIl SalInity Researr:h InstJtute. Kama/-132001

Introduction

Groundwater IS a major source for Imgallon and dnnkmg water supplies and'rts quality IS a measure of Its sUitability as a source of water for Imgatlon and. drinking purposes The composition of. groundwater reflects ,"puts from the atmosphere, from water-soil and rock Interactions 10 flow path, as well as from

, pollutant sources such as agnculture, deforestation, mlmng. domestic and industnal wastes Groundwater quality data published recently at naUonal scale by the Central Ground Water Board reveal the presence of unhealthy quantities of fluonde In many parts of the country (CGWB, 2005). Twenty states in the country have been affected WIth high flumide groundwaters As such, any degradation of groundwater quality by excess fluonde can have senous repercussions on agncultural produce quality as well as on human 'and animal health through food chain, direct consumpllon or both '

Such waters have often been used for growing crolls, vegetables and fodders and have affected the crop produce quality In terms of higher fluonde content which causes fluorOSIs disease in humans and animals upon continuous Ingestion Small amounts of total flucnde less than 6 ing/day through food and water prevent dental canes In children and adults but the continuous Ingestion of higher amount (>60 mglday) results In dental fluoroSIS In I",~al stage leading to skeletal and neurological HuoroslS In humans and animals The high concentrations of fluonde are associated With Na-HC03 type of groundwater and correlated positively With Na. HC03• SAR and RSC to ldenllfy the potential areas for treatment There are reports of an Increase inCidence of dental caries, yellOWing teeth and twisted limbs among people of all age groups In the 'country Simple mitigation measures such as aVOid fluonde rich food Items and vegetables. and drinking water, Increase diet supplementation With calCium. magnesium and vltamm-C and drink safe water have been suggested to the affected people to contain the disease

Groundwater Quality

Groundwater quality parameters suCh as IlH. EC. Ca, Mg. Na, K. C03 • HCo,. SO. ancl CI are determined USI"9 standare! methods and procedures (APHA, 2005). The quality of groundwater IS detemllned on the baSIS of the follOWing hazare!s to agriculture and publiC health

• Salinity hazard • SodlClty hazard • Alkalinity hazard • Specific Ion tOXICIty hazard (FlUOride)

Saliruty hazard (total concentration of soluble salts) IS the sl"9le most Important crltena used for determining quality of .rngabon water It IS measured In terms of electncal conductIVIty (EC) In declSlemen per metre (dS/m) A water which might be SUitable for Imgallon on the baSIS of EC may not be sUllable If the concentration of sodium IS high and leads to SodlClty hazard to SOil Its hazard IS measured by sodium adsorption ratio (SAR) of the water uSing equation 1 Alkalinity hazard to SOils IS expected when lITIgation water containing sum of carbonate and bicarbonate higher than the sum of calCIum and magnesium Ions It IS measured by reSidual sodium carbonate (RSC) uSing equation 2 It leads to development of alkali Salls upon long-term Imgallon Specific Ion tOXICity hazard IS assessed for IndiVidual Ion and It IS conSidered for fluonde Ion of interest •

SAN= /Va

J(Ca~Mg) (1 )

~C = (HCO, + CO,) - (Ca + Mg) (2)

INhere. ions In the equations are expressed as milli equivalent per litre (men)

Classification of Groundwaters

Groundwater quality 15 grouped mto seven classes based on EC; SAR and RSC and the gUidelines for SUitability of Irngavon are gIven In Table 1

implication of Ffuoride Rich frrigation Water on Agnculture and Public Health

Table 1 GUldelmes for groundwater sUltaplilty for lrilgatlon

S No Water quahty E;:C (dS/m) SAR (m-mOVI)1Il RSC(men)

1 Good <2 < 10 <25

2 Sal"'"

• Marginally sahne 2-4 < 10 <25

• Salma >4 < 10 <25

~ High SAR sahne > 10 <25

3 Alkah waters

• Marginally alkali <4 < 10 25-40

• Alkah <4 <10 >40

• HI\jl\11 al\<.al\ 'Ianabie > 11) >41}

Occurrence of Excess Fluoride In Groundwater

Most natural waters usually contain small amounts of fluoride, but groundwater contains high concentrabons of fluoride mainly from ge0geOlc source Fluonde content In groundwater vanes from region to region and IS dependent upon' the factolS such as the amount of rainfall, air temperat~re, source of water recharge, type of geological formation and SOil and rock minerals When rainfall percolates through SOils and rocks, It leaches out fluorides to the groundwater Groundwater conlinuously Interacts With fluonde nch rock minerals WIthin saturated zone and IS cOntaminated With high flUOride Globally, natLlrally occurnng high concentrations of fluonde In groundwater have been reported In 25 countnes of the world and In 12 Asian countnes including China, Bangladesh, Sn lanka, Pakistan, Iran and Iraq (WHO, 2006) In India, high concentrations of fluonde In groundwater have been reported to occur In 203 affected dlstncts In 20 states (Andhra Pradesh, Assam, Bihar, Chhatllsgarh, Deihl, GUlara~ Haryana, Jharkhand, Karnataka, Kerala, Madhya Prad'esh, Maharashlra, O'nssa, p'unlab, RaJasthan, Tamil Nadu, Uttar Pradesh, Uttaranchal, West Bengal, Chandlgarh) The first ever case of high fluonde, groundwater and fluorosIS In India was detected In Andhra Pradesh In the earty 1930s, In the country, 25 million population are actually affected wrth fluorOSIs and 66 million people are at nsk Including 6 mllhon children In the 6-14 years age group In the country (UIlJICEF, 1999) High fluoride In groundwater IS a natronal problem and IS spread across across a variety of agr(Hlcologlcal regions VIZ Thar' desert, Gangebc allUVial plains, Deccan plateau, etc The highest concentration of ftuonde In groundwaters in the country (480 mQn) has been reported from Rewan dlstnct In Haryana and the second highest (42 5 mgll) from Muktsar dlstnct In Punlab (Table 2) In north-west India, 60 dlstncts out of 78 (32, 4, 8 and 16 In Ralasthan, Deihl, Punlab and Haryana respectively) have been 'plagued Wlth occurrence of h<gh fiuonde In groundWater Of late, sixteen districts of the state have been put on ffuonde red alert from Its geogemc source except In Panchkula, Ambala and Yamunanagar The average concentrations of fluonde In groundwater In the state range between 1 52-12 80 mgll With the highest natural concentration reported being 46 mgllin the Karoll village of Rewan dlstnct Groundwater IS also contamInated to some extent by Industnes such as bnck kiln, aluminium, steel and phosphatiC fertilizers These Industries somebmes release thel( effluent water treated partially or fully onto the ground surface or Into the groundwater. The rocks nch In fluonde are fluorspar (CaF,) In sedimentary rocks, lime stones and sand stones), cryolite (Na,AIFPO.) In IgneouS and granite rocks, and fluorapatite (Ca3(PO),Ca(FCI)'i. and hydroxylapatite and are the sources of fluonde

Table 2 Highest concentration of fluonde In groundwalers of:affected slates In decreaSing order

SNo State (dlstnct) Highest conc S No State (district) Highest conc

~ Haryana [Rewan) 480 mgJl , B Orissa [Korapu\) 92mgn

2 Punlab (Muktsar) 425" 9 Bihar (Gaya) 81 " 3 Ralasthan (Nagaur) 400 " 10 Karnataka (Kolar) 78" 4 NCT (Deihl) 325" 11' 'Uttar Pradesh (Kannau!) 77" 5 Assam (Karbi 23.4 .. 12 Andhra Pradesh (Krishna) 7.t "

Anglong)

6 West Bengal 145" 13 ;Tamil Nadu (Erode) 70" (Blrbhum)

7 ,Gularat (Mehsana) 129" (Note Conc stands for concentration)

137

ChemIcal Changes 8; Nutnent Transfonnatlon In S~dlcJPoor Qualrty Water Irngated Solis

Association of High Fluoride with Different Groundwater Types

Geochemistry of groundwater IS~ dependent on agro-cJlmabc, topographical, sOils, geological and land use factors and IS further determined by the dlrectlC," of groundwater flow In order to target the dlstribullon Of high flUOride areas and their assOClation with different groundwater types, The most of the state IS covered under and and semi-arid region except Panchkula, Ambala and Yamunanagar being sub-humid, The geologic formations of the state belong to three main groups VIZ pre-cambnan rocks represented by Aravalll and Deihl systems In the south, tertiary rocks represented by Tundapathar senes to the' Sh,vahk rocks in the north, and quarternary aUUVlum, Quarternary alluvium occupies about 97 % of the area of the staie The north and north eastern parts and southern part of the state have higher elevation and the state has bowl shape topography With flat areas In south-central part creating a scenano of saline Salls and groundwaters Groundwater elevation contours In the state follow the topography The highest water table contour IS 496,1 m above the mean sea level In Panchkula dlstnct while the lowest is 176 m above the mean sea levet In Sirsa dlStnct Groundwaler has three major flow directions Viz, north to south, north-easl 10 south-west and soulh southwest to north north-east (Fig la) All these direCtIons at flow result In natural ground water flow towards parts of Rohlak, Bhiwam and Hissr districts ThiS ultimately causes sluggish ground water movement resulting In large water logged areas'

In the northern part of the state, the groundwater IS of good quality (EC< 2 dS/m, SAR ,,10 (m malA) 112 and RSC < 2 5 mell) and of Ca-HC03 type ThIS type of groundwater IS rarely nch In fluonde due to high concenlrahons of calCium and magnesium Ions Groundwater In parts of Sonlpat, Jlnd, Kamal, Kalthal, Fatehabad and Sirsa dlstncts IS of low salinity (EC "4, SAR "or> 10 and RSC erther 2 5-4 0 or > 4) and of Na-HC03Iype This type of waler also occurs In southern p~rt of Bhlwani and eastern pa,rts of Mahendragarh, Rewan, Gurgaon and Fandabad dlstncts High fluonde contents have been mainly aSSOCIated With sodlumbicarbonate Iype of groundwater wlhlch has relatively low calCium and m'agneslum and high Na and HCO, concenlrabons, Such waler types usually have high pH values above 7 ThiS informabon on chemical composilion of groundwater can be used as an IndlC<!tor 10 Iden)lfy areas of potenllal high fluonde problems The composition at groundwater changes progressively along a flowpath from Na-HCO, zone to Na-CL zone (HC03 ~ HC03 + SO, ~ SO, + HCO, ~ SO. + CI ~ Cll The groundwater In parts of Rohlak, Jhauar, Bhlwanl and H1sar dlstncts IS of high sallnrty (EC either 2-4 or > 4, SAR " or > 10 and RSC "25) and of Na-CI Iype Using the correlalion criteria, base maps and secondary informatio,n, four polennal zones of low, ~medlum, h'9h and very high concentratons of flUOride In Haryana (Fig 1b) were identified and relatively 'ranked 10 take up crop cutbng experimentation In high and very high fluoride zones for studYing the accumulation of fluonde In crops ThiS will help In developIOg mitigation strategies tor prevention of fluorOSIs 10

the study area. A pol expenmentation has been camed out to sludy the uplake and aCCUmulation of fluonde In wheat, bemeem and spinach plants With SIX concentrations of fluonde 0, 5, 10, 20, 40 and SO mgll at 1 9 EC, 10 SAR and 2 5 RSC synlhellc waters ~

-- liD

Legend Fluoride Pau0111i11 Zanes'"," ~ lew fllIcrkl! wale\'

t::I ~Ium nuortde: wafer

E;l High fluoride water

Iii Very high tl'uorldewater

,Fig 1: Groundwater flow direction map (a) and groundwater fluonde zone map (b) of Haryana

138

Implication of Fluonde Rich Imgatlon Water on Agnculture and Pubh~ Health

Total Dally Fluoride Intake Fluonde contents from all sources determine the human Intake of fluonde. There is no safe

prescnbed limit of fluonde for Irngatlon water, food, vegetables and fodders by the national or world health agenCieS Therefore, total dally safe fluonde Intake for an average adult IS used and It IS 6 0 to 8 0 mg per day from all the sources (Raja Reddy & Deme, 2000) It IS less for children and those affected With kidney disease The dally Intake of fluonde In endemic regions of the country vanes from,10 to 35 m9 from Winter to summer months

Implication, on Agriculture and Public Health

Agricultural crops VIZ food, vegetables and fodders are often grown In fluonde nch Salls, irrigated With fluonde nch groundwaters or wilh phosphatic fertilIZers or phospho-gypsum applied dunng reclamation High availability of fluonde IS tolerated by the most crops and do not affect crop germination and Yield and SOil properties, but the fluonde IS up-taken excessively and accumulated the unhealthy quantities In plant parts which Join the food chain that poses a SeriOUS threat to human and animal health The fluonde content of such food, vegetables and fodders vary from northern part to southern part of the state Only In southern dlstncts, Significant amount IS contributed from food whereas In the majonty of endemiC areas, the main contnbutlon comes from drinking water In non-endemlc areas, all food and vegetables contain permiSSible quantities of fluonde and the total dally Intake through an average human diet IS small whereas In endemiC areas. the fluonde content of food and vegetables are very high Therefore, the contnbutlon of food to the total dally Intake of fluonde is also high Staple diets rich In sorghum, ragl or bajra grown In south-westem districts of the state contain high fluonde which aggravates endemiCIty of fluorOSIs Fluonde content 1M food and vegetables was found to be moderate In the state, being the highest In Rajasthan and the lowest In l'unJab Within food crops, cereals, pulses and legumes retain the maximum fluonde content and the nuts and all seeds also contain relatively higher fluonde content (Table 3) Tea and black salt are most commonly used and have exceptionally high fluonde contents which vary from 122-260 mgll or more In different brands Each cup of tea may supply 0 3-0 5 mg of fluonde

Table 3 Fluonde content of food and other edible Items

S No Food Items FlUOride (mglkg) SNo Food Items Fluonde (mg/kg)

1 ·Wheat 46 13 Carrot 41

2 Rice 59 14 Mint 48

3 Maize, ,

56 1§ Tea 60 - 112

4 Gram 2.5 16 Coconut water 032-06

5 Soybean 40 17 Conander 23

S Cabbage 33 18 Ganlc 50

7 Tomato 34 19 Ginger 20

8 Cucumber 41 20 Turmenc 33

9 Ladyfinger 40 21- Rock salts 200-250

10 Spinach 2.0

22 Areca nut (supan) 36-120

11 BnnJal 1 '2

23 BeeUe leaf (pan) 76-120

12 Potato 28

24 Tobacco 32-38

(Source Adapted from Susheela, 2003)

FluorOSIs, caused by excessive intake of fluonde nch food,-dnnklng water or both, IS a public health disease It IS locally known as bankapattl In Rajasthan, lunJPunJ in UP, wah in GUjarat, and genu va/gum In Madhya Pradesh and Andhra Pradesh It is a ~eglected, disease In public health domain and has no treatment, but can be cured eaSily With a few interventions at indlvldual.level The fluonde Intake dependent upon consumption of food and dnnklng water IS determined by vanous factors such as body Size, phYSical actiVity, food habits and vanations in atmospheriC temperature and humidity Since India being a tropical country, the dally fluonde Intake IS very high In the affected areas Farmers and farm labourers eat nutntlOnally poor or unbalanced diet and dnnk lot of high fluonde water and are at nsk of developing manifestations of flUoroSIS ,FluoroSIS In Haryana IS taking ItS toll With a sharp flse In the number of people With dental fluoroSIS The cases of arthntls are on the rise In the state and are further aggravated by fluoroSIS Excess Intake of

ChemIcal Changes & Nutrient TransformalJOn In Sodtc/Poor Quality Water lITIgated Salls

/

fluonde can lead to three !yeps of fluorosIs VIZ dental, skeletal and non-skeletal (neurological) Affluent farmers In the state can afford to dnnk low fluonde water or minerai water whereas poor farmers and labourers can not afford to buy defluondatlon filters or minerai waters and they Will be affected With the disease sooner or later, ~II children liVing In endemic areas may have developed dental fluorOSIs or would develop It qUiCkly Those exposed to excess ingestion of fluonde beyond the age of 10 years would develop advance stages of flUOroSIS, Dental fluorOSIs affects the entire dental structure, resulting In Intense pain and decay of teeth With chalky and Inable nature Sketetal fluorOSIs IS formed due to higher Intake of total fluonde (>10 mglday) through diet and water and Its symptoms are body pain, lethargy, tingling sensabo~s, abdominal breathing and bending of bones hlndenng natural movements ,

Various dietary components influence the absorption of fluonde from the gut as salts of calCium, magnesium and aluminum are added to diet reduce the quantum of fluonde absorption on account of the

,.formation of their less soluble compounds Food and drinking waters with high calcium and magnesium 'content also control the InCIdence of fluorosis Therefore, all other factors being equal, the InCidence of skeletal fluorOSIs are less where the calCium and magnesium content of groundwater IS high EndemiC fluorOSIs IS further complicated by factors such as malnutnbon In children ~and adults or calCIum and magnesium defiCiency In dally diet Animals Ingested With fluonde nch fodders and forages suffer from vanous stages of fluorOSIs VIZ dental and skeletal High fluonde can also cause the uptake ot food trom the paunch to decline and It can disturb the development of craws and causes low birth-weights Anrmals continuous Ingested With fluonde contaminated fodders and waters develop a disease of the teeth and bones of cattle callect 'ctarmous'

Remedial Measures FluorOSIs can easily be cured by taking Simple short and long term Interventions FluorOSIs affected

VIllages are diVIded Into two categones tor treatment - low and high endemiCIty on the basis of seventy of fluoroSIS. Villages of low endemiCity suffer tram dental fluoroSIS only A mass awareness campaign IS needed to let people know the problem and pOSSible solutions at thel( end NutrlbOnal enhancement of the diet With calCIum, magnesium and Vltamin-C supplementation needs to be proVided to children and adults to prevent further damages from fluorOSIs, Beside thIS, an alternate source of fluoride safe dnnklng water also needs to be prOVided

Villages of tngh endemlclly suffer !rom sllele\a\ and cnppllng lorms 01 ~uorosls Incluclng cental IllS Important to estimate the sources of fluonde to the dally Intake of humans and ammals In the affected Villages, fluo(lde Intake has to assessed from both food and water _The food With rich fluonde content such as sorghum, ragi or balra and tea should be aVOided as far as pOSSible to convrol the disease '" diet With high content of calCium, magnesium and vitamm-C need to be promoted Alternate source of safe dnnklng water or defluondated water, emplOYing one of fluoride removal techniques (adsorption and Ion exchange, preCipitation, electro-chemlcal and ~embraQe technique) needs to be proVided to the, affected people in the Village The Nalgonda (precipitation) technique at household level needs to be promoted In long term, fluonde nch groundwaters may be diluted by enhanCing groundwater recharge from ram fall and canals through an appropnate programme

Short lerm intervenlions

AVOid fluonde nch dnnklng water, food and vegetables

Use safe source of dnnklng water IncludIng rooflop rainwater harvesting, surface runoff harvesting, farm ponds, and defluondated water

Introduce nutnbonallntervenbons (enhancement ot calCium, I(on and vitamin C, elc in diet)

Long term mterventlon

Dilution of fluonde by artifiCial recharging and by adopbng effiCient lITIgation practices

ConclUSions

The country IS expenenclng a senous problem of high fluonde in groundwater mainly from geogenic source, The high fluorides are maInly aSSOCIated With Na-HC03 type of groundwater occumng In dIfferent parts of the country Food, vegetables and fodders grown With such Imgatlon waters contain unhealthy level of fluonde In agricultural produces which have ultimately affected human and animal health through the vanous stages' of fluorOSIs disease The disease could be detected by checking the teeth of schoolgolng children for fluorosis markers Rural people need to be senSitIzed of thiS slowly cnppling disease and ItS symptom through mass awareness and action programmes at govemment ~nd community level The ~adoptlon of short-term remedial measures suggested With people partlClpatory could address the problem and woll save million 'of children. and adults t~om suffenng of, fluorOSIs Adoption of long-term remedial meaSures such dilution of

140

Implication of Fluonde Rich Irrigation Waler on Agrjculture and Public Heallh

fluonde by enhancing groundwater recharge is necessary to solve the problem forever The PriCe of Inaction at either ends Will be cnppllng of the poor rural people and children ,n the state and country

Bibliography ! APHA, 2005 Standard MethOds for the Examlnabon of Water and Wastewater, "21 ~ Edillon, Amencan PubliC

Health Assoclabon, WaShington, D C 1368p "

CGWB 2005 Statawlse contamination of ground waler In soma aroas of the dlstnets due to vanous conlamlnants Central Ground Water Board, Fandabad, http Icgwd ,gov In

Mlnhas, P S and Samra, J S 2003, Quality assessment of water resou~s In the Indo-Gangatlc baSin palt In India Bulletin No 112003, Central 5011 Salinity Research Inst~ute, Kamal

Rala Reddy, D & Deme, 'S R 2000 Skeletal rFluorosi~ ~Apollo Hospital and FluorOSIs Vlmukthl Vedlka, Hyderbad, Andhra Pradesh httpllfluorosisinandhra om

Susheela, A K ,,2002 FluorOSIS In developing cOuntnes Remedial measures and approaches Proc' Indian Naln' SCI Acad (PINSA) B68, 389-400" . - " .

UNICEF, 1999 Fluonde 'In waler An,_ ,OverView Unicef, UNO, NewYor1< http Itwww unicef orgfproorammelweslinfolffuor htm

WHO 2006. Fluonda In dnnking water Fawell, J , Bailey, K, Chilton, J , Dahi. E, Fewtfell, Land Magara (EditOrs)" Y. WHO and IWA Publishing. London

141

Deficit Irrigation - An Option for Crop. Production under Water Scarce Conditions' /

R.K. Yadav and Kapila Shekhawat DJVJs;on of SOlIs and Grop Managl'menl Central SOil Saltmly Research Instil ute, Kama/- 132001

Introduction

Water IS absolutely essential and most fundamental need for human survival The very eXlstenae of .ooetle" "nd evolution of cultur.,s have relied on proper management.af water resouraes. At present, the global annual water resources are only 47196 km' (iWMI, 1998) ThiS IImlled supply IS not enough to meet the conhnuously Increasing demand for production of food and fast expanding urban and Induslnal sectors The shortage IS felt most by the densely populated developing world, ,However, now water shortage and Its wasteful use' are the two InconSistency aspects of water resources worldWide Due to these facts. the agncunure IS severely constramed by water lImItatIons As one of the most Important ecologIcal factors detemllnl"9 crop growth and development, -water defiCit plays a crucial role In affecting the Yields of crops Management o{ water IS highly location specific and deCISions for lITIgation scheduling are governed by SOil, crop" water characteristIcs and clirnahc factors Optimum crop YIelds and water use effiCIency (WUE) can be achieVed by bmmg optimum depth of imgatJons In such a way that non productIve evapotranspiratIon and drainage losses are mInImIzed IrrigatIon planning also consIsts of deCISions on how the available water should be apportioned among the different crops grown In a field Irngatlon optlmlza~on With defiCit "ngatlon involves deliberate water defiCit of some degree without Significant Yield reduction In crops The strategy IS also called as partIal lITIgatIon, regulated defiCIt irrigatIon, ET defiCit Imgallon and hmlted Imgatlon The fundamental goal of defiCit iITIgahon IS to Increase water use efficl,ency, eIther by redUCing IITIgabon depth, irrigati"9 the partial root zone area only like alternate furrows or Widely spaced furrows or ellmmatlng the least produchve lITIgatIons In any crop SOIl water defiCIts at some growth stages of crops Increase drought resistance and opt,m,ze dlstnbubon of photosynthates In t,ssues and organs, resulhng In hIgher grain YIeld and WUE as Ka"9 et al (2002) recorded about 20-45% higher wheat grain Yield under SImilar enVIronment by 30-60 mm of reduced lITIgation at JOinting

The acceptance for mmimal losses in Yields as a consequence of defiCit lITIgatIOn proVIdes an opportunity to explort these technIques to the fullest extent and necessitates fOCUSIng on water Use efficient ilTlga~on strategies hke evolVing less water reqUlnng crop genotypes, use of effiCient ImgatlOn methods as dnp and spnnkler, developing water effioont cropping patterns, IrngatlOn scheduling mcludlng defiCIt rmgallon, use of poor quality water and water harvesting and transfer of surface water from sUlplus areas

Strategies for Crop Produc:tion under Water Scarcity

Y,eld expressed as production per unIt of land IS the trad,llonal measure of prodUctiVity In agnculture However, water 15 the most limlilng resource and With the challenge to produce more WIth less water, productIon per unit of water has emerged as an Important concept For a farmer With scarce water supply, strategies to Increase the produdlYJty of water may lead to more Income and berter nutntlon Strateg,es thaI can be useful for Increasing the producliVlty of water and land may include I) allocation of less water to more stress' tolerant crops, II) planning for Irngatlon of crops during entlcal growth stages III) ImgallOns at lower adequacy or to some speCIfic area of crop root zone and IV) allOWing more depletIon of avaIlable SOil mOIsture

Allocation of Water to Tolerant Crops and Use of Efficient Irrigation Methods

Under water Scarcity, first opbon for water saving should be adoption of drought resistant crops and use of effiCIent Imga~on methods like drip and spnnkler The crops melude safflower, sorghum, pearl mIllet, cotton and cluster bean dunng khanf and gram, lentil, barley, mustard, Eruca sp and wheat dunng rebl Selection of cropSicultlvars and crop plans and other englneenng and agronofnlC operations hke proper water conveyance, land leveling and grading, weed control, optimum fertlhzer and plant protection measures playa great role In attaining hIgh productIVIty and mInimIZIng water losses,

The development of optimum crop plans for maximiZing net profit per unit of water and land depend upon the agro-cllmatlc conditions and ablhty of a fanner for opllmal use of other Inputs In semi-and regions of north-west 'ndla, pearl millet- Enuca-sunRower, pearl mll'eHnuslard, pearl mlilet- mustaro'ltona- sunRower, cluster bean - wheat. cowpea-pearl millet-wheat, moog bean-peart millet- wheat, cotton- wheat. are relatIvely more tolerant producllve crop plans Pearl millet 15 a major crop for khanf, however, IntercroPPln9 of moong bean or cQwpea can give additional grain and todder y,eld, respectively DUring rabl season Enuca sp, mustard and chick pea could be good options It is always adVisable to grow more fban one crop In entire a rea as It covers the nsk of faIlure of SIngle crop due to any dIsease, pests or adverse conditIons In addilion to

Deficit Irrigation-An Option for Cr,?p Production under Water Scarce Condlbons

arable crops groWing less water reqUiring horticultural, crops as ber, guava and aonla could also be very producllve opbons, Water requirement of different crops IS compiled In Table 1

Table 1 Water requirement of different crops, I

crop Water reqUJrement (mm)' crop Water requirement (mm) Wheat 350-400 Paddy / 12~0-1400 Bartey 200-250 Cotton 400-500 Gram 150-170 Groundnut 250-300 Peas 200-250 Green pea/cowpea 200-250 Mustard , 150-200 Pigeon pea 300-350 Lentil 150-160 Sugarcane 1400-1500 Peart millet 200-250 Potato 400-450 Maize 350-400 Sunflower 300-350

Critical Growth Stage ICGS) Approach

Another strategy for saving water IS to apply Imgabon only at some speCific growth stages of crops Mo<sture stress at all the stages of crop growth does not have equal effect. I~ general most cnvcal stages In determinate crops are seedhng and flowenng Imgabon of crops at cnup'1 stages IS essenbal as inadequate water availability at these stages can result In drasbc Yield reduction Imgatlon IS given to crops'accordlng to their cnucal stages, whereas depth of lITIgation depends on water holding capaCity of the 5011. Thus, here Imgatlons are scheduled to optimize crop Yields and water use effiCiency (WUE) In such a way that non productive evapotranspiration and drainage losses are minimized, and pOSSible Inevitable water defiCits COinCide With least'sensluve growth Penod. ThiS approach IS recommended when the water holding capaCity of the Sallis> 200 mm per liter of 5011 depth With depth of 5011 being> 1 meter, Imgatlon scheduling at cn~cal growth stages IS most practical as farmers, Imgauon and agncultural offiCials know these stages well and also do not require any instruments or database but needs only keen field observatl,oris .and bmely release water The entlcal growth stages 'of different crops, their penod and the effect of water stress are listed In Table 2 As far as practical Impllcabons of thiS approach are concemed, It economizes the use of Imgatlon water due to Increased rotal produc!Jon by supplYing defiCit IITIgabon to more area

Out of five cntlcal growth stages of wheat and barley, crown root Initiation and flowering are prlonty stages for Imgabon Similarly, Inadequate water supply at pre-flowenng, flowenng and earty pod formation stages In gram has an adverse affect on growth and Yield From the three cntlcal stages for water stress, flowenng and pod filling are cruCial In case of mustard Square formation, flowering and boll development are the three cobcal stages of cotton Imgabon. Sunflower has four cntlcal growth stages but highest Yield can be obtained by giving imgauons at Inlbal stage, flowering stage and grain filhng (Yield formation) stage Groundnut has four cntlcal growth stages and flowenng and pegging stages are cntlcal for "ngatlon The' cribea! stages for water stress in sorghum are seedling establishment, reproductive pnmordial, fiowenng and grain filling stage; among these seedling and flowering stages are most cntical In case of pearl millet, 9ut of three senSitive stages, headmg is found to be most cn~cal for water stress

Irrigation at Lower Adequacy or To 'Some Specific Area of Crop Root Zone

The rate of 5011 water depletion by any crop governs the Interval between two Imgatlons Normally the irrigation IS applied at 50 % depletion of available \yater In the root zone The Intervals are kept shorte~, dunng summer and ,n sandy soils than winter and the clay Salls Imgatlon scheduling helps In deCiding the desIred depth of Imgabon and Its nght time so that optimum Crop Yields ale obtained It Involves maximizing of lITIgation effiCiency by minimizing water runoff and deep percolation The lITIgation scheduling methods could be based on ,) climatic approach, Ii) monitonng of soli water and JII) sOI/-crop- climate approach Some of the findings are discussed below Two degree regulated water defiCits (50% -M and 75% -S) depletion of available SOil mOisture, and no water deficit (N) were Imposed on wheat at dlHerent stages VIZ up to )Olntlng (eaMy vegetative), jOinting to booting (late vegetative), booting to heading (ea~y reproductive) and heading to grain filling and matunty (late reproduc!Jve) Wheat yield, biomass, Yield attributes, water use effiCiency In treatment SNNM, MNNS and MNNM were better th~n no stress (Table3)

Relatively deeper root system benefiCial to better use of water stored In deeper 5011 depths under regulated water deficits could be the baSIS higher wheat Yield and water use effiCiency Simlla~y scheduling Imgation at 75% depletion of available 5011 mOisture In pea~ millet had no adverse effect on quantity and most of the quality traits (Table 4) of dry forage, and water-use effiCiency Increased With higher levels of water stress, therefore pearl millet can be considered as a SUitable forage crop for water stress

143

ChemIcal Changes &, Nutnent Transformation In SochcJPoor Quality Water Imgated Salls ,

" Table 2 Identified cntlcalstages and Ihe" duration In some crops

/

Crop / Cntlcal stages, their duration (days after planting) and effects Wheat Crown root Tlllenng (40-45): Late 10lnbng (55- Flowenng (9c}-

InlliallOn (2c}-25), Reduced 60), Ear length 95), ,Size of Dough 110), weight

(105-Test

Barley

Gram

Mustard

Sunflower

Groundnut

Sorghum

Pearlmillet

Reduced - root effective tillers and no; of grains grains, growth and bllers ~

"CRI (2c}-25), Root TIllenng (40-45), JOlnbng (5c}-55), \

Flowering \ (Sc}- Dough growth and tillers Reduced Ear length and 85), Size of 100),

Early vegetative (35-40) vegetative growth

Vegetative 35), Growth branching

(25-and

Early 'Vegetative (35-40), Height

Seedling l",ballOn (_3(}.35), Growth

Seedling Establishment (18-25), Vegetative growth

Early Veg (Zc}-25) 'vegetative growth

effecbve bllers no of grains grains ,weight Flowenng (40- Pod development Grain fili,ng-45): Reduced (70-75), less' (11c}-120), ftowenng pods and Reduced test

Flowering (60-65) Reduced flowenng

shedding Pod filling t05) number weight

weight (to(}' -seed and

Flowenng (85- Boll Square forinabon '55)

(45- 95), Flowers and development Ripening (130-140), Quality

Lall~ vegetative (50-55), Size of buds

Flowenng (45-50), flower drop

Reproducbve pnmordlal (4c}-45), Reproductive parts

'Heading (55-60) head length

boll shedding (115-125), Boll

Flowenng (70-, 75), Flower size

Pegging (5c}-55), Number of pods

Flowenng (65-70); Less fertilization

Grain filling ( 65-70)

opening and sIZe Yield formation -(90-100), Grain wt and 011 content

,Pod formation -(65-65) Pod and test weight· Grain filling (75- -85), Lower test weight

Table 3 Wheat yield, biomass (t ha''), harvest Index, water use (mm) and efficlE!ncy (Kg ha"mm)

Treatment Grain Yield Biomass Harvest Index Water applied Water use WUE NNNN 48 128 037 295 371 1294 MNNM 5,7 '139 041 245 360 1583 MNNS 54 129 042 205 348 1551 SNNM 55 128 043 235 356 1544

Table 4 The average forage quality parameters (%) In different water stress levels

Forage' Quality Parameters Severe (75% ASWO) Moderate (50, % ASWD), _Non-stress

(95-Test

Leaf Stem Leaf Stem Leaf Stern _____::.....---

63 ai' Digestible Dry Matter (%) 5731 c 6495' 5834- 638- 6002'

Crude Protein (%) 165' 988" 1831' '9 11" 18 a9' 87'

water-Soluble Carbohydrates (%) 572' 1577' 538' 14 01'" 498' 12 11'

ACid Detergent Fiber (%) 3999' 3199- 3843' 3301' 3791' 3376' __::.::.---

Means followed by a Similar letter are not Significantly different at the 5% level of probability

144

Deficit Imgatlon-A.n OptIOn for Crop P~Ud.lon under Water Scarce Condlhons

Imgatlons based on leaf water potential at ,whiCh photosynthesIs starts receding IS an Important approach of deficit Imgabon scheduling Cntlcal leaf water potentials for relative photosynthebc activities of different Crops worked out by vanous workers have been compiled and presented In following _table - It has alsO been observed that In general 75% of photosynthetic effiCiency of most of drought tolerant crops can be maintained by applying onty 50% of fulllmgation wali.r '

Table 5 Leaf water 'I' (bars) for full, 75% and 50% photosynthebc effiCiency of .dlfferent crops ,

Crop Leaf water 'I' (t 2 bars) Crop Leaf water 'I' (r 2 bars) Full 75% 50% Full 75% 50%

VVheat -68 -94 -226 Pea~ millet -79 -to 4 -246 Barley -87 -12,3 -274 Sorghum -67 -93 -224 Chickpea -8.1 -10,6 -247 Cluster bean -64 -9 6 -21 8 , Mustard -84 -11 8 -271 ! Green gram -6.5 -8.8 -197 Eruca sp -89 -145 -30.4

Partial root zone drylng

Here biochemical responses of plants to water stress are used to achieve a balance between vegetabve and reprodudlve development No slgnlflcant redudlon In Yield due to PRO was recorded even WIth half amount of "rlgaron In Vines As SOil water availability falls after the cessa~on of Imgabon, the absClslc aCid IS synthesized In the drying roots and transported to the leaves In the transplcabon stream (Loveys et 8/, 1999) and consequently stomata respond by reduCing aperture, thereby restndlng water loss Improvement In WUE. results from parbal stomatal closure because the reducbon In photosynthesIS was proportionately less as oompared to loss ot water Early attempts of allOWing a part of the Vine root system dry keeping \tie remainder well watered were confounded by the transient nature of the response to drying part of \tie root system However, by SWitching the wet and dry sectors of the root zone on regular baSIS, thiS transient response was overcome (Dry et af, 2000).

Fig 1 Schemalic diagram of PRO drying uSing two above-ground drip lines In a vineyard

A number of long-term, large-scate field expenments on vine vanetles With a range of Imgatlon methods have been oonducted by Loveys et a/ (IS99) and Dry et.1 (2000) They Included two standard 2 or 411lreslh discharge dnp emitters per vine In the Inter-vine space placed at 450 mm from the vine trunk (Fig 1) and subsurface drip lines, one on each Side of the vme row at a depth of 200-250 mm and 350-400 mm from the centre of the row The Intention was to create two wetted zones per Vine that could be altemately lITIgated on a cycle of approximately two weeks 5011 mOisture sensors were Installed In each zone to assess infiltration of water applied to the other. Satisfactory separabon of wet and dry zones In a range of SOil types under field OOndl~ons was observed in these tnals. Partial root zone drymg With furrow/flood "ngallOn has also been foUnd successful In experiments With pears and Clbrus and In commerCial vineyards In New South Wales, Australia (Clancy, 1999), and With other perennial row-crop fruits

145

Chemical Changes & Nutnent Transformation In SadlclPoor QualIfy Water Imgated SOils

Bibliography !'

Buchong, Z , Gaobao, H , and Yanhong, Z 2006 Yield perfonnance of wheat under regulated defiCJ! Irrlgalion I~ an and area Agnc. Water Manage 79 28-42

Clancy, A 1999 Rlverina has the capaCIty to deliver diverse requirements Australian VlIlculture 3 38-42 Dry, P R , LQveys, B R , Stoll, M., Stewart, D & McCarthy, M G 2000 Partial rootzone drying - an update

Australlsn Grapegrower and Wlnemaker 436a' 35-39 ' \

II!\iMI 1998 International Water Management Institute Research Report No 19. \ Kang, S , L.mg, Y., Cal, Hand Gu, B (2202) Effects of limited Irrlgabon on Yield and water use efficiency of

wheal in loess plateau China Agric Water Manage 55 203-216. Loveys, B R , Dry, P R , & McCarthy, M G 1999 USing plant physiology to Improve the water use effiCiency of . horticultural crops Acta Hartlcul/uraa 537 167-199

146

Characterization of Wastewater for Irrigation

R.K. Yadav and Khajanchl Lal D,v,s,on of SOil and Crop Management I Central SOil Salmlty Research Instllute, Kamal- 132 001, Haryana

Introd~ction

Guidelines on treatment and discharge of wastewater are observed In developed world, but .resource. constrained developing countries like Indlal dispose either raw or partlaUytreated wastewater In surface streams or make use In pen-uroan agncutture DIsposal of wastewater In streams cause thelT eutrophication but land appllcabon for imgabon serves as a low cost reliable altematrve Though Imgatlon WIth wastewater IS an age-old practice bul rt'IS getting renewed 'attentlon because of generation of huge volumes of wastewater by ever Increasing global populauon, urbantzatlon and ,Industnallzation Unlled Nations Population 1)lVIslon, 2000 reporl suggests that at present about 200 millIon m' per day wastewater is generated by 2 billion urban populations of developing countnes and most of rt IS not treated Problem of Wastewater generation and tre~tment In developing countnes will further aggravate If the Unrted Nations' millennium development goal of redUCing the population WIthout water supply, santtabon and sewelS to half by the tum of thiS century IS achieved (VIIHO, 2001), because about 88% of thiS growth In urbamzatlon and Industnallzabon 15 projected to take place III the Clues of these resource poor developing oountnes (Rattan Lal 2006) BeSides domestiC wastewater, accelerated diverse industnallzatlon generates effluents containing vanable concentrations of orgamc compoUrlds, dissolved toxins and u))recovered metJals. These indusmal effluents get mixed WIth sewage and storm water b<lC8use In developing countnes these are discharged through Single system Exponentially Increasing urbanlzabon and Industnallzauon IS not only uSIng large areas of produc!Jve agncultural land but also prodUCing large volumeS of wastewater that have become a serious enVIronmental threat In most countnes Wastewater generated thus IS a direct source of surface water-logging, groundwater contamination and salinlZabon or SOIl s,,;kness around CItieS Such unplanned disposal of mUniCIpal wastes causes development of many bIg lakes of wastewater In and arPund all blQ C1bes In fact all the rivers have beoame big open sewer drains and lakes and ponds as sewage dumps However. availability of such enormous volumes of variable composition raw or partially treated wastewater provides an opportunity for utilization of thelT Imgatlon and nutnent potenbal in the already water scarc:e semi-and regions where supply of fresh water to agnculture IS bound to reduce further from present share of 85 to 68% by 2050 Particularly the situation IS lIkely to be alarmingly severe In 30 most densely populated developing oauntnes like Egypllndla, Iran, Nlgena and TUnisia. Importance of wastewater for developing oountnes can be gauged from the facts that about 70"10 of present Imgauon requIrement in closed basIn Middle Eastern countnes IS met by wastewater (Abu-Zeld et al 2004) Similarly In India, producbon worth US $ 670 milliOn and employment eqUivalent to 130 million days can be generated by augmentalion of Imgabon and supply of nutnents WIth partially lreated sewage to vegetable, fodder and grain crops (Mlnhas and Samra 2004) But raw or rartlally treated such wastewater often has more than permiSSible levels of heavy metals (FJ!amo at al 2007) In thelT earher reports Yadav at 8' (2003) also recorded more than permiSSIble contents of Cd, Cr,' NI and Pb ,n the partially treated wastewater dIsposed at different urban locations In Haryana The sustained unregulated use of such wastewater also poses nsk of accumulauon of unrecovered non-essentlal metals In soils, crops grown and ground water Thus before resortIng to the use of wastewater in agnculiure, Its charactenzatlon for SUitability for Imgatlon IS very essential As of Increasing oompebbon from othar more sectors of economy, agnculiural sector to meel Its demands for Imgabon water, will have to Increasing rely on these wastewater as an alternate source for Imgabon particularly In pen-urban areas' Thus Inventones on these main sources of pollution have become essential from the point of VIew of Imgabon

Sources 6f Wastewater

In general wastewater IS grey domestic (WIthout human excreta), black domestic \<'Ith human excrela, or Industnal wastewater. Domestic wastewater consists of discharges from householOS. Insblutlons and commercial bUildIngs whIle mdustnal wastewater IS the effluents dIscharged by vanable t1lanufactunng units and food processing plants

Wastewater Quantity

, Total wastewater generated from all major industnal sourced In India is 83,048 MLD that Includes 66,700 MLD of cooling water generated from thermal power plants and out of remainIng 16,348 MLD another 7,275 MLD IS generated as bOiler blow down water and overflow from ash ponds Second ~Igger contnbutor IS small scale engineering Industnes Of thiS, electroplating un lis are most polluting unltG Other Significant contnbutolS to Industnal effluents are paper, textile, steel and sugar Industnes Latest estimates suggest that about 22900 MLD of domestiC wastewater IS generated In different Cities of our countries In(ormatlon on wastewater charactenstlcs and its flow rates are Important In deSigning and operalio~ of collection and dISPOsal facllilies as well as In knOWIng thelT Imgatlon potential for agncultural purposes rhus, the volume of sewage available for Imgatlon In different dlstncts of Haryana was computed on the ba~ls of thelT present

CherTllcal Changes & ~utnent Transformabon In SadlclPoor Quality Water Imgated Sods

populatIon and 70% of the awter allowance per head In each dlstnct .Quantlty of total sewage generated and prolectlons for, the year 2025 for Haryana state are presented in table 1 The total quantum of sewage generated IS 485 MLD, WIth the maxImum at Fandabad beIng 104 MLD and minImum at Mahendergarh, at 6 3 MLD Th,s quntum IS almost 4 fold than eartler predIctIons of 1986 Similarty prolectlons for year 2025 indicate that this quantum WIll be around 728 MLO

These effluents have the potenbal for Imgatlng aboG! 650 ha of land on dally baSIS or alternallvely about 024 million ha on annual baSIS Consldenng average Imgaton Interval of 20 days, 'thiS wastewater would have potenbal for supplYing supplemental Imgatlon to faCIlity to about 11,700 ha per annum Taking water requirement of vegetable, fodder and cereal producllons systems In Haryana type of climatiC condlbons as 110. 105 and 165 em, respeellvely, 'and average rainfall of 50 em, the wastewatel can augment Imgatlon supplies to 29,500, 32.500 and 1600 ha of land under respective productlo,n systems Use,of wastewater for Imgatlon Will aVOid pollution of water bodies and envlro,n!l'ental hazards like public health and foul smell

fable 1 Dlstnset-wlse sewage generation In Haryana

Dlstnet Sewage generation (MLD)

Present Prolectlons for 2025 Ambala 257 386 Bhiwam 175 263 Fandabad 104 1 1562 Fatehabad 98 147 Gurgaon 202 303 Hlsar 332 498 Jhanar 153 230 Jlnd 199 299 Kalthal 179 269 Kamal 308 462 Kurukshetra 208 312 Mahendergarh 62 93 Panchkula 193 290 Pampat 284 426 Rewan 8.2 12,3 Rohtak' 281 422 Sirsa 211 317 Sonepat 304 456 YamUlianagar 28.3 425 Total 485_2 728.3

Composition of Wastewater

Though actual composlbon of wasiewater may dlffer.from community to community but all muniCIpal wastewater contain. organic matter, nulnents (N, P, K and mlcnonulnents), dissolved inorganic minerals. tOXIC chemIcals and pathogens However, the final composlMn of raw wastewater depends on the source of water supply, types and numbers of InduSt"",1 unrts-discharging effluents, and level of treatment given Roubne measurements of mumclpal wastewater pertain to water pollubon parameters like BOD, suspended solids and COD But agnculturally Important chemical charactensbcs as elemental compOSition and compounds that affect SOil properties and crop growth are sporadically mOnitored Chemical characteristics of effluents of some industries-are given In table 2

The malor contnbutors of pollutIon In tenns of BOD are dlstiliertes followed by paper mills Distillery effluents are very cOncentrated and thus difficult to treat. Paper and board mills also generate heavy organiC pollution load. Other slgmficant contnbutors of organic load are sugar mills and tannenes Industries generating chemical pollution Can be diVided In two categones I II those generating high TOS as wastes of phannaceutlcals. rayon plants, chemicals, caUStiC soda, soap. detergents and smelters etc while second type Include those Units whiCh, generate tOXIC wastes like pesbcldes. smelters, Inorgamc chemicals, orgamc chemicals, steel plants and tannenes Distilleries, textile Units, phannaceutlcals and rayon plants contribute to TDS, Whereas thennal power plants followed by paper mills and tannenes generate suspended solids loads Ferblizer plants generate toxic wastes as cyanide and arsemc Steel plants and 011 refinenes contnbute to phenols while englneenng umts, refinenes and vanaspab Industry release Oils and -greases In the

, . -

148

Characterization of Waste Water for Irrigation

eTMronment Tanneries add Cr and fertilizer unItS also add fluonde to the system SlmllaMy, causnc soda units release Hg In environment

Tabla 2. Chemical charactenstics of some Industnal wastewater !

Industry' PI-! EC 55 (000) BOD COD N (ppm) P K (dS m") (000) (000) , (ppm) (ppm)'

Distillery. ' 45 460 1.2·'40 45-75 27·110 1000- 280- 6600-1900 310 10000 ,

Fertiliser 95 223 0259 108 .3,4 15 Textile 11 0 1.0-1 5 022·2.0 075-80 Tannery 95 22 32 1.0·30 Paper 101 1 5 062·125 1.1·1 6 0.80 , 168 '15-43 Dye 11.8 8·11 068-1.0 1 16-1 8 - 30-35 7·9 8-13

Dairy 80. 1·514 069-132 09·22 43-180 14·59 1':!-'39 Sugar 6.0 095 15-1 8 065-.82 006-.09 11·15, 7-8 .30-40 Food 52 081 12·20 2-4 9-12 Refinery 7.1' 18 191 0.048 032 140 18' Eclectroplate ,6-89 24 006-038

._

To Identify the areas in' Haryari. those have loads of pollutants beyond the water quality standards, the composition of municipal wastewater being disposed in different districts was monitored ConSiderable variations In their composlbons were observed amongst the sewage water generated in different dlstncts as well as seasons. In general, these wastewaters had low salt content and were neutral to slightly alkaline (Table 3) The cationic and anionIC consbtuents In these followed the order of Na > Mg > Ca > K and HCO, > CI > CO, The 5AR and R5C of these wastewater averaged 35 and 5 3 me 1" while Ca Mg raM> 1.' all !nese parameters Indicate that these water could be explOited for imgallOn purpose Without any adverse effect on SOils Sewage from Mahendergarh, Kelthal and Rewan districts had R5C > 6 me L" mainly because of· groundwater quality. Contents of trace and heavy metals were Within pennisslble limits. But in some of Industrial townships like Ambala, Panlpat, Sonepat and Faridabad had higher metal contents Malar sources of metals are Industfles, ~mall workshops, road washings and human excreta

Table 3. Average imgatlon charactenstlcs of sewage generated In Haryana·

Parameters Untreated Treated Range Average Range Average

EC (dS m·l) 0.9-32 1 9 a B-3 a 1 B SAR 14-6.2 3.5 005-4 B 3.4 RSC (me L") -86 53 1.1-82 34 Na 07·128 69 '07·104 66 Ca 23-83 36 23-4.B 34 Mg 21·71 42 1 5·5 1 40 CO, -33 1 2 05-32 1 9 Heo, '7 1·169 109 61-141 89 CI 1.4-146 75 14-10 a 66

Pollution and Public Heatth Paramel&rs

TDS In sewage ranged between 06 _ 3.3 g L" and these are on higher Side than permissible levels. thiS could be because of colieCbon wastewater through open drains containing conSiderable quantities of clays and Silt getting mixed wMh sewage BOD and COD of wastewater ranged from 176 to 345 ppm and 233 to 457 ppm, respectively Ambala sewage had maximum BOD nad COD Most of nitrogen In wastewater IS found In NH •• N (39 ppm) These parameters indicate that these should not be allowed to be disposed In water bodies as these may deteflorate aquatic envlronmenl Consldenng the agrocJlmabc conditions 01 Haryana, the 1110st of wastewater generated are SUitable for Imgatlon purposes

E Health hazards assoCiated With disposal of raw or partially treated sewage are mOnitored In terms of CO", F coli, total bactenal counts, Salmonella and ShIgella The populabons of E, coil and F coil are

COnSiderably higher 4 x 10· per 100 ml 01 wastewater Bactenal counts and fungi were also high than

t49

Chemical Changes ~ Nutnent Transformation In SodldPoor Quall~ Water Irngated SOils

/

permissible levels Although other pathogenic bacteria were not detected but "presence of high levels of coliform bactena Indicates towards health hazards from use of these wastewater

/ Seasonal Variations

Considerable vanallons are nobced wrth of sampling The pH Increased from 7 6 dunng winter to 8 1 In summer and declined to 7 7 dunng post-ra,ny season Salt content also Increased from 1 6 In winter to 1 9 In summer and further to 2 0 dS m" in post-rainy season Average BOD of sewage before entenng STP was 222, 239 and 261 ppm dunng Winter, summer and post-rainy season, respectIVely Similarly, COD get reduced to 240 and 246 ppm In Winter and post-rany seasons, while the values are around 384 ppm In

summer Lesser nitrification In winter results In higher NH4." (475 ppm) than summer (36 4 ppm) and postrainy (28 2 ppm) Amongst calions, Na Increased while Ca decreased dunng summer and post-rainy seasons, whereas K remained unchanged In anions, CI contents Increase markedly In summer while CO, and HCO, was almost Similar, thereby RSC of wastewater remain lower dunng summer, Higher contents of metals are observed dunng summer penods

Treatment Effects

Quality of sewage Improves With primary treatment given in terms of Reduction of BOD and COD BOD reduced to 100 ppm that is'the permisSible limit for land ~dlsposal Overall reduction In COD has been observed to the extent of 215 ppm froll) onglnal value of 315 ppm but that stili remains higher than perT[llsslble levels Contents of Nand K are reduced while P remains unchanged Na, Ca, Mg, CO, and HCO, contents also do not change With primary treatment and thus SAR and RSC are also not affected, Contents of metals have been Increased With treatment but pathogen loads reduced slighUy, The major advantage of conventional STPs seems to be reduction of only organic loads while these remain Ineffective In r9ducmg the levels of soluble metals and other Ions. '

Nutrient Potenllal

In fact" additions of macro- and mlcronutnents and organic matter for condilloning of Salls are inseparable from sewage IITIgalion and thus their use can diminish their requirements for fertilizers, sewage from different dlstncts In general are rated high In terms of plant nutnents contents, Contents of malor plant nutnents i e N, P and K, averaged 45 g, 6 9 and 62 4 ppm, respectively. Samples analyzed for mlcronutnents status indicate 0 17, 1 01 and 0.024 ppm, respecbvely of Zn, Fe and Cu Thus potential for the supply of major nutnents like N, P, K With iITIgatlon IS 34 4. 5 2 and 46 7 kg ha" in addition to 130, 760 and 20 g of Zn, Fe and Cu, respectively (Table 4)

Table 4 Nutnent poten~al of sewage In Haryana

Nutnent Contents Nutnent added Contnbubon Price Value (ppm) (kg ImQ .') (t year") iRs 1") (Rs Million)

N 459 344 8140 10434 8493 P 69 52 1221 15625 1908 K 624 467 11046 7330 8097

Zn 017 013 31 48000 167 Fe 101 076 1788

Cu 0024 002 43

Supplied nutr1ents are expected to be ubllzed ,more effiCiently as these are added In splits and the total nutnents added dUring crop growth penod Will be suffiCient for successful crop production Also It IS a fact these effluents contain appreciable amounts of organic matter that Improves SOil conditions From the concentrations of respective elements and quantum of sewage, It IS esbmated that these effluents have potential to oontnbute about 58 4 tonnes dat' and 20,872 tomes yea,' cumulatively of all nutrients In Haryana 662679, 17178 fnd 3950 tomes year" of N, P and K were used dunng 2001-2002, whereas the potential of sewage IS worked out to be 8140, 121 and 11046 tomes year" Thus approximately 24% of total mlcronutnents used can be supplied through s~wage IITIgalion

Conclusions

Sewage in Haryana have high imgatlon and nulnent potential, thus If used effiCiently can augment the awter supplies In pen-urban agnculture in addlbon to recycllnQ of nutnents Some of effluents had high BOD, COD, TDS, NH4-N, tOXIC metals like Cd, Cr, NI and Pb and pathogens those limit their disposal Into water bodies MoOilonng of disposal SItes IS recommended for tOXIC elements accumulations and pathogenS for their Impacts on health associated features of the farmers and other workers ulll,z,ng thiS wastewater at their farms' ~

150

Characterization of Waste Water for Irrtgabon

Bibliography - ,

Abu-Zeld, K , Abdel-Megeed A , Elbadawy; 0 ,2004 Potential for water demand management In Arab region InternatIOnal water demand management conference, May 39 - June 3, 2004, Dead Sea, Ministry of Water and Irngatlon, USAlD, Jordan I . .

Fltamo, D, ltana, F, Olsson, M, 2007 Total contents and sequential extraction of heavy metals in salls Imgated WIth wastewater, Akakl, Ethiopia Envmm Manage 39 178 - 193 . . -/

Mlnhas, P S, Samra, J S, 2004 Wastewater Use in Pen-urban Agriculture, Impacts and Opportunities Central SOil Sallmty Research Institute Tech Bull 212004, Kamal, India

Rattan Lal, 2006 Perspective managing SOils for feeding a global populatIOn of 1 0 bllllo~ J SCI Food Agnc 86, 2273-2284

WHO (World Health Organization), 2001, Global Water Supply and Sanltabon 'Assessment 2.900 l3epo!l WHOIUNICEF JOint Momtonng Programme for Water Supply and Sanitation, New YorK

Vadav, R K.; Chaturvedl, R. K , Dubey, s., K "JOShi, P K and Mmhas, P S 2003 Potentials and hazards. asso~ated, WIth sewage irrigation In Haryana Indian J Agn[ SCI 73 (95), 248-255

151

/ Conjunctive Use of Sewage Water for. Crop Production " . .

,/ Khajanchl Lal, R,K. Yadav and Gajender Yadav D,v,s,on o( SOil and Crop Management Central Soli Sallmty Research InsMute, Kamal-132001, Haryana

Introduction

Sustainable management of 5011 and water resources IS the key and most essential parameter for the livelihood and employment safety. However. these natural resources· are being gradually contaminated because of usage of large quanbties of wastewater produoed from continually. expanding populabon along With an exponential industnal growth and urbanization. Due to resource constraints and prohibitive costs of convenbonaLtreament, In developing countnes larger portions of wastewater are disposed-off either raw or after partial lreamenl Urban drainage systems in developing countries mix domestic and mdustnal wastewater and stomn water, often discharging the wastewater into natural waterways, polluting water used by farmers and other downstream users In pen-urban agnculture In India the Ganges River receIVes about 120,000 cubic meters of sewage effluent per day, affecting downstream domestic and agricultural use and threatening human health Land IS the most logical sink for wastewater disposal, particularly in land locked areas as Imgabon Around cities In developing countnes, farmers use wastewater for Imgatlng high value crops like vegetables and food grains from reSidential, commercial, and Industrial sources, sometimes diluted but often without !reament Wastewater use IS prevalent because of Scarcity of fresh water and added advantages of wastewater VIZ a source of plant nutrients, assured irrigation, and lack of altemate water sources resulting In higher crop Yields and Improvement In SOil ferbllty. The practice of wastewater Ir"gatlon IS Widely adopted by resource poor famners overlooking the potenbal health risks Farmers suffer due to contact w~h wastewater, while consumers are at nsk from eating vegetables and cereals Irngated WIth wastewater Wastewater will be increasingly used In coming years also because of higher fresh water allocation to more remuneratIve sectors like Industry and munlClpallbes Agnculture IS the Single largest user which consumes about 70% of the total fresh water abstraction. Therefore, under the fresh water Scarcity for agriculture, even the wastewater WIll be used for Imgatlon causing the pollution of natural resources Wastewater IS the water that has been used In domestic or Industnal processes and dunng the utilization process ItS quahty deteriorates because of excessive soluble salts, metals, metallOids, pathogens, other organic and Inorganic pollutants Therefore, wastewater usaga has certain negative environmental Impacts In the fomn of pathogens causing diseases, heavy metal accumulation and SOil salinization To contain the III effects, sound management strategies are to be deVised to protect these resources from further degradation For planned StrategiC wastewater use, a coherent programme involVing govemment poliCIes, 'polluter pays' pnnclple, awareness, regular health check up, forest establishment, effioent microbial strains, wet lands, cultivation of remunerative non-edlble crops, application of organic and InorganiC amendments, blo-filters IS to be framed and Implemented Conjunctive and regulated water usa both In cycliC and miXing mode may be one of the Important strategies to mitigate or reduce the adverse impacts of wastewater irrigation

Rationale behind the ConJunctive Wastewater Use

Large volumes of wastewptar are retumed to tha hydrologiC system m urban areas, where only 15-25% of water diverted or Withdrawn IS consumed. Worldwide, margmal-quallty water Will become an Increasingly Important component of agncultural water supplies, particularly m water-scarce countnes At least 2 million . hectares {hal are Imgated with untreated, partly treated, diluted, or treated wastewater The estimated area would be larger If the land Irngated from nvers and canals that receive wastewater were conSidered Wastewater use Will Increase In India, as the proportion of freshwater," agricultural dellvenes declines from 85% today to 77% by 2025, reflectmg rising demand for freshwater In clbes Many of the smalJscale fanmers In developing countnes using untreated or diluted wastewater for irrigation likely feel fortunate to have any water supply, given their mabllity to purchase higher quality surface water or 10 pump groundwater. Public poliCY planners should conSider wastewater and saline or sodlc water when evaluating national water management strategies to optimize the use of limited water resources

N ulrlent Supply by wastewater Irrigation

The amount of nutnents in 1,000 cubiC meters of wastewater Irngatlon per hectare can vary conSiderably' 16 - 62 kilograms (kg) total nitrogen, 4 - 24 kg phosphorus, 2 - 69 kg potaSSIum, 18 - 208 kg calCium, g - 110 kg magnesium, and 27 - 182 kg sodium The famn-Ievel nutrlSnt value of wastewater WIll vary With oonstituent loads, soli conditions, crop chOioes, and the cost and availability of Inorganic ferbhzers The nutrients In mUniCipal wastewater can contribute to crop growth, but periodic mOnitoring 15 needed to aVOid imbalanced nutnent supply. ExceSSive nutrients can _cause undeSirable vegetabve growth and delayed or

Conjunctive Use of Sewage Water for Crop Production

uneven maturrty and pollute surfaoo and groundwater Therefore, perrodlc mOnitoring IS required to estimate the nutrient loads In wastewater and adjust fertilizer applications

Water Quality Irrigation Concerns

As long as treated muniCipal wastewater {I1ee~ Imgabon water quality cntena and state regulations govemlng disease causing organisms In the Water, trey should be considered safe for agrrcultural use The feaSibility of uSing treated mUnicipal wastewater as a Source of lITIgation depends upon .Its quality ThiS In turn depends upon the quality of the municipal water supply, the nature of the constituents added dunng water use, and the kind and degree of wastewater treatment Wastewater constituents that ~n degrade water quality for lrogatlon .nclude salts, nutnents and trace contam.nants The Blochem.cal Oxygen demand (BOD), one of the most Important indicators of pollution, wa~ observed h'ghest In Amlakhadl at Ankleshwar (714 mg/L) followed by Ghaggar at Moonak, Punjab (626 mgA), Khan at Lall Village, Ahmedabad (320 mg/L), Musl at Hyderabad (225 mg/L) Due to high BOD dissolved o>'Ygen In these stretches was observed most of the time either nil or very)ow ina ,resu'its '",olea)e )na) )ne OTY'dllR<'l!Irt. 'trdllMrJ, "l.'llltammrdllUh 'Ulttimmm "Cb u, 1:rtI1tll, Jh w.l!er bodies because of discharges of domestl~ wastewater mostly In untreated form from the urban centres of the country and there IS gradual degradatIOn In water qll_'liity The municipal corporabons of vanous urban aglomerabons are not able to treat sew~ge thereby increasing the untreated sewage load ThiS IS further aggravated as the receIVIng water bod.~S also do not have adequate water for dllubon Faecal Coliform another Important indicator of pollution wa5 found highest In Yamuna nver at Agra, Nizamuddin, Mazawall and Okhla (MPN 52 .106 to 37x106) followed by"Hlndon after confluence With Knshm (11x106 to 46x105), Ganga at Dakshlneshwar & Ulubena (11X106 to 2 8x105)

Heavy Metals Estimation in Groundwater

Through cation exchange, chemical exchange, chemical sorpbon, prec'pltabon, ,and complexabon reacbons, metallic Ions are readily removed from wastewater and are concentrated in sludge SOil particles act to further sequester most heavy metals, and thIS preference of metals for particulates has been observed often In agncultural solis Therefore heavy metal cabons would not be expected to leach out of the unsaturated 5011 zone Into ground water. In fact, the nsk of ground water contamlnabon IS used only to determIne the heavy metal standard for h~xa-valent chromium Hexavalent chromium IS an unstable and rare fonn of chromium, and IS rapidly reduced In most environmental conditions to Its tnvalent fonn, Which IS qUite Immobile In SOils and not expected to leac~ to ground water

Effects of Conjunctive Use of Wastewater In Crops

Vegetables

The use of sewage water alone Or its use With tube well water (1.1) under varying levels of fertilizer appllcabon (50, 75 and 100 % of recommended dose) In sweet com (khanf) - cabbage I cauliflower {rabl} -okra (summer) crops In GUlarat" Improved the crop yields over only tube well water The maXimum improvement In crop yields due to sewage .mgabon was 30 4 q an~ e 5 q ha"' egUivalents to about 8 to 9 per cent In cauliflower and sweet com, respectively The results of the pooled analYSIS indicated that the sewage applicabon was Significantly supenor over tube well Imgatlon In increasing crop Yields which was at par With combined use of sewage and tube well water (1'1) (Table 1) The benefiCial effect of the sewage could be ascnbed to the addition of nutnents as well as orgaOlc matter to the SOil Sewage use showed saVing of Nitrogen by 25 per cent In the crops Vii, cabbage I cauliflower and okra which received' dlTect sewage lnigabon as well as In sweet com (kharifl due to cumulative reSidual effect of sewage Imgatlon Where mUTIIClpal wastewater IS used to ITrlgat<1 crops, uselS must take Into account nutTients (nitrogen and Phosphorous) accompanying the water an~ adjust ferbll>;er practices accordingly Under certain SOil-plant systems, It is recommended that SOil p~osphorus levels" be mOOltor~d so that the accumulation of SOil ';I1.~,?'I;,()1'U" tlce" Tlc\ e'AreeO =Jllet:l\»lelilmt./(lf'Jmlll~ 'lhrod. 1,'ffi,""'~ib 'I'

However, the quality of the sewage With respect to presence of heavy metals should be looked )nto as .t cont~lned average heavy metals VIZ, Co (O 06 ppm), Cd (O 03 ppm), Cr (O 06 ppm), NI (0 18 PPrT)) and Pb (O 11 ppm) which caused an Increase In the DTPA- extractable heavy metals status after four years a"s' compared to tube well alone or tube well water and sewage (1 1) lITIgation (Fig 1) Thus. use of sewage and tube well water (1 1) has been found more advantageous to minimize the load of heavy metals In the SOil over yealS

153

C~emlcal Changes & Nutrient iransformatlon in SadlclPoor Quality Water Imgated SOils

Table 1 Effect of sewage water With graded levels of fertilizer on crop Yields (q ha") /

Treatment Imgailon (I) water

Tube well (T)

Sewage water{S)

T S (I' 1)

1.8

1.6

1.4 -E 1.2 a. a. 1 ~ -" 0.8 CI) -" 0 0.6 ()

0.4

0.2

0

Fertilizer Level

50% 75% 100% Mean 50% 75% 100% Mean 50% 75% 100% Mean

Sequence -II (2002-04)

Cauliflower - Okra -Sweet com

Cauliflower Head Okra milt' Sweet com cobs

2554 626 952 '260 9 72 7\ 99 5 2674 648 103 2613 667 992 2738 630 1105 2817 2897 2817 2591 .

268,5 2727 2668

766 789 729 641 77,6 715 710

1039 108

1(i77 1030 105.5 1074 1053

mlnitial (;aTw rmSW mS+T

Cd Co Cr NI Pb

Heavy metals

Fig 1 Effect of tube well and sewage water "ngatlon on DTPA..,xtractable heavy metals In SOil (after 4 year)

The partitioning of absorbed heavy metals In dlfferfJnt plant parts like fruit, leaves and root indicated that the heavy metals VIZ, Cr was accumulated In both roots and leaves almost equally wbereas Co, NI, Cd and Pb were found more concentrated In leaves fol/owed by roots of okra and cauliflower Only a small fraction of the absorbed heavy metals was translocated to frUits (Fig 2) However, consumption of leaves by animals may be a matter of concern from animal heallh po' of view Thus, the plant Itself has bUild the Internal mechanism of preventing the accumulation of heavy ,netals In edible parts but needs momtonng for heavy metal contents In other plant parts and soli However, contam,"a~on of edible parts With pathogens as IS malter of concern, for human health If the vegetables are consumed In raw form

164

ConJundrve Use of Sewage Water for Crop Produc1Jon

~ ~ , , '14.00'

;bT~1 rn5w ~8 S+J

~12:00i; I .-'

, " , J .

. I

- .. 10.00;'

f ,~_~ .",,_s ....-.~

'E' . 0. "8~ijO -

, ,0.

, , "_' , , jUt

, , 6:00 I ,

'C , , 0

, , - • •

(J , ,

4.00 -, , • , •

, , ~

I • I , , • , , , ,

I , ,

2.00:, • • , , , , , , ,

rIb , , ,

rom rm I: , , , , ,

r.Th .

0:00 ....... , , ,

0 3lujz, .c 0 3: '"' z' .0 0 '0 - Z .c 0 Il.', 0 U Il. U. U U Il. ~-

Fruit 'leaves' Root ."~-..... - -.. ,;

8R~~iit Rarts

Fig 2 Heavy m~tals partitioning In different cauliflower parts under tubewell and sewage Imgatlon

SOil Cd was Significantly correlated With clay content, pH, EC and CEC Cadmium availability Index decreased With Increase In sOIl depth The Cd conlents found In soil and different vegetable Imgated With sewage water ara given In Table 2 Leafy tissue accumulated Cd about tWIce that of fruit portion, The results suggested that prolonged Ingestion of sewage Imgated leafy vegetables can develop such Cd levels In human bOdy that may cause a number of Illnesses

Table 2 Cadmium contents in sewage Imgated Falslabad, Pakistan agncultural SOils and vegetables

SOlI under Cd concentration (mg kg' )

vegetable SOil depth (em) Plant 0-15 15-30 30-60 Leaf FrUit

Bitter gourd 029 024 016 018 008 CaUliflower 027 026 0.19 019 007 Eggplant '025 026 026 017 010 fenugreek 033 027 017 024 Okra 029 024 027 016 010 Oman 028 026 018 017 018 Pumpkin 030 022 017 018 0,11 Spinach 034 030 026 023 Mean 029 026 015 019 008

Use ofTreated and Untreated Industnal Effluents for Imga~on In Coarse Millets

In general the Industrial effluent have high salt concentration, oxygen demand (BOD and COD) as well heavy metal load but With the treatment of the effluents In sewage treatment plant, the organic load and salt concentnatlon can be reduced to a significant extent In' a field experiment on sorghum and pearl millet ~pS conducted at Umaraya dunng 2001-04, sole use of untreated effluent generated from dyes, organic and Inorganic chemicals and pharmaceutJcals Industnes was the most harmful than the treated one or the

155

Chemical Changes & Nutrient TransforrnaUon In SodlciPoor Quality Water Irrigated Soils

• /

conjunctive use of treated and untreated effluents WIth tube well water In 1 1 ratio (Fig 3) Better crop Yields were recorded Wl1h treated effluent Irngabon 1han the untreated when both were applied In conjunction with tube well water In 1 1 rabo Accumulation of different heavy'metals (Cd, Cr, NI, and Co) showed no particular Increasing or decreaSing trend With ""gatlon by treated and untreated effluents applied alone or In conjunction With tube well water However, In case of lead the bUild up was higher when the fields were Irrigated Wltll untreated effluents compared to Its application after treatment ,

, , 14 9TW QUntreat. o Treat. DUntreat.+TW D Treated + TW 12 ,...

~

10 -- ~

8 ~

~',

~ ...-,,-, r-:' .-. [~ 6 - ='~ , ' . --"-

~ ~ i:P, - I,' ,

. I 4 ~ i?= , ~ , ' . ' , ,

2 ,

' - - L &;!

, I r.,::;J: ,I D - :~ J~ '. 'i.

0

Cabbage head Sorghum green Pearlmillet grain Pea rlmillel (tlha) fodder (tlha) (tlha) fodder(t1ha)

Fig 3 Yields of mixed Industnal effluent ""gated pearimlUet -cabbage- sorghum (fodder)

Further, the 5011 contamination due to heavy metals loading was also remarkably less under alternate use of effluents With tube well water (11) (Fig 4) The sOlllmgated With untreated wastewater had more salinity and organic carnon content (Fig 5)

1.2 EJlnitial [JTW o Untre.

E 1 o Treat. IlJ Untre.+TW I!! Treat. + TW 8: O.B ., - 0.6 c .s 0.4 c t-S: 0

u 0.2 , '. 0 ,

Cd Co Cr NI Pb

Treabnents

Fig 4 DTPA-extractable heavy metals In 3 years mixed Industnal effluents irrigated 5011

30·~C = X 10-1 I:Jlnitial DTW o Untreat.

25.0 ~I--D Treated g Untreat. ... TW IJ Treated + TW

20.0 ,..... -

15.0 ~ . 10.0 .

..

5.0 ' " . 0.0

r- - , r lc I· I' [ :L:<I

EC (dSlm) pH OC (g/kg)

"

Fig 5 Effect of 3 years ml!'ed Induslnal effluents Irrigation on Important 5011 properties

'.

156

Conjunctive Use C?f Se~ag_e Water for Crop Prod_L!ctlon

Conjunctive use of wastewater with tube weJJ water seems to be better compared to soJe use of wastewater In controJJlng the heavy metaJ bUild In 5011 and crops Under water Scarcity conditions, those crops In which heavy metals are not translocated t6 the edible parts could be Imgated up to some extent with treated industnal effluents In conjunction wrth fresh )Vater However, the 5011 health and crop quality should be regularty monotored for pos51ble bUIldup of heavy metals as well as salinity -

- ' -- - 1

Health Hazards wlth'Wastewater US" c

Human health nsk. from wastewater include exposure 'to pathogens, helminth Infections, and heavy metals' Leafy vegetables, 'eaten raw, Can transmit contamlnatlo1 from farm fields to consumers Hookworm Infections are transmitted by direct exposure to contaminated water and SOils A survey along the Musl River on Hyderabad, India revealed the lransfer of metal Ions from wastewater to cow's milk through fodder (para grass) Irngated WIth wastewater, About 4%'of grass samples showed excessive amounts of cadm'ium, and all samples showed excessive lead Milk samples were contaminated With metal Ions ranging from 1 2 to 40 limes permiSSible levels Leafy vegetables accumulate greater amounts'of certain metals like cadmium than do non-leafy species, GeneraJJy, metal concentrations In plant tissue Increase WIth metal concentrations on ,mgatlon water, arid ronce,ntr!!t,ons In roots usually~are,hlgher ,than concentrations in leaves Globally.the diseases caused by was~wilJ,er are.res~onsible_for the loss of a large number of human lives (Table 3).

Table 3 Annual global mortality and disability-adJusted life years lost due to ~q_me dlseases .. of .related to wastewater use ,n agnculture

D,sease Number of DALYs· ~omments deaths

Diarrhea 1,79~,000 61,966,000 Almost all (99 80/0) deaths occur In developing countries, most (90%) of them among children

TyphOid fever 600,000 Estimated 16 million cases a year Ascanasl~ 3,000 1,817,000 Estimated 1 45 bllhon infections, 350

million suffer adverse health effects Hookworm disease 3,000 59,000 Estimated 1 3 bllhon Infections, 150

million suffer adverse health effects Lymphatic fila~asls 0 5,777,000 MosqUito vectors of filanasls breed In

contaminated water, does not cause death but leads to severe disability

Hepalltls A Estimated 1 4 million cases a year, serological eVidence of pnor Infection ranges from 15% to nearly 100%

DAL Ys· Disability-adJusted hfe years lost due to disease, reflect the time lost due to disability or death from a disease, compared WIth a long I'fe free of disability In the absence of the disease DAL Ys descnbe the health of a population or burden of disease due to a speCific disease or nsk factor.

Strategies and Future Plans

• Water qualtty can be tmproved by stonng reclaimed water tn reservoirs that proVide peak-equahzatlon ' capaCity, which oncreases the rehabllrty of supply and Improves the rate of reuse and can even reduce fecal coliform levelS In water

• Dnp Irrigation can protect farmers and consumers by minimizing crop and human exposure, but pretreatment of wastewater IS needed to aVOid clogging of emitters

• A combination of farm-level and post-harvest measures can be used to protect consumers, such as prodUCing Industnal or nonedlble crops or products that require cooking before consumption

• Farmers also can stop applYing wastewater long before harvest, to reduce potential harm to consumers • Vegetables can be washed before sale or consumption, and storage methods can be ,mprClled • PubliC agencies can Implement child ImmunIZation campaigns against diseases that can be transmitted

through wastewater use and target selected populations for penodlc antlhelmlnthlc campaigns • The nutnents tn mUnicipal wastewater can contribute to crop growth, but periodiC monltonng IS needed to

aVOid Imbalanced nutnent supply • Untreated wastewater should not be used on crops that are likely to transmit contaminants or pathogens

to consumers •

157

Chemical Changes & Nutrient Transformation In SOdu:/Poo~ Quality Water Irrigated Salls

" • BUilding of large-scale conventional treatment systems is financially not \/lable Therefora, altemate technical low cost options like cultivation of crops on raised beds devised should be followed

• The so..,c;.s, from where discharged effluent has no or little treatments are to delineated and need to address separately, •

• The wastewaters produced from different sources (domestic, urban end industries) must be assessed separately for their nutrient content, effects on crop yield, and quality and pOSSible harmful enVIronmental ~ctsoo~, \

• Though·the use of wastewater is an old age practice but the Information on cost benefit ratio under different situation indifferent crops including fodder Is not available which need to be ,cI~arly understood before making the pDllcies for its use In agriculture. "

•. Management options for the usage of Industrial effluents In, terms of low cost chemical treatments, agronomic, cultural practices, ,oxidation ponds, dilution either In mixing or cycliC mode are to be devised for sustainable appllcabon under different agro climatic conditions tOI minimize the degradation of our valuable naturalll!_sources,

• Estimation and Isolation of microbial population not limited only to faecai coliform. but also the ,other organisms like nematodes, protozoa etc thriving under the'sltuatlons 'where domesnc, Industnal effluents have been added on long term baSIS should also be made to predict the Impacts of waste water use on biological prDpertles end health of soil

• For·the cases where the effluents With no or little treatment options are to be applied, sinking capacity of SOil, performance and carrying capacity of different remunerative crop species haVing non-edlble

.economic parts but producing large biomess production including trees which are known to sequester, tolerate and accumulate higher leWlis ot heavy metals must be studied for phytoremediatlon ot soils contaminated.

• Keeping these In View a wastewater should be seen In totality and treated like a commodity, which can be a resource for agrlculture If used proparly but can be a disaster If applied indlscnmlnately In an unSCIentific manner

158

Bloremedlatlon of Wastewater for Removal of Heavy Metals through Mlcrobes_

P.K.Joshl Division of Soils and Crop ManaQemEmt Central SOil Salimty Research Institute. Kemal-132001. Haryana

IntroductIon

Use of wastewater In agnculture has Increased In recent years due to Inherent treatment capaCity of soil and high contents of major and mlcronutnents In It. However. wastewater. partlcula~y from Industries_ contains high contents 01 heavy metals which enter into human beings and -animals through food chain TMrefore, to avoid their entry in food chain, It is desirable to remove them from wastewater- through low cost technology before its use in agriculture· Biomass of microbes act as edsoroent for heavy_metals present In wastewater Ability to remove heavy metal_s from wastewater varies greatly among microbes and needs 10 beexplOited uSing effiCient microbes.

LaboratorY Experiment

Laboratory expenments conducted at CSSRI. Kamal for bloremedlatlon of heavy metals through micro-orgamsms showed encouraging results Ninety three bacterial and eIQhty one fungallsolales tolerant 10 Pd, Cd, Cr and NI (25 ppm) like were Isolated from sewage and sludge samples collected from Karnal. Panipat and Sonepat districts of Haryana Three effiCient OM decompOSing fungi namely Aspergillus 8wamorii, Phanaerochaele chrysosponum and Trichoderma vlnde \ll&re isolated from Microbiology diVision of IARI, New Delhi Out of ninety threa bacterial isolates, 14 were tolerant to Cd, 8 to Cr, 44 to Pb, and 29 to NI Similarly, out of eighty one fungal isolates, 9 each were tolerant to Cd and Cr, 34 to Pb and 29 to NI. MajoCity of microorganisms tolerated heavy metais up to 400 ppm. Removal of lead from liqUid medium containing lead at 50. 100 and 400 ppm was studied using four fungal isolates (F2, F3, F7,F8) and threa fungal cultures (A awamom, T wid", and P_ chryosponum, Table 1)

Table 1 Lead removal by fungi from potato dextrose broth containing 400 ppm Pb

Fungus Pb uptake (mg/g) Removal ("10)

A ewamoni 692 173 T.Vlnde 73.2 183 P chrysosponum 612 153 F2 631 158 F3 113.1 283 F7 161 40 F8 12_8 32

The metal uptake from "quid medium was found to be dependant on concentration of lead In the medium Maximum uptake of lead by different fungi occurred at 400 ppm concentration of lead and was In the range of 12 76 to 113.08 mg g.' dry weight of fungus. Encouraging results were obtained for removal 01 heavy metal by some of the bactensl Isolates from "quid media containing 50 ppm of heavy metal I e. 24 mg of Cd g-' of biomass of Isolate BCd4. 1 9 mg g-' by BCd-l0. 28 B mg of Pb g-' by BPb-14, 54 mg of NI g-' of Isolate BNI-IS. 2.1 mg of Cr by BCr-23 Some of the bactenal isolates (BS-15 and BS-26) and fungallsolales (FCr-06, FCd-09, FNi-27, FS21, FS-22, FS-23. FS-26) and fungi (T vinde. A awamoni, P.chrysosponum and A mdulans) were found tolerant to liquid containing 125 ppm each of Pb, Cd, NI and Cr The above results indicate potential of some of the fungal cultures and bactenallsolates for removal of heavy metals like Pb, Cd, NI and Cr from "qulds through adsorption.

The maximum uptake of lead at 400 ppm concentration was by Isolate F3 (113 08 mg g-') followed by Tnchodenna vinde (73.21 mg gO') The order of lead uptake by fungi at 400 ppm concentration was F3 ~ Tnchodenna vlnde ". Aspergillus awamo,;; ". F2 ". Phanerochaete chrysosponum > F7 > FB The dned biomass (500 mg) of Tnchoderma vtnde and fungal Isolate F2 removed 89_8 and 666 percenl of lead from water containing 100 ppm of lead at pH 5 0 afler 6 hours of contact (Table 2)

Chemical Changes & Nutrient Transfom1atlon In SodlcIPoor Quality Water Irrigated Solis

/

Table 2 Adsorpllo_n of Pb from 100 ppm Pb containing water by fungal biomass /

Fungal blomass(mg/100ml) _ 5

10 20 50 foo 200 500

Blosorpbon (%) T vmde

33 89 171 ~5_1

432 484 898

Blosorpbon ('!oj F2 37 137 112 122 233 387-

'S88

Similarly, In another adsorpbon study, fungi A awamomi and A flavus removed_251 and 44 4 per cent of Cd from water containing 100 PPm of Cd after 4 hr at pH 50 INt 500 mg doses of fungal biomass (Table 3)- _

Table 3 Adsorpbon of Cadmium from water containing 100 ppm of Cd by fungus

Fungal biomass (mg/l00 ml) Blosorpbon(%) A-awamom BlOsOrpbon{%) A ftavus -5 00 00 10 89 45 20 100 138 50 16.9 160 100 22S 355 200 226 355 500 251 444

160

Modelling Techniques for Conjunctive Water Use Planning of Saline & Canal Water

M,J, Kaledhonkar DIvIsion of Imgallon & Dramage Engmeenng I Cenlral Sod Salinity Researr;h Institute, Kamal, ~ 32001 Ha,yana

Introduction

, In-and and semi and regions of Indo-Gangetic plains farmers are uSing low quality groundwaters due to limited supplies of better quality Imgallon waters (Singh et al , 1992) Irrigation waters contalnln9 high levels of sallmty and'sodlclty may be detnmental to'crop production and may reduce 5011 water Intake rates (TanJI, 1997) Continuous use of saline water for crop production enhances the sOil salmlsallOn High contents of soluble salts,accumulated In 5011 can Significantly decrease the value and productivity of agncultural lands Also cases of Irn9atlon Induced waterlogging and soli sallmsabon have been reported In commands of many Imgallon projects like Western Yamuna Canal System, Chambal System and Indira Gandhi Nahar PanyoJana (Rao et ai, 1995, Aheer et ai, 1995, HooJa et ai, 1,995)-

Several research orgamsabons and agncultural unlverslbes are conducting field expenments on different crops to proVide water quality gUidelines for Imgatlon purposes (Ayers and Westcot, 1985, Ayers and TanJI, 1981, Gupta et ai, 1994), to ,assess the Impact of poor quality Irngatlon water on SOil quality, crop Yield and, to find optimal management strategy for use of such waters The gUidelines for use of poor quality waters given by the Ayers and Westcot (1985) conSider the number of cntena such-as effects of salimty on the availability of 5011 water to plants and need to maintain the favourable water balance In the root zone, Interactive eff~cts of sodlclty (SAR or sodium adsorption ratio) and salinity (Ee or electncal conductiVity) on 5011 water intake rates and SOil permeablllty; speclfic Ion tOXICity to senslbve plants; and miscellaneous constituents of concern such as mtrogen and metals that have potential to leach Into groundwater. These gUidelines are based on assumption that at least 15% of the applied Imgatlon water percolates below the root zone The gUidelines apply not only to fresh waters but also to waste waters for evaluating their SUitability for Imgatlon All ,India Coordinated Research Project (AICRP). on Saline Water Use, Central SOil Salinity Research Institute (CSSRI), Haryana Agricultural ~nlve,rslty (I;iAU) and Punjab Agricultural Unlversoty (PAU) recommended realistic gUidelines on utiliSing poor, quality ~ters, applicable to Indian monsoon based agriculture In addition to water quality parameters, Importance of SOil texture, crop· tolerance, rainfall and concentration ot'sOII solutIOn due to evapotranspiration have also -been recognised In developing these gUidelines (Gupta, et al ,1994) However, such gUidelines are usually based on relatively Simple and ofien empirical relations Stili there are many cntlcal Issues, which need speCial attention for solutions. Modeling has been found as a good tool in understanding the Complex problems and finding the remedies A number of models such as SALTMOD (Oosterbaan, 1989), SGMP (Boonstra, 1989), RAHYSMOD (Rao et ai, 1994), model by Aslam and Skogerboe (1995), UNSATCHEM (Slmunek et ai, 1996), SWAP (Van Dam et ai, 1997), model by Lamsal et al (1999) and case studies (Aragues et ai, 1985, Singh and Singh, 1997, S,munek et ai, 1997, Smets et ai, 1997, Prathapar and Qureshi, 1999) are available to address Issues related to Imgatlon and sahnlty-alkallnity management In agncultural fields Few examples of recent modeling studies are discussed below

Prathapar and Qureshi (1999) modeled the effects of defiCit [mgatlon on SOil salinity, depth to water table and transplrallon in monsoonal semi-and zones In Punjab, Pakistan The Simulation results showed that prOViSion of 80 percent of cumula~ve evapotranspiration reqUIrements as Ifflgatlon might result In acceptable limits of root zone salinity and depth to watertable Under thiS management option, subsurface drainage system might not be a neceSSity, Singh and Singh (1997) studied 'Irngatlon scheduling for wheat crop under ' deep water table condition to mlnln1lSe the percolallon loss It was observed that light but frequent Irngations to light textured Salls as compared to medium textured Salls were reqUired to maintain optimum crop Yield and hydrodynamiC equllibnum. Simunek et al (1997) evaluated sodlc 5011 reclamatlon,strategles on the baSIS of the quantitY' of water needed, quilntlty of amendments used and time reqUired for reclamation Pnmanly chemical reactions such as cation' exchange, preCipitation and dissolution of solid phases (reclamation amendments), effect of solution composition on the SOil hydrauliC properties, and changes In water flow and solute transport rates were conSidered. Smets et al. (1997) assessed the Impact of Irngabon practices (defined In terms of Irngabon quanbty, quality and frequency) on SOil salinity and crop transpiration of cotton and wheat In conjunctive use enVIronment The Interval of Irngatlon appeared to be promising management option for farmers to control 5011 sallmty and to optimise the crop transpirallOn It was observed that the SOil texture conSiderably affec:ls the water and salt balances Consldenng the Importance of modeling In understanding the sallmty-alkallnlty, processes and deahng the related management Issues, In the present study, the UNSATCHEM model IS calibrated and validated with expenmental data of saline water use for Wheat and cotton crops reported by Naresh et al (1993) Further Simulations were carned out by the model to have better InSight about the effec:ls of Imgabon water quahty, SOil texture, conjunctive use strategies and sahne water use gUidehnes on management of sahnltY In agncultural fields

ChemIcal Changes & ,Nutnent Transformatron In Soolc/Poor Quality Water Imgated Saris

/

Input Data for C,alibratlon and Validation of UNSATCHEM for Saline Water Use/

For ,calibration and vallda~on of UNSATCHEM model, the Input files were prepared by uSing field data reported by Naresh et al (1993) These data are based on therr expenment conducted on field plots (4 0 x 40 m 'siZe) at the farm of R.B S , College of Agnculture, Blchuri (Agra) dunng 1989-1991 on a sandy loam SOil to compare the crop responses and sahnoty bUild up in SQlls for ootton (GossYPlum hlrsulum) and wheat (Tnt/cum aestlVurn) crops under mixing and cyclic modes of.the saline and non-saline waters The field plots were lined With polyethylene sheet down to a depth of 0 9 m to aVOid lateral fluxes' of water and salts The submodels for tranSient flow, chemical transport and water extraction from the root zone were used In Simulations The options for root growth, heat transport, CO, production and ItS transport were not used due to lack of data Cotton and wheat crops were grown In rotation for two years (May 1989-ApnI1991) on fixed plots and were imgated under different Imgatlon water quality treatments First wheat crop (12~ November 1989-22"" March 1990) and second cotton crop (22"· May1990- 6~ November 1990) were conSidered for slmulaloon study, The onglnal expenment had Sight treatments for different conjunctive use modes Saline and canal waters used In the experiment had salinity equal to 12 dS/m and 06 dSlm, respectively. Details of the Input data preparation for wheat and cotton crop Simulations are discussed In following paragraphs

Irrigation treatments

Data on two imgatlon treatments of the wheat crop namely ,Treatment A (the aliernate Irroga~on With canal and saline water starting With application of canal water for pre-sowlng Imgatlon) and Treatment B (the blendmg of canal and saline water In equal proportoons 1.1) were used for calibration and validation of the UNSATCHEM, respectively Wheat crop penod receMid the rainfall of 5 6 ern Three post-sowing Irrigations (on 25th

, 57th and 83'" day) of 7 em each were applied beSides the pre-soWing Irrlgallon of 7 em .Imgaloon schedules were based on the recommendations for non-saline Imgated SOils of the area The COnjUnctive use mode was also applicable to pre-soWing Irrlga~on Rainfall events were Incorporated With Irngalion events The electncal conductiVity of rainfall water was assumed to be 01 dS/m The USWB open pan evaporation dunng crop penod was 384 mm, which was analysed to determine potential transporation, SOil evaporation and plant transpiration (Feddes at al : 1974, Singh, 1983) The average seasonal crop factor for wheat was taken as 061 The growth stage Wise crop factors were adopted from Michael (1978) Appropnate time dependent atmospheric and solute boundary conditions were selected for top boundary' The pondlng of water was allowed Without surface runoff The land at expenmental site was well drained and the water table always remained below 4 m dunng study periOd Free drainage COndition was assumed at lower boundary Saline water was syntheSised by dissolVing deslrild amounts of NaCI, Na,S04, CaCl, and MgSO, In canal water to achieve EC of saline Imgatlon water as' 12 0 dS/ni and SAR equal to 10 (mmoIJl)" The EC and SAR of saline water were used to get approximate concentrations of different cations and anions 10 saline water ~ Quality parameters of saline, mIXed and rainfall waters are given In Table 1 Other waters mentioned_In Table I were also prepared arllfiaally by adlustlng cation and anion concentrations, and were used for the generation of different scenanos by the UNSATCHEM model

Table ~ Quality parameters'of saline, mIXed and rainfall water

Water type Ca++ Mg++ Na> K' 504 - cr Alk EC

mmolJl dS/m

SWciv 3900 2440 5620 040 6500 5000 500 1200 'CW 276 1.73 120 031 100 400 100 060

Mixed .2088 1307 2870 036 3300 27.00 300 630 Rainfall 040 030 020' 010 0.50 050 000 010

SWSAR5 2266 1510 2172 052 2500 3000 500 600

SWSAR25 :501 334 51.15 050 2500 3000 500 600

SWa-R,d, 2266 1510 2172 052 2000 3500 500 600

SWS04-f\,oh 2266 15,10 21.72 0,52 3500 2000 5'00 600

SWLoog '2000 1400 3150 050 2900 3300 400 660

Alk = 2 CO, - + HCO, ' + OH ' - H·

Soil data

The cation exchange capacrty (CEC) of 5011 In the field plots for 0 00-1 05m was 86-147 mmol,/kg The CaCO, was less than 1%, while organic matter was less than 05%. The InI~al SOil sallmty at the tome of sOWlng'of wheat crop was gIVen It was used to estimate the approximate dissolved and adsOrbed~u~ntltles of different Ions The Gapon selectivity CoeffiCient KG for Na-Ca exchange was taken as 035 mole" II'" The value was well wl~m, the range gLven by Pooma et 8.1. (1990) for slmllar·type of l Salls In nearby State of

162

Modellmg Techniques for ConjunctIVe Water Use Plannrng of Saline and Canal Water'

Haryana The exchange coefficient for K-Ca exchange was taken as 0 35 mOlc-~/r~ Average values of selected 5011 water retention and hydraulic conductIVIty parameters (9" 9., a, ~ and K.) for sandy loam SOIl textural class were selected according to Rawls (1982) Rao (1998) compared mOisture content values on volume baSIS at field capaCIty and pennanent Wilting pOint for different textural classes of Indian allUVial SOils With United States Salls (Rawls, 1982) He found good agreement between the Indian and United States SOils , Root environment ,/

, The root depth for wheat crop was taken as 100 em Mlnhas and Gupta (1993) suggested the nonlinear root water uptake pattern However, Prasad (1988) used linear root water uptake pattern By tnal and error dUring callbrabon, hnear root water uptake pallern was found better for thiS particular case Field data

, 3 ~ related to the C02 concentrabon were not available The C02 concentrallon (em cm ) was assumed to Increase hnearly from 0 00033 at the 5011 surface to 0022 at 30 ern depth It reduced to 00025 (at 32 em) and remained constant up [0 50cm Below, a constant concentration of 00008 em' em" was assumed conSidering some trapped air In sub ,layerS A time Invanant C02 concentration was prescnbed The sensrtlVIty to water and sahnrty stress was defined _by the emplncal parameters h", = -2000 ern and h50 (osmotic) = -1 e+20 ern (Van Dam and Aslam, 1997) The pa",meter hoc> represents the pressure head at Which water extnaCllon rate is reduced by 50 percent The constant SOIl temperature of 25 degree CelSIUS and the dlsperslVIty of 10 ern were assumed Molecular diffuSion was neglected For Simulation dunng vahdabon run, all parameters, which were used for the calibration case remained unchanged, and only the Imgatlon water quahty was adjusted The model was calibrated and validated With observed salinity profiles of respective Imgatlon treatments at the time of wheat harvest

Calibration and Validation of UNSATCHEM for Saline Water Use

In cotton-wheat crop rotation, second cotton crop came In, between first and second wheat crop In case of the cotton crop salinity profiles at the time of sOWIng and harvest were not repMed by Naresh et al (1993) For a particular Irrigation treatment of cotton~wheat crop rotallon, the first wheat crop was harvested on 22'· March 1990 and on the same plot the second cottan crop was sawn an 22M May 1990 alter pre sOWIng Irrigation Similarly, after the harvest of second cotton crop on 6th November 1990, the second wheat crop was sown on 25" November 1990 after pre-sowing Imgabon The salinity profile at the harvest of first wheat crop and the sOWIng of second wheat crop were reported by Naresh et al (1993), which might be treated as approximate initial and final salinity profiles for the second cation crop It was expected that depth wise salinity values at the harvest of first wheat and the sowing of second wheat crop would be slightly different than values at the sOWIng and harvest of second cotton crop due to pre-sowing Imgatlons applied to the second cotton and second wheat crop_ However, trends of salinity profiles might find some Similarity Therefore, trends of Simulated sahnlty profiles at harvest of second cotton crop were compared With trends of observed sallmty profiles at sowing of second wheat crop The Simulations In case of cotton crop were carned out for two Imgallon treatments namely Treatment C (first two Irngallons by canal water followed by rest of the lITIgatIOns by saline water) and Treatment D (an alternate Imgatlon With saline and canal water starting With application of saline water for pre-soWing Imgatlon) The Treatment C was used for calibration, while Treatment D was used for vahdallon of the UNSATCHEM model Two Imgatlon treatments selected for cotton crop were different than wheat crop treatments so that the UNSATCHEM model would be tested for different types of scenanos generally practiced by the fanmers The total amount of rainfall dunng cotton crop penod was 58 em, Two Imgatlons of 7 cm each on 15th and 147" day were applied beSides the pre-sowing Irrigation of 7 em The quality of Imgatlon water was deCided as per conjunctive use strategy Rainfall events were Incorporated With Imgatlon events The EC and SAR of saline water were 12 0 dS/m and 10 (mmoldl) " It was assumed that the rainfall water had electncal conductiVity equal to 0 I'dS/m The quality para[l1eters of different waters are given In Table 1 The USWB open pan evaporallon dUring cotton crop penod was 1113 mm, which was analysed to determine potential tr<lnSpiratlon, SOil evaporation and plant transpiration (Feddes et ai, 1974; Singh, 1983) The average seasonal crop factor for cotton was taken as 070 The crop stage Wise crop factors were adopted from Michael (1978) As discussed above, the salinity profile at harvest of first wheat crop was treated as Imtlal sallnlty"profile for second collon crop Assumptions about the 5011 phySICOchemical data, lower boundary, top boundary, C02 concentrations, dlspersltlvlty were kept same like wheat crop Simulations The root depth for the collon crop was taken as 120 em By tnal and error dunng cahbratlOn, non-hnear root water uptake pattem was found better for thiS particular case The Simulated profiles from cahbratlon and valldallon run were compared With respective pre-soWing salinity profiles for wheat crop

Comparison of simulated and observed salinity profiles

The model was calibrated and validated With ObseNed salinity profiles of respecllve Imgatlon treatments at the time of wheat harvest Simulated and observed sahnrty profiles for Treaument A (calibration) are shown In Fig la The good agreement between these profiles was obtained by adjusting the dlsperSlllvlty value and by assuming hnear root water uptake pattern Again Without further adjustment In parameter values, Simulated salinity profile for Treatment B (validation) was deterrmned (Fig lb) It IS eVident from thiS the figure that there IS good agreement of Simulated and observed salinity profiles and thus established the vahdlty of the model and assumptions made for the callbrallon

163

Chemical Changes & Nutnenl Tran~formatlOn In SodlcJPoor Quality Water Imgated SOils

-' -'

ECe IdS/m) EGe (dS/~)

0 10 20 0 10 20

0 0

) -30 -30 \

E E --Obs .!!. !:!. £; -60 " -60 • "- --ObI 1!. • • I - ---Sm Q •

-gO a -90 • ----Sim

-120 -120

a. Calibration (Wheat) b. Validation (Wheat)

Fig 1 Cahbrallon and vahdation of UNSATCHEM for Treatment A and Treatment B

The simulated profile at the halVest of cotton crop was compared With obselVed sahmty profile at ,the sawing of next (second) wheat crop In case of callbrabon (Treatment C) and vahdatlon (Treatment D) trends of simulated profiles are matching well With observed profiles (Fig 2a & b) It IS also Important to note that observed sahnlty values are lower than the Simulated values In both the treatments It IS mainly because of the pre-sOWIng Imgabon It also suggests that the assumpbons made about the approximate mltlal and final salinity profiles for cotton crop are correct Thus, the UNSATCHEM model can be used for different crops

EC. (dS/m) ECo (dS/m)

0 10 20 0 10 20 0 0

II -30 -30 ! E

E e .!!.

I) 5 -60 ) '--ObI t -60 "-

• --obs & --Sm

" -90 -90 --Sm

-120

-120 (b) Validation (Cotton) (a) Calibration (Cotton)

FIg 2, Cal.bratlon a,nd vahdabon of UNSATCHEM for Tn;atment C,and Treatment D

Simulation Scenarios'

The calibrated and validated UNSATCHEM model Was used for Slmulallons to Investigate effects 01 Irrigation water quality. so.1 texture, temporal changes In Imgatlon water quality (conjunctive use practices) and long-tenn ,saline water use on SOil sallmsaton Details of these' slmulabons are explained In subsequent paragraphs

Effects of irrigation water quality parameters on 5011 salinity

Quahty of saline Irngabon water IS generally defined by electncal conductiVity (EC) assuming that ItS reSidual sodium carbonate (RSC) IS less than 2 5 It is a necessart condition, as per quahty gUidelines otherwise the Imgatlon water IS treated as alkah water. Under speCIal Situations, other quality parameters like sodium adsorption ratio (SAR), MgH/Ca' ratio and crlso.- ratio are also conSidered USing the input data of wheat cahbratlon simulation, UNSATCH EM Simulations for wheat crop With four sahne waters haVing EC as 3, 4, 5 and 6 dS/m were carried out to assess the effect of I("gatlon water sahmty on sahnisalion of root zone The -root zone was assumed of homogeneous sandy loam SOil The CEC and Gapon selectiVity coeffiCient (Ko) were assumed as 86 mmold\lg and 035 molc-"'Ir" No ramfall event was considered dunng crop penod Pre-soWing lI'ogabon and 3 post sowing "ngallons were assumed by salIne water Other data related to Initial condllions, boundary conditions and CO, concentration profile were adopted from the wheat cahbrallon IOput

164

Modelling TechnIques for Conjunctive Water Use Planning of Saline and Canal Water

and kept same for all simulations Three addl~onal simulations were done for above-mentioned each saline water assuming ramfall of 6, 9 and 12 cm dUring crop growing penod Average salinity values for 0-90 ern 5011 layer were dete,!T1Ined from different Simulations assuming effective root zone depth for wheat crop as 90em The weighted average of llrigatlon water In case of each Simulation was determined assuming the salinity of rainfall water as 0 1 9S/m The relation between' weighted salJQlty of IrrigatIOn water and average root zone salimty was studied '

'/, / , The weighted average salinity of Imgation water and the average root zone salinity at harvest of

wheat crop determined from UNSATCHEM Simulations are plotted In Fig 3 The figure Indicates that linear relationship eXists between these two vafl8bles Mien (1986) applied Imgallon waters of dIfferent sal,mlles to potatoes and peanuts through dnp system, alternately and after mixing It was found that crop responded to weighted average salinity regardless to conjunctive usli mode Therefore, the average root zone sallOlly at harvest can be good Indicator of the crop Yield Oostertlaan et al (1990) developed a relationship between crop y,eld and root zone sahnity at haIVest for wheat, mustard and barley crops uSing field data at Sampla, Haryana They found that the relation between Yield and salinity IS scattered and can be expressed With envelope curves There eXits a cntlcal (threshold) value of SOil salinity below whlcli the Yield IS unaffected by sallmty, whereas beyond thiS value the Yield decreases WIth InGreaslng salinity It IS Important to note that the Initial salinity of the 5011 also Influences the sahmty at haIVest In case of winter crops

j2 8 c • 'ii 6 • .. _ .. m • c~ 4 ~ ... o E lIin .... 0.., 2 2-..

0 '" ~ m 0 2 4 6 8 ~

Weighted IrrlgaUon water .alinlty IdSlm)

Fig 3 Effect of Imgatlon water salinity on root zone salinity

Water quality gUidelines also speaK about the use of gypsum when the SAR of saline water IS greater than 20 though the RSC IS less than 2 5 mmoldl Two SimulatIons were conducted for wheat crop WIth saline waters haVing same EC as 6 dS/m, but different SAR values as 5 and 25 (mmoIJI) % The root zone was assumed homogeneous and rainfall events were Ignored. All other data were adopted from the wheat callbra~on Input and kept same for both slmulatJons, Two more Simulations were done for wheat crop by adopting all data from earlier Simulations expect little change In Imgatlon water quality The EC of sahne water was taken as 6 dS/m However, crlso. - ratios were assumed as 1 75 and 0 57, respectively

The root zone salmlty profiles for wheat crop due to different SAR waters (SAR=5 and 25 (mmoIJl) "l haVing same salimty (EC = 6 dS/m) were stUdied usong UNSATCHEM output It IS observed that root zone salinity values In case of higher SAR water are higher though Imgabon water salinity was same for both the waters In case low SAR water more preclp~atlon of calCite IS obseIVed compared to high SAR waters It might be due to more availability of Ca" Ions 10 Irngatlon water The more preCIpitation of calCite may reduce root zone salinity In case of low SAR waters The SAR and, ESP values are also higher In case of high SAR wat~r It suggests that high SAR saline water With no RSC also promotes the sodlficabon and gypsum appllcabon might be reqUired to reverse It

he root zone salIOlty profiles for wheat crop due to two saline waters havIOg same electrical conducbVlty (EC = 6 dS/m) but different CrISO,-ratlo (175 and 057) were studIed uSing UNSATCHEM Simulations It IS observed that root zone salimty values are higher for water haVing higher CrISO, - ratio (chlonde rich waters) though Irrigation water salinity was same for both the waters In case of lower CrlSo,rabo (sulphate rich water), the complex aqueous species of SO,- WIth Ca", Mg" and Na', K' might reduce the root zone salimty Slmila~y, It IS expected that the root zone salimty on use of HC03- nch water would be less due to preclplta~on of CaCO, The alkalinity of water increases With HC03- concentralion Simulations With saline waters haVing different Mg"/Ca" ratios were not done assuming that Ca" and Mg" might behave Similarly It means that more Mg" Ions would be added at eXChange complex on use of Mg" nch waters It detenorates the SOil structure and decreases the 5011 productiVity (Michael, 1978) Therefore, use of gypsum IS recommended If and Mg·'/Ca" ralio lITIgation water IS more than 3 (Gupta et al , 1994)

165

Chemical Changes & Nulnet'\t Transformation In SOdlclPool' Quahty Water Irngated SOils

/

Effect of soli teJdure on soil salinity

SOI~,texture Influences the pennlssible limit for electriCal cond~ctlvlty of saline "ngatlon water It oncreases w~h decrease in clay percentage It suggests that,textural properties of the sOil Involved In solute transport be controlled by clay content 'The solute transport under saline condition IS a non-reactive transport Therefore, 5011 properties like hydraulic conduclvlty and saturated water content are Important than callan exchange capacity To understand the relatJon between soli texture and sallmsaMn, UNSATCHEM simulations for wheat crop With two textural classes (sandy loam and loam) were earned out The Initial and boundary conditions were adopted tram' wheat calibratIOn simulation Input The aver~ge values of selected SOil water retention and hydraulic conducllvlty parameters (8" e., D, ~ and 1<,) for two textural classes were selected according to Rawls (1982) and Rao (1988) The Irrigallon water of 3 dS/m was used and four Imgatlons, each of 7 em depth, were applied The salt balance of entire flow region was calculated. The length of enllre flow region was 120 cm Assuming surface area of 1 em', centrol volume for flaw region became 120 em' The salt balance calculations were dane USing mmol, as unit '

The salt balance calculations for control volume of the flow region based SimUlation results for two textural classes are gIven In Table 2. It suggests that the change In storage of the salts IS hlQher for loam sO/I than the sandy loam SOil ThiS may be due to ,higher saturated water content of loam 5011 (I e 0434) compared to sandy loam SOil (I e 04(2) The saturated hydraulic conductiVity of sandy loam and loam SOils are 62 16 and 16.32 omfday However, leaching amounts In both cases are negligible The resuns suggest that the Influence of saturated water content on sallmsatlon process IS higher m companson to saturated hydraulic conductlvrty of the SOIL The preclpltallon of calCite IS also affected by saturat!!d water content The preCIpitation IS qUJcker In case of sandy loam soil due low water content

Table 2 Salt balance (mmol,) components for wheat crop With different textures

Salt balance Component

Sandy loam loam

Inlbal

056 070

Through Irrigation

084 ()84

At harvest Change In storage

092 036 113 () 43

Effects of temporal changes in irrigation water quality on soli salinity

Leaching

001 GOO

PreCIpitation

047 041

Temporal changes In Irrigation water quality can also Influence the sallnlsatlon process These changes generally occur when farmers get occaSional supply of good quality canal water In 'tliat !I/tuatlon. either alternate or mIx mode of sa,lIne and canal water IS preferred depending on the availability of canal water. Effects of these pracbces on SOil sallmsation were investIgated by slmulabng With calibration and validaJlon input data of wheat crop but Ignonng raInfall events

Salinity profiles under altemate mode (SW CW) and mix (1 1) mode for wheat crop are studied In case of alternate mode, there IS salin Isaban and desallnlsatlOn of surface 5011 layers With application of saline and canal water, respectively, This process continues With alternate use of saline and canal water In case of mlx'mode, depth of penetration of saJlnlty profile and sallnltv values Increase Wllh amount of the mIxed waler It IS also observed that In alternate and mix modes salinity values below 40 cm are almost same It Indicates that conjunctive use modes mfluence the salinity In surface SOil layers only It mlg~t happen because saline and canai'waters. which are applied separately, might be mlxl~g thoroughly While penetrating to 40 em depth The above diSCUSSion provides the InSight Into sallnlsabon process under alternate and mix modes

Simulations were also carned out for five conjunctive use modes namely, SW CW, CW SW, 2CW 2SW. 2SW 2CWand M,x (1 1) Four irrigations (at pre sOWIng, on 25~ day, 57th day and 83'" day), each of 7 em, were applied under each mode Post SOWIng irTIgatlons were given on Critical crop growth stages such as crop root Inibabon, tillering and late JOIning and flowenng, respectIVely (Michael, 1978) The quahty of the Irrigation water was decided as per the conjunctive use mode Conjunctive use mode was applied from pre sowing "ngation The root zone was assumed homogeneous with CEC and K" being equat to 86 mmolclkg and 0.35 mol,'~fr", respectively The root water uptake pattern, Imtlal and boundary COnditions were adopted from the calibration Simulation Input According to Mass and Pass (1989), Vegetabve stages (crown root Initiation. tillering and late JOinting) are more sensitive than reproductive (fiowenng) and maturallOn (milk and dough) stages The temporal changes In root zone salinity under different oonjunctlve use modes were mvesllDated conSidering senSitIVity of the wheat crop to decide preference of one COnjuncllve use mode over the other The results of the twa published field studies on conjunctive use of saltne and canal water are analysed In view of the preferences among the conjunctive use modes

166

Modelling Techniques for Co"iunctlve Water Use Planning of Saline and Canal Water

The temporal changes In root zone sailnlty Influence the root water uptake and crop Yields Th,e average roel zone sallmly values with lime under five different conlunctlve use modes, for wheat crop, are, shown In Fig 4, In case of mix (II) mode, the ,average root zone salinity IS Increasing linearly With time For alternate (SW CW and CW SW) modes, sall,nlty values are fluctuating depending on the Irngatlon water quality In case of 2CW 2SW mode, the root zone sallmty decreases to 1 77 dS/m from IMitlal value of 2 56 dS/m With application of two ClInal waters However, It Increases rapidly With two saline water lITIgations For 2SW 2CW case, Initially sallmty builds up rapidly With two saline waters and decreases With canal waters In all five'modes, salt load added through Imgatlon water IS same but the average sallmty values at harvest are not same It IS Interesting that sallmty at harvest fer CW SW,2CW 2SW modes IS almest same Similarly, sallmty at harvest for SW CWand 2SW 2CW modes IS same, The salinity at harvest for mix mode (1 1) IS In between above two categones, ~

l! ~ 10 'iii " • ,. e ~ -~.e 5 0'" e:!!. e 01 f m 0 >

'" 0 50 100 150

Tim. (days I

---SWCW

"""CWSW -2CW2SW

--'"2SW2CW

-MIX(11)

Fig 4 Temporal changes In salinity under different conjunctive use modes

Preference order for conjunctive use practices

Considenng sensrtJvrty of wheat crop to sallnrty, among different conjunctive use modes (Fig 4), the 2 CW 2 SW should be good optJon as root zone sahnrty under thiS mode remains Jow for almost two months dunng Imbal crop groWIng penOd The CW SW mode ensures Jow salInity for Inlbal one month The mix (1 1) mOde should be preferable over SW CWoptlon It IS obvious that 2 SW 2 CW mOde wouJd get least preference The preference order for ,conJunc!Jve use prac!Jces IS given In Table 3 Though amount of sa~ load added under different conjunctive use modes IS same, temporaJ changes In root zone salinity are different Therefore, selection of proper conJunc!J~ use mode IS reqUired for saJIMIty management at root zone

Table 3 Preference order for conjunctive use practices

S ConjunctIve Descnptlon Rank No use practice

All canal All canal Irngatlons 2 2CW 2SW Two canal and two 2

saline water Irngatlons 3 CWSW Canal and saline ,water 3

aJtem¥te Irrigation

4 M,x (1:1) ImgatJon by canal and 4 s<1llne water miX (1 1)

5 SW CW Sail ne and canaJ water 5 aJtemate ""gabon

6 2SW 2CW Two saline and two 6 canal water IITIgalions

Wheat Yields (Vha) by Naresh et al (1993)

545 522

538

496

4 01

Wheat Yields (tlha) by Sharma et al (1994)

649 625

625

609

608

Wheat Yields reported by Naresh et al (1993) and Sharma et al (1994) have also been gIVen In Table 3 to dISCUSS validIty of preference order In case of wheat Yields reported by Naresh et al (1993) the highest Yield of 5 45 tlha was reported, where all lITigations were given by canaJ water The Yield under 2CW 2SW mode was 5 22 tlha, which was lower than CW SW mode, i e 5 38 tlha ThiS might have happened due

167

Chemical Changes & Nutnent TransformallOn In Sodlc/Poor Quality Water Imgated SOils

,,-to different Inlbal salinity values, which affected seedhng emergence rate The eme'rgence rate reported for 2CW 2SW and CW SW modes are 92 and 99%, respectively This suggests the Importance of maintaining low salinity at time of germination Yield under Cw. SW mode (I.e 5 38 tlha) was higher than SW CW mode (I e 4 01 tI~a) and mix mode (I e 496 tlha). The mix (11) mode performed better than SW CW mode The weighted salinity of Irngatlon water for different conjunctve use modes was 5 3 dS/m Rainfall dunng the crop penod was considered dunng esbmatlng the weighted s!llInlty .

\

In case of wheat Yields reported by Sharma et al (1994), the highest Wheat Yield of 6 49 tlha was reported, where all four Irngallons were given by canal waler Yield under 2CW 2SW mode was sllghlly lower (; e 6 25 tiM) than canal waler Irrigation The Yields of CW SW, SW CW and 2SW. 2CW were 625. 6 09 and 608 tlha, respecbvely Field expenment was of three years, but dunng the first year, the 2SW 2CW mode was not conducted Therefore, Yield dala related 10 second year have been discussed here The similar trends were also followed by the Yield dala of remaining years II IS Interesllng to note that Yield under 2CW 2SW mode IS exactly same hke CWo SW mode. Similarly, YIeld under 2SW 2CW mode IS almost same to Sw. CW mode ThiS Indicates that root zone salinity al cn~cal growth stage of the crop Influences the crop Yield at harvest For the remaining years, Yield differences between 2CW 2SW and CW SW alternate as well as 2SW- 2CW and SW CW alternate are very low The expenment did not Include treatment related to mIx (1: 1 ) mode of conlunctive use Conjunctive use plan was Implemented by Naresh et al (1993) from pre-sowing Irngabon However, Shanna et al (1994) used canal waler for pre-soWing Imgatlon and Implemented conjunctive use mode for all post- sowing Irngallons only Therefore~ Sharma et al (1994) reported higher wheat yIelds than Naresh et at (1993) for the conjunctIve use modes. It indIcates the Importance of presowng Imgallon by canal (good quality) water The above diSCUSSion suggests that mltlal salimty, quality of pre-soWing water and conlunctlve use practices have a great influence on temporal changes In root zone salinity and these changes affect the wheat Yield '

long-tenm sustainable use of saline water

long -term sustainable use of saline waler In agnculture IS needed In seml-and and and regions. where water Scarcity and water qualIty both threaten the crop producbon and productiVity The Simulations bll thiS stage were aimed to understand Ihe effect of Individual vanable on sallmsatlon process by IgnOring the vanability other vanables Long-Ierm slmulallOns for Wheat -cotton rotallon for the penod of SIX years were conducted to understand the long-term elfeClS of salme water use partIcularly under Indian monsoon based agnculture_ It was Important to know whether long-tenn Simulations can help In preparallon of gUidelines If it IS so, the long-term field expenments can be aVOided to certain extent The 5011 data at the farm of R B S College of Agriculture, Blchun (Agra) were adopted from Naresh et al (1993). The 5011 texture IS sandy loam Thus, the soli belongs to mOderately coarse category, which has clay content Within 10 to 20% Annual ralnfail 01 the stallon 15 more than 550 mm For moderately C<iarse soli With annual rainfall more than 550 mm. the saline water haVing EC up to 10 dS/m might be used for salinity tolerant crops as per water quality gUidelines For sensillve and semi -tolerant crops, the upper l,mits of EC are 3 and 8 dS/m, respecbvely It IS recommended that field shOUld be kept fallow If higher salinity walers are used In low ramfall areas and SAR IS more than 20 On the baSIS of long-term expenment on Wheat- pearlmJilet rotation at Agra. Gupta et al (1994) reported that 90% of relatiVe Yield could be obtained If water salinity is 66 dS/m In case of long term Simulation for wheat- cotton rotallon, the "ngatlon water sallmty was also taken as 66 dS/m Annual ramfall amounts of the station for penod of SIX years were assumed as 620. 660. 710. 580. 650 and 735 mm The rainfall amounts for wheat panod were taken approximately as 98. 79. 85. 69, 78 and 86 mm For cotton penod values were taken as 695. 560, 602, 492, 551 and 623 mm. The annual USWB open pan evaporatIon values for SIX years were assumed as 1370, 1500. 1420, 1560, 1510, 1400 mm The pan evaporation values for wheat q-op period continuously for SIX years were taken as 411, 450, 425, 468, 453 and 420 mm The values for cotton crop penod were taken as 646, 926. 877, 963,_932 and 864 mm The Atmosphenc boundary was assumed at lop boundary while free drainage was assumed at lower boundary Imllal condition -for first Wheat crop was adopted from Naresh et al (1993) Pre sOWIng imgatlon and four posl sOWIng "ngatlons by sahne water were given 10 ali SIX wheat cropS For first, third and Sixth cotton crops, pre sowing and two post sOWIng Irngatlons were gIven as rainfall amounts dunng the crop periodS were above 600 mm For remammg cotton crops, pre sowing and Ihree posl sOWIng Imgatlons were given due to InsuffiCient rainfall dUring crop penods The seasonal crop factor for wheat and cotton were assumed as 061 and 0 7, respectively The data Input of the UNSATCHEM model IS such that It Simulates unsaturated solute transport for smgle crop-Within a season If the model IS to be applied for long term slmulaton, 1115 necessary to assume thai bOth crops have Similar reollng depth and root water uptake pattem Non -linear root water uptake was conSidered for wheat as well as for cotton crop The crop roobng depth was assumed as 100 em for both the crops The temporal Changes In SOIl sahmty were studIed uSing UNSATCHEM output The average salrmly and SAR values for 0-90 em depth at wheat and cotton harvest were determined to assess sustainability of saline water use in long term under mOnSoon type of climate The temporal changes In Ihe average root zone salinity and SAR values under wheat-cotton rota!Jon are shown In Fig 5a and b, respectively .

168

Modellmg Techniques for ConjunctIVe Water Use Planning of Saline and Canal Water

• c _

2 E

~~ of! ~:l5 •• > • ..

8

4

0

0 365 730 1095 1460 1825 2190 Time Idav)

(a)

o 365 730 1085 1460 1825 2190

TIme (day)

(b)

Fig 5 Temporal changes In root zone sahnlty and SAR under wheat-cotton crop rotation

TIlere IS sallmsabon dunng wheat crop and desahnlsation dunng cotton cnap Highest and lowest sahnlty values are observed at cotton and wheat harvest (Fig 5a), respectively The lowest sahnrty value at cotton harvest is dependent on the rainfall amount dunng monsoon season The SAR has Increased till the end of second year (Fig 5b), as soil solution was reaching In eqUlllbnum With applied sahne water Thereafter, small ftuctuabons In SAR values are due to seasonal vanatlons In rainfall amounts The Fig 5a Indicates that there IS no positive salinity bUild up at root zone In long-term: Therefore, saline water of sahmty 66 dS/m can be used on susta,"abl~ baSIS on long term baSIS on sandy loam SOIl. There are different agre-chmanc zones '" India, where weather, groundwater quality and SOil condlbons vary The long-term slmulallons can be effectively used to find safe salinity limits of Irngatlon waters for different agre-cllmatlc zones Such Simulations can help to avoid repetitive expenments

Conclusions

On the baSIs-simulated results, a linear relation IS observed between the weighted average sahmty of Imgabon water and average root zone sallmty at harvest of wheat crop The root zone sallmty values In case of higher SAR water are higher compared to low SAR water haVing same salinity It may due to more precIpitation of CaCO, for low SAR waters High SAR water even With no RSC promotes sodlficatlon and gypsum application IS reqUIred to reverse It The root zone salinity decreases With decrease In CI-/SO,- - ratio of Irngatlon water TIlls may be due to formation of complex aqueous species of SO,- With Ca· ... Mg", Na' and K', Slml!arly, root zone sahnlty on use of HCO,- rich water would be less due to preclprtatlon of CaC03

MagneSium, carbonate and bicarbonate nch waters reqUire application of gypsum to maintain favourable adsorbed calCium status at exchange complex The SOil texture Influences the salinisatlOn process The results suggest that the Influenoa of sallurated water content on sallnlsatlon process IS higher In comparison to satur.ated hydraulic conductivity of the SOil The preference order (I e, 2CW 2SW, CW SW alternate, M,x (1 1), SW' CW alternate, and 2SW 2CW), obtained on baSIS of Simulation results consldenng temporal changes In root zone salinity and senslbvlty of wheat crop to salinity, was validated With two sets of experimental data Imtlal root zone salinity Influences the wheat Yields under conjunctive Yields Therefore, Irrespective of conjunctive use mode, pre-soWing Imgatlon should preferably be given With good quality water, as It mlghllmprove germination and might ensure low salinity at root zone (at least for one month) till first post SOWIng Irrigation at crown root Imtlatlon stage In optimal cOnjunctive use planning fonhe wheat crop, the salinity stress should be delayed as much as pOSSible and st"!~ should be kept always Within permissible limits Long-term slmulabons based on water qualrty use gUidelines Indicate that It IS pOSSible to use the sahne water In wheat - cotton crop rotation on sustainable baSIS Such simulations can be used to find SUitable Imgabon water quality conSidering the senSitiVity of the crop ThiS approach can be helpful·in aVOiding the repetitive experiments

t69

Chemical Changes & Nutnent Transformation in Sodlc/Poor Quality Water Irrigated Salls

Notations used_,

2CW 2SW/ r ,

2SW 2CW

CW SW EC, h50

h5O(osmobC)

/

conjunctive use mode, where first two canal, water Irngatlons are followed by two salme water lITIgatIOns ' conJunclive use made, where first two saline water "ngatlons are followed by two ,canal water Imgatlons , conjunctive use mode, where canal and sallne water applied alternately electncal conductivity of saturation extract (dS/m) ,~

pressure head at Which water extraction rate by plant IS reduced by 50% due to water stress (em) pressure head at which water extraction rate by plant is reduced by 50'i, due to sallmty stress (em)

'KG Gapon selectiVity coeffiCient (moldl)"" Ks saturated hydraulic conductiVity (emlday) MIX (1 1) conJuncllve use mode, where canal and saline water are blended before appllcabon Mixed water as result of blending of saline water (SWC&v) and canal water In 1 1, proportion SW saline water SW CW conjunctive use mode, where saline and canal water applied alternately SWC&v saline water used In calibration and validation treatments SWa ... och saline water With EC as 6 0 dSlm and CI"ISO,- ratio as 1 75' SWLmg saline water With EC 66 dSlm and used In long tenm Simulations SWSAR25 saline water With EC as 6 0 dSlm and SAR as 25 SWSAR5 saline water With EC as 6 0 dSlm and SAR as 5 SW"""""", salme water With EC as 6 0 dSlm and CrlSO, - ratio as 0 57 USVIIB Umted State Weather Bureau a, ~ parameters Sr reSidual water content (-J 9s saturated water content (-)

Bibliography

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Aragues R, TanJI KK, Quilez D, Alberto F, FaCi J, Machin J, Amue JL 1985 Calibration and venficallon of an Imgatlon return flow, hydrosallnlty model./mg SCI 6, B5-94

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Ayers RS, Westcot DW 19B5 Water quality for agriculture 1m & Dram Paper 29, Rev 1. FAO, Rome, Italy, p 174

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Gupta RK, Singh NT, Sethi M 1994 Ground waterquahtr fonmgatlon m india Tech Buil No 19 Central SOil Salinity Research Institute, Karnal, India, p 13

HooJa R, Shnmvas V, Shamne G. 19Q5 Water1oggl~g and salinity problems In IGNP, Ralsstan In Rao KVGK, Agarwal MC, Singh OP, Oosterbaan RJ (Eds) Proc Recfamatlon and Management of Watertogged Salme SOils, Organised by CSSRI, Kamal and HAU, Hlsar at CSSRI, Kamal, 5"' - 8"' Apnl 19~ pp 141-159

Lamsal K, Paudyal, GN, Seed, M, 1999. Model for assessing Impact of salinity on SOil water availability and crop Yield Agnc Water Manage_ 41, 57-70

Mass EV, Pass JA, 1989 Salt senslbvity of wheat at vanous growth stages Img SCI 10 29-40

Michael AM 1978 Imgal/on Th(}ory and Practloo V,kas Publishing House Pvt Ltd ,p 801

Mien A, Shalhevet J, Stolzy LH, Sinai G, Steinhardt R, 1986 Managing multi-SOUrce Irngatlon water of dlfferont sallmlles for optimal crop production BARD Tech Rep 1 '402-481 Volcani Center, Bet Dagan, Israel p 172

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Modelling Techniques for Conjunctive Water Use Planning of Saline and Canal Water

Mlnhas PS, Gupta RK, 1993 Conjunctive use of sahne and non-saJlne waters III Validation and apphca~ons for a transient model for wheat Agnc Water Manage 23, 149-160

Naresh Rl( Minhas PS, Goyal, AK, Cnauhan, CPS, Gupta RK 1993 ConJunclive use of saline and nonsahne waters II Field compansons of cycliC uses and mixing for wheat Agnc_ Water Manage 23,139-148

Oosterbaan RJ 1989 Sa#mod Intematlonallnstltute for Land Reclamation and Improvmenl, Wagenlngen, p_ 49., I ' ,

Oosterbaan RJ, Snrama DP, Singh KN, Rao KVGK, 1990 Crop production and SOil sahmty Evaluation of field data from India by segmented hnear regression In. Amer MH, Abu-Zel~ MA (Eds), Proc Land Drainage for Sallmty Control In And and Semi And Regions 25" Feb -2 Mar 1990, Cairo, Egypt, Vol. II, pp 52-62. r

Paonia SR, Singh M, Pal R 1990 Predicting sodlficatlon of SOil upon "ngatlon With high reSidual sodium carbonate wate"n the-presence and absence of gypsum J Indian Soc Soil 38, 713-718

, ~ - , Prasad R .1988. A linear root water uptake model J Hydrol 99,297-306 Prathapar SA, Qureshi AS. 1999 Modelling effects of defiCIt irrigation on SOil sahnlty, depth to water table and

transplrabon In semi-and zones WIth monsoonal rains Water Resour Dev 15 (112), 141-159

Rao KVGK, Boonstra J, Oosterbaan RJ 1994 RAHYSMOD Regional agra-hydro salimty model Descnptlan of pnnclples International Institute for Land ReclamatIOn and Improvement, Ws'gemngen, The Netherlands

Rao KVGK, Kamra SI<, Kumbhare PS 1995 Drainage naqUirements of allUVial SOils of Haryana In Rao KVGK. Agarwal, MC, Singh OP, Oosterbaan RJ (Eds) Proc Reclamation and Management of Waterlogged Saline SOils, Organised by CSSRI, Kamal and HAU, Hlsar at CSSRI, K!lmal, 5".- B'" Apnl 1994, pp 36-, 49

Rao NH, 1998 Grouping water storage properties of Indian SOils 'tor SOil water balance model applications Agnc Water Manage 36, 99-109

Rawls WJ, Brakensrek DL, Saxton KE 1982 Estimabng sOlf water propertJes Trans ASAE 25(5), 1316-1320 and 1328

Sharma DP, Rao KVGK, Singh KN, Kumbhare, PS, Oosterbaan RJ 1994 Conjunctive use of saline and nonsaline waters In semi and regions 1m, SCI 15,25-33

Simunek, J, Suarez, D L" '1997 Alkali SOil reclamation uSlng'multlcomponent transport modehng J, Irng and Dram Engrg ASCE 123(5), 367-376

Simunek J, Suarez DL, Sejna M 1996 The UNSA rCHEM sollWare package for slmulatmg the one dimensional vanab/y saturated water "ow, heat transport, carbon dIOXide production and transport, and mulltcomponent solute lransport With maJor Ion equillbnum and kmetlc chemistry, Version 2, Research Report No 141, US Sahnlty Lal;mratory, ARS, USDA, Riverside, California, p 186

SlnghOP 1983 C"mateofKama~Bull No 8,CSSRI, Kamal,[ndla,p68 SIn9h R, Singh J, 1997 lITIgatIOn planning In wheat (Tntlcum aesllvum) under deep water table conditions

through simulabon modelhng Agnc Water Manage 33, 19-29 Singh RB, Mlnhas PS, Chauhan CPS, Gupta RK 1992 Effect of nigh sallOity and SAR waters on sahnls~tlon,

sodlficatlon and Yields of pearl millet and wheat Agnc Water Manage _21, 93-105

Smets SMP, Kuper M, VanDam J, Feddes RA 1997 SahnlsaliOn and crop tra';sprr~tl~n of lITIgated fields In Pakistan's Punjab Agn,?, Water Manage, 35, 43-60

TanJI KK 1997 Irrigation With marginal quahty waters Issues J Img and Dram Engrg ASeE, 123(3), 165-169

Van Dam JC, Aslam M 1997 Soil sallntty in relalton to ImgatJon water quality, SOIl type and fanner managemert. .lQlematlonal Water Management Institute, Pakistan, p 34

Van Dam JC, Huygen J, Wesseling JG, 'Feddes RA, Kabat P, van Walsum PEV, Groenendljk, P van Dlepen CA 1997 SWAP version 2 a Theory Simulation of water How, solUte transport and plant growth In the 5011- water- atmosphere-plant enVironment_ Wagenmgen, DLO Slanng Centrum and Wagemngen Agncultural University Technlcsl Document 45, The Nethe~ands, p 136

171

Fertigation for Quality Horticultural Produce / ,

Satyendra Kumar and C.K. Saxena DIVIsion of/mgatlon and Dramage Engmeerlng Central Sol/ Sallmty Research InsMute, Kama/-132001, H_aryana.

Introduction

In changing marl<etlng scenario. emphaSIS In agnculture production has shifted from merely quantity to quahty products. Practical expenence and sClenbfie investigation have shown that pre-harvest inputs have Significant Infiuence on Yield and post harvest attnbutes. Water and nutrient are two'maJor Inputs In agnculture EffiCient management of these mputs holds the key of quahty erop production Quality crop production Influences the net profit and Will have even more Importance In iuture For maximum growth yield, better quality and longer shelf life, cropltree should receive fuM water requirement. Speclftc nutnent requirement should also be met to get better post harvest attnbutes Hence, to produce better quality crop, an effiCient, umform and reliable Irngatlon and nUlnent delivery IS reqUired, MlcrO-Ifngatlon faCilaates appJlcation of controlled quantity of water and nutrient In the VICinity of each plant such that the crop water and nulnent demand IS almost matched WIth ""gallon water supphes The process to apply nutnent With Imgatlon IS called feitlgatlon Fertlgatlon has potential to e'nsure availability of nght combmatlon of water and nuinents In the root zone, satisfying the plants total and temporal reqUirement of these two mputs, Fertigabon permits applYing fertilizers In small quantities at a bme matchln9 With the plant nutnent need Besides, It IS considered eco-fnendly, as It IS avoid leaching of fertilizer and soluble chemicals

Water and Nutrient Management Influence Quality of Horticultural Produce

Most of the horlicultural produce contains about 70 to 95 percent water ,n many cases For example, strawberry fruit has more than 90% water content, while oman, tomato and most of other vegetables contain more than 70% mOisture Because they contain so much water, thelf Yield and quality suffer very qUICkly from water stress dUring entlcal production penod If water shortage occurs early In the crop's development, matunty may be delayed and Yield often reauced If mOisture shortage occurs latter In growing seasons, quality IS often reduced even though Yield IS not affected Most vegetables are rather shallow rooted and even a short penod of tw<r three days of stress can hurt marketable Yield Adequate ""9abon Increase sIze and weight of IndiVidual fruit and prevent defects such as toughness, strong favor, poor tiP fill and pod fill, cracking blossom-end rot and misshapen fruit On the other hand, It reduces soluble solids If ,applied dunng frUit development The keeping quality of produce also greatly affected by timing and frequency of IrrigatIOn applied For example, oman bulbs grown under low SOil mOisture regimes are usually smaller and tend to loose more mOisture and dry earlier dunng storage Similarly, smail-SIZed bulbs with higher surface area loose more moisture because water vapour losses occur lengthWIse from the Side of onion, thus dry earlier than large-sized bulbs Further, mtrogen has an adverse effect on storablhty of onions The crop grown With higher dozes of N tend to rot and sprout earlier dunng storage

An effective Irrlgabon management alone IS ,not enough for quality crop production unless appropnate technologies for managing the other Inputs are adopted It IS well known fact that fertilizers play an Important and Vital role'ln maximizing the agnculture production and quality of produce along With other inputs One of the major nutnents In detemmnlng crop quality IS potassium availability to the plant The most Importanl function of POtaSSium In plant metabolism IS enzyme actlvabon Accumulation of carbohydrates and organic aCids IS highly dependent on optimal photosynthesIs, the IntenSity of which is related to K status In the plant Fertlgatlon and foliar feeding With potassium nitrate have proven to be highly effiCient means of fulfilling the potassium requirements of many crops The combination of potassium and nitrate ,n thiS fertilizer has been found to be highly benefiCial In Improving fruit size, dry matler, color, taste ,and integrity and resistance ,to blohc and abiotic stress for CitruS and tomato fruitS, Vanous studies carned oul In India and abroad confirm Influences of SOil mOisture and nutrient regimes on quality and self life of horticultural produces Some are mentioned here for ready references '

Sugar concentration of tomato fruit can be readily manipulated by altenng the water relations of the plant through Irrigation Light, temperature and water supply dunng cultivation can manipulate the dry matter of the frUit tissue or the soluble solids In fruit jUice (Hole and Bleche,1999) Colla at al (1999) also observed that water stress improved quality of tomato fruits by Increasing soluble solids and aCidity Clark et al (1991) reported that quality of tomatOes was not adversely affected by redUCing high Nand K fertilizer level (336 and 558 kg ha") to low ferlillzer level (224 and 372 kg ha") RedUCing Irngatlon by 25% before frUit set and by as much as 50% In fruit development and npenlng stages resulted In to no Significant decrease of soluble solids Yield Most quahty components (Bnx, acidity, colour and TSS percentage) were best at 0 7 maximum evapotransp"atlon (ETM) as compared to 1 0 and 1 3 ETM (Branthome at af, 1994), EI-Gizawy at al (1993) found that total protem concentration and N contents In omon bulb Increased significantly With decreaSing SOil

Fertlgatlon for Quality Horllcullural Produce

mOISture level but pungency and TSS, Na and Mg contents were not affected by sOil mOisture level. While weight loss ,of bulb stored after treated With gamma-radla~on waS not affected by soil mOisture level but Increased significantly with Increasing N fe~llIzer application rate, The percentages of dry bulbs and mass loss of garlic between 60 and 120 days after harves\ Increase linearly Wllh N, however, Ihey were not affected by water tension levels (Marouelll at al., 2002), Yield, dry mater Yield. speCific gravity and blo-chemlcal parameters of Onion bulb were significantly Influenced by on farm water and nutrient management (Kumar el al. 2007) Hotchmuth al al (1994) obServed frult'quallty 01 orange In N fertlgatlon was slightly reduced by Increaslng.N rate (e g Peel thickness was InCreased by up to 10%) Fertlgatlon increased Yield of quality grapes. berry diameter and sugar accumulation (Ferrela et al . '2000) Drip'lrngatlon produced frUit of Vale'nCia orange With lower frUit aCidity as compared to mlcrospnnkler imgated crop. While ascorbic aCid was 'higher With mlcro-spnnkler applYing the same volume'as the'dnp system (Deldda af af 2000) Verreynene al al (2001) found that defiCIt Irngallon mcreases the TSS (2-17%) and the ClIne aCId levels (9-13%) External frUit color and JUice content was,not affected but frUit diameter (10%) decreased Hassan af al (2002) reported Ihat maintenance of the higher soil mOisture regime (Imgabon at 40% ASM depletion level) Improved the total soluble sohds (TSS) and lotal sugar conlent of htchl frun An Increase In the ASM depletion level consloerably reduced the TSS and sugar content and Increased aCidity,

Why Fertigation?

Imbalance use of fertilizer creates different types of SOil and enVIronmental threats InjudicIous use of Imgallon coupled With chemicals and fertilizers has aggravated the problems of 5011 salinity and alkalinity. polluted water and many other human and live stock health hazards Lethal salt contamination has also been observed In groundwater as well as In SOil due to excess usa of ferlihzer under tradlbonal fert,llzabon The excess use of fertilizer may be the need of agnculture for Increasing our production but conventional method of fertilization leads to nutnent losses as well as health hazard Apart from thiS. a major porlion of fertilizer IS being Imported and the nation IS paying a huge amount tn light of these facts, fertlQabon IS essential and need of hour for sustainable agnculture. healthy enVironment, quality produce and better Income from agnculture , Fertlgatlo~ not only faCIlitates optlmlzabon of nutnent supply adjusted to the speCific reqUirements of the crops at different stages of growth 'and development but also save the money by conserving 'a Significant amount of ferlillzer to be leached as In tradlbonal application It also minimizes the,soll and water pollution hazards by controlled fertilizer applicallOn.

Apart from the benefits discussed above. fertlgabon hava some other advantages over tradibonal fertlhzatlon Some of these are

I) Every plant received a regular flow of both water and nutrients directly In the root zone resuiling In Improving growth and increasing the productiVity

II) Nutnents can be applied as and when required III) Since. the nutrients directly reach to rhlzosphere In liqUid form so there IS no loss of nutnents, espeCially

through volatilization IV) Major and micro-nutrients are supplied In one solution to plants, It gIVes better root absorption and

consequently higher Yield and good quality v) Safer application methods eliminate the danger of burning the plant root system, as the fertilizer IS greatly

diluted In the "ngabon water vi) SaVing of labour. time. energy and overall application cost VII) Saving of nutnent reqUIrement per unit area which. ul~mately results In saving In quanbty of ferbllzers

nearly 25 to 50 per cent of recommended level VI") Since most soluble fertilizers are blended With chelated micro-nutrients. there IS no necessity to go for

·aodltlonal mlcro-nutnent mixture or sprays which ultimately helpS,ln reducing Ihe additional cost on labour and iillX\ures and ImproVing thE! produce quality

Desprte of the various advantages, fertlgatlon is yet to be popularIZed In India There are several constraints In adop~on of fertlgatlon technology In our country The major constraints faced by farmers are as follows

i) The lack of information about availability of fertlgabon components and baSIC knowledge about the system .

iI) Fertlgatlon system needs regular malnlenance along With constant monitoring III) Non-availability of liqUid ferlillzers at reasonable rates IV) Lack of research and development effOrts In developing fertilizers tor fertlgatlon v) Lack of Information about the specific use of nutnent In fertlgatlon for different crops under Indian

,condition

173

Chemical Changes & Nutnent Transformatlol'llfl. Sodle/Poor Quality Water Imgated SOils , ,

, /

Methods of Fertlgatlon

FertlQ{~on systems should be able to regulate the quantity and duration of applications, proportion of fertilizers and the starting and finishing time The common methods of fertlgatlon are

Suction Injection , SUeIJon of fertilizer through the Intake of the pump is a common method' of applicatIOn and IS the

Simplest method The pumping Unit develops a negative pressure In ~s suction pipe unless the, suction IS flooded ThiS negative pressure can be used to draw fertilizer solutions Into the pump A pipe or hose delivers the fenhlizer solution from an open supply tank to the suction pipe The rate of delivery IS controlled by a valve ThiS connection must be tight to prevent air entry mto the pump Another hose or pipe' connected to the discharge side of the pump can fill the supply tank WIth water A high-pressure float valve' can be used to regulate this inflow into the tank If necessary the system can be automated With a direct-acting solenoid valve For multiple block usage, two or more tanks can be set up In senes and operated when reqUIred

Pressure differential Injection

A pressure differential tank system IS based on the pnnclple of a pressure differential being created by a valve, pressure regulation, elbows or pipe frielJon 1M the mainline, forCIng water througn a bypass pipe mto a pressure tank and out again, carrying a varying amount of dissolved fertiliser A pressure differential ventun system can be Installed as a bypass or mline The ventun causes a rapid change In velOCity producing a reduced pressure (vacuum) which draws the ferohser solution Into the hne InjeelJon rates of 2 htres to 3000 htres per hour can be achieved

Pump injection

ThiS IS the most common method of Injection of fertiliser Into lITIgation systems' _1"jeeIJon energy IS proVided by electnc motors, Impeller-dnven power Units and water-driven hydraulic motor5 -The pumps are usually rotary, gear, piston or diaphragm-type which deliver fertiliser solution from the supply tank Into the pressunsed mainline ThiS method can be very accurate Pumps are generally not simple," deSign and can InClude a number of moving parts, so wear and breakdown are more likely The three systems available are electnc Injection pumps, piston-activated pumps and diaphragm-activated pumps Plston-aclivated and dlaphragm-actlvated pumps are both hydrauliC injection pumps and dam Inate the fertigatlon market at present

Strategies for Fertigatlon

Continuous application

Fernliser IS applied at a constant rate from Imgatlon start to finish The total amount IS Injected regardless of water discharge rate

Three-stage appllcaUon

I"'gabon starts WIthout fertilisers InjectIon begins when the ground IS wet Injection cuts out before the irnga~on cycle IS completed Remainder of the Imgatlon cycle allows the fertiliser to be flushed out of the system '

Proportional application

The Injection rate IS proportional to the water discharge rate, e g one litre of solution to '1000 Iitres of Irngallon water ThiS method has the advantage of being extremely Simple and allows fOr Increased fertlgatlon dur1ng penods of high water demand when most numents are reqUired

Quantitative application

Nutnent solution IS applied in a calculated amount to each irrigation block, e g 20 litres to block A, 40 Iitres to block B ThiS method IS SUited to automation and allows the placement of the nutnents- to be accurately controlled

Forms of Fertilizers for Fertigatlon

Llquld_ fertilizers

These are solutions which contain one or more plant nutnents In liquid or suspension form Ideally, there should be baSIC solullon compounds containing plant food elements SUited to the crop need and 'lallor made" to farm requirements At present. hquld fertilizers are not popular In India as compared \0 most

174

Fertlgallon for Quality HorbcuHural Produce

advanced ccuntnes as the elaborate Infrastructure 'needed fur the transportation, storage, hamlllng, dlstnbutlfl'l and application of these fertilizers IS not very well developed

Water soluble fertilizers

The wholly water soluble fert,llzelS are present In solid form which are completely soluble In water carrying two or more malar as well as mlcro-nutnents traoed as altemallve to IiquLd and conventtonal. fertilizers I , Suitable nutrients

Nitrogen and potaSsi,um are the major liquid nutnents, which are, used more effiCiently through fertig-ation For thiS purpose, urea,\arnmonlum -sulphate, 'ammonium nitrate and potassium nitrate are being used Mostly urea is used successfully In fertlgatlon as a nitrogen source than other nitrogenous fertilizers Urea IS a highly' water soluble fertilizer, normally' does not react With water to form Ions and relatively free from clogging problems If necessary, magnesium sulphate may be used for magnesium Mlcronut"ents'such as '"on, zinc elc may also be applied as chelate form In order to prevent precIpitation With IIngallon water and subsequenl clogging of emltters/sp"nkler Copper as copper sulphate- (CuS04) IS also safe to use In micro IlIIgatlon system when proper amount IS used Potassium fertilIZers such as potassium sulphate, potassium mtrate and potassium chlonde may be applied through micro ""gatton as and when needed Potassium rate can be reduced When applied through fertigatlon Phosphorus can not be used In fertlgatlon because of Its tendency to clogglni{ of emitler /spnnkler and limited movement In the Salls Solubility of some fertilIZers With water IS given In table 1

Table 1 Water solubility aml nutrient content of fertilizer applLed through fertlgation

N~trient ApprOXimately solubility In Nutrient content (%) 100 parts cold water N P K- Others

Urea 78 46 Ammomum nitrate 118 ~35 Ammonium sulphate 71 21 Ortho phosphonc aCid 550 49' , Potassium sulphate 72 46 180 S Potassium chlonde 35 60 Sodl~m molybdat~ 56 40Mo Manganese Sulphate 105 250 Mn Zinc sulphate 75 220Zn

Frequency of Fertlgation

Fertilizers can be Injected into Irrigation system at vanous frequencies as -once a day, on alternate days or even once a week Frequency depemls on ""9atlon scheduling, 5011 type, nutnents requlremen! of crop and the farmer'S preferences (Lacaao and SmaJstrla , 1989) In any case, It IS extremely Important that the nutnents applied In Irngatlon are not subjected to leaching either dUling that "ligation or dunng subsequent illlgalions

Injection Duration and Rate of Fertilizer Solution

The fertilizer duration depends on the type of SOil, nutnent and water reqUirements of the crop MaXimum Injection duration of 45 min to 60 min IS generally recommended With enough time of flushing of fertilizer reSidues frorri dnp lines before shutting the pump off (Clark et a/, 1990) Injection rale refers to the volume of ferullzer solution Injected dunng speCific penod of time To Inject the fertilizer solution a predetermined injection rate, the selected ferulizer applicator should be calibrated before starting the fertlgallon: After calibration, the duration of Injection for different fertilizers may change as It depends on the concentration of the fertilIZers on the stock solution and the des lied quantity 6f nutrients to be applied dunng nay fertlgatlon The discharge through the, applicator depends upon the durallon of Irngatlon as well as fertlgatlon The follOWing equation IS used to determine the '"JeGbon rate of fertilizer Injector (Keller and Karmeli, 1975)

Q, = (RF x A) / (nfx <; x b) - (1)

INhere Q, IS the Injection rate 'of fertilizer solui,on, lih, C IS concentration of the fertJllZers In the stock solution, I, duration of ferugatlon, h; RF IS recommended dose of fertilizer for the crop, kg/ha and Area to be fertlgated In ha

175

Chemical Changes & Nutnent Transformation In SodlctPoor Quality Water Irrigated SOils - ,

/ , If different stock solutions are prepared for supplYing different nutnents, their respective Inlectlon rates may be determined separately Selecting inlectlon rate of anyone nutrient, fertilizer Injector IS calibrated and then revised InJe"!,on penods for different stock solutions are determ~ned , Concentration of Nutrients in Irrigation Water

The actual concentrabon of nutrients needed In Irngatlon water depend on the fertilizing matenal and the crop reqUIrement The nutnent concentration In Irngation water IS determined as follows (JenslOn, 1980) ,

Ct = (Fn x 10 6J / (VdX nfx R,) - (2)

\lVhere Ct IS concentratIon of nutnents ,n the Irngatlon water, ppm, F" IS the nutnent requirement, kg/ha, Vd IS average water requirement l daY-', nf IS number of femgatlons dunng dunng the crop season,-and R" IS the ratIo between fert,l,zallon time and ""gabon time (~It)

[!o's and Don'ts ofFertigatlon

_ The factors affecting the fertlgatlon !nvolve the Imgabon system, quality of water, solubility" of fertilizers and compabbility of fertIlizers The most SUitable method for fertlgabon IS dnp migstlon system The most Important criteria for the SUitability of an Imgatlon system for fertlgabon IS accuracy of water application which largely depends upon proper deSigning and installation of dnp system and availability of correct equipment tor injecting fertJllzers The effiCIent use of ferIJlizers requires access to Informabon on SOil fertility and understanding of nutnent balance 10 SOil Water IS an Ideal camer of fertilIZers and rain water IS most SUitable for Imgatlon Water haVing a pH of 5 5 to 6 5, EC less than 0 1, low level of carbonate, bicarbonate, sodium, chlonne and free from heavy metals IS considered good for fertlgatlon The tollowlng baSIC mixing rules of compabbliity may be adopted for effiCJent fertigallon

I) Always fill the mixing container with 50 to 75 per ceni of required water to be used In the mix II) Always add the fertilizer matenals to the water In the mixing container before adding dry solid fertilizers

The addrtlonal flUid Will provide some heat In case the dry fertilizers have the charactenstlc of making solutions cold

III) Always add the dry Ingredients slowly With the Circulation or agitation to prevent the formaton of large, Insoluble or slowly soluble lumps

IV) Always put aCid IOta water, not water into aCJd v) Never mix an aCid or aCidified fertilizer With the chlonnes, whether the chlOrine IS In gas form or In liqUid

form such as sodium hypochlonte A toxIC chlonne gas Will form Never store acids and chlonne together In the same room

VI) Do not attempt to mix anhydrous ammonia directly With any kind of aCJd The reaction IS Violent and Immediate, VII) Do not attempt to mIX concentrated fertJI,zer solutions dlrectiy Wllh other concentrated fertilizer ,solullons

VIII) Do oot mix a compound containing sulphate With another compound containing caICJum. The result Will be mixture of Insoluble gypsum Which can clog dnp emitters or filters

IX) Always check With chemical supplier for Information about insolubility and incompatibility x) Since fertilIZer solutions are applied In a very small doses, and If Injected In separate locations In the

Imgatlon line, many Incompatibility problems tend to disappear, XI) The Jar test IS essential when It comes to deCiding If solutions can be Simultaneously Injected Inlo the

Imgabon system

XII) Do ndt mix phosphorus containing fertilizer With another ferIJllzers containing calCium Without first pertom,,"g the Jar test -

XIII) Never use extremely hard water because n combines With phosphate, neutral polyphosphate or sulphate compounds to _torm Insoluble substances

Special Care during Fertigallon

1 Fertilizer tank or piston pump may be used to Inject water soluble fertilizer solution 2 For precise placement of.both water and fertilizer, It IS necessary to use pressure compensating drippers

Instead of micro-tubes, 3 If It Is not pOSSible to apply doses dally In that case an altemate day application IS advisable

4 Necessa'Y changes In the schedule can be made based on sOIVpetlole anaJysls results 5 Fertigaoon should be done In the last half an hour of the total Imgatlon penod apd then continue dnp

system for another about 5-6 minutes after complebon of fertlgatlon 6 The concentration of the solution should never exceed more than 10 per cent

176

FertlgatJon for Quality Horticultural Produce

7 SpeCial-conslderabon- must be given to the products used and Imgatlon water qUality when injecting phosphorous materlaj

Ferbgatlon enables to apply nutnent In lIesired frequency and concentratJon 'It appropnate bme_ Looking to the fact that quality and yield of horticultural crops can be manipulated by controlling the water and nutnent supply dunng crop growth, femgatlOn m'ay play an Important role In enhancln!) the production ofhomcultural crop with betler quality But there IS urgent need 10 develop ferllgallon achedule for Indian conditions under different agro-climatlC zones and different types of salls for cultivating different horticultural crops

Bibliography

Branthome, X, Peley, Y , Machado, j Rand Blche, B J, 1994 Influence of dnp Irngatlon On the lechnologlcal charactensbcs of processing tomatoes, Acta-Hortlcufture 376,285-290

Clark, G A, Stanley, C 0 ,_Maynard, D N , Hotchmutch, G J , Hanlon, E A and Haman, D J, 1991 Water and ferthzer management of mlcrO-lngated fresh market tomatoes Trans of the ASAE 34 429-435

Clark, G A, SmaJstrla, A G, Haman, D J and_ Zazueta, F S 1990 Injection of chemicals Into Imgabon Systems, Rates, Volumes and Injecbon Peneds Flonda Cooperative Ext&ns,on Bull"'in no 250 12

Colla, G , Casa, R, CascIo, B L Saccardo, F., Tempennl, 0, leOni, C, La-CasCIo, B, and- Bleche B J. 1999 Response of processing' tomato' to water regimes and fertlllZabon In -Central I!aly ',<Icta: Horticulture Proceed'ng of s,xth ,nter. ISHS Symposium o~ the processing tomata and worKshop on ,mgation and fertlgahon ofprocassing lomalo, Pamplona, Spain, 25-29 May 199B 4B7531-535.

Deldda, P, FIIIgl]eddu, M Rand Detlon, S 2000 Progress report on the Influence of Irrgalion system on Yield and frurt quality in velenelll orange (CitruS Sonensls L) Pncoceedmgs of the· mternatlonal soc,ely of' 9,lnculturo T'" Intemat,onalc,lruseongross, Ameale, Italy 8-13 Mrach 2643-645

EI-Glzawy, M, Abdallah, E M H , Mohamed, A RG and Abdalla, A A G, 1993 Effe,t Of SOIl mOisture and nitrogen levels on chemical composlhon ofol1lon bulbs and on onion storability after treatment WIth gamma-rad,abon Bulletin offacufty of Agnculture Unlvers,ty of Cairo, 44 169-182

Femele, E, Somentl, M and Tameone, A, 2000. Fertlgatlon of table grapes and assessment of quantity an,d quality Informatore-Agrano. 56(13) 49-51

Hassan, M A, AVljlt, J" Sursh, C P. Chaltopadhyay, P K and Jana, A, 2002 Studies on the effect of different SOIl mOisture deplebon levels and mulching on YIeld and frUit quality of litchi CV BOrT1bal Research-oncrops 3 (2) 389-364.

Hole, L C and Bleche, B 'J, 1999. The phYSiological baSIS for Improving tomato quality Acta. Horticulture 48733-40.

Jensen, M E 1960 DeSign and operation of farm Imgatlon Systems ASAE Monograj:)h, no 3,Amenean Society of Agm;ultural Engineers, pp. 717

Keller J and Karmell, D 1975' Tnckle Imgatlon DeSign (1 st Ed) Rain BIrd Spnn~ler manufaClunng cooporatlon, Glendora, pp 133

Kumar, Satyendra, Imtlyaz, M and Kumar, A 2007 Effect of dlfferenllal SOil mOisture and nutrient regimes on post harvest attributes of ol1lon (Allium cepa L), Sc,ent,a Hort,eulturae 112(2) 121-1~9

LOcaS"O, S J and Smajst~a, A G 1989 Dnp Imgated Tomatoes as Affected by Waler quality and Nand K Application Timing for Tnckle Irngated Tomatoes Proceedmgs of Flonda State Hort1culluffl Soc,ely, no 102 307

Verreynne, J S , Raba, E and Theron, KI ,2001 The effect of comb,ned deficit Imgatlon '1nd summer trunck girdling on the Internal fru~ quality of "Mansol" ciementlnes Scient,a Hort,culturae 91 (1-2) 25·:n

177

Design of Surface Drip Irrigation System with Saline Water and 'Its Effect on Crop Growth and Yield

/ . , C.K; Saxena and S.K. Gupta D,v,s,on of ImgellOn & Dralnege Engmeenng Cenlral SOil Salmlty Research Inslltute, Kamal-132001, Haryaria

Introduction

The shnnkmg fresh waler resources have mobvaled many resaarchers 10 Investigate and evaluate the' use of poor quality saline water usmg IIl'lproved imgabon techniques such as trtckle Imgatlon. ThE) Inckle I mgabon 'has some proven advantages over other irrtgabon methods like conserval1on of water through reduced evaporabon, deep percolation and runoff losses As such, trickle Imgatlon helps 10 achieve high 'Imgallon effiCiendes Since in thiS system, penods of maine stress are minimal, the system has given high production and productivity In most field tnals It IS mainly due to the ablhty of thiS technique to resutt In no or mlmmal matrlc stress that blunts the adverse effect of osmotic stress In splle of thiS researchers have engaged themselves 10 minimize the adverse effect of osmobe stress In tnckle Imgauon. The additional advantage of thiS techmque emerges from the fact that when either land or waler or both resources ara of poor quality, the syslem has funclioned well WIth mlmmum adverse Impact on crop produclion (Pandey et ai, 20G8) In the process of saline water applica~on through a POint source of tnckie, salts get accumulated In the root zone adversely Impacting the crop producllon as well as causmg concern to the sustainable producllViIy The knowledge of wetted soli volume and lIS extent has remained of great Interest Since the accumulation of the salts IS towards the outer wetted 20ne. the knowledge of the actual shape and size below the pOint source of tnckle Imgallon remained a concern to researchers who have stUdied or modelled the flow around a point source (Ben-Asher at 81, 1978, Brandt et a/. 1971, Bresler, 1971, Provenzano, 2007; Raats, 1971. Wamck, 1974, Wamck, 1985, WoOding. 1968 and Zur, 1996) The modellers have approximated the shape of the wetted volume as a rectangular or square oclumn (Keller and Bllesner. 1990), a hemisphere (Ben-Asher et ai, 1986 and Jalswal et ai, 2001), a cylmder (Amoozegar-Fard at aI, 1984 and Schwartzman and Zur, 1986) and a truncated ellipSOid (Zur, 19OO) These assumptions have led to equations, which are either too simplisbc -or somewhat complex The objectives of thIS article are three fold first of all, to examine whether some other shape of the wetted volume would give reasonably good results VIS-a-VIS the eXlsbng shapes and solutions Secondly, a salt water balance approach to see the satt bUild-up In the wetted soil volume to asseSs the need of prOViding addllional wetted volume. As such, a new shape of the wetted SOil volume has Ileen assumed In thiS paper and compared wdh some of the eXlsbng solulions Thirdly, the Impact of the Inckle With saline Imgatlon on Yield has been related through the review of woil< done WIthin the country Finally, the new equation and salt balance -approach has been used to demonstrate the invelSe methodology to deSign the tnckle imgatlon With saline Imgallon water

Volume of Various Shapes of the Welted Zone

, The wetted soil volume below a point source of tnckls Irngal10n could be represanted by many shapes Some of these shapes Include a square column (Fig 1 a), cylmdncal column (FiQ.l b), seml-elilpsoid (Fig 1 c). truncated ellipSOid (Fig 1 d). VIhllle the first IW'O shapes are qUite a Simple representabon. the later two shapes are more reahsbe In croer be examine whether some new shap<:ls oould be uSed to represent the wetted SOil volume, a comblnabon of cylindrical column (sunple) and seml-elllpsDl{i (reaJlstJc) was hypothesIZed and used to develop the equatJon tilr the wetted 5011 volume (FiQ 1 e) The new shape (Fig 1 e) conSiders the wetted SOil volume as a cyllndncal oclumn up to a depth h, while the lower poroon from h onwards up be the depth a (towl depth d; a + h), IS a seml-9lhpsold.

I--w:-: --11 , i

, (.)

Square column

_w~---I

.~.

(c) Semi-ellIpsoid

(d) (e) Trunc:Elteq CombinatIon ellipSOid (Cyj,nder

Fig 1 SchematiC representation of different shapes for ocmputatlon of wetted volume

Design of Surface bnp tmgatlOn System With Saline Water & Its Effect on Crop Growth ~ Xletd

Table 1 Formulae for computation of wetted volume uSing vanous shapes

S No Shape Formula

f Square column V ~ w'd (1)

2 Cyllndncal"column V TT wZd

(2) = .Y 4

t 3 Seml-eilipsoid V rr W~d (3) = 6

4 Tnuncated ellipsoid V 118w'(1 + 3h ~~J (4) 6 2a f2a' .' '

5 Combination (cylinder + seml-eilipsold) V = l1aw' (1 + 3h) 6 2a

(5)

The formulae for computallons of the wattea sOil volume uSing these shapes are presented In Table 1. In all the formulae reported In Table 1, the notations used are described as folloWing

a = Semi-maJor aXIs or vertical polar radiUS of ellipsoid [L], b = Seml-ITImor axis or equatorial radius of ellipsoid [L], c = Second semi-minor axiS or equatonal radiUS of ellipsoid [L], d = Total depth to which wetting zone extends below an emitter [L] (In case of Eq (4) and

(5), d= h + a), h = Depth of minor axiS or equatorl8l radiUS from the SOil surface In case of an ellipsoid

Eq (4) or the depth to which the cyllndncal column IS assumed to ="n case of Eq (5)[LJ,

V = TotaJ wetted 5011 volume [L'], w = maximum Width of the wetted SOil volume (In case of an ellipsoid It IS the mmor aXIs or equatonal diameter of,the wetted soil volume; which in the homogeneous Salls would be w = 2b" 2c) [L]

Management Controlled Wetted Volume

Consldenng the fact that the SOil water stored In the root volume should support the peak seasonal demand between !\yo successive Irngatlons subjected to management allowable defiCit, Zur (1986j defined the management controlled wetted volume Vm, for umt area as follows

Where,

v _ Amount of water applIed In one Imgabon III - M~ )( MAD

Dwu x- I Me x MAD

Vm = Management controlled'wetted SOil (volume per unit area) [L3/L\ Owu =Average dally water use (Volume/Unit IIme/umt area e g. Vday-m )[LT'], I" Irngallon Interval [T], Me = MOisture holding capaCIty [L 3, L ,,], and MAD = Management allowed defiCit (fraction).

(6)

The' management contrOlled wetted volume IS a key parameter If Its depth and WIdth are selected OPbmally It IS opllmal to match the maximum Width of wetted volume With the SpaCing between emitters as well as between laterals unless overlap of the wetted volume IS deSired Schwartzman ,and 'Zur (1986) had developed tollOWlng relationships between emitter discharge, hydraulic conductIVIty, depth and Width of the wetted volume

(7)

Where, k, = Hydraulic conductiVity of soil [LT'], q = Emitter discharge [L "T'], wand d have the same meaning meaning as for Eq (1) to (5)

Comblrung Eq (5) of Table 1 and Eq (7) and consldenng no movement of water front below the root Zone (no deep percolation losses) and power to d as 0 33, the emitter discharge for the deSired wetted volume Vm may be computed USing follOWing relationship

179

Chemical Changes & Nvtnent Transformation In Sodlc/Poor Quality Water ImgateCi Salls

/

_ ,26k,wVro

q /, ( 3h) J / "ad 1 + 2a

(8)

Accumulated Salt Balance \ ,

The amount of initial salts present In the root zone could be calculated by the follOWing relationship - \ ' ,-S," Co Vm (9)

V\lhere, $, = Initial salt present in the wetted zone [MJ, Co= Initial salt concentratio~ In the root zone [Ml -;

The total salt accumula~on In the wetted volume beneath the emitter formed by a constant rate of discharge, for an applicatiOn time t With <:ertam salt concentrabon of Imgatlon water, can be computed uSing the mass balance equation as:

Where,

S, = C,q t

5, = total salt added In the wetted volume, [Ml C, = salt concentration In Imgabon water, [ML "l q = emitter discharge rate, [L "T'J t = time of Irngatlon, [T]

(10)

However, the lobal seasonal salt accumulatJon can also be computed by the followlOg ,,:ilabonsh,p

s, = C,Dwul N= C, Vm Me MAD N (11 )

Where N IS the total number of imgabons and other notations are as descnbed earlier ConSidering no movemen! 01 water Iron! below the roo! zone, the concentrallOn 01 lola) acwmulaled salls IOf the season Within the wetting volume may be computed by

(12)

Where, C, = Seasonal accumulated salt concentralton (e g, gn) [M L "J

As we know that while uSing saline Imgatlon, the Improved mOisture condition In the VICInity of emitter offsets'the InhibitIOn effect of accumulated salts or the higher salt concentration (Mltchetakls et 81. 1993) Along With these observattons like above, II has also been reported that the salt concentration Increases With distance away from emllters as the most of the salt gets transported along With the Imgatlon water away from the source (Oron fit ai, 1995, Wan et aJ, 2007) For salt balance and practJcal pOint of View, It IS assumed that the sal(already present in the wetted 5011 volume and that applied With the Imgatlon water accumulates In two zones WIthin that volume_ The Inner zone Where the average salt concentration is e<1ual to the concentratIOn of Imgatton water While the rest salts accumulate in the outer zone along the wetting front These zones therefore, cOmpnse by a certain fractional values of wetting vQlume If the Inner fraction of the wetted SOil volume IS conSidered as 1 (where 1 < 1, practJcal range could be 0 2 - 0 7), then the outer fraction would be (1-~ The equafion -of Salt balance for these zones can be wntten uSing Eqs (9) and (11) and replaCing the values of $, and S,ln Eq (12) as 101l0Wing ,

Co Vm + C, Vm Me MAD N = 1 C, V", + (1-1) C, Vm

Where, c, = Average seasonal salt concentration In the outer fraction of Vm (e 9 gfl) [M Li

From Eq (13) C, can be calculated as

C, = C, + C,(N M,MAD -I) (1 -- I)

(13)

(14)

Clearly, the salt concentration In the outer fractJon C" depends upon the inibal concentration of salt, salinity of the Imgatlon water, number of Imgatlons, available SOil mOisture and the management allowable

180

Design of Surface Dnp Irngatlon System With Saline Water & Its Effect on Crop Growth & Yield

defiCIt SInce the dally water use 15 same, the amount of water applied per Irngatlon Increases or decreases by number of lITIgatIon Hence an ,ncreased wetted 5011 volume would result In dIlutIon and reduced concentratIon of C, The value of management volume Vm (Eq 6) computed after revIsing the value of I due to change of N can be used for the deSIgn purpose In caSe of sahne Imgallon , Materials and Methods

, The relative values of the wetted volume computed uSing vanous models (Table 1) were compared WIth the computed volume from the truncated ellIpsoid for SImilar rat<os of hla values to comment upon thelf relat,ve accuracy For the deSign procedure of tnckle system for saline water Imgated lands, desk studies are caITIed out uSing pracbcal field sltua~ons For the example Includ~d In thiS paper a clay loam 5011 WIth a mOisture holdIng capaCIty of 019 m'lm' and a saturated hydrauliC conducbVlIy of 6 x 10" mlhr was conSidered A salt sensillve vegetable crop of 90 days duration was conSidered WIth an average dally water consumption of 5 Vday/m' and a salt threshold value of 2 58 gil The crop was supposed to be Irrigated for 60 days at an Imgabon Interval varying from 1 day to 5 days The salt conCentration of the Ifngatlon water was assumed to be a 5,1,2,3 and 4 gil The value of Inrtlal salt concentration In the root zone S" was assumed as 05 gA It was also assumed that sa~ concentration In the Inner 80 per cent of the welted volume IS malmalned at the concentrabon level of Imgabon water (1= 0.8), while the outer 20 per cent of .It, caITIeS the rest of the accumulated salts The. seasonal accumulated satt concentration was computed for the outer twenty percent of the wetted volume uSing the mass balance approach to comment upon the need for addlUonal wetted volume and design procedure

Results and Discussions

The wetted volume for a square column was observed to be almost 100 per cent more than the semi ellipsOid. while for a cyllndncal column It was about 50 per cent more Since the semi-ellipsoid IS relatively a belter descnpllOn of the welted SOil volume under a trickle source, the square or cylindrical shapes seem unrealistiC According to Zur (1996), a truncated ellIpsoid IS stili better descnptlon than a semi-ellipsoid, a comparison between the seml-ellipsOId, tnuneated ellipsoid and a combination of a cyhnder w,th semi-ellipsoid reveal that the latter shape gives results which are ,n between the seml-elilpsoid and a truncated ellipsoid The maximum error of around 20 per cent occur when hla = 1 which IS almost an Impracllcal propos Ilion In practice For practical situations where h/a s a 5, the error 's always less than 5 per cent and IS almost negllg,ble at lower hla values Therefore, It would be reasonable to use the proposed shape to deSign a tflckle lITIgation system Assummg that the cyllndncal shape of the wetted 5011 volume e>Ctends to 0 , m below the SOil surface for vanous values of WIdth w, and depths h welted volume 15 reported In FIg 2. It may be noted that the trand and shape of these curves are similar to truncated ellipsoid as reported by Zur (1996) Clearly, for a certain wetted volume, one can get several depth and WIdth combinations (Fig 2) Some of the extreme values may be Impractical but are Included to show the trend of the data sets

700

600

500

~ 400 ::J

g 300

!I 200

100

0

h = 01 m

0 02

......o--d = 02 m ____ d= 04m

....,._d= 06m

""""ir- d = 0 8 m ___,_d = 10m

--o-d= 12m

04 06 Width. m

08

Fig. 2. Theorebcally calculated wetted 5011 volume at different WIdth for vanous depths at h = a 1 m uSing combination model

The mass balance of sa~s WIthin the wetted 5011 volume was eamed out assuming no adsorption. no deep percolabon and no salt uptake by the plants As expected, the average salt bUild-up In the wetted soli volume was QUite very fast and It Increased IInea~y WIth the number of ,,,,gallOn For pracbcal situations the salt accumulabon Within the wetted 5011 volume was partlboned Into an Inner fracbon I of the wetted volume where the salt concentraton remaIned equal to thai of the Imgallon water, while the salt concentration In the outer fraction (1-~ of the wetted volume could be assessed WIth the use of Eq (14) ThiS equation when used to draw a senes of CUlVes asSumIng vanous levels of satt concentrabon of ImgatlOn water C" for I = a 8 revealed a decreaSIng

181

Chemical Changes &. Nutnent Transformation In SodlclPoor auallty Water Imgated SOils

/

trend In seasonal'accumulated salt concentration With Increase In wetted volume for vanous salt concentrations of Imgatlon water (Fig 3) Since the salt tolerance level tar crops and the sallnlly of the Irngaton water are known before deSign, the management wetted volume Vm should ensure that the seasonal salt conoentrallon C,IS less than the threshold level of the crop A higher value of Q could be reduced by decreaSing the value of N (Eq 14), which results a higher value of management wetted volume Vm (Fig 3) ,

For the example used in this study, assu";ing that" the vegetable crop was "ngated 30 tmes In the seasen at an Imgatlon Interval of 2 days With saline water haVing salt concentration of 2 gn, the management volume Vm computed for thiS case was 175 liters (Eq 6) USing Eq (12) the computed value of average seasonal salt accumulaton ooncentratlon C. comes out to be 393 gil INIllle the concentraton In the Inner 80 per cent of the volume remained at Co of 2 gil, the sa~ concentrallon In the rest outer volume C,waS COmputed to be 11 64

-gil thiS concentration level exceeds the crop's tolerance level and hence the wetted volume needs to be I,ncreased Consldenng Eq (14), the value of sail concentration In the outer fraction of welted volume C, can be reduced by decreaSing the value of number of irrigation N although the total water apphed remalns'the same due 10 same dally waler use Dw If the value of N IS reduced 10 14 the sail concentrabon C, was oblalned-at 2 5 gil (" 3 90 dS/m), which IS Within the tolerance limit For thiS Value of N, the management volume Vm IS oomputed to about 375 hters Therefore, thiS reVlsed value of management controlled volume should now be used In deSign calculation for the spacing and the discharge uSing Eq (8)

25

~ 20

C 0

15 ~ "E Ql u B 10 u

1ti (/) 5

0 a

~ , \ \ ' \ \ \

, \ '..

" ' , , \

\ "

, \, , \ ,

.... .

o 5 gil

--1 a gil

-·-,-2 a gil

----30gll

_40gll

~- 25 gil I awl

, .... " , .~ "-_ ....... .. ------_ ....... ..

_-_-..-7..-... -.=.-_~ .....

100 200 300 400 500 600 Welted IOlume, liter

Fig 3 Seasonal accumulated salt concentration at vanous salinity levels of Irngalion water In the outer 20 percent of the wetted volume

The results of the discharge computabons are pleSented graphically In FIQ 4(a to e), keeping a value of II as a 1 m, the total wetted depth and Width were vaned between 30-90 ern and 25-125 ern respecbvely uSing Eq (8) for different lmgabon Intervals It IS seen from the ~gure that to achieve a hl9her Width but sll11llar depth, a hJgher discharge may be reqUired at any ImgatJon Interval The very high emitter discharge values are of no practical Importance, however, these were kept to show the nature and the trend of data From the example mentioned In preVlOUS paragraph (an Imgabon mterval I of 5 days IS resulted for N=14) that while deSigning a system lor dally ImgaIJon fOr a depth between 80-90 an and emitter spaang between 70-1()() ern, an emitter WIth discharge of about 5 Vhr may be required (Fig 4 e) •

Therefore, on the baSIS of this, followmg steps are suggested to deSign a tnckle system when saline lITIgation waler IS used to Irrigate the crop

1 Estimate Ihe management controlled wetted SOil volume, Vm, uSing [:q (6) for Vano"s ,mgatlon Intervals 2 Compute seasonal accumulated salt ooncentrabon level C, uSing Eq (14), for vanous sallmtles of IITIgallon

water for certain value of I 3 If C,IS greater than the threshold value, then compute the number of lITIgations required to maintain the C,

equal to or below the tolerance level of the crop Then re-calculate welted SOil volume Vm corresponding to number of Irrlgallon USing Eq (6), -

4 For the Vm, calculate the acceptable combinations lor depth and maXimal Width of Ihe welted volume to be computed uSing combmatJon modellEq (5) or Fig (1)]

5 From Eq (8), compute emitter discharge q for the above depth d and Width w comblnallons for a given value of k.

182

Design of Surface Dnp Imgatlon System with Saline Water & lis Effect on Crop Growth & Yield

~r------------------------'

_2Scm

-SOan

---75QTl

-'oo.cm~

- - -125an

25 ,-----------------_, OS ,-----~-------

D'

•• 40 50 ~ 70 Depd"an

• day 20

3 day

.. ""

.,

Fig 4, Computed emitter dlschal'ge and depth of welted front for the maximal welted diameter (Width) at 1 to 5 days imgation Intervals

Drip irrigation in salt-affected environment

The area under dnp IS hkely to mcrease dramatically In the lime to come yet the expenences of drip Irngalion under salt, affected enVIronment are limited Although In many countnes particularly In Israel, sahne/sodlc waters are extensively and 'ntensively used With dnp Irngatlon so much so that It has become a normal pracbce If one has to look for the expenmental evidenoes, one has to go back to more than 25-30 years before sinoe currently research organlzabons do not Indulge In such expenmentallon to prove the benefits of dnp irrigabon, As an example, good Informalion on the relative ments of dnp and sprinkler systems' was made available way back In 1970 (Fig 5) The data clearly reveal the supenonty of dnp over the spnnkler method at all salinity levels for all the crops (Fig 5)

i 80

'" ~

, ~

~ " "

D'

"

:.~~.-~:- -.!'~~ -- --j)---0",\

0, ~7~ d

'-!II D 0,

Il ~'-

D1U~ SI-'RJI'IKUJ[

"'~u 0 C

TOMA1OD 0 • '>WEIT('llllN" • • r,fUSIi1o!D..oNS ~ •

Fig 5 Vanallon In Yield With sahne water In dnp and sprinkler Irngatlon (Source Godberg and

Under the Indian conditions, Agrawal and Khanna (1963) reported the results of an expenmental tnal conducted at CCS HAU, Hlsar, for growing radish crop With saline tube well water (EC = 6 5 dS m") and good quality canal water (EC = 0,25 dS m") The fesults fevealed the ulility of dnp Irngabon "' two ways The Yield

183

Chemical Changes & Nutrient Transformation In SodlclPoor Quahty Water Irngated Salls

. , was higher With dnp being maximum In subsurface than surface dnp (Table 2) The Yield reduction was much less In case of saline water In dnp as compared to surface Ir"gabon. However, It may be menboned thai benefits of .subsurface dnp are not always forthcoming and th~ usefulness has to be Investigated consldenng the sOil, crop, salinity of Ihe sOil and waler elc

Table 2. Waler use efficiency under different methods of Irngabon with saline and good quality water ~- '

Good quality water Sahnewater

Method of IITIgalion (EC= 025 dS m") (EC'; 6 5 dS m")

Yield WUE Yield WUE (t ha") (kg ha" cm") (t ha") (kg ha·1 cm")

, Subsurface dnp 268 3000 236 2600

Surface drip 175 1900 1 57 1800

Surface Irngatlon at 35 mm 'CPE 164 1400 099 900

Surface "ogatlon at 60 mm C PE 139 1200 0.67 600

Field expeoments were also conducted at CCS HAU farm for tomato, cauliflower, cabbage, brlnJsl, watermelon, grapes, colton, and sugarcane under deep water table condlll6ns (:> 5m) and shallow water table condrtlons «15m) In sandy loam 50115 to study the comparative performance of dnp lITIgation with saline tube well waler (EC=6 5 dS m") and good quality canal water (EC = a 28 dS m") for different Irrigation schedules based on ratio of the depth of ,mgallon to the potential evapotranspiration (lWIPET) varying from 0 3 to 1 0 Dnp Irngallon performed belter under deep water table condilions but the performance of drip Irngatlon under shallow water table conditions was mixed (Singh and Kumar, 1989, Singh at ai, 1990 and Singh and Kumar, 1994)

Kumar and Sivanappan, (1983) concluded that drip ImgallOn gave higher crop Yield than any other Imgallon method when HTigabng With saline water They developed ISO-SOIl salinity curves for the root-zone at different durations from the day of appllcabon of 5 levels of sahne water (Ee 085, 25, 50, 75, and 100 dS m") In e~ual amount by micro-tube, noZzle and Orifice type emitters They prescnbed that saline waler haVing an EC of 75 dS m·1 IS safe for growing Crop With the dnp Irngabon·

Jain (1984) reported that dnp lines Installed at 90 and 150.ern distance In paired rows of tomato and cotton Increased the Yields almost 3 times over the conventional flood ""gatlon method and attained 30-50 per cent economy In water use He also reported that salt concentration In root zone under dnp wss minimum at the dnp points Compared to the dnp pOints, salt concentration was twice at 10-15 em distance and thnce at 30-60 ern Similarly mOisture conlem at dnp pOints was 20 and 40 per cent higher respecbvely as compared to those at 30 and 60 em distance. The major. drawback of Imgabon With dnppers IS the high sslt concentr<won that develops at the wetting front Accumulated salt cause difficulties ,n the planting of subsequent crops because effecbve leaching of salts reqUIre flooding Another problem reported IS the clogging of dnppers due to precipitation of salts

Table 3 Yield, imgalian depth, water use effiCiency and SOil EC for tomato

Year IWIPET Yield Irngatlon depth WUE EC (t ha") (em) (kg ha·1 cm") (dS m")

07 5.47 40.4 135 203 1986 05 1514 294 515 082

03 1422 212 610 070

07 1306 381 343 083 1987 05 12.23 300 397 032

03 783 235 333 055

Subba Rao et al (1987) observed up to 50 per cent decrease In Yield of tomato when EC of irrigation water exceeded 6 dS m·1 Singh and Kumar (1988) studied the comparative performance of tnckle and subsurface Irrigation systems on tomato at different EC and IWIPET ratios Results reported In Table 3 explain the effect of Irrlgabon scheduling on Yield and salt bUild-up Apparently, a low IWIPET ratio for Imgatlon scheduling seems to be preferable to get high Yields, save water and to minimize salt build-up

Jain and Pareek (1989) observed that salt accumUlation was mlmmal In dnp Irngabon when saline waters of EC ranging from 2 7 to 9 0 were used to Irrigate date palm trees SlmLlar results were reported by Singh et al (1990) when sadie waters containing RSC 2.1,845 and 1245 meq 1" were applied to grow the

184

Design of Surface Dnp Irngatlon System with Saline Water & Its Effect on Crop Growth & Yield

klnnow (CItrus retlculata) plantabon Drip Irrigation system was also found more effective In the establishment of fruit garden on salt affected salls (DwIVedl at ai, 1990) whereas Pampaltlwar et al (1993) reported higher water use efficiency With drip method of Imgatlon over the conventional method ' ,

I Irngatlng tomato and bnn/al crops through drIp uSing canal water, and waters of 4 and 8 dS m" at

three IW/CPE levels (0 75, 1 00 and 1 25) at different ImgaliOn intervals of 2, 3 and 4 dayS gave belter Yield at higher IW/CPE ralios (CSSRI, 2000), It was ~Iso observea that when total amount of water apphcatlon remained constant, 13 and 33 per cent h,gher,Yleld was observed at irngatlon Intervals of 3" and 4 days In

comparls"~n to the mterval of 2 days ,In an~the~ study on tomato under dnp, the Yield decreased from 38 7 to 29 8 t ha as the salinity of ""galion water Increased from 0 21 to 5 dS m' , which was about 24 per cent less over the normal water application (Kadam and Fatel, 2001)

Drip Irrigation Studies at CSSRI, KamallAICRP Centers

Studies on dnp ''''galion have been conducted at CSSRI, Kamal Sinca Its Incaplion Three levels of RSC 06, 4,and 8 meq r' (at a fixed value of EC of 3 dS m"') were given through drip Imgatlon In k,nnow orchards at 3 I hr' at an Imgatlon Interval of 3 days The dlstnbutlon 'of mOisture, chlOrides, SAR and the nutrient status were monitored in the root zone (CSSRI, 1986) Since rainfall dUring monsoon season leached down the salts, no bUild-up of salts was observed over the years

A study conducted on sugarcane at Tnchurnpalll centre of AICRP on Salt Affected Salls and Use of Sahne Water In Agriculture revealed that Irngatlon scheduhng under dnp With alkah waters (pH 88, EC 22 dS m"', RSC 129 meq r' and SAR 182) at 60 per cent of pan evaporation (PE) gave higher water use effiCiency than 80 and 100 per cent of PE and farmers' practice (surface Imgatlon), under both the sub-treatments of no gypsum or 50 per cent applicatJon of gypsum requIrement (Table 4) (CSSRI, 2000)

Table 4 Effect of "ngalion schedules on growth and yield of sugancane under drip irngation

Main treatments Yield (t ha" ) Water apphed Water use efficiency (t ha" em' )

of ,"'gat,on at 50 per cent of No Depth Reduction In 50 per cent of No gypsum

percentage of PE gypsum gypsum (em) water gypsum requIrement appllcalion requirement apphcatlon applied (%)

100 993 956 448 7,14 221 213

80 1074 985 338 4201 318 291

60 '966 911 230 10869 420 396 , Farmers' practiCe 995 93'8 480 207 195

Singh ef a/ (2000) comparee the plant performance and the SOil sahnlty before and after three years of appllcabon of 0 4,40,80 and 120 dS m"' saline water through dnp and baSin ,"'gat,on In sapota crop at Khanpur farm, CSSRI-RRS, Anand, GUIarat The plant performance and the SOil salinity after the experiment showed that dnp Irngatlon had performed belter for growth of plant and less salinity bUlld- up was observed compared to the baSin me1l1ods In all the treatments

An expenment was conducted at AICRP, Agrs to assess the tolerance of tomato-chllh rotation With treatment combinations of sahne IITIgalion ,water (Canal, EC .. 4 and 6 dS/m) and "ngatlon schedule (IW/CPE ratio 075, 1 00 and 1 25) (CSSRI, 2007) Irrigation mterval for dnp Irngallon was 4 days and depth of water apphcatlon In each Irngatlon was 4 em, The fruit Yield of tomato decreased Significantly With Increasing EC .. In both dnp and surface uTigation system \Ni\h EC .. 4 and 6 (dSlm), the tomato fru,t Yield reduced by 16 and 37 In 2003-04 and 28 and 49 percent In 2004-05 In drip Irngatlon and 17 and 39 and 23 and 46 percent In surface I<Tlgalion system respectively (Table 5) Since the Yield In surface and dnp methods of IITIgalion did not vary much, ~ could be Inferred 1I1at drip Imgabon me1l10d could not playa slgmficant role in case of tomato at these salinity levels "Although data are not available to confirm the observa!lon, Irngatlon scheduling being same In the two methods, advantage of dnp Irrigation to faclhtate frequent application of water was not ubl,zed In the present set-up However, eqUivalent Yield of tomato could be obtamed With 25-30 percent less water In dnp than With surface,method Amongst the IW/CPE rabos 075 to 1 00 ratio could be used After the harvest of winter tomato, chilli was transplanted during summer season The satlne imgation affected chilli more in 2003 COmpared to 2004 'The Yield With EC .. 4 (dS/m) "declined by 78 peroent In 2004 and 42 percent In 2005 over SAW At higher EC .. 8 dS/m crop failed completely inboth the years, Overall, growing of the chilli crop IS not. a?vlsable" With saline water dunng summer season

185

Chemical Changes & Nutnent Transformation in Sodlc:/Poor Quality Water Imgated SOils , ,

/

Table 5 ,

Interaction effect between EC and IWICPE ratio on frUit yield (Uha) of tomato and chilli In dnp and / surface Imgatlon

, , EC .. levels (dSlm) ,

EC .. levels (dSlm) IWICPE ratio Mean Mean

Control 4 8 Control 4 8 Dnp Irngatlon Surface Imgatlon

Tomato 2003-2004 " 075 2647 21.74 1866 2229 2645 2248\ 1731 2208 100 2863 2346 1707 2305 2639 2254 ,1695 2196 125 2852 2372 1698 2307 2779 21.99 1500 2161 Mean 2787 2297 1757 2687 2234 1642

2004-2005

0.75 5302 3795 2751 3949 5003 4083 2505 3864 1 00 5358 3778 2631 3922 4464 3343 246 3422 125 5059 3788 2578 3808 44.'14 3293 2255 3331 Mean 5240 3787 2653 A637 3573 2407 Chilli 2004

075 1 71 014 062 240 008 083 100 205 050 102 274 024 099 1.25 244 070 105 276 041 1 06 Mean 207 045 26:l 024

2005 075 480 325 010 272 492 285 259 1 00 501 276 010 2.62 511 1 74 228 125 545 288 010 281 501 1 62 221

Mean 509 296 010 501 432

The frUit Yield of ch,lli ,n 2005-06 (winter season) significantly decreased with increasing EC .. levels In both drip and surface imgatlon system (Table 6). The EC", 4 and 8 <:ISlm reduced the frUit Yield by 36 and 40 percent In dnp Irrigallon and 40 and 54 percent In surface ImgaIJon system, respectively The IWICPE ratJo treatments were found non-significant

TabJe 6 . Effect of EC and IWICPE ratio on Yield (Uha) of chilli In drip and surface Irrlgallon

IWICPE rallo EC,w levels (dS/m)

Mean EC .. levels (dSlm)

Mean Control 4 8 Control '4' 8

Dnp Imgallon Surface Imgatlon 075 1540 9 82 943 1155 1024 638 560 741 100 1560 987 926 11 58 1034 636 434 701 125 '1474 952 864 1097 1030 563 428 674 Average 1521 9.74 910 1030 613 474 CD 5% Salinity 68 107 IWICPE ratio NS NS EC X IWICPE NS NS

Conclusions

Dnp IrngaIJon technology under the saline environment could be qUite sUitable and useful, ,t ensures Increased crop Yield, higher fertilizer and water use effiCienCIes, reduced water and energy consumplion and weed problems, as studies have reported Its use for several horticultural and vegetable pops, particularly which are Widely spaced Development of a sound data bases on crops With different 5011 and water quality howllver, st,ll needs upgradatlon But In the absence of detailed information, rts populanty and adoption IS lacking and needs to be mereased through awareness and training to the users

186·

Design of Surface Dnp Irngatlon System With Saline Water & Its Effect on Crop Growth & Yield

The wetted volume given by the proposed combination model of cyllndncal column with a semlellipsoid IS reasonably close to wetted volume given by the eXlsbng truncated ellipsoid model Since the model IS relabvely simple, It IS recommended for use In the deSign of tnckle Imgabon systems Since, so far the deSign of tnckle irrigation has been linked to fresh water applications, the proposed methodology IS extended to saline water Imgatlon This methodology could be used for both the fresh water application as well as for saline water Imgatlon Increased management wetted volume can result In a low salt concentration that would be sUitable for a crop while uSing the same concentration of saline water for Imgatlon

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Sln9h, P, Kumar, R, Agarwal, M C , and Mangal, J L 1990 Performance of dnp and surface ImgatJon for tomato In heavy SOils Proc XllntematJonal Convention on Use of Plashes In Agricunure, NCPA. New Deihl 67-72

Singh, Pratap and Kumar, R 1988 Comparanve performance of tneXIe and sub-surface Imganon systems for tomato In Management of Imgabon Systems Ed Tyagl, N K, JOShi, P K, Gupta, R K, Singh, NT, Proceedings of the Nabon;'1 Symposium on managemenrt of Imgabon System Feb 24-27,1988, CSSRI, Kamal 73-aO

Singh, Plarap and Kumar, R 1989 Compalabve perfolTT1ance of tneXIe Imgabon for tomato J Agnl Engg, ISAE 26(1) 39-48

Singh, Platap and Kumar, R 2000 Campalabve performance of dnp Imgabon for vegetable and ootton In heavy solis wrth shallow water table Proc Intematlonal Conference on MIcrO and Spnnkler Imgallon Systems, Jalgaon 87-92.

Singh, Platap and Kumar, R 1994 Effect of Imganon methods for cauliflower grown In heavy SOIls wrth shallow watertable J Agril' Engg ,ISAE 3136-43

Singh, Pratap 2000 Pressunzed Irrigation systems for enhanced water use effiCiency With saline waters Lecture notes - training course on Use of saline water for Imgatlon (26th June - 16'" July 2000) IDNP, CSSRI, Kamal' 299-308.

Singh, R, Das, M, Kundu, D K and Kar, G 2000 Prospect of USing saline water In fluvenbc eutnochrept through dnp Imgabon Proceedings of the nabonal Seminar on M,,:ro·lrrigabon Research In India Status and PerspedNes for the 21· Century, Bhubaneswar, July 27-28, 1998 255- 257,

Singh, V P , Samra, J S ,Gill, H S 1990 Use of poor qualrty water through drip system In klnnow orchards: tn, Proc Xllntemabonal Congress on the use of PlastICS In Agnculture Oxford & IBH Pub Co Pvt Ltd, ~ Deihl 165-175

Subba Rao, N Subblah, G V and Rarnalah, B 1987 Effect of saline water on tomato Yield And SOil properties J Indian Soc Soli Sa Reseanch 5(2) 407409

Wan, S , Y Kang, D Wang, S P Liu and P Feng LI 2007 Effect of anp Irrigation With saline water on tomato (LycoperslCun esculantum Mill) Yield and water use In serm-humld area Agncuftural Water Management, 90 63-74.

Warnk, A W 1974 Time dependent Iineanzed Inmtratlon I POint source SOlI SCience Society of Amenca Proceedings, 38 383-386

Warnk. A W 1985 POint and line Infiitratlon - Calculation of the Wetted 5011 surface SOil SCience Soclely of .AmencaJoumal,.49 1581-1583

Wooding, R A 1968 Steady mfiltratlon from a shallow Circular pond Waler Resources Research, 4 1259-1273

Zur, B 1996 Wetted 5011 volume as design objective In trickle Imgatlon Imgatlon SCience, 16 101-105

188

Subsurface Drip Irrigation for Utifization of Sewage Water

R.S.Pandey DIvIsIon of InigatJOn 8, Drainage Engmeenng J Central SOJI Sahm/y Research Insflluta, Kama/-132001

Introduction

The wastewater can be broadly grouped mto two major categories-the sewage water and the Industnal wastewater In most CJtles and to~ns these two waters are disposed oft together and resulting qualrty may change from place to place depending upon the nature of the Industry Contranly, II IS easy to manage the sewage water, as Its qualIty characteristICS are known Though the quality of sewage water dIffers from place to place and season to season. it IS neutral to slightly alkali In reaction, low," salt content and high In pathogeniC microorganism The water rarefy contains heavy metals unless mixed With Industhaf"wastewater, which may be tOXIC to plants and may cause adverse effect to human being by entering Into food chain It contains nutnents and organrc matter, which may_,ncrease the SOil fertllrty The constituents of Concern in wastewat~r treatment .and \Y8stewater ir)lgation'aie Irsted In Table 1

Table 1 Constituents of eon cern In wastewater treatment and rrngatlon WIth reclaimed wastewater

Constituents Suspended solids

Biodegradable organics

Pathogens

Nutrients

Stable (refractory) Organics

Hydrogen Ion activity

Heavy metal

Dissolved morganrcs

ReSidual chlorrne

Measured parameters Suspended solids InCluding volatile' and fixed solrds

Biochemical demand, Chemical demand

oxygen oxygen

Indicator organisms. total and fecal colrform bactena

,Nitrogen Phosphorus Potassium

SpeCific compounds (e g phenols, pestiCides, chlonnated hydrocarbons)

pH

SpeCific elements (eg Cd, Zn NI, Hg)

Total dissolved sohd, electrrcal conduc~vlty, speCJfic elements (e g Na, Ca, Mg. CI. B) Free and combine chlorine

Reason for concern Suspended solids can lead to the development of sludge depOSits and anaerobiC condlbons when untreated wastewater IS discharged In the aquatic enVironment Excess ,amount of suspended solids cause plugging In the rrngatlon system Compose pnnclpally of proteins, carbohydrates, and fats If discharged to the envrronment, therr biological decompOSition can lead to the depletion of dissolved oxygen In receiving waters and to development of sep"c condition Communrcable diseases can be transmitted by the pathogens In wastewater. bactena ViruS. parasites N, p, and K are essential nutnents for plant growth, and their presence normally enhances the value of water for Il'{lgatlon When discharged to the aquatic envrronment. narogen and phosphorus can lead to the growth of undesrrable aquatic hfe When discharged In excessive amounts on land, nitrogen can also lead to the pollution of ground water These organics tend to resist conventional methods wastewater treatment Some organrc compounds are tOXIC rn envrronment ,and therr presence may limit the SUitability of wastewater The pH of wastewater affects metal solubllrty as well as alkalrnrty of the 5011 Normal range 15 6 5·8 5, but rndustnal waste can alter pH Significantly Some heavy metals accumulate rn the environment and are tOXIC to plants and animals Therr presence may limit the SUitability of wastewater to rrngatlon Excess sallnrty may damage some crops SpeCific Ions such as chlonne, sodium, boron, are tOXIC to some crops Sodium may pose soil permeability problem

Excess amount of free available chlorrne (> 005 mgll CI, ) may cause leaf tiP bum and damage some senslbve crops However, most chlorrne In reclaimed wastewater IS In combJOed form, which cloes not cause crop damage Some concerns are expressed as to the tOXIC effect, of chlorrnated organics In regard to groundwater con tamlnatlon

Chemical Changes & Nutnent transformation In Sodu:/Poor Quality Water Imgated SOils

/ Different Appro~ches of Disposal of Sewage Water

• DISPos!,1 into surface waler body • Disposals Into low lYing areas and ponds • Soak pil disposal • Sewage lnealmenl plants • 5011 aquifer Irealmenl system • Oxidation ponds and fish culture • Sewage for agnculture

Mostly In India, the muniCipalities collect sewage through sewer system and pump It out directly from the main sewer or collection tank (sump) Into a nearby drain, stream or river body, Which ultimately JOins the nver of the area Almost all the nvers Including Ganga and Yamuna and many sea beaches hilve thus been polluted to an alarming level Whene such outlets ane not naturally available, It IS simply dumped Into ilear by low-lYing area or pond, As a nesult of such an unplanned dl,sposal of mumclpal waste, many' big' lakes of sewage can be seen in and around the big Cliles causmg ground waler and surface water contammaIJon and envrronmental pollution Soak pit disposal system IS generally used for Individual household Sewage is allowed to go In to the Pit Without any pre-treatment, from where It IS ultimately soaked Into the SOil, which contaminates the groundwaler

tn sewage treatment plant sewage, water IS stored In ponds, which ane arranged In parallel andlor senes The size and depth of ponds vanes to allow different retention time and make the poSSibility of aerobiC and anaoroblc decompOSition of organic matter of sewage water. Sludge is removed from the sewage, which reduces its BOD and concentration of tOXIC elements Depending upon the degree of purrficatlon, the effluent 15 calletl as pnma~, seccnda~ and lerua~ lJealetl sewage was\e....aler The \100100 waslewater can be Ilseo for Irrrgation purpose andlor safel,y discharged Into the nver body

Sewage for Agriculture

IrrfgatiO" methods

Different methods are used or could be used to apply good quality Irrrgation water The efficiency of these methods differs from each other on account of vanatlon In deep percolation and evaporation losses (Table 2) Thus to save rrngabon water and energy and to enhance productIVity, selection of advanced Imgatlon method would be necessal)' This Increase In productiVity IS attnbuted to conditions of optimum mOlstUr9 In the rool zone Ihat affects In proper aeration to the plants and reduced penods of mOisture stress ThiS condition can be eaSily marntalned by the drrp rrrrgatlon, whene It is possible to make frequent rrngatlon as per requirement of the crops I

Table 2. Application effiCienCies of different rrngabon methods

5 No Type of Imgabon method

1 Flood, border, furrow, check basll1, bed and furrow 2 Spnnkler 3 Dnp

Application effiCiency ('!o)

<60 80~5

90-95

The eva~oraUon losses are the maXImum in the ca.se ot tlaad, oarder, and ctleck oasln The evaporation losses are reduced In the baSin and furrows, as only a part of the SOil IS flooded The evaporation losses are further reduced In Ihe case of spnnkler Irrrgation as most of the water IS held by capilianty In the case of dnp Imgatlon flooding can be altogether avoldetl, which reduces the evaporation losses Moreover In most cases It would be not necessal)' to wet the entire field For example rn the case of vegetable crops, only BO% of the wetted area can serve the purpose where as In the case of frUit trees approximately 20% the anea IS requrred to be Irrigated In the case of subsurface dnp irrigation there IS maximum reduction In evaporation losses as emitters are buned In the 5011 which reduces the mOisture content on the 5011 surface

Expansion of drip Irrigation In India

Research expenments on dnp Imgabon In India were inl!lated In tha early se_bes In many state agncullural unlversrnes and research organizations The spread was quite fast dunng the last decade, when lis coverage touched 03 million ha (Table 3) ThIS spread is mostly for good qualily water and saline water The highest coverage IS In the state of Maharashtra followed by Kamataka, Tamil Nedu, Andhra Pradesh and RaJasthan According to SrvanapPan (1999), aboUI2B 5 m ha could be covered under dnp Imgabon, which 15 likely to be achieved by the year 2020125

190

Subsurface Dnp Irrfgabon tor Utlllzatfon of Sewage Water

However, at an annual compound growth rate of adoptJon of dnp ImgatJon assessed at present at 12 per cenl rt would take about 8 years to bnng addrironal erie miliran hectare area under dnp Imgaban

Table 3 Growth of drip Imgatlon In India

Year 1970 1985 1989 Area (,000) ha Nil 15 '120

(Source Kumar and Srngh, 2002, Praveen Raa, 2002)

Crop wise area distribution under drip Irrigation

1994, 1999 2002 709 3000 3554

Area coverage unde(dnp system for different crops In 1'992 and 1998 are given In Table 4, shOWing an Increase !n Its adoptIOn partICUlarly in ":'115, vegetables, sugarcane and cotton Major rncrease In dnp Imgated area has been In banana, Citrus, coconut, grapes, mango, and pomegranate under frUit crops There IS also a substantial Increase In the anea under cash crops of sugarcane and cotton

Table 4, Area coverage (ha) under drrp "ngatlOn for selected crops In India

Crop Year Year

1992 1998 Crop 1992 1998 Sugarcane 3888 18000 Coconut 2596 48361 Cotton 383 5462 Grapes 12048 29630 Vegetable 1537 4515 Guava 1543 4930 Fruits 39500 186600 Mango 4747 21863 Arecanut 208 5665 Papaya 873 2115 Banana 6767 26565 Pomegranate 5437 15250 Bear 704 4700 Sapota' 849 5125 CitruS 3879 22210 Strawtlerry 200 1700

Economic analysiS of drip Irrigation in India

Reddy et al. (2004) made an economic analYSIS of the Important crops grown With dnp Imgatlon In India Data on aver~ge Yield, water reqUirement, water savrng, fertilizer saVing and their cost were collected from Irterature and pnces of agnculture commodities were taken from Govt of IndIa reports Y,eld pattern (Table 5) reveals that maximum Yield Increase was In vegetables (60%) followed by frUits (40%), sugarcane (33%) and cotton (27'Yo) Similarly, water saving ranged from 53 to 56% The saving In fertilIZer waS about 30% for all the selected crops Based on the above data, additional Income expected uSing drrp system were calculated and IS presented In Table 5 AddItIonal returns due to Increase In y,eld ranged from Rs 16, 767 to 29,566 per ha, With maxrmum in sugarcane and mlnrmum In cotton The benefit from water saving ranged from Rs 660 to 3612 per ha (approximate water pnre Rs 3/ha-mm, Tiwari et al ,1996) The benefit from fertllrzer saving was estImated at Rs. 450 to 600 per ha for eXlstrng rate of ferillrzer The cost of ferlllrzer IS estimated based on the recommended dose for the respectJve crops The cost benefit rallo was calculated for these crops (Table 6) The maximum cost benefit rabo was found for ":'Its followed by sugarcane, vegetables and cotton The nel benefit IS the maxImum for Sugarcane followed by fruits, vegetable and cotton.

Utilization of sewage water through drip Irrigation

Water shortage associated With Intensive depletion of underground aqUifers has prompted the search for altematlve water sources It has lad to secondarY treated domestic wastewater being conSidered for Irrlgalron of field crop and raw eaten vegetable crops (Oron et al , 1991) Secondary domestic wastewater IS now beIng used on a relat,vely large scale, mostly In deyeloped countries, for field crops and landscape Imgatlon, groundwater recharge, and storage In recreational ~nters . In a few cases, tertiary or advanced treatment of the wastewater is reqUired (KirkpatrIck and Asano, 1986)

The concept of water saving might seem to GOntradlct the Idea of maintaining maxImum Yield from Imgated crops. The conflict might be more Significant In and zones With limited natural, high quality, P9/ffianent water source. A pOSSIble nemedy to this conflict IS to use non-convenllonal water" such as domestic treated wastewater, applIed by dnp rrrigairon. USIng a subsurface drip rrngatlon system can further Increase the efficiency of water applrcatlon (Phene et 81 ,1985) The other advantages of use of dnp Imgatlon system With sewage water are that no aerosols are formed, water logging due to runoff and deep percolation is negligIble and the only contact With the water occurs when the product to be consumed touches the SOIl; the product of the plants groWing above the SOil being practically deVOid at pathogens when the dnp system IS buned In the sailor covered by the plastiC sheets (Caprl'l and SClcolone, 2004)

191

Chemical Changes & Nutnenl Transformation In SodlcIPoor Quahty Water Imgated Solis

/

Table 5 Total returns expected from selected crops under drip Irngabon system / .

Input " Cost economICS Crops Sugarcane Cotton Fruits Vegetables

Yield Yield (tlha) 128 2,3 9 '11 Increase (%) 33 27 40 60 Seiling price (RS/t) 700 27000 6000 4000 Addilional Returns (Rs/ha) 29566 16767 21600 26400

Water Required (mmtha) 2150 895 1200 400 Saving (%) Benefit (RS/ha) 56 53 55 55

3612 1423 1980 660

Fertilizer Cost (Rstha) 2000, 1700 1500 1500 SaVIng (%) 30 30 30 30 Benefit (Rs/ha) 600 510 450 450 Total Return (Rslha) 33780 18700 24030 27510

Table 6 Benefit cost rabo for selected crops under dnp system

Crop Cost of dnp system (Rs/ha) Benefit (Rstha) B C RatiO

Total Annual Total Net Sugarcane 50000 14000 33780 19780 241 Cotton 50000 14000 18700 4700 134 FrUits 25000 7000 24030 17030 343 Vegetables 65000 18200 27510 9310 1.51

It IS eVldent from above examples that some degree of treatment was provided to untreated muniCIpal wastewater before It could be used for agncultural or landscape lITIgation ThiS is the prevalent norms and practice In the developed countnes, The degree of pre application treatment IS conSidered to be an important factor In the planning, deSign, and management of wastewater Imgatlon system Pre application treatment of wastewater IS practiced keeping In View the follOWing reasons (Asano et at, 1985),

• Protect publiC health • • Prevent nUisance condition dunng storage • Prevent damage to crops and solis

Present status of utilization of sewage water In India

Currently, about 30% of untreated sewage water IS being utilized to grow vegetable crops around urban center uSing surface method of irngabon ThiS practice, beSides a health nsk to the farmers and the consumers 'of the product, IS causing enormous ground water contamination since excessive deep percolation losses can not be aVOided Moreover the productiVity of land and waler IS qUite less, which could be Increased substantially by adapting dnp irngatlon Around 60% of sewage water IS directly disposed off In surface water bodieS and low IYlTlg areas causing groundwater and surface water contamination and lTleffiCient use of our water resources VisualiZing the alarming level of environmental pollution, around 10 '4 of sewage water IS belTlg treated in conventJonal sewage treatment plants generatlTlg mostly pnmary treated sewage water These waters are also ullllzed tor Imgatlon purpose With surface method of Irngatlon

A case study on the use of domestic wastewater through drip Irrigation

At Central SOil Salinity Research Institute, Kamal, sewage water IS collected In sump through gravity and It IS pumped Into an unlined pond after every 24 hours The amount of sewage water IS around 83,000 lit t day The quality of the domestiC wastewater is showry In Table 7 The most of the sewage water In the pond was recharging the groundwater and there was foul smell ne~r the pond

192

Subsurface Dnp Imgabon for UtIlization of Sewage Water

Table 7 Composition of domestic wastewater at CSSRI Kamal

S No Parameter Values 1 pH 7,93 2, EC (dS/ni) 098 3 BOD, (mgll) 198 4. COD (mgll) 249 5 NH.-N (mgll) 129 6 NO,-N (mgll) 2.43 7 HCO, (m eq /I) 789 8 P (mgil) 406 9 !< (m eq II) 029 10 'Na (m eq II) 238 11, Ca (m eq II) 2j9 12. rig (m eq 1/)

, 320

13 Zn (mg/l) 024 14 Fe (mgll) 094 15 Mn (mgll) 003 16 Pb (mgll) 016 17 Cd (mgll) 001 18 Cr (mg/l) NO 19 E coli 1100 ml 10'"

20 Total suspended solid (mg II) 100

For safe. economical and effiCIent utilization of sewage water an expenment was conducted to Irrigate lady finger and cabbage crop With untreated domesllc wastewater through drip "ngallon Both surface ana subsurface dnp imgatlon were tned In subsurface dnp .rngabon em.tters were laId 30 em below the sOli surface A separate emitter was prOVided tor each plant In both the methods of Irngatlon The lady finger crop, was grown dunng April to September The amount of domestic wastewater applied was 53 cm whereas total crop water requlre"1ent was 89 em (Table 8) The rest crop water requirement was met by rainfall The Cabbage crop was grown during October to February The amount of domestic wastewater applied was 194 cm while total water reqUirement was 26 83 em (Table 9) The other part of the crop water reqUirement was met by rainfall The Yield of lady finger crop was higher I e 1472!/ha In the case of subsurface drip Irrigation as compared to 8 0 tlha In the case of surface dnp lrngallon (Table 8) In the case of cabbage crop the YIeld was higher In the case of surface drip Imgallon i e. 33 56 t/ha compared to 29 00 tlha In the case of subsurface dnp irrigalion (Table 9) Low Yield In the case of cabbage crop dunng subsurface Irrigation may be due to the shallow root system of the cabbage plants and the depth of subsurface em.tters (30 em) which prevented adequate water supply

Table 8 Water use effiCiency In the case of lady finger crop dunng surface and subsurface drip Irrigation

Total water requirement (em)

8911

Sewage water applied

5307

Yield of lady finger (!/ha) Surface Subsurface 805 1472

Water use effiCiency (tlhalem) Surface Subsurface 0089 0 H4

Table 9 Water use effiCiency In the case of cabbage crop dunng surface and subsurface drip Imgatlon

Total water requIrement (em)

2683

Sewage water applied

1941

Yield of cabbage (tlha) Surface Subsurface 3356, 2900

Clogging of the emitters and its effect on application efficiency

Water use effiCiency (tlha/em)

Surface Subsurface 1 27 1 16

One of the advantages of dnp Irrigation IS Its potentral to attain high application effiCiency But clogging of the emitters may encounter thiS advantage Dunng three years of expenmentallon, the emitters were clogged to some extent resulting in decrease In application effiCiency (Tables 10 & 11) Clogging of the emrtters affected the hydraulics perfonnance of the system In two ways It reduced the discharge rate of the emitters as well as It affected the umfonnlty coeffiCient. whIch IS inversely proportion to the coeffiCient of

193

Chemical Changes & Nutnent Transformation In SadlclPoar Quality Water Imgated Solis

/ vanatlon In tne case of surface dnp Imgalion emitters dlscnarge rate reduced to 05% compared to 12% In the case of subsurface dnp Irngatlon The coefficient of vanaben Increased to 0 16 and 023 In the case of surface and subsurface dnp irngatlon respectively from therr initial values of 0 077 and 0 078 In tlte time span of 3 years I Clearly there was more clogging effect In the case of subsurface dnp irrigation compared to surface dnp Imgabon This could be due to the entry of SOil particles In the subsurface emitters ,

Table 10 Vanatlon In discharge rate and coeffiCient of vanalion of emitters flow duru1g three years of expenmentatlon '"

Mean discharge rate Surface dnp Inlbal After 3 years

385 383

Subsurface dnp Initial After 3 years

387 337

CoeffiCient of vanabon

Surface Inlbal After 3 years

0077 0,16

\

SUbsu,rface Initial After 3 years

0078 023

Table 11 Estimated application effiCiency dunng 3 years of expenmentatlon In drip Imgatlon methods and Its companson to border Imgabon

Surface dnp Irngatlon Subsurface dnp Imgabon Border Inilial After 3 years Imbal After 3 years 92% 85% 92% 72% 60%

Deep percolation losses

The dnp lITIgation system saves the water in two ways (1) reducllon In evaporation losses could reduce the nel application of Irngallon water and (2) Increase," appllcabon effiCiency could further reduce the deep percolation losses The eSbmaled deep percolation losses are shown in Table 12. There was 46 em of deep percolation losses In the case of border Imgatlon compared to only 20 em In the case of subsurface dnp Irngabon after 3 years of use of the wastewaler RedUCing the clogging of Ihe emitters can reduce Ihe deep perccl"tlon losses and It may attain the value of 4 3 CO)

Table 12 Estlmaled deep percolallOn losses In dlfferenllrrigatlOn methods

Crop Surface dnp Subsurface dnp Border Initial After 3 years Inilial After 3 years

Lady finger 40 85 30 144 353 Cabbage 15 31 13 56 129

Soil and crop produce contamination

SOil and plant produce contammabon depends to a large extent on Ihe applied effluent quality, SOil condltlons\ end the technology of application The microorganism content In the effluent was qUite high i e around 10 'liDO ml (Table 7) which reduced to 10'1100 gm of sOil In the case ofsurface dnp "ngatlon (Table 13) In,the case of subsurface drip Irngation, 5011 surface was found free from pathogemc microorganism Indicated by E coli (Table 13) Plant produces I e lady finger and cabbage balls were found free from contamination of pathogens in both the Irrigation methods Apart from crop produce, uncontaminated SOil surface may also save fann workers 10 be affected by disease dunng Inter culture operation In the case of subsurface dnp Irngatlon, •

Table 13 D,stnbulion of the pathogeniC microorganisM Indicated by E coli In the SOil Irrigated With surface and subsullaee dnp Irrigabon

Distance from the Depth from the E coli 1100 gm of SOil

S No plant, em plant, em Surface Subsurface

0 0 10 0

2 0 30 10' 10'

3 25 0 10' 0

4 25 30 10" 102

194

Subsurface Dnp Imgatlon tor Utilization of Sewage Water

UtIlization of Sewage Water through Subsurface oifp Iirlgation on Fruit Crops

In vegetable crops almost whole area IS Imgated which Increases the chances of contamination and dosure spacng of dippers I'Tld laterals Increases the cost of dnp system To get better results expenment IS being conducted on frurt crops. The two frurt crops I e guava and amla were grown With spacng of 4 5 m and 60 m. In Initial three years to utilize the space between the fruit crops, the papaya seedlings were transplanted WIth the' spacing of 15m as an Inter fruit crops In thiS case prassure-compensatlng dnppers were used which may neutralize the better results In case of dogging as obtained In prevIous vegetable crop expenment , ,

Limitations

In 'the present study, the domestic 'Y"stewater used, was contamlng negligible amount of heavy metals But many times the mUnicipal wastewater may contain heavy metals of significant amount and for those cases the SUitable management practices would be reqUired for their sustamable use

Conclusions!

Drip irrigabon technology ensures Increased crop Yield, high water use effiCiency, reduced water and energy consumption. Dnp Irngatlon has a potential' of utiliZing sewage water In agnculture Disposal of the sewage wastewater IS a senous problem espeCially 10 developmg countries, which IS causing groundwater and SUITace water contamination and creating environmental pollution The conventional method of disposal of sewage water (sewage treatment plants) ane cost Intensive and beyond the reach of many mUnlClpalibes The use of sewage water through subsurface dnp Imgatlon may help to solve the disposal problem and finding a solution, which may be economically Viable Though Its adaptation for effiCient utilization of good quality and salme water IS steadily increasing 10 India still there are few challenges Investment needs being high, the technology could be populanzed through one Window system of finanCial assistance Including subSidy Its large-scale expansion will reduce many of its shortcomings, which Will also encourage the use of sewage water through drip "ngatlon

Bibliogl'3phy

Asano, T, R G Smith, and G Tchobangoglous,1985 Municipal wastewater Treatments and reclaimed water characterlsts In irrigation With Reclaimed MuniCipal Wastewater-A GUidance Manual, edited by G Stuart Pettygrove and Takashl Asano

Capra, A and B SClcolone, 2004 Emitters and filter tests for wastewater reuse by dnp Imgatlon Agncultural Water Managemen~ 68, 135-149

Kirkham, W R ,and Asano,T 1986 Evaluabon of tertiary treatment system for wastewater neclamabon and reuse Water Sci. Tech, 18 (10), 83-95.

Kumar, Ashwanl and AK Singh. 2002 ImproVing nutnent and water use effiCIency through fertlgabon J yvater Management 10(1&2),42-48

Oron, Gideon, Joel Demalach, Zafnr Hoffman and Rodlca Cabotaru, 1991. SubsuITace mlcrolmgatlon With effluents Journal of Imgatlon and Drainage Engineering, 117(1),25-37

Praveen Rao, V. 2002. Dnp imgabon and rts applICation in fanners' fields of Ind.. Irr Recent Advances .n Imgabon Management for Freid Crops Ed Chlmamuthu, C R , Velayutham, A, Ramasamy, S, Sankaran, N, and S D Sundersingh Centre of Advance Studies In Agronomy, Tamil Nadu Agnc UnlV, CoImbalore 66 - 70

Phene, C J , Hutmacher, R B, , Davrs, KR ,and McConmc, R L 1985 Subsurface dnp lIligalion offers suooess CalifAnz. Farm press, 7/8 (40), 24-31.

Reddy, KS, R M Singh, Kvr ,Rao and D M Bhandarkar,2004 EconomiC feaslbllrtv of dnp Imgatlon system in India Agnculture Englneenng Today, 28(1-2), pp 65-69

Sivanappan, R K 1999 Status and perspectives of mlcro-Imgatlon research In India. Proceedl';'.9S of the National Seminar on Mlcro-Irngabon Research in India Status and Perspectives for the 21 Century, Bhubaneswar July 27-28,1998 Inslitulion of Engineers (India) 17-29

195

/'

Scope of Skimming and Rechar!)e of Groundwater in Salt-Affected Areas

S.K.Kamra· / DIvIsion of Imgation & Dramag9 Engm99nng CIiIntral SOIl Sallntty Research Inshtuta, KanTsl

Introduction , About 70% of Irngallon and 60% of drinking water requirements of India are met from groundwater

sources Proliferation of about 20 million private open wells/shallow tubewells and 90,000 deep public tubewells has been vital for about seven-fold increase In Indla's Irngabon potenbal over the last five decades Due to easy access, operational convenience and private ownership, the groundwater development In the country has been quick but unregulated and has resulted In groundwater dechne In more than 10% of the couTi\ris aTea 'n \'ne suswpo'()\e s\,,\~ <j, k~m. 'i'~~~" ~~rIfo, '\lidj?loW, 'I',Oi1IOi1/Q, 'f-'lm~aJt,,,, 'f-;m/", Madhya Pradesh, Maharashtra, Punjab, ~ajasthan, Tamil Nadu and Uttar Pradesh, declining water levels a,,~ faCing gradual deepening of the eXisting 9bstractlon structures causing escalallon in the cost of pumping At cu rrent rate of development, about two filth of the country's area IS hkely to be over -exploited (groundwater abstraction> 85% of annual replenishment) by 2017, Declining water levels In the and and semi-and areas are often accompanied by Increase In solute concentrations and detenoration of ground water quahty Saline water Ingress has occurred In the coastal ,.eglons of West Bengal, GUjarat, Tamil Nadu, Pondlcherry and other states due to dechnlng ground water levels Central Ground Water Board (CGWB) and other agencjes including research institutes, universities and NGOs have conducted. a large number of studies on Induced recharge through a number of methods such as injection wells, check dams, subsurface dykes an'd surface spreading In several declining watertable areas in the country. Similar reported studies for shallow/saline groundwater regions are limited

Development of groundwater to meet imgallon, dnnklng, and industrial demands of growing populabon IS severely hampered by the e~croachment of saline water In response to fresh water Withdrawals Upcomng IS a phenomenon due to which tna interface of fresh and saline waters IS deformed In the shape of a cone With Its top entenng In the lower end of the well screen, resulting In a gradual detenoratlon In the pumped water quality BeSides extensive coastal regions of the country, upconing IS also prevalent in Inland areas where excessive Withdrawal of usable fresh water overlYing saline groundwater results In Inferior water quality and degradabon of the aqUifer In partlcul@r, Imgated areas in many and and semi-arid regions are underlain by aquifers of poor quahty where very little groundwater development taKes place resulbng In waterlogging and secondary SOil salinization Such a slluatlon eXIsts In a major part of the southwest Haryana, Rajasthan and Punjab states and Similar reports are c;amlng from other states as well, Under these conditions, It IS aimed that the saline water IS not disturbed and "fforts should be made to selectively skim fresh water accumulated due to recharge from rainfall, Irngation a~d/ or canal seepage over the native sahne groundwater through speCially deSigned skimming structures anO by enhanCing groundwater recharge,

In this paper, basiC features of different skimming structures are discussed In the context of Indian conditions Further, field expenences on certain newly Introduced technologies for skimming and recharging of fresh water In saline groundwater' regionS of Haryana, Andhra Pradesh, Gu]arat and Tamil Nadu under National Agricultural Technology Project (tJA TP) are reViewed In the end, sahent observatiOns and emerging Issues relabng to skimming and recharging technologies for saline groundwater regions are presented

Groundwa!er Skimming Structures

Various skimming well oonfigurat1ons such as slngle:mulb-stralner, radial collector and scavenger wells (Fig 1) are pOSSible to selectively ab~tract fresh water from thin layers overlYing sahne groundwater The 'oaSIC ccncep't OT a)) sKlmmmg s'uUCtuTes ' .. '<1> nwht 'IT", 'iII'''' ',«"", .«, ~.ru-. 'io '_1 '<1> n"""'I;':" ~"""=t<11, contribution of aqUifer zones of acceptable quality to pumped water (Sufi et a/., 1998) A single well (Fig la) IS used In unconfined aqUifers in most parts of India While using these wells In sahne groundwater regions, well penetration IS kept deep Into the fresh water layer With a large gap between the bottom of the well and the fresh-saline water interface These types of tubewell drainage projects have been executed at Masltawah '" IGNP (Hooja et ai, 1995), Ghaggar depreSsJonal areas In Rajasthan and in Fatehabad branch area of Haryana

A multi-strainer well (Fig 1b), wit~ relabvely shallower penetration than Single well, can be used for water table control With diminished upcom(Jg In fresh water layers of restricted depth The system consIsts of closely spaced Interconnected wells, each of low capacity, pumped by a central suction pump Such structures are being extenSively used close to canalsJ distributaries In Punjab in India (Shakya, 2002) and In the Indus plains of Pakistan (Sufi et a/, 1998, Mazhar Saeed at ai, 2003) There are sporadiC reports on the


use of these systems rn margmally saltne regions of Haryana, Rajasthan, Andhra Pradesh and Tamil Nadu In India. Air leakage and pnmlng problems have been reported from most of these studies

Radial collector wells consisting of an open well and mput radial drains on one or more sides (Fig 1 c) Involve shallower penetration than a single vertical well operaMg at the same discharge Since the radial drams collect water from shallow depths, upcomng of sahne water from lower depths IS prevented Large diameter open skimming wells expenmented at Hlsar In Haryana (Kumar and Singh, 1995) and at LUMI-I<IDham In Rajasthan (HooJa et al , 1995) and a draui hne - sump based Doruvu iechnology embalked on a large scale In coastal sandy Salls of Andhra Pradesh (Raghu Babu et al , 1999, Raghu Babu et aI, 2004, NATP, 2005) are the local vanants of radial collector wel!s.

Scavenger wells (Fig 1d) Involve simultaneous abstraction of fresh and saltne waters through two wells haVing screens In different quality zones, for controllmg the rise of Interrace The scavenger wells have been tested in the lower Indus basm of Pakistan (Sufi et aI, 1998) and have shown their potential In skimming of fresh wateri Despite apparent problem of qlsposal of saline water, the scope of scavenger wells needs testing for cases Involvlng'two cavity wells (non-strainer tubewells common In saltne groundwater regions of Indo-Gangetic plams) Installed at different depths or a combination of a strainer and a caVity wells Geological, hydrological and geo-chemlcal charactenstlcs_of aqUifers must be studied In an Integrated way to study the hydraultcs and to evaluate the perronmance of these skimming structures.

To Jlump

-_._;;. ' - --.. • .Ji :?=",'.:-.'

~.

,r:,," ,"'t .1:-- " ".:=: Fresh Wate ~-;~-

Intart.!'lce

I Saline Wflte~

b) Mutu-straIner Willi

c) Rildlal collector well' d) scav~nger we"

Fig 1 Different types of fresh water skimming wells

National Agricultural Technology Project

A NATP project 'Technologies for Skimming and Recharging Fresh Water In Salme Groundwater Regions' has been operated at CSSRI (the lead centre) and four collaborating centres Over a panod of about 5 years, the project has made Impressive accomphshments in proposing, testing and evolVing groundwater skimming and recharging technologies In saline groundwater regions of Haryana, Andhra Pradesh, GUJarat and Tamil Nadu Features of the promising technologies are bnefly discussed below

197

Chemical Changes II Nutnent Transformation In SodlclPoor Quality Water Imgated 50115

(a) Haryana /

The north-westem State of Haryana IS a pi"t of IndcK3angellc alluvial plalOs About two third of the geograp~lciil area IS currently undertalO With saline groundwater i'nd the situation IS detenoratlng further due to dlsproporllonate pumping vis-a-vIS groundwater recharge In most of the marginally saline groundwater regions, low discharge shallow caVity wells are used for ImgallOn, which are Ine1<penslve pumping structures not reqUlnng strainer. Deep tubewells are not feasible due to increaSing groundwater salinity With depth while many shallow tubewells are abandoned due to upconm9 of saline water from Ihe deeper layers

. " A skimming cum recharge structure (Fig 2) Was constructed at a downstream location prone 10 runoff floodIOg at Village Jagsl/Sarfabad In Saffidon block of JIOd dlstncl The system consists of two cavity tubeWells, Installed at 7 m and 40 m depth 10 the respec\lve fresh and saline groundwater zones, which can be operated separately or together to obtain water of different qualities The system IS Similar In features to a

" scavenger type skimming structure (Fig 1 d) discussed above but consists of caVity wells Instead of strainer tubewells. A recharge chamber of 6 m x 25m x 2 m Size and contalnIOg a graded filter of fine sand, coarse sand, graveJ and boulders was constructed close by to facIlitate recharging of one or both caVities With filtered runoff dunng rainy season or excess canal water The objective was to IOcrease the availability of good water In upper caVity or improve the quality 01 lower caVity tor pOSSible use at time of water Scarcity

Kamra et al (2006) report general Improvement In the groundwater regime of area due to combined effect of the natural and imposed recharge interventions The estimated recharge rates through Injection in caVity wells were low at about one quarter 01 the pumping rates under shallow groundwater conditions

G I. PI.,. 111 em III ..

e,vlty I

....... __ .......

Fig 2 Groundwater s~mmlng cum recharging structure at Jagsi/ Sarfabad (Dlslt Jind, Haryana)

(b) CoastaJ sandy solis of Andhra Prades~ and Tamil Nadu

In Andhra Pradesh, about 1 74 Jakh ha coastal sandy Salls are charactenzed by good quahty water floallng over salIOe ground water at shallow depths which can not be extracted With convenbonal tube wells These Salls occur In. a 10 km Wide and 972 km long slnp extending from Ichapuram '" S"kakulam district to

196


Tada in Nellore district The annuaJ rainfall in this belt ranges from 700-1200 mm With an average of 855 mm. Farmers traditionally draw out manuatry the fresh water that collects In dug out conical pi1s locally called dorovus and use it for cultivation of vegetables, flower plants and raising crop nurseries. Similar practices involving shallow pits (locally called Oothu Kuzhl) are prevalent in nearly 600 km long coast line and 6.B lakh he coastal area in Tamil Nadu. These doru'tllJS waste about 20% fraction of the productive coastal sands and are also subjected to high evaporation losses.

Over last decade, a ramal collector well type (Fig. 1c) skimmlng structure. called 'Improved Doruvu', has been evo1ved through All India Coordirn;lted Research Project on Saline Water Scheme at 8apatJa in Guntur District of Andhra Pradesh. The radial arms (perforated drain lines of 30-40 m length) installed af 2-4 m depth skim fresh water from thin z.ones and carry it to an open wen (called sump) from one or more sides (Fig 3). The system yields a discharge of 5 to 1S litres/second or more depending upon number of arms and nature of sand and can operate in combination with sprinkler/drip system. The system has been extensively adopted at more than 60 sites in 17 villages in Guntur and Prakasam districts of Andhra Pradesh. A major deterrent for large-scale adoption among small and marginal farmers had been the high cost and lack of optimal designs and layouts for sustained supply of fresh water.

Geo-hydrological and geophysical studies, conducted under NATP project in Gun1ur district in Andhra Pradesh and Nagapattinam district in Tamil Nadu, indicate the existence of a sand layer of less than 8-10 m followed by a clay layer sa1urated with saUne water. The EC of water increases with depth and with increasing nearness to the sea. Radial collector wells of different designs (2 to 4 drain lines at same or variable depth and drain length) were evaluated for hydraulics and economics at a number of sites in these districts of Andhra Pradesh and Tamil Nadu. Pumping tests indicated 90 m as the safe spacing between two skimming wells. The tracer studies revealed that radial arm contributed 80% of pumped water while the remaining 20 % came from the bottom of the 'Nell. Multiple filter point systems (Fig. 1b), tested at a number of sites in these districts. indicated limited scope tor skimming due to insuffiCIent water in the flow domain. The improved Doruvu technology was found to increase the farmers' income by 25 to 40% due to enhanced crop )field but is extremely costly at about Rs. 50,0001 for two ann wells. Horizontal drilling of radial drains needs to be standardized for sandy soils to reduce the cost of installation of these structures.

Fig. 3. Installation of radial collector type sKimming well at Bapat'a CAP)

199

Chemical Changes & Nutnent Transformation In SodlclPoor Quality Water Irrigated SOils

/ (c) Groun~ater recharge In saline groundwater regions of GuJarat and Tamil Nadu

, , ' Under NATP project, groundwater recharge through farm and percolatIon ponds was evaluated lor

saline groundwater regIons In the rocky regions of GUjarat and Tamil Nadu The sIte Khapat In Porbander distnct of GUlarat (annual raInfall" 500 mm) has 1 0-1.5 m th~ck clayey SOIl followed by sedImentary fractured aquIfers Two dug wells at thIS site were recharged separately uSIng runoff from raInfall harvested In two farm ponds after _filtrabon through a deSIgned sand-gravel-boulder filter The concept IS displayed In FIg 4 The enhanced _recharge dunng 2004 resulted in Improved groundwater aV3llaMty as well as ~Ignlficant reductIon In sallMy of waters (from 95 to 09 dSm-1 and 37 to 1.2 dSm", respectIvely) In two wells SImilarly the recharge potenllal of percolation ponds (of about 3000 m' capacIty) constructed In shallow clayey SOils underlaIn by Igneous fractured rocks uSIng harvesled runoff was evaluated at two sItes (Aruppukottal, Virudhunagar dlstnct, Fig 4; Ramanathapuram, Ramanathpuram dlstnct) In TamIl Nadu At Aruppukottal, studIes on rechargIng an abandoned open well uSIng filtered excess runoff proVIded very promIsing results '" terms of Improvement In ava,lab,ltty and quality of well water.

The research output of NATP project IS pavIng the way for commIssIoning of larger groundwater skImming projects In coastal sandy naglons of Andhra Pradesh and TamIl Nadu and artIfiCIal recharge projects In Haryana, GUjarai and TamIl Nadu Further detaIls on the features ancl performance evaluation of the above and a few addItIonal groundwater skimmIng and recharge structures can be found In NATP (2005)

t-. os.

,I"l;", F\_ _'. ~~::-:_----'J" I"

", ' , . _'"

roND

': " " .,

, " . " • ,. J ~

FIG. GROUND WATER RECHARGE PO"!D AND SANO FILTER FOR WELL RECHARGE

F,g" Rainwater harvesbng and groundwater recharge model at RRS. Aruppukotial (Tamil Nadu)

Salient ObservaUons and Emerging Issues

1 RadIal collector well type structures have conSIderable scope In coastal sandy SOIls for skImming of fresh water from thin sandy zones The cost 01 the system can be considerably reduced by standardiZing the technIques for honzontal dnlling of drainS In sandy SOIls

2 The performance of skimmIng structures In coastal sandy SOIls is SIgnIficantly Influenced by the depth and nature (coarse/fine) of sand Govt may proVIde subSIdy for Installabon of these structures In the Identified areas Multiple well pOint systems have reslncted scope for skImmIng In coastal sandy SOIls due to Ilmded depth of sand column

3 IndiVIdual farmer onented recharging schemes are SOCIally viable and have betler chance of success and sustenance than the commuOlty!govt sponsored and maintained large recharge systems

4 . Jncorporatlon of small and Jess costly recharge filters in the existIng or abandoned dug wells! tubewells can contribute to SIgnificantly enhance groundwater recharge. DeSIgn of alternate filters for artifiCIal recharge structures needs to be tested for efficacy as well as economy

200


Projoct on GroundWater Reeharge In North West India

The sustainability of agncullure In north-weslem states of Punjab, Haryana and Uttar Pradesh,lsl Ihreatened due to an alanning declining rate of water table, Increasing pumping cost and related environmenlallmpacts The water prOductivity of Widely prevalent nre-wheat croPPing system In these states' IS decllMing Over the past decade, there has been an annual decilne of 2040 em In all fresh groundwater regions In Haryana The fanners are forced to u'se deep submersible pumps In place of centnfugal pumps resulting In extra expenditure and power consumption CSSRI has Implemented a number of ,nd,v,dual fanner based ground waler recharge structures Including vertical shafts and,lnexpenslve recharge filters to eXisting or abandoned tubewells In fanners' fields , . ' 1

The efforts on enhancement of groundwater recharge and water productiVity based on multiple use, of water, pond renovation, adophon of conservabon agncu~ure and crop dlverslficabon are being strengthened In major way In fanners' fields through a MIMIStry of Water Resources (GOI) funded project In 100 Villages In

the state of Haryana (50 srtes), Punjab (15 slles), Uttar Pradesh (10 sites) and GUjarat (25 sites) In the first 6 months, 25 sites have been Identified In' Kamal, Jlnd and Kalthal districts of Haryana based on reconnaissance ,surveys and Interaction With farmers, 10caLtubeweil techMiCIans and NGOs Out of these, recharge shafts (Fig 5) are being Installed at 16 srtes which consist of bore hole of 45 em <I> and varying depths (depending on lithology) filled With gravel pack of 1,5 - 20 em diameter (~) to carry fittered recharge, water to favourable sandy zones To safeguard against clogging, the surface runoff from rainfall or excess canal water IS first passed through a graded filter consisting on coarse sand and smaller size gravel In a chamber_of 1 65 m x_1 65 m x 18m size The borehole of the recharge shaft was Installed In the middle of the filtenng uMil To prolong the effectiveness of the shaft agalns~ clogging from subsurface layers, a high pressure pvc pipe of 12 5 em $, slotted at sandy zones, IS prOVided in the middle of the hole for compressed air Circulation after a couple of years

The recharge shaft IS very Simple In deSign and easy to construct and maintain and serves the sole pUipose of groundwater recharge J?fter every major storm, the filtered sediments collected on the surface of coarse sand need to be cleaned and replaced With addLtlonal sand It can be constructed at convenient locatons by indiVidual fanners, preferably In depressional areas where runoff of surrounding areas collects The cost of the recharge shaft can va,y from Rs 35,000- 40,000/- for 45 em ~ shafts of 3040 m depth , ,

----- Bore hoI. (46 em +l

12 Ii em • PVC slotted pipe (10kg/cma

pre.$Surel rorcomprassed air circulation

Fig 5 DeSign of recharge shaft for selected sites (depth vanes from site to site)

Similarly caVity tubewell type reCharge structures haVing prOViSion for filtrabon of runoff have been proposed for 6 sites while Integrated fanning systems InvolVing fann ponds for agnculturel vegetablesihorllcultureifish culture have been proposed In marginally saline groundwater regions at 3 sites In Haryana A detailed questionnaire for collection of relevant Information on SOil, hydro-geology, crop production and farmers' Incomes has been prepared to evaluate the Impact of Introduced Interventions

201

Chemical Changes & Nutrient Transformation In SodlcJPoor Quality Water Imgated SOils

/ Simlart studies are being undertaken at C:SSRI Regional Research Stalion, Bharuch In state of GUJarat, where 11 sites have, been identified so far for ,ntroduc!Jon of groundwater recharge, Integrated farming system and pond renovation mtervenllOns

'/ Concluding Remarks

Overdraft and excessive pumpll1g In several coastal and Imgated areas in semi-and regions of India IS causing groundwater salinization and I~fenor pumped water quality due to upcomng of saline water from the lower saline zones Under such conditiOns, It is Imperative to selectively skim thin layers of fresh water accumulated Over the saline groundwater through specially deSigned skimming structures and by enhanCing groundwater recharge Field appraisal elf new technologies for skimming and recharging of fresh water In sahne groundwater regions of Haryana, Andhra Pradesh, GUlarat and Tamil Nadu IS' carned out A clear perception emerging out of these studies IS that groundwater recharge IS extremely Important In saline

'groundwater regions, either alone Of In combination WIth skimming systems BeSides, augmenting groundwater resources, recharge can also help In Improving groundwater quality. Further IndIVIdual farmer based skimming and recharging structures are social Viability and have better chance of success and sustenance than the communltyl govt operated'and maintained systems Such structures should be promoted In big way In the country to arrest the declining of water table as well as to enhance the water produc!Jvlty

Bibliography

HooJa, R , Shnnlvas, V, Sharma, G, 1995 Wate~ogglng and salinity problems In IGNP, Rajasthan In Rao, K V G K, Agarwal, M C, Slng~, O,P, Oosterbaan, R J (Ed) Reclamation and Management of Wate~ogged Saline SOils, NlltlonaJ Seminar Proc CSSRI, Kamal and HAU, Hissar (IndoNethe~ands Collaborative ProJect) 141-159

Kamra, S K , Anchal, V., Aswal, S , and Lal, K 2006 Groundwater recharge through caVity wells In saline groundwater regions In Rech~rge systems for protecting and enhanCing groundwater resources Proc 5" International Symposium on Management of AqUifer Recharge (ISMAR5), Be~ln (Germany), June 11- 16, 2005, IHP:- VI Series on Groundwater No 13,699- 704

Kumar, R and Singh, J 1995 Drainage systems for groundwater management In Rao, K V G K, Agarwal, M C, Singh, 0 P, Oosterbaan, R J (Ed) Redamalion and Management of Wate~ogged Saline SOIls, Nallonal Seminar Proceedings CSSRI, Kamal and HAU, Hlssaf (Indo- Netherlands Collaborative Project) 50- 62

Mazhar Saeed, M , Ashraf, M and Asgh~r, M N (2003). Hydraulic and hydro- salinity behavour of skimming wellS under different pumping regimes Agncultural Water ManagemBnt, 61(3), 163-177

Nabonal Agricultural Technology Project (2005) Techn%gles for Sklmmmg and Rechargmg Fresh Water In Salme Groundwater RegIons, Final Progress Report, Central SOil Salinity Research Insbtute, Kamal (Haryana), India

Ragu,Babu, M, Prasad, P R K , Subbalah, G.v., Khan, M and Mlnhas, P S , 1999 Subsurface fresh skimming system Improved doruvu technology, Bullelln No 1/99, 19p. Central SOil Salinity Research Institute, Kamal, 39 pp (+125 pages appendices)

Raghu Babu, M, RaJendra Prasad, Band Snkanth, I (2004) Subsurface sklmmmg fechmques for coastal sandy Salls NATP Bulletin No 1/2004, Salme Water Scheme, Bapatla (Andhra Pradesh), India

Shakya, S K (2002) Agricultural dramagiJ under actual farmmg condItIons on watershed baSIS Department of SOil and Water Englneenng, Punjab Agncultural UnlvelSity, Ludhlana (PunJab), India

Sufi, A B: Lalif, M, Skogerboe, G V 1998 Simulating sklmml~g well techniques for sustained explOitation of groundwater Irngallon and Drainage Systems 12 203- 226

202

Blodrainage for Combating Waterlogging and Salinity

J.e. Dagar, Jeet Ram' and Gurbachan Singh DIVIS/on of SO/I and Crop Management I Central SOIl Salinity Research Institute, Kamal-132001. Haryana , Haryana Forest Department. Panchkula - 134109

, Introduction

Irrigated agricUlture covenng about 17% of the total cropped area of the world contnbutes 40% of the total food producbon (INCID 2003) In India also. ·about one-third area under Irngabon produces two-third 'of the food grains RecogniZing the fact that Imgatlon IS an essential Input for Increasing and sustaining the agncultural production, partJcula~y In and and semi-and regions. large Investments have been made wo~d over dunng trie last 50 years for Its expansion In thiS penod, the net Irngabon potential has Increased from 95 mllhon hectare (Mha) to 260 Mha In the world and from 22 5 Mha to 57 Mha In India (INCID 2003) ExpanSion of Imgabon In the'past prOVided large dividends In terms of Increased food production and nutntlonal secunty However, Introduction of canallmgatlon In and and' semi arid regions WIthout provIsion of adequate'dralnage causes nse In ground water table leading to waterloggmg and secondalY sallO/sabon PresenUy, about onethird of the world's Inrigated area faces the threat of water logging, about 60 Mha IS already water logged and 20Mha IS salt affected (Heuperman et a/. 2002) As per estimate of Mlmstry of Water Resources, In canal command areas of the country 246 Mha is waterlogged and 330 Mha saa affected (MOWR 1991) The problem IS ve,1Y serious In and 'and semi and regions where under ground water IS of poor quahty The problems of water logging and sallmty can be effectively tackled by conventional sub-surface drainage systems provided these are properly deSigned, Installed, maintained and operated, But these are more expensive and sometimes cause environmental problems The hmltatlons and shortcomings of the conventional engineering based drainage systems call for alternative approaches to keep the agriculture sustainable over the long term The alternative approaches must be effective, affordable, SOCially acceptable, enVIronment !nendly, sustainable and upgrade natural resources of land and water. Blodralnage compnslng of deep rooted veg!9tatlon With high rate of transplrabOn seems the promiSing option,

Cone~pt of Biodralnage

Blodralnage may be defined as 'pumpmg of excess soli water uSing b,a-energy through deep-rooted vegetatIOn With high rate of transpiration' The blodralnage system conSists of fast groWing tree speCies, which absorb water from the capillary fnnge located above the ground water table, The absorbed water IS translocated to different parts of plants and finally more than 98% of the absorbed water IS transpired Into the atmosphere mainly through the stomata ThiS combined process of absorption, translocation and transpiration of excess ground water Into the atmosphere by the deep rooted vegetation conceptualizes bl(Hirainage (Fig, 1)

Fig 1.,Conoept I)f blOralnage

Fast growing Eucalyptus species like known for luxunous water consumption under excess' sOil mOisture condition are SUitable for blodralnage These species can be planted In blocks In the form of farm forestry or along the field boundary In the fonm of agroforestry Other SUitable species for block plantabons are Casuanna glauca, Termma"a BIJUna, Pongamla pmnata and Syzyg/Um cummll etc

Chemical Changes & Nutnent Transformation In SodlclPoor QualIty Water Imgated SOIls

, /

Merits of Blod~lnage over Conventional Drainage systems

The merits of blodralnage technique over the convenbonal englneenng based sub-surface drainage systems afe

• Relabvely less costly to .alse biodralnage plantabons • No maintenance cost from 3'" year onward

'\ • No operabonal cost, as plants use their blo-energyin draining out the excess ground water Into

atmosphere "-• Increase In worth WIth age Instead of depreciation • No need of any drainage outfall and disposal of drainage effluent • No environmental problem, as the plants drain out filtered fresh water Into the atm_l?sphere • In- Situ solution of the problem of water logging and salinity "( • Preventive as well as curative system for waterlogging and salinity • Combined dralnage- cum - disposal system ' • Moderates surrounding temperature by transpiration and also frost, cold and heat wave Impacts • Helps ,In carbon sequestrabon and carbon credits • M~lgates the problem of dlmate change and contnbutes to Increased forest cover • Punfies the atmosphere by absorbing Co, and releaSing 02 • Acts as Wind break and shelter belts In agroforestry system • Provides higher Income to the farmer due to the production of food, fodder, fuel wood and small timber • ProVldes assured parbClpabon as blodralnage plantabons on farmer's field belong to the ,nd,v,dual

farmers

Where'to Apply?

Thornburn and George (1999) observed that the evaporation from the 5011 takes place up to a depth of 4 m (Fig 2) Therefore, we must plan to keep this 4 m soil depth free from waterlogging to minimize the process of secondary sallnlsabon of SOils and to sustain the crop productlv~ In canal command areas located In and and semi-and regions, For thiS, we need fast growing trees like Eucalyptus having therr root system penetrabng at least up to thiS depth The blo-dralnage technique could be applied In two oontexts VIZ 'curative (for water waterlogged areas) and prevenbve (for potenllally waterlogg~d areas),

.600:'

'500'~'

400

300

c::o ~ 200 , :;-, ..... ~.: ·'00

~

o

o 2 3 4 5

'Water table'deptb,(nl)

Fig 2 Relationship between evaporation and water table depth In different 5011 types

As per Ground Water Cell, Department of Agncu~ure, Panchkula, Hartana; In Haryana, the waterlogged area (ground water table WIthin 3 m) has been reported to be 322 45 thousand ha (7 3%) of total geographical area) dunng June 2007 and 444 thousand ha (100%) In October 2007 Under such precanous condlbons, failure to take appropnate remedial measures, the lITIgation benefits will be negated It Will result In displacement of labour from agnculture sector, Increased flow of wall< force from VIllages to Clbes, WIdening Income dlspantles and dedlne In sustalnability of secondary and tertiary sectors It WIll also cause dedlne In agricultural production, III effects on Gross Domesllc Production GOP) and decline In export potential of Important crops and Increase In Import bill The potential waterlogged area haVing ground water table between 3 to 10 m was 17 million ha (3887%) dUring June and 161 million ha (3637%) In October 2007 ThiS area al~o reqUlr~_s urgent a!\enbon of policy makers otherwise thiS sizabfe agncultural land WIll convert Into wet desert

Blodralnage IS a Viable altemate opbon for the reclamabon and management of waterlogged saline SOils In canal command areas Situations where conventional surface and sub-surface drainage IS not feaSible

204

Blodrslnage for Combatlng Wat-e00g91ng and Sallmty

and IS costly, blodralnage alone and In combination With drainage should be practiced, ThiS approach of integrabng trees like Eucalyptus having high transpiration rate as a part of farming In nSlng ground water areas In canal commands has tremendous scope to reclaim land, Improve productIVIty, Increase forest cover, eam camon credit for farmers and clean environment Now there IS a strong case for developmg policy gUidelines for promotion of blodralnage for generating livelihood secunty and poverty alleViation of farmers In Imgated arid and semi-and regions

Case Studios

Inferences of studies carried out by Jeet Ram et al (2007) pertaining to the effect of two 18 years old Eucalyptus tere/Jcorms planta~ons s~uated 350 m apart on the shallow ground water table of semi-and region haVing allUVial sandy loam 5011 revealed thai "

• Throughout the study, the ground water table undemeath the plantations remained lower than the ground water table underneath the adjacent fields Without plantation

I .- The average ground water table undemeath the plantations was 091 m lower than the average natural

(control) ground water table In the adjacent fields

.- The ground-~ater table underneath the plantations was-affected up to a maximum depth of 5 63 m below the ground level -

• The spatial extent of lowenng of ground water tabte underneath the adjacent fields was up to a distance of more than 730 m from the edge of a plantatIOn

• The drawdown In the ground water table developed due to the effect of a plantation was Similar to the cone of depreSSion of a pumping welt

• The draWdown in the ground water table developed due to the JOint effect of two plantations was Similar to the combined cone of depreSSion of two pumping wells,

• The drawdown curve_ of ground water table underneath the fieids located between two plantations was 'almost fiat Indlcabng Uniform lo~nng of ground water table '-

• Sa~ has accumulated neither In the ground water table nor In the capillary fringe above the ground water table as there was no co-relation between the salinity and ground water table

• Eucalyptus trees were drawi~g \"'lter from the ground water table as th~ roots have reached," the zone of capillary fnnge

Thus, In shallow ground water table areas of semi-arid region haVing allUVial sandy loam SOil, the plantabons of E fereficomis act as blo-pumps and parallel stnp plantabons of thiS speCies should be raised for the Uniform drawdown of shallow ground water table Further stUdies at Puthl Research Farm In Hlsar dlstnct revealed that, the ground water table undemeath the plantabon stnps was lower than the adjacent fields (Figure 3) DUring April, 2005, when trees were two years and three months old, the average draw down under plantabon was 18 em The average draw down dunng the period: Apnl 2005 to April 2008 due, to plantation was 85 em The spatial extent of lowenng of ground water table In the adjacent fields was beyond a distance of 66 m from the edge of outer strips

]:'

Ob •• rvuWa

• • WellNo 1 ~ ,1

ooo.;=~~--c~~~~~~~~ __ -~ __ ~~ __ ~ ___ ~~, "~ :~,:-~_APriL~ZXl!5:"": ) \~"'pril-2lll8

, " "~I:

" ' ~, fp " i

..(I_jQ "

x . ' " " . •

,.~-

.~~ ; , ~,

j~ , '. ~l' .i: r>" t:

" ~'

Figure 3. Trend of ground water table under plantations and adjacent fields

205

Chemical Changes & Nutnent Transformallon In SodlclPoor QUoIillty Water Imgated Salls

/ , Pumping from a well In a water table aquifer (u~confined aquifer) develops a cone of depression In

the ground water table by lowenng the ground water table near the well Further, If the cones of depression of two puinPI~g wells ove~ap, then It IS said to be well Interference It these wells are operated 'simultaneouSly, they develop a combined cone at depression In PUthl research plot, the shape at drawdown curves of ground water table was Similar to the combined cone of depreSSion of 4 pumping wells worKing simultaneously for a long duration Farmers harvested a total wood biomass (bmber ,suitable for poleslbaliles and pulp wood) of 36 t ha ,1 from 5 year and 4 months old trees haVing average girth of 56 cm, average height 18 m, total volume 47 m'l ha and mean annual Increment of 8 7 m'l hal year Benefil-<:ost ratio at the discount rate of 12% of first rotabon (5 years and 4 months) of strlp-plantatlons was 3 1 against 1 3,1 of agricultural crops In Haryana and It would be many-fold tor next 3 to 4 rotations due to negligible cost of maintenance of copplced Eucalyptus

Further experiments conducted In CSSRI (CSSRI Annual Report 2005-07) indicated that the average transpiration rates In three years old plantations mOnitored dunng seven months from May to December 2003 were found to be 29,5, 198 and 144 liters per day per plant '" low, optimum and high denSIties, respecbvely which comes to be 189, 339, 945 mm dunng thiS penod In August to December 2005 the average transpiration values Increased to 56 5, 307 and 189 liters per day per plant In i'Elspectlve categones DUring September 2006 the transpiration rate was 60, 49 and 40 liters per day per plant In low, optimum and high plantallon denSity, respectively Atter SIX years, annual total consumptive use of water was higher 2200 mm under high denSIty and 1300 mm In low denSIty plantation, which IS qUite reasonable,amount of waler But to achreve the higher dlsposalnoadlng rate of waste water we have'to compromise With tlmberlWood value Earlier Chhabra and Thakur (1998) conducted expenments for 4 years by Installing a senes of Iyslmelers made from RCC hume PipeS With diameter of 1 2m and depth of 25m PVC perforated pipes, covered With nylon gauze were inserted In the Iyslmeters at depth of 1 0, 1 5 and 20m, respecbvely for supply of water of desired salinity from a plaslic reservoir Each iyslmeter was planted wrth a three month old sapling of Eucalyptus terotlcomls or Bambusa arundinaCIJ8 The results showed that the blodrainage ,was highest when the ground water salinity was lowest Its magnitude decreased With Increase In salinity of the ground water These studies however, Indicated much higher rate of transpiration In terms of bladralnage "capacity In mm as Compared to our results ,n above--menlloned expenment '

Farmers' Attitude and Recommendations

Initially, the farmers of Puth, Village were not Willing to have tree plantabon on their farm lands because of the pnonty on the production of food grains and fodder But, atter obserVing the growth and sUlVlVal of parallel stnp plantations of clonal E. tereticomls and expected higher finanCial returns from wood production, almost all the farmers of this Village as well as the fanmers of other Villages have been approaching (Figure 27) the Forest Department (Govt of Haryana) to develop Similar plantatJons on their farm lands As" a result, 2500 ha water logged area on farmers' fields has been brought under blodralnage stnp plantations dunng 2008-O9 Properly deSigned parallel StriP plantations of E teretlcomls should be raised for the uniform reclamation of waterlogged areas of semi-arid regions having allUVial sandy loam 50115 Blcidramage plantabons must also be raised on potenllal waterlogged areas, (speCifically where ground water level)s 3-6 m) to prevent their conversion Into wet desert Sewage water can safely be used for wood production (alslng Eucalyptus trees Instead of uSing such waters for food and fodder crops PoliCY gUidelines for promotion of blodralnage for generating livelihood security, earning carbon credit and povertY alleViation of farmers In iITIgated and and semi-and regions should be formulated

Bibliography

Chhabra, R and Thakur, N P 1998 lyslmeter stUdy on thE> use of biodralnage to control waterlogging and seoondary salinisabon In (canal) lITIgated andlseml-and enVironment Imgatlon and Drainage Syslems 12' 265-88 •

CSSRI, 2004-07' CSSRI Annual Reports Central 5011 Salinity Research Institute, Kamal (India)

Heuperman, A F, Kapoor, A Sand Denecl<e, H W 2002 Blodramage-PnnClpals, Expenences and Applications Knowledge SyntheSIS Report No 6 International Program for Technology & Research In IrngaliOn & Drainage, IPTRID Secretanat, FAO, Rome, pp79,

INCID, 2003 Blodramage Status m India and other countries - Indian National Committee on Imgabon and Drainage (INCID), New Deihl, India, pp 40

Jeet Ram, Garg, V K, Toky, ° p, Mmhas, P S, Tomar, 0, S, Dagar, J C and Kamra, S K 2007 Blodralnage potental of Eucalyptus tereliCornis for reclamation of shallow water table areas In north-west India Agroforestry Systems 69 147-$5 '

MOWR 1991 MiniStry of Water Resources, Govt of India Report of the wor1<1ng group on waterlogging, SOIl ,salinity and alkalinity (mu,;eograph)

Thorburn PJ and George RJ 1999 Intenm gUidelines for' re-vegetatlng areas with shallow saline water tables Agroforestry over shallow water tables Water and Salinity Issues In Agroforestry No 4 RIRDC Publication No 99/36 RIRDC Project No WS 967-7 pp 13

206

Utilization of Salt·Affected Soils and Saline Water for Agroforestry

J.e. Dagat; Gurbachan Singh and O. S. Toma; D,v,s,on of SOil and Crop Management I • Reltred Pnnclpal SCientist .

Central SOil Salmlty Research Institute, Kernal· ,132001, Hal'/ana

Introduction

Vast tracts of and and semi-and land In the world including India lie barren because the 'vegeta~on suffers due to excessive salts In SOil and water deficits assoCIated With scanty ,and uneven dlstnbutlon of rainfall and long dry spells following rainY season Most of these lands usually lack water supplies for supplemental Imgatlon, except for the ground water that IS often very, deep, saline and aquifers are' low Yielding The'rehabilitatlon of these degraded lands IS limited to possibilities' a) SUitable planting techniques for alkali and saline SOils and Irngatlon With saline waters, b) th~ exploitation of plants native to and and saline enVIronments and c) deVISing effiCient systems for uSing limited saline water resources either by preventing Its unproducbve evaporation loss -to the dry environment or drainage below rooting zone 'In the past, efforts towards ubl,zatlon of salty lands and saline waters mainly aimed at enhanCIng the production of annual crops and high value frUit trees as the nobon of Imgated forestry plantations has been conSidered to be less attractive !lfforestatlon 'programmes, thus generally result In poor stands and tree growth mainly due to reluctance of foresters to use saline waters Dunng past two decades, CSSRI has developed planbng techniques for salty lands and use of saline waters for establishment of seedlings and evaluated several eJ(obc and mdlgenous forest and fruit tree speCIes for rehabll~atlon of these degraded lands (~Inhas at a/ 1998, Dagar at a/ 2001; T~mar ot 81 2003, Singh and Dagar 2005) Some of these results have been mentioned here In brief

Suitable Planting Methods for Salt·Affected Lands

In order to rehabilitate salt affecied"ands, appropnate tree planting techniques and chOiceS of tree species are very crUCial fOr reducing mortality and consequenUy for Improvement In the Imllal establishment of saplings Since alkaline and saline SOils differ from each other, methods of workmg the Salls Will also be different For example, In alkali Salls a hard kankar layer of calcium carbonate IS generally found at a depth of about 1 25 to 1.5 m ThiS layer acts as a bamer for root penetration The layer, therefore, has to be broken first to allow proper, development of roots However, saline SOils do not reqUire such preparalion, as they do not have any such bamers These reqUire special techniques of afforestabon so that salt contents In root zone are minimized We must, therefore, diagnose the 50115 first and then choose the method accordingly

Plantation of alkali lands

The Ideal planting method for alkali solis should prOVide a favorable SOIl environment such as by breaking the hard kankar layer, replacement of exchangeable Sodium and add~lonal nutntlon 01 tree speCIes for optlffium root growth Keeping this view In mind, plt-auger-hole technique of tree plantabon has been developed by the sClenllsts of CSSRI In thiS planting method, auger-holes 0115-20 em dIameter are made to pierce the hard kankar layer up to 150'-180 em deep, With the help of a tractor-mounted auger aller digging Pits of 35 em x 35 em Auger holes are refilled With onglnal SOil, 3 kg gypsum, 6 kg FYM, 10 g ZnSO., and small quanbty of InsectiCIde to take care of termites Sodlclty tolerant tree saplings of 6·9 months old are planted In the refilled pit-auger holes followed by Irngabon With buckets Two to three Irrlgabons are Immedl8tely needed for establishment of saplln9s ThIS method enables the plant roots to grow at a faster rate towards deeper 5011 layers where suffiCient mOisture and nutnents are available In alkali SOils The kankar layer, which creates hlndraru::e In the development of plant roots, IS broken In the process of making holes The post-auger hole planbng technique was furlher refined by prOViding sub-surface plantmg and furrow Irrigation method (SPFIM) Th~ Pits of 45 em in sIZe are prepared manually and the p,t-holes beyond the kankar layer are dug with the augers (15-20 em diameter) and then these Pits are connected by Irngatlon furrow

Plantation of saline lands

Central SOil Salinity Research Instllute, Kamal has been conducting several long-term expenments for developing afforestabon technologies on highly saline wate~ogged 50115 The results suggested that furrow Planting Improved the survival and growth of tree species as compared to ndge planllng method BeSides reducing the water applicatIOn oasis, rt Improves umfolTTlity In water application and helps in creating a favorable zone of low salinity below the Sill of the furrow through downward and lateral fiuxes of water making salts move away from the furrow (root zone) espeCially when low salinity water IS used Creation of such niches favored the establishment of young seedlings of trees Moreover, such a system seems to be more \liable from practical lIIewpolnt of undertaking large-scale plantations of trees

Chemical Changes & ,Nutnent Transformation In SodldPoor Quality Water Imgated SOlis

, Suitable Forest Tree Species

/ Alkali lands

The choice of speCies for alkail lands IS determined by the ability of tree SPecies to survive and withstand adverse conditions of excess SodlClty Tolerant. tree speCies overcome hl!jh concentrations of SodlClty by different regulatory mechanisms There are, very few Wlld plant species, which are able to grow on highly sodlc Salls (pH >10) On the basIs of expenmenls conducted on highly alkall,soll ProSOPIS jullflora, Acacia mlotlca, Casuanna eqUisetrfolla, Tamanx articulate, Eucalyptus teret,com/s and parklnsoma aculeata demonstrated a higher toleranca The biomass of 7 years old 'T articulata, A mlotlca and p, jullflora was 97 3, 696 and 513 t ha", respectively. Singh at al (2008) reported 1922 to 565 the" air-dry biomass from different species raised on high sodlc SOil (Table 1) The data on sOir ameilorabon Indicated that tree plantaTIons reduca 5011 pH, ESP and Improve organic carbon status P jullflara helped In redUCing pH and ESP and Increasing organic carbon maximum as compared to 'other species (Table 2)

Table 1 Above-ground biomass (t ha-') of different SpeCies grown on highly sod,c SOil

Tree species Stem Branch Leaf Total

Tenninalla arjuna 2376 10.70 713 4162 Azadm'lchta mdlca 11.17 621 184 1922 ProsOPIS /uldlora 2773 26.60 217 5650 Pongaml8 pmnata 905 1445 310 2660 Casuanna equlsetlfolla 2860 915 435 4210 Prosopis alba '1470 1110 1.95 2'175 AcacIa mlotlca 2215 2614 246 5075 Eucalyptus taref/comls ,22.40 527 210 '3177 Ptthecelloblum dulce 23.50 661 1~ 3225 CasslB starnes 1430 565 1 70 2165 LSD (p=O 05) 243 463 121 542

Table 2 Ameliorative effects of different species after 10 years

Tree specIes pH EG,(dS m·l) OC (9 kg") ESP Bulk density (I m") (1 2)

Inlbal 106 143 06 65-92 157 Termmalla arjuna 98 039 35 60 147 Azadlrechta indIca 98 033 27 56 148 ProsOPIS jullflora 95 030 43 51 132 Pongamla pinnata 97 061 40 54. 136 Casuanna eqUisellfolla 100 126 36 71 1 21 ProSOPIS alba 99 063 33 64 1 37 Acacia ni/ollca 97 077 35 56 129 Eucalyptus teret'com,s 98 086 24 62 1.36 P,lhecellob,um dulc9 99 070 27 65 125 CassIa slamea 10 a 069 26 71 146 LSD (p=O 05) 026 031 16 3.67· 005

Sourca Songh af al (2008)

For saline tands

The main problems 01 these SOIls are htgh water table, high salimty, Impeded draonage and poor SOli aerallon. Only those tree speCIes can be raised, which tolerate these stresses simultaneously It has been expenenced that the tree speCIes which transpire less water are more sullable for SUch Salls than those 'transpire high amount of water. In general. the plantabons of fuel wood are better for saline waterlogged soils than umber wood species More than 40 tree speCies of and and semi - and areas were eValuated at research farm, Sampla Based upon penod,cal observallons woody speCIes like AcaCia fameslana, Parkmsama aculeata and ProSOPIS jullflora were rated the most tolerant to water10gged salinity and could be grown satlsfactonly on SOils' WIth salinity levels up to 50 dS j m In thelf root transmission zone Tree species like

206

Utilization of Salt-affected SOlis and Saline ~ater for Agroforestry

Acacia nilo/ica, A tonllS, Casuanna glauca, C. obesa and C eqUisabfolia could grow on sites with ECe varying from 10 - 25 dS m·' It was concluded that the Wi!te~ogged saline conditions affected the survival and growth of tree speaes used for afforestation the most because the salt accumulation near the roollng zone was directly attnbU1ed to ground water fluctuations and the underground water was also saline The biomass of P lullflora and C. glauca was the highest (98 and 96 t ha·', respectively) followed by A. mlotlca (52 - 67 t ha· ') and A loml/s (41 t ha·') when planted w~h sub surface or furrow techniques (Table 3) proving that these are the most sUitable speCIes for salme waterlogged salls (Tomar at 81 1998)

/

~ , ' Table 3 Biomass estimation of trees after 9 yearS of planting on saline 50115

Tree speaes Method of sOil salinity ECe range Range of water Estimated planting , at 0 -120 em depth table salinity EC bIomass

(dS m·') (dS m·') (t ha·')

AcaCia Mollce! Subsurface 106 - 25 3 27 - 33 52 Furrow 11,1-210 17 - 27 67

A tottilis Subsurface 68-281 12 -33 41 Ridge 197-291 12 -33 6

Eucalyptus t;,!maldulenSis Furrow 10.0-179 10 - 35 28 PrOSOPIS juldlora Subsurface 10.3 - 240 32-36 98

Ridge 235 - 57.5 32 - 36 65 Casuanna aquisallfolla Furrow 56-207 10 - 31 28 C. glauca Furrow 65-339 12 -19 96 Cobesa Furrow 90- 195 12 - 19 38 Laucaana leucocephala Subsurface 69- 23 9 10 - 25 30 Tamanxsp Furrow 82-2t.3 10 - 32 12

Source Tomar et al. (1998)

Raising Trees Irrlgating with Saline Water

Field expenments were conducted In calcareous 50115 at air Reserved Forest, Hlsar The expenmental SIte represented semi-and monsoonal climate With annual rainfall of 430 mm and most 01 which (70-80%) occurs dunng July-September Potential evapc>-1ransp,ratlon generally exceeds rainfall The experimental SOil was sandy loam In texture and highly calcareous In nature (CaCOJ 1 B to 15 0 %) The transplanting of 6 months old saplings of 31 tree speaes was done qunng August, 1991 In auger-holes made ,n the furrows Spacmg between the furrows was kept at 25m and plant to plant 20m The V - shaped furrows (20 em deep and 60 em Wide at the~top) were made With the help of tractor dnven furrow maker Saplings were irngated With saline water (EC/w B 5-10 dS m·') dunng the early establishment stage The performance rating of the evaluated species IS summanzed In Table-4

Table 4 Performance rabngs of tree species With saline water imgatlon (EClw 10 dS m·')

Performance rating

Very promising

PromIsing Poor

Tree species

Azadlrachta mdlca, AcaCia mloltcB, A tomlls, A famaslana, Cassia Slamea, Eucalyptus teretlcomis, Feronia IImonla, ProSOPIS luflflora, P cmerana, Plthecel/ob/Um dulce, Salvadora perslca, S oleoidas, Tamarix arilculata Nella azedarach. CasSIa fistula, Zlzlphus mauntiana Acacia auncultforrnis, Bauhmla vanegata, CassIa glauca, C lavan/ca, Crescentla alata, Pongamia pmnata, Syzyglum cumlni, Tecomel/a undulata

During saline Im~atlon the SOil salinity tended to nse dunng the penod of saline Irngation It ranged between 5 &-10 4 dS m· In 0-1 2m SOil, with an average of 686 dS m·' after one year FollOWing the cessation ollmgabon, salt got redistributed In the SOil With a major component being got pushed downward With the monsoon rains. Thus, salinity was reduced to 5 Q-6 a dS m·' In surface 12m SOil after 2-5 years of dlscontmUing Imgallon (5 and 8 years after transplanting). ThiS was as a consequence of seasonal concentrabon of rainfall dunng monsoons and some episodiC events of rainfall dUring thiS penod. Moreover, It has earlier been reported With this furrow plantmg method that the most 01 rainwater concentrates In furrows as a result of runoff from the Inter rem area and gets Infiltrated from thiS zone only Thus, It helps to push the salts beyond the roobng medIum of transplanted tree saplings Litter fall from the most of tree species resulted In an Improvement of organic carnon content of the underlYing SOils The prominent species where COnSiderable enhancements in organic carnon contents (> a 4 %) were observed were AcaCIa tOrillis, CassIa

209

Chemical Changes & Nutnent Transformation In Sodl~oor Quahty Water Imgated SOils

/ , Siamea, and ProSOPIS luldlora The effects of such speC/es were vividly more In the upper 0-30 cm layer as compared to the lower layers

/ Evaluation and Identification of Promising Forage Grasses

A field experiment was conducted during 1993-1997 to evaluate the suitability of nine forage grasses to saline Imgation (EClw 85-100 dS m") and optimIZe its schedule, The average forage Yield was found to be 065 t ha" in grazed condition and 2 4t ha" when protected but when brought under judicIouS saline Imganon (EClw 8-10 dS m''), the grasses raised on the same land could produce from 4 4 to 16 9 t ha' dry forage from different grasses (Table 5) Pamcum laevtfoltum produced maximum forage biomass under all the treatments followed by P maXimum Even In the lean penod (when people are forced to lead nomadiC life along with their herds of cattle) sufficient forage was available from all these perennial grasses Scheduling the saline Imgatlon at DlwlCPE rallO of 04, improved the yields by about 20% while no further Improvement was 'obtained With enhanced sahne "ngation supplies. ,

Table 5 Average (3 years) 'dry matter Yield (t ha') of different grasses Imgated With saline (10 dS m") water

Grass species , Imgatlon WIth saline water With DlwlCPE

CW 02 04 08 Mean Brachlana mutica 1415 954 1215 11 72 11 89 Cenchrus sel1gerus 561 .464 457 436 480 Cyncxion dactylon 13,53 691 923 1020 1047 Pan/cum anbdotale 1505 9,34 11.41 1177 ·11 89

P COIoratum 1502 695 1029 8,93 1030 p, laevrfollum 22,16 1349 16,85 16,88 1734 p, maxrmum(cultlvated) 1923 1087 1304 1272 1396 P. maximum (Wild) 21,59 1400 14,72 1372 1601 PVlfgatum 17,93 9.95 1210 1136 12,83 Mean 1603 g 74 1160 1130 1217

Source: Tomar et al (2003)

Frull Based Agroforeslry System

. One field experiment was IMlated 1M 2002 Involving three frUit tree species namely karonda (Canssa carandus), aonwla (Embllca officinalls) and bael (Aegle marmalos) impOSing four treatments T, = traditional nng method, irrigating With avallabte low sallmty water of EC 5-8 dS m", T 2 = planted In furrows Imgabng w~h low salinity water (as above), T. = planted In furrows and IITIgaling With water of high salinity (EC 8-12 dS m''), and T 3 = planted in furrows lITIgating alternately WIth above two waters In thiS expenment, the plant-to- plant distance was kept 4 m (2 m In karonda) and row-to- row distance 5 m One time imgabon was supplied In each dry month The Inter-spaces are being culbvated With arable crops VIZ cluster beanlpearl millet as khan! crop(S) and barley as rabl crop

Tabl~ 6 'Gram & straw yield (I he") of mter-crops along.Wlth fruit trees dunng ft.:st year I

FrUit trees Crops T, T2 T. T. Grain Straw Grain Straw Grain Straw Grain Straw

Karonda PeMmlliet 245 11,2 251 1126 235 11 25 2.16 1065 Cluster bean 085 263 091 296 079 251 070 246

Anwta Pearl millet 250 1096 264 1132 225 1100 1.96 10.46 C luster bean 096 331 103 343 095 320 091 286

Bael Pearl millet 200 1045 225 11 05 184 1000 1 72 985 Cluster bean 092 300 0,97 331 0,90 295 066 274

Grain Straw P millet C bean P millet C bean

Between fruit trees (A) 0134 0073 NS 0425 LSD Between treatments (B} 0097 NS NS 0189

(005) Interactions (A) x (8) NS NS NS NS

210

UbllZatlon of Salt·affected SOli' and Saline Water for Agroforestry

Table 7 Grain and straw Yield (t ha") of barley and cluster bean With different plantations dunng 2006-07

FrUit tree Treatment Yield of barley Yield of cluster bean Grain Straw Grain Straw

T, 4.01 4,15 1.60 2.70 Karonda T2 410 421 183 263

369 / , T3 381 1 78 237

T. 340 3.49 168 252 T, 4.38 458 180 272

Aonwla T2 423 ,432 185 2.77 T3 3.84 402 1.63 244 T. 3.52 361 1.50 227

I T, 385 ; 399 1.53 224 Bael _T2 396 4.08 163 234

T3 362 3.73 Vl6 200 T. 326 3.34 1.45 189

Dunng first year of establishment, on an avere~e, 24t ha" gram 8nd 106 t ha" alr~ry fodder as straw of pearl millet and 0 0 87 t ha" grain and 2 6 t ha' straw of cluster bean could be harvested from Inter· crops duMng Kharif season and 3 3t he"' gram and 35t ha"' straw of barley was harvested dunng Rab, season (Teble 6) Dunng next three years also good crop of barley and cluster bean was harvested (Table 7) Among non-conventlonal crops castor (Ricinus communis), Aloe vera, Dill (Anelhum graveo/ens), tara-mira (Eruca sativa), Isabgol (Plantago ovata) and lemon grass (Cymbopogon flexuosus) could be cultivated successfully Agronomic pracbces for Isabgol and lemon grass have been developed .

Conclusions

The highly alkali Salls (pH>10) may be rehabilitated with tree species such as Tamanx art,culata, Pmsopis jullflota, and AcaCia nilot,ca. The waterlogged saline sods may be successfully brought under exobc species such as Prosop's Ju/,flora, Casuanna g/auca; C eqUlset,fol,a, Acac,a fameSiana, A tort,/,s, A ntlot,ca, and Eucalyptus camaldulenSis These speCies also ameliorated the 5011 For and.solls Irngated With saline water, the recommended species include. Tamarix art,culata, ProsoP's Juldlora, Feroma /imoma, Eucalyptus teral,comls, Acac,a ntloltca, A. forbl,s, A forbl,s (hybnd) and Cass,a s,amea These species not only produced economic Yields (>20 Vha) but also rmproved SOil condlbons i.e. In" terms of organic matter and phYSical properties Grasses such as Pamcum laeVigatum and P. maximum can produce good forage With saline IITIgabon. FrUit-based agfoforestry system" involVing Ber, AnOWla, Karonda," Bael and Ka,th as frUit trees and low water requiring crops such as cluster bean, pearl millet and barley as Inter-<:rops IS most sUitable for calcareous Salls Imgatm9 with saline water Non-oonvenbonal crops such as castor, Aloe vera, Dill, tara·mlra (Eruca sat,va), Isabgol, senna and lemon grass could be cultivated successfully.

Bibliography

Oagar, J C, Singh, G and Singh, N. T 2001, Evaluation of forest and frUit trees used for rehabilitation of semland alkali Salls In Indra. Arid Land Research and Management 15: 115-133

Mlnhas, P S, Sharma, 0 P and. Patil, S G. (Eds) 1998 25 years of Research on Management of Salt· , affected SOils and Use of Salme Water in Agnculturo Central SOIl Salinity Research Institute, Kamal 220p

Singh, Gunubachan and Oagar, J C 2005 Groening Sad,c Lands Blchh,an Model Technical Bullebn No 212005 CSSRI, Karnallndla pp 51.

Singh, Y. P, Sharma, 0 K, Singh, G , Nayak, A K, Mrshra, V, K. and Singh, R 2008 Altemate Land Use Management for Sad,c So,ls CSSRI Technical Bull No. 212006, CSSRI, Kamal, pp 16

Tomar, O. S, Gupta, Raj K and Dagar, J C 1998, Afforestation techniques and evaluation of different tree speCies for waterlogged saline soils in semland troPICS. And 5011 Research and Rehab,ltlat,on 12 301-16

Tomar, O.S, Mmhas, P S , Sharma, V K, Singh, Y P. and Gupta, R K 2003 Performance of 31 tree speCies and SOil conditions In a plantabon established With saline Ir"gatlon Forost Ecology and Management 177.333-346.

211

/

Tree Plantation in Saline and Sodic Soils

/ o.s. Toma'" and R.K. Yadav * Retired Pnnclpal SCientist DIVIsion of Soli and Crop Management Cenlral SOil Salmity Research Institute. Kamal- 132001

Introduction

Out of 329 million ha geographical land area of our country, about 175 million ha suffers from different problems and is getting further degraded through natural or man made procesSes MaJortiy of these are categonsed as wastelands because of constraints like water-logging,. salinity, sodlclty, lack of depth, and sandy, stony or gravelly SOils As no additIOnal land IS available for hOrizontal expansion of agriculture, we need to find out Viable technologies for ut,llzallon of eXlsbng land resources Including the wastelands In order to meet future food, fodder and fuel reqUirements SOIl salinity and alkalinity have degraded about 6 73 million ha of land A large acreage In canal-Irngated tracts of and and semi-and regions suffers from water-logging and salimty and the resultant loss to crop productIOn, Already a Sizeable area has gone out of culbvatlon In almost all canal commands making the landscape deVOid of any vegetation except a few hardy trees and grass species like Salvadora persrca, Cappans deCidua, ProSOPIS jullflora, AcaCia mlotlca, Desmostachya blpinnata, Sporobolus spp , Kochla mdlca and Suaeda mantima

As per our nabonal fonast policy, about 33% of tho country's geographical area should be brought under forest and tree cover, Government of India had set a target to Increase the forest cover up to 25% In 10" five year plan But' according to latest report of forest sUivey of India (2001), the forest cover In the country IS 675,538 km2

, constituting only 20 55% of lis total geographical area Out of .thIS, dense forest constitutes 1268% and open forest 7 87% The forest cover In the hili dlstncts IS only 38 34 % In companson to the deSired extent of 66% area Availability of fuel wood In our country lacks demand lind thus afforestation of all types of lands otherwise conSidered unsuitable for arable crops IS must Salt affected SOIls represent one such category of lands. Alternate use of such lands IS an option of great promise In View of the growing demand for fuel wood and fodder and also for enVIronmental conslderaoons For reclamatJon and management purposes, salt affected SOils In India are broadly placed under two gloups alkali and saline About 3,77 m ha SOils In India are alkali and· are characterized by high pH (> 85), large presence 01 caibonates and blcaibonates of sodium, exchangeable sodium percentage above 15, vanable EC, low fertility and very poor phYSical properties, which support very little vegetation On the other hand, main causes that render remaining saline SOils unfavourable to plant growth Include excess amounts of neutral soluble salts chiefly chlondes and sulphates of sodium, magnesium and calCium causing osmotic stress;specl~c Ion tOXICity and nutrioonal disorders Often high water table conditions In such soils cause impeded drainage Coupled With thiS, the poor quality of ground water IS responSible for desertification of saline areas, Consldenng the vast scope of putting salt-affected soils under forests, a number of tree species have been evaluated for their tolerance to alkalinity and salinity

Suitable Methods for PlantaUOIis

In order to rehabilitate salt affected SOils, appropriate tree planting techniques and chOice of tree speCIes are very cruCial for redUCing mortality and Improving Inilial establishment of saplings Since alkaline and saline soils differ from each other:methods of working With these SOils will also bE. different For example, In alkali SOils a hard kankar layer of calCium caibonate IS generally found at 1 25 to 1 5m depth ThiS layer acts as Ii bamer for root penetration and has to be proken fif!\t to allow proper development of roots However, saline SOils do not reqUire such preparabon, as they do not have any hard bamer but reqUire speaal afforestation techniques so that salt contents In root zone ana minimized INa must, therefore, diagnose the SOils first and then choose the method accordingly

Sodie soils

Ideal planting method for alkali soils should proVide a favourable SOil enVIronment such as by breaking the hard kankar layer, replacement of exchangeable sodium and addlbonal nutnbon of tree speCIes for opomum root growth Prevailing planting methods for afforestation of alkali Salls arE' sale PIts, pit-auger hole, and ndge-trench However, among these planbng methods, results of p~- auger hole planting method have been found promising over other methods In thiS planting method, auger-holes of 15-20 cm diameter are made 10 pierce Ihe hard kankar layer up 10 150 -180 em deep Holes are made wllh help of a Iractormounted auger after digging pits of 35 em X 35 cm Auger holes are refilled With anginal SOil, 3 kg gypsum, 8 kg FYM, 10 g ZnS04, and small quantity of aldnn or BHC to take care of termites Tree saplings of 6-9 months old are planted In the refilled pit-auger holes followed by lITIgation With buckets Two to three Irngatlons are Immediately needep for establishment of saplings, ThiS method enables the plant roots to grow at a faster

Tree PlantatlOn In Saline and Sadie SOils

rale towards deeper sOil layers where sufficient mOisture and nulnents are available In alkali salls The kankar layer, which creates hindrance In the development of plant roots, IS broken In the process of making holes,

Pit-planting In Pits of 90 x 90 x 90 em size was evaluated by Sandhu and Abrol (1981) who laid out two expenments at CSSRI, Kamal research farm In one expenment, the treatments Included vanous dimenSions of auger and Pit holes Second experiment Investigated the effects of composition of filling m"ctures and perfOimance of two tree species VIZ Eucalyptus teret/comls and A mlohca In the first ~lmel\t, Eucalyptus plants failed to establish In the trealment where the auger tloles tied been replaced With anginal SOil because' plants apparently cOUld not tolerate highly SodlC condilions However, In the same treatment 38 % of the planted AcaCia plants survived, Indicating Its adaptability to the highly adverse SOil conditions However, the plant height and growth were poor Application at 3 and 6 kg gypsum resulted in Increased surVival and growth of both the speCies, However, 50 % and 31 % of the Eucalyptus plants died In

the two treatments Addition 6f farmyard manure along With 3 kg gypsum Increased growth, and Eucalyptus performed better than AcaCia InclUSion of sand In the auger holes further Improved the performance of the two speCies' In the second expenment, Eucalyptus trees grew to an average height of 466 m and attained a girth of about 18 em in 16 months In treatm'ents where the auger holes were of 15 em diameter and 180 em deep Simlla~y, AcaCia showed excellent growth In thiS treatment, Auger holes of 180 em depth proVided a favourable enVIronment for root growth and penetraten A layer of concre~ons at 87 to 139 em was responsible for restricted root penetration, and growth was checked In shallow auger holes treatments

Saline soils

For more than a decade, Central SOil Salinity Research Ins~tute, Kamal has been conductmg several long-term expenments for developing afforestation technologies on highly saline wate~ogged Salls at Its experimental farm, Sampla (Tomar et al., 1998) For suocessful allorestabon program In saline waterlogged Sltuabons,.selectlon of proper planMg technique IS of utmost Importance The technique should be such that the rain water IS ubllzed ,to the maximum pOSSible extent and the salt concentration m the actve root zone of young plants is kept at a mmlmum level such that the adverse effect of high salinity of soil and ground water IS minimized and the bad effect of high water table could be aVOided Simultaneously, To achieve thiS objective, three planting methods VIZ sub-surface, ridge-1rench, and furrow methods were t~ed for the Initial establishment of tree saplings In the sub-surface plan~ng method, normal pits of 45 x 45 x 45 em size were prepared and since the major salt concentrabon remains In the surface 30 em layer, the saplings were planted at a depth of 30 em from the surface which was a less hosble zone of satt concentration Earthen nn9s were prOVided around each sapling for applYing Imgatlon water by buckets or pitchers In case of ndge-trench method, the ndges were prepared 1 5, 3 0 and 4 5 m Wide at the top, middle and bottom, respectively With 40-em height from the onglnal soil surface. The saplings were planted on top of the ridges and like sub-surface planting, earthen nrigs were also made around each sapling planted on the rtdges for applYing "ngabon water Tops of the Mdges were also prOVided With penpheral bunds to store rain water on the ndges for leaching of soluble salts whereas In furrow plan\lng technique, a tractor dnven furrow maker was used to create about 60 em Wide and 20 em deep furrows and saplings were plante<:! at sill of the furrows lITIgation with good quality water was applied to tree saplings In furrows as and when required and volume of "ngatlon water was kept uniform In sub-surface and ridge-trench methods However, in case of furrow planting the volume of "ngatlon water applied was more because of higher volume of area filled With i"'gatlon water Observations such as SUrvival percentage, and height and girth of plants were recorded regula~y for 9 years after transplanting of saplings, Observed records suggested that furrow planting improved the survival and growth of tree speCies as compared to other two methods due to greater desalinization' of SOIl profile With uniform application at' Imga~on water, BeSides redUCing the water' application costs, rt Improves Uniformity In water application and helps In creating a favourable zone of low salinity below the Sill of the furrow through down ward and lateral fluxes 01 water making salts move away from the furrow (root zone) espeCially when low salinity water IS used , Creabon of such niches favoured the establishment of young seedlings of trees However, sub-surface method showed better performance than the ndge-trench method Salt accumulation In the root zone of trees was substanllally higher In the ndges than other planting methods Due to higher salinity In the ridges, saplings planted on the ndges generally remained at more disadvantageous poslliOn, resulting In the" lower survival and poor growth. Similarly, difficulties In conserving rainwater on top of the ridges were also observed Thus, by way of furrow plantmg technique, rt IS pOSSible to keep salt concentration relatively low In the rooting zone of tree saplings such that they are able to escape the adverse effects of salinity Moreover, thiS system seems to be more viable from practical VieWPOint of undertaking large-scale plantatIOns of trees

Suitable Tree Species

Species for sodie lands

Normally firewood speCies are grown on alkali Salls The chOice of species that should be grown IS determined by the ability of tree species to survive and Withstand adverse condl~ons of excess exchangeable Na TOlerant tree species overcome high concentrations of sodlclty by different regulatory mechanisms There are very few Wild plant speCies, which are able to grow on highly sodlc Salls A field tnal was Imllated dunng

213

ChemIcal Changes & Nutnent TransformatIon In SadIe/Poor QualIty Water Imgated SOIls

/ , 1995 at SIV11 farm, near Lucknow to evaluate the relatIve performance of Some tree specIes VIZ AceCia mlallca, AZBdlfachta mdlca, CassIa Slamea, Casuanna eqUlsebfoila, Eucalyplus terellcomis, P,thecelloblum dulce, Pongamla plnnata, ProSOP'S alba, PrOSOPlS jullflora and Tarmlnalla aquna on alkali sOils (Tomar and Kumar, 1009) Almost all the speCies have shown good performance Similar results have been reported by many other workers Yadav and Pathak (1967) and Dagar (1995) observed that forest speCies under different naturat flora conditions varied in their toleranCIS Ln, different states of India So,!,e' preliminary expenments showed that AcaCIa mlotlca, Azadlrachta mdlca, Alb,zz,a procera and ProSOPIS luJdlora exhibit better performance when planted In 0 5 m deep Pits filled with good 5011 P luldlora and A _ mlotlca Showed higher tolerance than Azadlfachta mdlca, Butea monospenna, Oalbergla SISSOO, Pongam/a 'pinnata and Tannlnalla af}una Eucalyptus teretlcomls could be grown when the sOil pH remained lower than 90 and soluble sa~ content was 03% On the baSIS of experiments-conducted on highly alkali sOil at Gudda Farm, Gill (1985) reported that A mlol/ca, P jullnora, Casuanna eqUlse!JfoiJa, A lebbeck, Parkm$oma aculeata demonstrated

,'hlgher tolerance than Azadlfacta mdlcII, Molla azadeiach, D SISSOO, Syzyglum frucllcosum, Populus dolloldes and Morus indlell while SyzyglUm cumlm failed to SUlVlve P_ ju,,"orll, A mlotlca and C eqUlsettfolla perfOimed well In highly alka" sad and E terellcomls grew well dunng ",illal two years but the_growth started slOWing thereafter, whereas Mella azaderach proved infenor, A mlohca was found more tolerant than E teretlcoms and Parkmsoma aculeata (Grewal, 1984) Eucalyptus camaldulonsis and E teretlcomls were found more promising than Eucalyptus cltnodora and EucalytJtus alba,

In another study earned out by by Gill and Abrol (1986), Prosopls, AcaclII and Casuaflna were found promising for afforestation of alkali SOils and Eucalyptus perfonned weil dunng ,mllal 2 years, but growth slowed thereafter, and Ma!M failed completely Batra (1988) found Casuarina gliluca to be more tolerant than C eqUisetlfolia and Casuanna obesa ProSOPIS juldlora can be grown satlsfactonliln Salls of pH 9 0 to 9 6 and EC 06 to 1 23 dS m-' even without appllcallOn of any amendment Dagar and Singh (1992) reported that P lul,flora was an ideal tree for highly alkal,ne 5011 Singh and Gill (1990) compiled Informallon shoWing that p, luldlora, , A_ mlotlca and C eqUisetifo/la were more tolerant than T IIftlculata, T aljuna, A lebbeck, P plnnata, Sesbama sesban, E teretlcoms and other sensilive tree species such as D SISSOO, Morus alba, Grevlflla robusta, A indica, Tectona grandls and P deltO/des Dagar et al (2001) in a comprehanslve study for 7 years on hl9hly alkali SOli With pH >10 at Saraswall Range Forest site evaluated about 30 tree SpecIes (Table 1) alter planting them In two auger depths (Shallow not piercing Kanker pan and deep auger piercing Kanker pan) and concluded that for such high pH SOils though many species had good survival but P. jullflora, A mlobca, T.arilculata, and E tenbeamls are the only most sUitable species which had some kind of growth and biomass Biomass of 7 years old T arilculata W(lS 97 3 t ha-' In deep augers and 31 7 t ha-' In shallow augers (Table 2) A mlotlca produced 69 8 t ha-' In deep augers and 39 1 t h-' In shallow auger planted trees, and P juldlora produced 51 3 and 220 1 t ha-' In deep and shallow augers, respectively (Table 2) For alkali black cotton sOlls_(vertlsols) beslds Prosopis jullflora as a native check, Aiadlrachta mdlca and Eucalyptus teretlcomls have been found most SUitable species (Mlnhas, 2001)

Species for saline landS

Like SUitable planting technique, saline Salls also require the proper selection of tree species lor making afforestallon programme successful As the main problem of these SOils are high water table, high salinity, impeded drainage and poor 5011 aeration, only those ,tree speCies should be raised which can tolerate these stresses Simultaneously, It has been expenenced that the tree speeles which transpire less water are more SUitable for such SOils than those transpire high amount of water In general, the plantations of fuel wood are better for saline waterlogged Salls than timber wood speCies Only recently, however, attention IS being paid to accommodate the species of mdustnallmportance for highly saline degraded areas Some all Yielding species like Sallcomla blgelovlI and Salvadara perslca are gaining Importance for highly salme waterlogged SOils or when irngated With sea water, These spe~ies have been cultivated With success on black cotton saline SOilS ''''gallng With high saline water More than 40 nallve and exotic tree species of and and semi-and areas were evaluated at CSSRI, research farm, Sampla by Tomar at al (1998) Based upon penodlcal observallons for survival, he'9ht anel girth of experimental plants, woody speCIes like AcaCia fameslana, Parklnsoma aculeata" ProSOP/S lullflora and Tama(lx spp halte been rated most tolerant to waterlogged saline areas and could be grown salisfacto"ly on soils WIth salinity levels up to 50 dS m-' In their root transmISSion zone Tree species as AcaCIa mlailca, A tonlls, Casuanna glauca, C obesa and C eqU/$ellfoila could grow on sites WIth ECe varymg from 10 - 2S dS m-' It was concluded that the waterlogged saline conditions had most adverse effect on survival and growth of tree species used for afforestation because the salt accumulallon near the roollng zone was directly attnbuted to ground water fluctuations and the groundwater sa"nlty, Performance of some Important tree species after 9 years of growth has been compared when these were grown With different methods of plantation The data on biomass (Table 3) of P ju!Jflar8 and C glauca 13987 was the h'ghest (98 and 96 t ha-') followed by A mlotlca (52 - 67 t ha-I) and A toftiliS, (41 t ha-') when planted With sub-surface or furrow techniques proving that these are the SUitable species for salme waterlogged SOils Amongst evaluation of Eucalyptus speCies, Marear et ai, (1990) also reported greater tolerance of Eucalyptus camaldulensls In waterlogged saline SOils,

214

Tree Plantation In Saline and Sadie Solis

Table 1. Survival, height anc:! diameter at stump height COSH) 01 7 years forest trees on highly alkali SOil

Tree speCies Survival % Height (m) OSH (em)

O' J S·· 0 S 0 S

Prosopis Julillora 97 65 396 259 83 53 AcaCIa ntlollca 82 77 366 2.31 86 6A

J r

Tamarix articulate 69 74 324 256 73 54

Eucal Terellcom.s 90 76 413 341 60 51

Dalbergla SISSOO 86 84 199 187 61 5.3

p.thecel/obwm dulce 87 70 170 r 162 54 42

Termmafia afJuna 92 87 1.51 145 51 48 Kigella pmn.ata 93 58 143 110 5.2 50

Cordia rolhi 79 76 104 092 40 n Pari{fnsoma a_culeata 80 77 236 189 41 33

Anthoc Cadamba 81 ~ '68 072 068 42 37

Acacia leucophloea 59 '45 224 1.77 48 47

Tamanndus mdica 270 15 1.30 129 41 36

Cas Eq~isetifolia 0 0 0 0 0 a Pongamla pmnata 0 0 0 0 0 0

AlblZIB lebbek a 0 0 0 a 0

CasSl8 Slamea 0 0 a 0 0 0 Butea monosperma a a a a a a Leuc Leucocephala 0 0 0 0 a a Bombax C9Jba 0 0 0 0 0 0

Bambusa arundinacea 0 0 0 a 0 a LSD (P - 0 05) Auger depth 9 048' 036 Tree species 14 046 1.11

InteractJon 20 065 NS

D' = Deep auger depth, , S" = Shallow auger depth, NS =' Not Significant ,

Table 2 Biomass of different tree species (Mg ha' .,) after 7 years 01 planting on alkali SOil

Treespooes Deep aUger-holes Shallow auger-holes

Tamarx articulata 973 317

AcaCia mloflca 69.8 391

ProSOPIS Juldlora. 513 221

Eucalyptus tereticomls 144 520

Pllhecel/oblUm dulce 396 214

Termmalla arjuna ,68 1.76

De/bergla SISSOO 1 75 1.18

Cordia rothll 148 062 Kigella pmnata 1 17 049

Parl<msoma aculeata 115 0.90

LSO (p - 0 05) Tree species - 5 94, Auger depths - 1 17; Interaction - 3 70

215

Chemical Changes & t-:Jutnent Transformation In SadlclPoar Qualrty Water Imgated Sorls

/ Table 3. Biomass, estimation of trees after 9 years of Planbng on saline sOils

/

Tree species· Planting Method SOil Sallmty(dS m-I) Water Table Biomass . ,. In 1 2m depth Salinity (dS m-') (Mgha")

AcaCIa m/otlca Subsurface 106-253 27 -33 52 Furrow ILl - 210 17 - 27 67

A tortilis Subsurface 68 - 28 1 12 '-33 41 Ridge 197-291 12 - 33- 6

Eucalyptus camaldulensis Furrow 100-179 10 - 35 28

Prosopis juliflora Subsurface 103-240 32 - 36, 98 Ridge 235-575 32 - 36 65

Casuanna eqUlsetJfolia . Furrow 56- 20 7 10 - 31 28

C glauca 13987 Furrow 65-339 12 - 19 96

C obesa 27 Furrow 90- 195 12 -19 38 Laueaana leueocephala Subsurface 69- 23 9 10 - 25 30 Tamanx sp Furrow 82 - 21 3 10 - 32 12

Ameliorative Effect of Plantation

The useful effects of plantation on SOils are well known VIi1th the establishment of trees. the physical, chemical and biological properties of salt affected SOils are improved In many ways The roots of tolerant trees penetrate In the SOil and improve the penneabillty which faCilitates leaching of salts The trees also have the potential for exeluslon of salts'through absorption However, the amelioration of salt affected solis due to tree plantation depends upon the type of SOil primarily

Sadie soils

The benefiCial effect of tree plantabon on alkali SOils have been reported by many workers 'Yadav and Singh (1970) reported that plantation of ProSOPIS juliflora decreased SOil pH and soluble salts, and Increased organic matter In surface 15 em SOil near Aligarh. Similar types of observations were reported by (Gill et al 1987) on the baSIS of their 5 year old study conducted In highly alkali SOil at Gudha lann of CSSRI, Kamal Ameliorative effects of 20 yealS old plantations appeared in the order of ProSOPIS juIJflora :> Acacia mlotlca > Termmalia arjuna > Alblzzia lebbeck :> .Eucalyptus terelicomls (Singh et al. 1989) Dagar et al (2001) reported changes In SOil properties due to promising tree species at thE! age of 7 years The maximum reduction In ESP and pH was obselVed under the trees of Tamanx articulata and It waS followed by Prosapls juliflora and AcaCia mlotJca Increase In orgamc C in the surface 15 em layer under Tamanx articulata was o 23 %, under ProsOP'S juIJflora 0 26 % and under AcaCia mlotJ'ca 0 10 %

Saline waterlogged soils

The benefiCial effect of tree plantation on SOil structure and Infiltration etc IS well documented In the literature The tree plantation for lowenng of water table In saline waterlogged areas has been quoted as one of the major benefit The effects of lowenng of water table on a range of Eucalyptus spp In Australia are well documented (Heuperman, 1991) Tomar el al (1994) on the baSIS of a 7 year old study conducted In saline waterlogged SOils reported that water tabJe dunng most of active growth phase of plantation remained deeper (an average of 5 cm) under tree canopy apparently due to higher evapotransp,rabon In comparison to barren land sites However, such a process may enhance salt accumulation beneath plantations and high salt accumulations at thiS Juncture may eventually kill the trees The relevant obselVatlons taken after 8 years of planting suggested that most of the salts 1:omong up from groundwater were concentrating on the region Qf 1 6 - 12m SOil depth from where most of the water uptake by tree roots was thought to be occumng where as salts were conSiderably reduced under tree canopies In the upper 5011 layers (0- 0 6 m depth) and on the whole trees resulted useful effects on SOil health

Bibliography

Batra, l 1988 Performance of Casuanna sp , their nodulation pattern and nitrogen fixallon Annual Report CSSRI. Kamal, India pp 122-24

Dagar, J C. 1995. Ecology of halophytiC vegetation In tndla a review International Journal of Ecology & EnVlfonmental SCiences 21' 273-296

Dagar. J C and Singh, G 1992 Reelamabon of sa~ affected waste lands through agro-forestry systems in Jndla In National Symposium of Resource Management for sustamed crop production. Indian Society of Agronomy, New Deihl, India Feb 25 - 28, 1992.

216

Tree Plantation In Saline and Sodle SOils

Dagar, J C , Singh, G and Singh, NT 2001 Evaluation of forest and frUit trees used for rehabllilaiion of semiartd alkali salls In India And SOIls & Rehabtlllation -.

Gill, H S 1985. Studies on the avaluabon of selected tree species for tihelr tolerance to SodlClty and mechanical Impedence In a highly sodic S911 With particular reference to root growth behaviour P'h D Thesis Kurukshetra University, Kurukshet~, India (unpubflshed)

Gill, H Sand Abrol. I P 1986 Salt affected SOil. and their amelioration tihrough afforestation. In Pnnsley, RT. And SWift, M J (oos) Amelioration of sOil by trees Commonwealth SCience CounCil, London. UK pp

'43-53 I

Gill, H S , Abrol, I P. and Samra, J S 1987. Natural cycilng throu9h litter producbon in young plantabons ot . Acacia mlotica and Eucalyptus tertrcomlS In a highly alkali sOil Forest Ecol and Mgmt 22 57-69

Heuperman, A (Ed) 1991 Tre_es as a tool for'resource management In Irngated areas _Proc Symp. Held at Insl of Sustainable Agri, Tatura. July 23, 1991 ~20 P

Lune, S, Ben, ·A.R., Zeidman, M-;-ZUthl, Y and DaVid, Y 1991 Imgatlon of pomegranates, pears and table grapes Wltih brackIsh water, fruit qualitx'and storage polenbal A/on-Honeta.45 12. 979-983

Maresr, NE,.Leppert, PM" Humphreys, E, MUlrheacjWA. Lelrj, AVander 1990 Salt.and water-logging tolerance of frost resistant eucalyptus Proceedmgs of a symposium held at Albury, New South Wales; Australra on September 18-20 , 1989 373-374 pp

Mlnhas, P S 2001 Final-Report. Evaluabng tree plantahons for control of salr'miy and water tabies, funded by Department of Wasteland Development, MiniStry of Rural Development, Government of India. New Deihl, Coordinating Uni~ AICRP Salme Water Use, CSSRI, Kamal, India 105 pp

Sandhu, S Sand Abrol, I P' 1981 Growth responses of Eucalyptus ferel,com/s and Acacia mlol/ca to selected cultural treatments in a highly SadlC SOIl Indian Journal of Agncuffural SCience 51 43743

Singh, G B and Gill, H S 1990. Raising trees in alkalr Salls Wastelands News 6 15-18.

Tomar, 0 S and Kumar, S. 1999. Alternate land use systems Evaluatron of multipurpose tree species for firewood, forage and hmber producbon In highly alkali Salls Ann Rep CSSRI. Kamal. p 19-20

Tomar, 0 S , Mlnhas, P S and Gupta, Raj K 1994 Potentialities of afforestation of,waterlogged saline Salls In Agroforestry systems for degraded lands ( Eds) P Singh. P.S Pathak and M M Roy Oxford and IBH Publishing Co Pvt Ltd New Deihl, 1 111-120

Tomar, 0 S, Gupta, Raj K and Dagar, J C 1998. Afforestatron'lechnlques and evaluation of different tree speCIes for wate~ogged salrne SOils In semland tropIcs And SOil Res Rehab 12 301-16

Yadav, J S P. and Pathak, T C (1967) Study of saline and alkaline Salls and therr pOSSible Improvement by afforestation \ Journal So/I and Water ConselVatlon, India, 5 24 - 29

Yadav, J S P and Singh, K (1970) Tolerance of certain forest species to varying degrees of salimty and alkalr Indian Forester 96 . 587 - 99

217

/ Grasses for ,Alkali Soil and Their Reclamation Effect'

/ Ashok Kumar and R.K. Yadav Division of Sol/ and Crop Management Central Sol/ Sallmty Research Institute. Kamal-132 001. Haryana

Introduction

There IS enOIlTlOus pressure on 329 million hectares .land of our country due to ever Increasing human and animal populaton In India, nea~y 7 million hectare of land IS under culbvated forage crops, which can meet only 46% of the total fodder requirement. Because of preferental food need for human beings,. no addlbonal gOOd land can be spared for forage production To meet out the fodder shortage. we Will have to depe,nd on degraded or wastelands In the SutlaJ - Ganga plains of Jndla. a large portion of agncuttural land IS alkali WIth dominance of caibonates and bicarbOnates of sodium Tt]ese solis _ are highly diSpersed In nature and the barren alkali lands may have pH as high as 10 7 By definition, a soli IS called alkali If the pH of the saturated extract IS greater than 8.5 and exchangeable sodium percentage (ESP) IS more than 15 Wlth- vanable -levels of ECe ExcesSIVe exchangeable sodium on the SOil exchange delenorates the phYSical, chemical and biologiCal properties of these SOils and as a result growth of most of the field crops is adversely affected QUite a large area of alkali lands belong to common lands, including panchayat lands With no property rtght of IndIViduals IS unmanaged. These alkaline lands could be ideally ubllZ<id for groWIng forage grnsses, selVlng as pasture lands and subsequently reclaiming them for other crops and more palatable forage grasses. For reclamation o(alkali SOils, It has been recommended that nc::e-wheat rotation should be followed for at least 3 year after application of amendments To reclaim one-hectare alkali land having pH greater than 10 about 12 to 15 tonnes of gypsum IS req'Ulred The current prtce of gypsum IS more than Rs 1200 per tonne WIthout subSidy but a subSidy of 75% IS being given to marginal tallTlers and WIth thiS subSidy the cost comes to about Rs 300 per tonne Even With thiS much subSidy small and marginal fallTlers are unable to apply gypsum Also, It IS not poSSible for the Govemment under the eXlsbng condlbons to continue the subsidy forever, hence rt IS essental to develop attemate technologies for ubllZallon of these barren lands. This paper reports the resul1s of several field and green house studies conducted at the Central SOil Salinity Research Insbtute, Kamal and elsewhere to suggest that which forage grasses should be grown In alkali SOils at different stages of SOIl degradation due. to alkalization and also the redamabon brought about OWing to groWing of grasses '

Grasses In Atkall Conditions

Natural gl3sses

In alkali SOils, naturally prevailing grass spedes as Sporobolus margmatus, S dlander, Desmostachya bl{Jlnnala, Kochla Indica and Suaeda mantlma are found However, other species such as DicanthlUm annulatum, Cappans aphyfla, Cynodon dactyton,' Andropogon squanosus, Sporobolus ooromande/lanus can also be nobced On IO)Y lYing areas where water IS Ilabre to accumulate for any length of bme, Leplochloa fusca, commonly called Kamal grass In India IS found In abundance Most of the natural grasses found In alkali SOil are very coarse With very Irtlle nutntve value except a few like Kamal grass, BellTluda grass, DlcsnlhlUm annulalurn etc As pOinted out ea~ler, Kamal grass grows well where water accumulates, so the land should be shaped In such a way to accumulate m8Ximum rainwater. For thiS, rt IS suggested that alkali land should be bunded to make smaller plots Simple bundlng or closure of alkali lands Will encourage the palatable grasses to grow and to control the coarse grasses .

Forage grasses

OVer the past three decades, severnl expenments In barren alkali fields and green hOuse have been conducted to find out SUitable forage grass speaes for alkali SOils Graded doses of gypsum were applied In the field expenments to make different levels of alkalinlbes (ESP) However, for green house studies SOil was taken el\ller from \lle al\\ali ~elds I1Self or ESP leIIeIs were created a!\lliC1al~ b'1 mIXIng olfferen\ amounts of soO,um bicarbonate In normal soil The results are summarized In the follOWIng paragraphs

Rve grasses Ie, hybnd Napier (Penmsetum typhOldes), para grass {Brachlana muflca (Forsk ) stapf], setana grass (Selana specialala), gUinea grass (Pamcum maxImum) and BelTTluda grass were grown In alkali field condlbons applied With different gypsum doses (0,3.12,625,937 and 125 t ha') to evaluate their tolerance to alkali condlbons (Kumar and Yadav, 1999) There was no Yield reducbon In BellTluda grass up to an ESP of SO, about 30 and 60 percent Yield reducbons were recorded at ESP 75 and 90 respectively Para grass showed a reduction of 30% at ESP SO, whereas Setana grass and hybnd Napier exhibited more than 60% Yield reduction at ESP 0140 but In GUinea grass there was 90% Yield reduction at an ESP of 40, hence It IS conSidered as sensrtlve to high ESP (fable 1)

Grasses for Alkali SOil and Their RecJamatlon Effed

Table 1. Green forage Yield (Mg ha") of grasses and forage crops on normal and alkali SOil

Alkali sOil Botanical name Normal SOil pH= 66 92 96 100 104

ESP = 15 30 50 70 90 Brachlana mul1ca 100 100 90, 70 50 40 Cenchrus allans 25 10 0 0 0 0 Chlans gayana 60 63 65 63 60 50 Cynocion dac1ylon 40 40 40 40 30 25 Cynodon dactylon (Coastal) 40 40 40 35 28 20 LeptoclJloa fusea 35 40 42 45 45 40 Pamcum anhdolale 75

1 75 75 60 30 20

" Pan/cum maximum 60 60 65 60 45 35 Pamcum maximum 75 ·65' 20 8 0 0 Pennisetum, pedlcel/atum 10 0 0 0 0 0 Penn/setum purpreu,,! 100 100 75 40 15 0 S&tana anoops 75 75 60 40 15 0

The performance of Marvel grass (Dicanfhlum annulatum), Rhodes grass (Chlons gayana), Bermuda grass Sunnam grass and Urochloa stolondera was evaluated in green house expenment USing 5, 25, 64, 78 and 85 as ESP levels (Kumar at al 1960) Sunnam grass and Urochloa stoIontfera failed to grow except at lower ESP levels and hence were replaced by Pangola grass and Kamal grass The results showed that Rhodes grass produced slgmficanUy higher total forage Yield as compared to oUher grasses Bermuda Yielded s'llnificanUy more than Kamal grass but was on par With Ma"",1 grass Pangola grass was Infenor to Kamal grass (Table 2) Low Yields of Kamal grass could be oWing to late planting compared with other grasses Forage yield of Kamal grass decreased at ESP 25 but there was no further decrease WIth Increase In ESP up to 85 However, under field condillons there was no such Inlbal yield reduction (Kumar et al 1980) T11e yield of Pangola grass and Mal\lel grass decreased contJnuously With Increasing ESP.' The percentage }'Ield reduction of grasses at highest ESP of 85 was of the order of 24, 44, 45 and 72 for Kamal grass, Bermuda grass, Rhodes grass, MalVel grass and Pangola grass, re~pectively .

Table 2. Green Yield, (g por') of grasses at different ESP levels

Grass ESP

Mean 5 25 64 78 85

MalVel grass 3073 2609 1982 178.1 1733 2276 Rhodes grass 4877 415.1 4091 3799 2679 3919 Bermuda grass 2832 2706 2476 2406 2021 2487 Pangola grass 176.1 1417 1133 755 488 1111 Kamal grass 2702 2095 2140 2082 2056 2215

Mean 3049 2636 2363 2164 1795

CDat5%= 23 5 for grasses or ESP: 51 4 fo"nteractlon

A field study was conducted to Investigate Uhe effects of three rates of gypsum (0, 5 2 and 104 t ha") on the performance of five grasses Kamal grass [Leptochfoa fusca (Linn )), rhodes grass (Chlons gayana, Kunth), blUe panic (Pan/cum antJrttale), Pamcum laevtfoflum and coastal bermuda grass (Cynodon dactylon [Linn 1 PelS ) In an eXiremely alkali SOil The Salls used had high ESP and pH In the top 15 em (94% and 106, respectively) For companson the difference In Uhe performance, the same grasses were also planted In a normal SOIL Number of cuts In the first year of planbng of grasses was vanable because of the growth of the grasses and their relative tolerance to alkallmty In normal SOil blue panic gave the largest (36 1 t ha") followed by P laevtfollum (33 1 t ha' '), coastal Bermuda produced the smallest YlE!ld of 135 t ha" (Table 3) The trend was different In alkali SOil, where blue panic and P. laevtfollum gave s'llmficanUy lower forage Yield than Rhodes and Kamal grasses, which did not differ slgnlficanUy In their mean Yields Rhodes grass produced the highest Yield (27 1 t ha") With the application of 5 2 t ha" of gypsum, but Kamal grass was more productive (188 t ha") when gypsum was not applied (Kumar and Abrol, 1983). In the second year, as In the filSt year, P laswallum and blue pa~IC gave the

'1Q

Chemical Changes & Nl!lnent Transformation in Sodu:/?oor Quality Water Imgated SOils

/

best YIelds In the normal soil Rhodes grass Yielded mOle than Kamal grass or coastal Bermuda In contrast to fi~1 year, Kamal 'grass produced lower Yield In normal sOil than alkali sOil at all rales of gypsum The relabve tolerance of trnise species was in the order of Kamal'grass > Rhodes grass> coastal Bermuda> blue pamc > Pan/cum laevdollUm Kamal grass, Rhodes grass and coastal Bermuda gave their maximum Yield In the second year of planTIng, blue panic In the third year of planTIng and Pan/cum laevtfollum In the fourth year The results showed that Rhodes grass IS recommended for such SItuatIOns as It maintains hrgtler productiVity over longer penods than other grasses Attemabvely blue panic and Panrcum laevtfollUm can be pianted ,n assoclabon wth Kamal grass to proVide a steady forage supply for a long ume, ' \

Table 3 Green forage Yield (t ha-l) of grasses In normal and alkali SOil With gypsum application

Gypsum Kamal grass P laeVlfol,um Bluepamc Rhodes grass C Bermuda (I ha") l M Yr 2"'Yr l M Yr 2'" Yr 1" Yr 2'" Yr I· Yr 2'" Yr I"'Yr 2'" Yr Normal soil

239 447 331 -942 381 843 241 704 135 437 Alkali sOil

0 188 516 25 139 38 165 125 707 40 283 52 199 489 91 578 90 502 271 825 69 '_ 334 104 202 495 76 463 79 423 213 797 63 320

CD (p=005) 1M Year 2"'Year

Grasses 26 23 Gypsum 102 24

Thus, Kamal grass can be rated as most tolerant grass to alkali sOil condrtlons as it did not show any Yield reduction even at the highest pH of 104, rather It gave more Yield on alkali sOil compared to on normal soil Rhodes grass is next best because it did not show reducbon up to a pH of 10 and beyond thiS also there was a small Yield reducbon In terms of green forage Yield, Rhodes grass gave higher yield than Kamal grass at all the pH levels Including at pH 104 because of Its greater Yield potential Gatton panic, Bermuda grass, Coastal Bermuda and Para grass are also tolerant grasses as these showed less than 50% Yield reduction up to a pH of 10 Blue paniC, Setana grass and hybrrd Napier can be regarded as moderately tolerant grasses as these showed good Yield up to a pH 96, the former two grasses shOWing less than 50% yield reduction GUinea grass, AnJan grass and Deenanath grass are sensitive to SOil alkalinity, almost failing even at pH 9 2

Package of Practices for Growing Grasses

• After Idenbficabon of SUitability of a partrcular grass to alkali SOil conditions, It is essential to know thai how to grow grasses or In other words what package of pracbces should be followed to grow grasses In alkali Salls As a result of several expenments conducted at CSSRI. Kamal. follOWIng padkage of pracbces for growing grasses have been evolved

La nd leveling

Proper leveling in alkali soil IS most Importarrt for Uniform and effecbve reclamaton To achieve this, the area to be leveled should be diVided In smaller plots With bunds In between, Bundlng also favou~ accumulaton of rainwater In these plots for effiCient leaching _

Flooding the plots

AllOWing the ImgaTIon or rain water 10 stand In the field for about a week wll help to leach Ihe salts, which In tum help grasses to establish better

Tlme'of plantlng

Planting/sowing of grasses should preferab" be done at or Just before the onset of monsoon 'In northern India, planbng of grasses In alkali Salls should be Clone by end of June or middle of July

Method of pia nling

, The grasses can be propagated vegetabve or by seeds Because of harsh 5011 condlbons In alkali Salls, germlnaton of seeds IS senous problem The smaller size of the seed further creates hindrance to the seed emergence Vegetabv;e rooted slips or stem cuttings can be used for plantng but all the grasses cannot be planted wth stem cultings PropagaTIon by rooted slips IS better method for planbng most of the grasses

220

Grasses for Alkali Soil and Their Reclamation Effect

Fertilizer application

To obtain higher yield from grasses and lOr the maintenance of nutrients and palatabilrty, rt IS recommended to apply 20-30 kg N ha-' after each cUt These soIls beIng defiCIent In available ZInc, the appllcabon of ZInc sulphate @ 25 kg ha-' In the first year may prove to be benefiCIal for the growth of grasses Immediately after the fertlllZ8r appllcabon either ImgatJon should be applied or altemabvely ferbllzer_can be applied after the rain when the land IS wet

-I lnigatlon and drainage

Irrigation just alter grass planting IS very essential. If monsoon IS delayed, first two Imgallons should be given at 8-10 days Interval Remaining Imgatlons can be given as per the water requirement of grass All the gras~ cannot WIthstand water loggIng so would require drainage

Tolerance to Waterlogglng/Submergence , I

It has been long established that plants growong under submerged condrtlons develop cortical alf space called aerenchyma Such aerenchymas are fi:lund In !ice (Oryza sa&va L) and Kamal grass (Leptochloa fusea L Kunth), a saH tolerant grass used as a pnmary colonIZer which grows well WIthout fertilIZer on saH affected SOIls In PakIstan (Malik et aI, (1986)_ QureshI et al (1982) also reported that Dlp/aehne fusea (Syn Kamal grass) has been shown to be most promising for producbon 01 summer fodder from waterlogged and saline SodlC solis Ashok Kumar and Abrol (1979) reported that an mcrease of flooding penod mcreased the YIeld of Kamal grass and Para grass whIle decreased that of coastal Bermuda and Bermuda grass In Rhodes grass, there was 41% Increase at 2 days floodIng but 6 8 and 12 3% decorease WIth an increase In floodIng to 4 and 8 days Coastal Bermuda and Bermuda iass showed a YIeld decrease of 45 8% and 43% respecblle)Y when subjected to AOOdlng for 8 days SInce, the yoelds of para grass and Kamal grass Increased With each Increased penod of floodIng, these grasses seem Ideal for" alkali sools

Relative AmelIoration 0' Afkall Soils by GrOwIng Grasses and Gypsum ApplIcation

To replace sodium from the soli complex, an amendment oontalnlng soluble calCIum IS reqUlred_ Generally lOr the reclamation of alkali SOil, the use of gypsum (CaSO,2H,o), which oontalns soluble Ca, IS recommended However, gypsum IS a costly input and costs at Rs_12001- per tonne A=rdlng to reclamabon technology as developed by_the CSSRI. Kamal graSs about 12to 15tonnes of gypsum IS reqUired to recalm onehectare land ThIs means about Rs 18,0001- IS needed for the cost of amendment only Vllhatever, success In the reclamabon programme of alkali SOil has been achIeved, It was because of subsIdy gIven to the farmers to the tune of 75% Even WIth thIS subsIdy, small farmers find rt dIfficult to redalm thelf lands Furthermore, Govemment cannot proVIde such hIgh subSIdy In the future ThIS, therefore, calls for a~emate methods of recamabon Biological recamabon through growing grasses seems to be one such altematJve Alkali Salls of India and PakIstan contaIn hIgh levels of caldum carbonate (CaCO,), whIch IS insoluble CaCa, can be made soluble by addIng aads or aCId formers However, rt could be best done by Initiating bIologIcal acbvty eIther through the addlbon of organic mailer or culbvallon of salt tolerant crops/plants

Vllhen grasses were grown In alkali Salls, there Was a progressive decrease In the pH and exchangeable sod,um status of SOil and an Increase In the Ca + Mg content and InfiltratIon rate of alkalI SOIl Grasses also Improve the organIc mailer oontent of alkalI sool Among several grasses testSd, Kamal grass Improved alkali sal' better than the remaining grasses In order to know whether arable crops can be grown after recaiming the alkali soli WIth grasses, several authors In IndIa and abroad have conducted a senes of field expenments The results of few of the expenments are presented in the lOliOWIng lInes In a field expenment, the effect of growong Kamal grass and Para grass as altemative to gypsum was studied in a highly alkaline 5011 With pH 10 6 and ESP of 94 The eight treatments in the study were (1) growing nee WIthout <lpplicabon of any amendme;'~ fOllowed by wheat, (2)' grOWIng nee after appllcabon of gypsum @ 125 t ha-', followed by whea~ (3) grOWIng Para grass wrthout the application of an amendment followed by nc:&Wfleat sequence after 1 year. (4) same as 2 after 2 yearS: (5) same as 2 alter 3 years (6) glOWIng Kamal grass WithOut amendment, followed by' nee-wheat sequence after 1 year, (7) same as 6, after 2 years, and (8) same as 6, after 3 years (Table 3) The results (Kumar and Abrol, 1984) IndIcated that the grasses grown for 2 years suffiClenUy ameliorated the 5011 for a successful nee-wheat sequence (Table 4) RIce YIelds In plots WIthout amendment were poSSIble In the thIrd_year and wheat In the fourlh year Y,elds of nce In plots where 125 t ha-', gypsum was applied and where Kamal grass ,was grown for 2 years did not dIffer signlficanUy AstlOk Kumar (1m) further reported 1hal after growong nee-wheat sequence tor five years relabvely less tolerant forage crops like Shallal, Berseem, teosInte and maIZe could be grown successfully

Chemical Changes & Nutnent Transformation In Sodlcl?oor Quality Water Imgated SOils

Table 4 Rlce-wh_eat Yields In alkalr soil treated with gypsum or grasses /

Yield (t ha- ) , Treatment, ,. 1979-80 198O-al 1981-82 1982-83 1983-84

Rice Wheat RJce Wheat Rice Wheat Rice Wheat Rice lI\Iheat N amend 0 0 10 0 46/ 0_6 57 , 27 51 38 Gypsum 37 26 45 13 58 34 65 '36 48 46 PI yr 38 01 58 1 6 68 33 54 47 P 2yr ·53 26 ' 59 34 , 51 49 P 3yr 56 30 59 43 K 1 yr 41 03 54 21 66 36 54 46 K2yr 6.1 34 58 38 52 52

~.3yr 58 32 55 41 CO (0 05) NS 05 05 06

• P=Para grass, ~= Kamal grass, .amend= Amendmentc Gypsum= 125 t ha-'

To probe further to biological redamabon by Kamal grass. one more field expenment was conducted In a hrghly deteriorated alkaline SOil (pH 106) from 1989 to 1992 In which two reclamabon technologies namely, growlng Kamal grass as a first crop in the absence of any amendment (biological reclamabOn) or applYing gypsum as a chemical amendmenl for different cropping sequences were compared The main difference In Kamal grass trealments from the earlier trealments was that previously Kamal grass was grown only for forage but In thiS study the trealment of decomposrbon was also Included Ttle trealments In this InvestlgaUon were (1) Kamal grass grown tor one year for forage WIthout SOIl amendment (KIF). (2) Kamal grass grown for one year WithOut amendmenl and harvested grass left 10 decompose on the srte (Kl0). (3) Kamal grass grown for two years for forage WIthout SOil amendment (K2F), (4) Kamal grass grown tor two years WIthOut amendment and the harvested grass left to decompose on the srte (K2D). (5) Kamal grass WIth gypsum applied at 14 t ha", followed by clovers dunng the WInter (KG). (6) Sorghum grown WIth gypsum al 14 I ha·'. followed by clovers during winter (SG). (7) noa grown WIth gypsum at 14 t ha", followed by dovers dunng WInter (RG), and (8) Dhamcha grown WIth gypsum at 14 t ha", followed by clovers dunng (OG) After the complete cycle of trealmentS, berseem (TrTfollUm alexandnnum) and shattal (T resupmatum) were grown in the WInter season while sorghum was grown as a summer test crop

Results showed that rice gave satisfactory YIelds In the first year of gypsum applrcabon bUt sorghum and dhamcha gave extremely poor YieldS. The Yield of Kamal grass was not affected by gypsum application In 1991-92, when clovers were grown as test crops, the yrelds of berseem and Shattal were not affected by the different trealments In 1992, the yield of sorghum was signlficantiy greater compared WIth other trealments when Kamal grass was grown for two years WIthout amendment and halVested grass was left to decompose (K2D) (Kumar at 81,1994) ThiS trealmerrt also showed a Slgmficantly higher bUild-up in organic carnon In the SOil Malrk al al (1986) observed that the growth of Kamal grass improved soil to the extent that some moderately tolerant crops Irke BrasslCa napus, a few selected sa~ tolerant vanebes of ba~ey and some tree speaes have also been grown sucoassfully_on ~ Sandhu and Qureshi (1986) repo~ed that the solis on which Kamal grass IS grown mIght Improve .sufficrently enough to support the growth of more sensrtlve legume Irke Sesbama aculeata ,

II IS, therefore. suggested thai before gnowng khanf forage crops, alkalr SOil should be amelrorated by grOWIng noa after appllcabon of gypsum or by growlng Kamal grass The' advantage of Kamal grass IS that II ameliorates SOil also and proVides reasonably palatable and nutn!JVe forage for livesiock

'Blbllography

Kumar, Ashok and Abrol, I P 1979 Performanoa of five perennial forage grasses as Influenced by gypsum levels in a highly SodlC SOil Indian J agnc. SCI 49. 473-4H

Kumar, Ashok and Abrol, I P. 1983 a Effect of gypsum on tropical grasses grown In normal and extremely sodlC SOil Expl. Agnc. 19 167-1H

Kumar, Ashok and Abrol, I P. 1983 Effect of penods of submergenoa on the performanoa of selected grasses IndIan J agnc SCI 53 694-{)98 .

Kumar, Ashok and Abrol, I P. 1984 studies' on the reclaiming effect of Kamal grass and Para grass grown In a highly sodle 5011 IndIan J agnc Sci 54 189-93

Kumar,Ashok, 1987 Relabve performanoa at Egypban and Persian clovers at dlfferenl levels of gypsum applrcabon In a barren alkali soli Indian J agnc Sci 57 157-162

Kumar, .Ashok, 1988 Long term forage YIelds of five tropIcal grasses on an extremely sodle SOil and resultanl SOil amelrorabon. Expl. Agnc 24. 89-96

222

Grasses for Alkali Sod and Their Reclamation Effect

Kumar, Ashok, 1990 Effect of gypsum com~)ared wrth that of grasses on the Yield of forage crops on a highly sodlC sOil Exp/. Agnc 26 185-188

Kumar, Ashok, Batra, Land Chhabra, R 191)4 Forage Yield of sOlghum and Winter clovers as affected by biological and chemical reclamation of a highly alkali 5011 Expl. Agnc 30 343-348

Kumar, Ashok and Yadav, R K 1999 Evaluation of forages under sahne and alkah conditions Forage Res 25(1)'.1-11. '

Malik, K A, Aslam, Z and NagV1, M, 1986 Kal/argrass- a plant of Salme salls, Nuclear Institute for • Agriculture, and Biology, Falslabad, pakistan 93 p

Qureshi, R H Sahm, M , Abdullah, M and Pitman, M G 1982 DIp/acn9 fusca An Australian salt tolerant grass used In pakistan Agnculture J Ausl Inst Agnc. SCI 48 195-199

Sat1dhu,GR. andQu~, RH. U175. Feas!bll"'< ofQJOWlnQ.Qf8en fodder In salme SOIls 01 the Induswest Bank NIAB- MICRO reportS vol 111. Nudear Institute for Agnculture and Biology, falslabad (Iyallpur) PakIStan

, " I

223

,-Organic Matter & Nutrient Dynamics in Agro-forestry System under Salt-Affected Soil /

'/ P. Dey and Gurbachan Singh Division of SOil and Crop Management Central SOIl Salmlty Researr;h InsMute. Kamal-132001. Haryana

Introduction

Reclamation of salt-affected soils by phYSical and chemical methods IS well known Biological approach, e g growing salt tolerant grasses, agncultural crops and forest tree species, had been followed by many workers (Mahmdra 1973, Bandyopadhyay sf af 1982, Misra sf sf 1985, Nath and Banerjee 1992, Singh and Dagar, 2005) WIth a view tO'reclalm saline and alkali lands In the present article, an attempt has been made to elUCidate the effect of agro-forestry on organic matter, nutnent dynamiCS, speCial vanablhty and amehorating effect WIth speCIal reference to SodlC sOil

Soli Variability

Extent of lateral vanablhty In surface soli as measured by mean, standard devlabon and co-efficlent of vanatlon for soil properties before the plantation and estabhshment of agroforestry are given below Fraetlle diagrams based on cumulative frequency dlstnbutlon functions showed that all 5011 parameters were normally dlstnbuted, Soil pH showed least vanatlon (CV = 739%) and CaC03 the highest (CV = 81 03%) which Will determme the number of samples to be drawn for a realistiC analYSIS (Dey at al 1999) ,

Table 1 Lateral vanablhty In soli parameters

SOil property Mean Standard deViation CV(%)

pH 95 070 7 EC (dS/m) 1 2 059 48 Organic C (glkg) 02 016 62 CaC03(gikg) 1 8 144 81

Available P (mglkg) 11 3 815 72

Lateral vanabJht'i In respect of 5011 pH under all the forest tree specieS was mll1lmUm and CaC03 content showed largest variation (CV = 76%) under ProsOPIS lullflora. 104 per cent for Da/bergla SISSOO and 67 per cent for Casuanna eqUisetlfoila. AcaCIa ni/oflca showed maximum coeffiCient of vanabon (CV = 91%) for orgamc carbon content (Mongla et sl 1997) In general, mrunmum vanabllity was recorded In the deepest SOil depth (0 60-110 m) for all the charactenslics and under all tree species tested (Mongla of af 1997)

Sample Requirement to Predict Soil Properties In Sadie Soli

It IS evident from above table that the number of samples requlled for obtaining or predicting mean value within a certain precision varied greatly with different parameters For example, at 90% confidence level that the mean value Will not deVIate beyond 10% of true mean, 178 observalions are requlled for CaC03 whereas only one sample WIll be enough for measunng pH (T~ble 2) Courtln af al (1983) while surveying the honzontal vanablhty of 19 phYSical and chemical properties In semi and 50115 of South-Western Columbia found that pH was least vanable Singh at al (1993) also reported least vanatlon In SOil pH from thell study of lateral vanabllity of five 5011 properties In a TYPIC Ustochreptln the semi and region of North-Western India The number of samples reqUired for surface 0-020 m SOil at 90% and 95% probablhty and 10% and 20% precision are given below (Mongls et a/ 1997),

Table 2 Number of 5011 samples requlled at preCision

SOIl property

pH EC (dS/m) Orgal1lc C (glkg) CaC03 (g/kg) Available P (mglkg)

No of samples regulled %10% precIsion %20% preCISion P=90% P=95% P=90% P=95% 1 2 1 1 I 64 90 16 22 111 157 28 39 178 251 44 63 142 200 35 50

Organic Matter and Nutnent Dynamics In Agro-forestry System under Salt-Affected 5011

Changes in Soil Properties

The sOil originally was highly SodlC throughout the profile pH and EC values were highest on the surface (107& 33 dS/m) and decreased with depth «Mongla et al 1996)) Organic C was very low (0 5 glkg) A sharp decrease In surface sOil pH, EC and lomc concentrations of water extract was observed WIthin three years of growth under all the planta~ons,' Ihe decrease being more under ProSOPIS julglof8 followed by Acacia mlotlca, Dalbergla sissoo and Casuanna eqUisetljolia However, pH and soluble salts Increased In the lower depths The Increase In the salts may be due to their translocation through leaching and lowenng of pH can be related to the organic matter accumula~on because of litter fall and their subsequent decomposition The lowest pH under ProsoplSjllllf/ora may be related with the highest amount of organic matter accumulabon as eVident by organic C content

IOnic compOSition of the water extract shows that CO;, HCOJ- and Na' were the dominant Ions In the sodlc sOils ,The IoniC concentrabon as a whole, decreased considerably on the surface follOWing tree plantation The decrease was highest In case of ProsOPIS juldlora while all the other species were almost at par to each other A general Increase In olllanic C content was observed throughout the profile under all the plantations, the Increase being more In the surface layer and the rate of Increase decreased with depth The Increase In organiC C was maximum ProsOPIS jullflora (3 2 glkg) and the least in Casuanna eqUlsehjolla (1 7 glkg) Fall In pH and soluble salts concentration and nse In organic carbon contents were also obselVed by Gill et ai, (1987) and Chhabra et al (1987)'wlth Prosopis juldlora and AcaCia ntlctlca Nath and Bane~ee (1992) also reported Similar results with Casuanna eqUlsehfolla Misra et al (1985) noted a lowenng of sOil pH and Improvement of SOil mtrogen In 1 oral expenment As regards the available nutnents, available P declined while an Increase In available K was observed under all the plantations

The highest value of available K was nobced under ProSOP'S juldlora ((Mongla at al 1996) The lowenng of avarlable P In the planted sites may be due to downward movement of sizeable portran of P along with other soluble salts to the lower depths (Chbabra et al 1981, Curtin at al 1992) The higher content of K may be due to release of K from the K-beanng minerals follOWing reclamallon and partly due to recycling of K on account of htter decompOSItion SimIlar have been the results reported by SIngh et af (1993) Available phosphorus (Wang Ilt af 1995) and potassIUm were reported to mcrease wrth the slablilty of organIc carbon (Keeny et al 2002) and Vice versa (Webb et al 2000) Sodium adsorpllon on clay complex Increased With SOil organic carbon depletion (Paonia, 1996) Thus SOIl organiC carbon IS dynamiC (Parton et al 2004) and a Widely accepted indicator (Lal, 2004), changing with land use and management history CalCium" carbonate content In the surface and subsurface 5011 decreased with growing of tree plantatrons, but It remained more or less constant in the lower honzons of the 5011 profiles Tree roots increase the CO, level in the SOil which helps mobiliZing and dissolVing In CaC03 and It results In exchange of Ca" With Na' on the SOil exchange complex, thus resulting In decreased calCium carbonate content on the surface and subsurface (Dey et al 2004) The Fe and Mn concentrallons In the profile Increased follOWIng plantatIOns, The highest concentratIons of these elements were observed In Casuanna eqUiselifol18 and the least In Prosopis jullflora Zn and Cu content rather regrstered a decrease follOWIng tree plantations The vanatlon In the concentrations of these mlcronutrlents in the SOil may be due to their dlfferen~al uptake by the trees 'and subsequent recycling In the SOil through litter decompOSition The afforeslabon of SodlC 5011 by tree planta~ons helps In reclamation of sodlc soli by lowering pH, Be and soluble salts of the SOil, crea~ng favourable root environment and bUilding organiC matter and fertility status of the SOIl

Tree Growth in Agro-forestry System vis-A-VIS Soil Properties In Sodlc Soil

The pruned biomass was found to be the maximum In case of ProSOP'S jullflora, followed by AcaCia mlotlca, Delbergla SISSOO and Casuanna eqUlseljfolla (Mangle et al 1996) Similar differences were obselVed , In plant height and diameter at stump height The differences In biomass weight may be attributed to differences In the nature and extent of canopy growth of different plantations Tree growth al stump height showed enough vanatlon in height and girth under SodlC SOil The relationships between growth and 5011 chemical traits showed that CaC03 content and EC were slgmficantly related to the height and girth of trees Multiple variate analysis showed thai tree girth could be Significantly descnbed by SOil properties Indicating tree gIrth to be a belter mdex of growth than tree height whIch resulted non-sl!lmficant co-effiClent of determination,

Model Agro-forestry System for Amelioration of Sodie Soil

SIIVI-pastoral model for blo-reclama~on of sodlc SOil (pH2 > 10) has been developed by CSSRI (Singh and Dagar, 2005) for production of fuel wood, fodder, pods and honey beSides reducing runoff volume, Increasing Infiltration, redUCing SOil alkalinity and Improving SOil fertility The process Involves planting of ProSOPIS juliflof8 and Kamal grass (Leptochloa fusea) together for 5 years After that Kamal grass IS replaced With Berseem or Shaftal ThiS IS non-chemlcal based eco-friendly technology for the rehabilitation of saltaffected Village Panchayat lands

225

Chemical Changes & Nutrient Transformation In SochclPoor Quality Water Imgated SOils

Bibliography /

Bandyopadhyay, A K , Bandyopadhyay, B.K and Yadav, J S P 1982 J IndIan Soc SOIl SCI 30 242

Chhabra, R" Abral, I P & Singh, M.V 19S1 SOIl SCI 132: 3Hi

Chhabra, R, Abral, J P & Chawla, K L 1987 Proc International Symp Affo(,9statlon Salt-Affected Salls, CSSRI, Kamal, 2 33 \

Curtin, 0, Selles. F & Steppuhn, H (1992) SO/I SCI 153409 \.-

Dey, P, AD Mongla and Gurbachan Singh (1999) Spatial variation of soil properties and tree growth parameters In agroforestry under sodlc sOil condition In Wasteland Development Challenges & Opportunities (A K Singh, K S Bhatia and J.P. Yadav eds), C S A University of Ago Technology, Kanpur and State Land Use Board, Dept of Planning, YOlana Bhawan, Lucknow, pp 168-172

,Dey, P, AD Mongla and Gurbachan Singh (2004). Performance of woody perennials In '!:9hly sodlc SOil of semland cllmabe region under land use pattern of agro-torestry In Proc 91 IndIan SCIence Congress, Chandlgarh, January 3 to 7, 2004, pp 49-50

Lal, R (2004) SOil quality industrialized and developing countries - Similarities and differences, In Managing 5011 quality, challenges IIi modem agnculture (P Schl0nnlng, S Elmholt, and B T Christensen. ads), CAB International, Wallingford, UK, pp. 297:..313

Mongia, AD, P Dey and Gulbachan Singh (1997) Impact of 5011 SodJClty on performance of some tree speCl6S A study of spatial vana~lllty J Indian Soc Soil Sci_ 45 (4) 810-812

Mongla, AD, P Dey and Gulbachan Singh (1998) Ameliorating effect of forest trees on a highly sodlc 5011 In

Haryana J IndIan Soc SOlI Sci, 48 (4) 6~68

Parton, W. Tappan, G" Ojlma, 0 and Tschakert, P (2004) Ecological Impact of hlstoncal and future land use pattem In Senegal J And EnVironments, 59 409

'Pooma, S R_ (19SB) Sorptlonlexchange of some numents and non-nument cations In SOils 16th Prof J N Mukhe~ee - ISSS Fou~datlon lecture, 63"' Annual Convention of Indian Society of SOil SCIence. Hlsar.

Singh, Gulbachan and Dagar, J C (2005) Greemng SadlC lands Blchhlan model Tech Bull No 212005, pp 51. Cantral 5011 Sahnity Research Insbtute, Kamal. .

Singh, Gulbachan, Singh, NT & Tomar, 0 S (1993a) Agroforestry in Saff-Affected SOIls Bull 17, pp 1-135, CSSRI, Kamal

Singh, R , Singh, B & Singh, Y (1993b) And SOIl Res Rehab. 7. 197

Wang, C , Gregorich, l J , Rees, H W, Walker, B D, Holmstrom, D. A , Keeny, E A, King, 0 , Kozak, L M. Mlchalyna, W, Nohn, M C, Webb, K T and Woodrow, F E (1995) Benchmar1< srtes for momtorlng agncu~ural soil qU<lhty In The health of our sOil-Towards sustainable agriculture In Canada (0 F Acton and L. J Gregonch eds), Center for Land and Biological Resource Research, Agriculture Canada and Agriculture Food Canada, Ottawa, pp 31-40 -

Webb, K T , Wang, C , Astatkle, T. and langille, 0 R (2000) canadIan J. SOIl SCIence, 80 567

226

Soil and Water Management for Sugarcane Production in Sodic Environment

V.I<. Arora CCS, Haryana Agncultural Umverslty, I RegIonal Research StatIon. Kamal - 132001. Haryana

Introduction

In India about 8.7 million hectares of land IS affected by varyIng degree of salinity out of which alkali SOils OCCUpies 25 million hectares of land Sugarcane. which Is very Important cash crop. IS also grown In these condllrons and the cane. production decreases when grown in SodlC condition The high pH, hIgh concentrabon of sodium salts present In water and SOil affects the plant growth and jUice quality The use of Imgatlon water WIth high reSIdual sodium carbonates (RSC) In sugarcane can detenorate phYSIco-chemical propertIes of the SOil and u~imately affects the cane Yield and JUice quality. unless JudiCiously used WIth SUItable amendment Irke gypsum Amending' such Salls and Imgatlon water WIth SUitable amendment VIZ

gypsum, pynte. FYM and press mud mitigate Ihe effect of sodium salts and WIll ,"crease the cane productiVity and enhance the JUice quality. Further development or selectIon or cultIVation of salt tolerant ventres may help In IncreasIng the cane y,eld and JUice quality

Effect of Sodie 5011 and RSC of Irrigation Water on Average Cane Yield and Yield Attributes

Sugarcane production decreases when grown In sadie condltron (Kumar at a/ 1 999) Excess of catrons like sodium and anions like carbonate, bicarbonate, presents In water and SOil affect plant growth and JUice qualIty (ValdiVia, 1978 and Kumar e/ a/1999) Under these conditions. the cane yields are decreased due to combination of osmotrc effect, reduction of waler availability, by direct Ion Injury or nutnlional Imbalance In the plant system The decline In the cane yield WIll depend on the varying degree of SodlClty In the 5011 and water Experiments conducted to evaluate the effect of reSidual sodium carbonates (RSC) of Imgatlon water on the growth and Yield of sugarcane grown on slerozem light textured 5011 IndIcated that for both plant and ratoon crops the average cane Yield of all the genotypes of sugarcane and cane Yield attnbutrng characters decreased Significantly WIth the Increase In RSC of Irrigation water 10 6.5 and 12,0 me L-' (35 and 51 % declrne In the average cane Yield for plant crop) For ratoon crop the corresponding decrease in the average cane Yield was less than the plant crop (only 14 and 21%) For both plant and ratoon crop the average cane yield of all the genotypes of sugarcane decreased significantly WIth the Increase in RSC of imgatlon water For plant crop 35 and 51 % decline in the average cane y,leld of eight genotypes was observed WIth the application of imgatron water of RSC 6.5 and 12 me L-', respectively. For ratoon crop the decrease In the average cane YIeld WIth apphcatlon of high RSC was less than the plant crop For ratoon crop only 14 to 21 % decrease In the average cane Yield of eight genotypes was observed WIth the appllca~on of Imgatlon water of RSC 65 and 12 me L-', respectively Average numbers of millable cane (000 ha-'), average number of Intemodes, average plant height (m), of the eight genotypes decreased Significantly WIth the Increase In RSC of Imgatlon water Similarly, Kumar (2004) conducted another expenment on Slerozem, medium lextured and Slightly SodlC SOil to evaluate the effect of residual sod,um carbonates (RSC) of Imgatlon water and GOldlC SOil and their amelioration With gypsum and pressmud on the cane Yield and JUice quality of SIX promising sugarcane vanetres The resuHs showed that application of sadie ground water With high RSC for Irn9atlon Significantly reduced the cane Yield, Yield attnbutlng characters, CCS% and sugar Yield of SIX vantles The SodlClty In 5011 and Imgatlon water detenorates the phYSical and chemical properties of the 5011 and affects plant growth and nulnent uptake.

Effect of Sadie Condition on Juice Quality of Sugarcane

Sodlc 5011 and water condition also affects the JUice quality of sugarcane. The salt Interferes In sugarcane producllon In two ways. first by decreaSing the cane Yield and secondly by affectong the sucrose content on the cane Kumar at a/_ (1999) found that IUlce extraction % (wel9ht of IUlcelwe,ght of cane) was decreased Significantly With the increase In RSC of Imgatlon water Amending RSC With gypsum decreased the adverse effect of RSC and Increased JUice extraction % For both plant and ratoon crop the average sugar YIeld of eight genotypes of sugarcane decreased Significantly WIth the mcrease In RSC, of Irngatlon water Amending RSC with gypsum ,"creased the average sugar Yield In Doth plant and ratoon crop Similarly, Kumar (2004) In anotl\er expenment conducted in sod,e 5011 WIth sodle Irngation water, observed that for bo~h plant and ratoon crops, the commercial cane sugar (CCS%) of all the vanetles of sugarcane were below than their average CCS% ThIS affected the over all sugar yield of vanous vane~es For both plant and ratoon crop the average sugar Yields of SIX vantles of sugarcane recorded under Imgatron With sodle water were low Amending RSC WIth gypsum or press mud Increased the average CCS% and sugar Yield In both plant and ratoon crop

Chemical Changes & Nutnent Transformation In SodlcJPoor Quality Water Irngated SOIls

./ Effect of Sodic Soil and Irrigation Water on Soil Properties and Plant Nutrient Uptake

The decline In cane Yield and IUlce quality with sOil SodlClty and lricrease In RSC of Imgatlon water /

may be due to deterioration effect of sodlCJty on physical and chemical properties of the sOil (Yadav and Kumar, 1994) Under alkali 5011 conditions the damage to crops IS not due to salt concentration only, as the COnductIVIty of 5011 solution In such sOil may be low The sodium Ions absorbed on clay and orgamc collides cause the dispersion of clay, which results In a loss of deSirable structure and development of puddled effect Such effect on phYSical properties reduced dramage, aeratIOn and microbial activities (Kumaraswamy, 1989) Poor surface and Internal drainage under semi-and conditions enhances the accumulation of salts In the roo! zone. High SodlClty also decreases the nutnent uptake particularly phosphorus, zinc, Iron and manganese (Kumaraswamy, 1989) and Increases of nrtrogen loss through volatilization (Fearon, 1988) Under such 5011

phosphorus 15 also fixed ChlorosiS of young leaves due to Iron defiCiency IS frequently observed espeCially In

ratoon crop Kumar et al (1999) found that under high RSC of Irriga~on water, the gerrmnatlon of sugarcane genotypes was affected and in some genotypes the defiCiency symptoms of zinc and Iron were observed Rozeff (1995), reviewed that high level of Na depressed the cane growth and aggravated Zn defiCiency symptoms In Hawaii Similarly Singh et a/ (1989) reported that In the expenment carned out on highly alkaline SOil In India (pH 9 7-10), Zn defiCiency was apparent In sugarcane plant In summer months Blackburn (1984), summanzed that In South Amcan Salls With increase In sodium adsorption rabo (SAR) the cane growth was severely affected.

Amendment of Sadie 5011 and Water

In sugarcane crop the hamnful effect of SodlC water/soil could be neutralized With the help of appllcabon of gypsum, pyotes, FYM, press mud, SUlphur and green manure (Johnston 1977, Ral et a/ 1976, Zerega and Adams 1991, and Henry and Rhebergen 1994) The organic manure not only mitigate the effect of sodlClty but also Increases the avallab,lIty of phosphorus and m,cro-nutnents such as In, Fe, Mn and Cu Use of organic manure Improves the SOil phYSical condition by proViding suffiCient drainage and aeration Kumar el al (1999), observed that amending RSC WIth gypsum decreased the adverse effect of RSC and Increased the YIeld In all genotypes 1M both plant and ratoon crops The cane YIeld of vanous ganotypes obtained under amended RSC of 6 5 and 120 me L" WIth gypsum treatment, were almost equal to the yield obtained under RSC 2 8 me L" treatment Simlla~y, Kumar (2004), found tIlat amending RSC of irngatlon water With gypsum or press mud cake, decreased the adverse effect of RSC and increased the cane ~Ield, Yield attnbutrng characters and Juice quality parameters In both plant and ratoon crop Both gypsum and press mud were equally effect,ve In amending the RSC Full amellora~on of RSC was Significantly supenor 10 half amellor~on Yadav (1995) reViewed that the Integrated use of press mud and fertilizer N Increase the recovery of fertilizer N beSide benefiCial effee! on phYSical, chemical and biological properoes of SOil Johnston (1977) reported that In the Nkwahnl Valley of South Africa, sahne SadlC SOil was drained and treated With gypsum (31 I ha") or sulphur (6 t ha') whereas control plots received no amellorants, the gypsum hael an ameliorative effect slightly supenor to that of sulphur Both. trealments were benefiCial than controls However Zerega at a/ (1995) conducted a field trial In Lara, Venezuela, on a fine loamy day SOil, phYSically degraded by high concentration of Na and Mg from ground water First crop and ratoon crop of 9 sugarcane cultlVars were given phosphorgypsum, S and calCIum nitrate. They found that the soil amendments had no sigmficant effect on chemical composition of sailor on cane t.'eld Singh at 8/ (1986), reported that the application of pyntes (4 t ha") anel sulhrtatlon press mud (20 t ha- ) to calcareous sahne sodic SOils resulted higher cane Yields of sugarcane to tile tune of 1945 and 20 52 t ha" Application of pyntes and sulphrtatlon press mud (20 t ha") Increase 0 5 to 1 5 units of sugar percent in cane and 1 5·to 3 t ha" estimated commercial cane ~ugar due to application of these amendments Ral et al (1980) reclaImed asoll of pH 90 With 20 t ha-' sulphltsatlon press mud cake and obtained an Increase In cane Yield by 263 q ha" Kanwar and Kapoor (1987) reported that application of press mud nas been found Increased cane length girth and population of millable cane of sugarcane The combinatIon of green manunng of dhalncha and use of gypsum In reclljlmlng sodlc condition IS also reccmmended (Yada'J and Kumar, 1994) The dhalncha fohage IS highly aCidiC, therefore reduces the pH of the SOil Further its extensive root system proliferation deep In the SOil helps In Improving aeration In these soils.

Breeding Or Selection of Salt Tolerant Sugracne Genotypes

Breeding of salt tolerance varieties IS difficult Selection of tolerant genotypes IS another approach which may help in sustaining the cane yield and Juice quality under such situations (Rozeff, 1995) Selection of tolerant genotypes to satt and their subsequent u1lllzatlon In a breeding programme may Improve the cana Yield and sugar quality. Kumar at a/. (1999) conducted the experiment to study the perfomnance of some promising sugarcane genotypes under these conditions The effect of RSC of Irngallon was vanable for different genotype (For example for the plant crop of CoH 97, 65 and 76 % and' for CoH 108, 9 and 20 0/0 decline 'In the cane Yield was observed With the applicaTIon of hIgh RSC Irngatlon water) Some of the genotypes for example CoH 99 was rather tolerant to high RSC levels whereas other genotypes like CoH 97 and CoH 35 and CoH 56 were more senSitIve to RSC The effect of high RSC on various genotypes of sugarcane was also vanable for the two plants stand I a plant and ratoon crop Mostly the average Yield levels

228

SOl' and Water Management for Sugarcane Production In Sodle Environment

obtained under ratoon crop were higher than the plant crop The established done of ratoon might be lees prone to high SadlC conditIOns Zerega et al (1995) concluded that In a field tnal In Lara, Venezuela on a flOe loamy clay sOil, physically degraded by high concentration of Na and Mg from ground water, five cultlvars out of mne were relatively tolerant to these advelSe condlbons Kumar (2004) observed that the effect of high RSC on vanous vantles of sugarcane was vanable Three of the vanbes, for example CoH 110, CoH 119 and CoS 767 were rather tolerant to high RSC levels whereas other vantles lil<e CoJ64, CoH92 and CoS8436 were more senslbve to RSC. Singh et al1989 camed out expenment,an hl~hlY all<ahne sOil (pH 97- 10) amended Wlth PYfltes (coantalfllng 30% S)@ 4 5 t ha-' and press mud 5 t he' Among five culbvars, highest Yielding cuftlvans in both the plant ( 1031 - 1156 t ha-') and ratoon crop (500- 5565 t ha-') were Bo 71 and Bo70.

Bibliography

Fearon, C G. 1988 Nitrogen nutnbon of sugar cane under Jamaican growing conditions - the penod 1950-1987 Proceedings West Indlfls Sugar T~chnologlsts' Conference 1986,23 475-463

Henry, F' C and W Rhebergen 1994 A review of the effecbveness of gypsum, filter caKe and deep ploughing for ameliorating Imgated duplex Salls In Swazlland- Proc South Afnca Sugar Tech Assoc pp 1-8

Johnston, M A 1977 Reclamation of a saline sodle 5011 In the Nl<walim Valley Proceedings of the 51st Annual Congress, South Afncan Sugar Technologists' ASSOCIation 42-46

Kanwar, R S and Kapoor J 1987. Direct and reSidual effects of sulphltatlon and carbonatIOn press mud cakes on yield, quality am! nutnbon of sugarcane. India" sugar crop J 13 (4) 1

Kumaraswamy, K 1989 Soli management most Important to get better Yield Klsan World 12 20-22

Kumar, VIJay Singh Su~an. Smgh Satyavir and Yadav, H D 1998 Performance of sugarcane genotype grown under sodlc 5011 and water conditions Agnl Water management 41. 1-9

Kumar, ViJay 2004 Effect of Sod'C Irrgation water on cane Yield and Juice quahty of different varlles of sugarcane grown m sodlC 5011 Indian Sugar 53 895-901

Rozell, N 1995 Sugarcane and salinity - a reView paper. Sugarcane 5 8-19 Ral, Y. Smgh D, Singh KD N, Prasad, C R and Prasad M 1980 Ubhzabon of waste products of sugar

Industry as a 5011 amenments VIs-a-VIS for recialmation of saline SodlC 5011 IndIan Sugar 30241

Singh, TN, H P, Singh, G Singh. 1989 Culbvallon of sugarcane In salty wastelands of eastern Uttar Pradesh Ind/an-Famllng.39 5,21-23

Singh K D N, C R. Prasad and Y P Singh 1986. Comparabve study of PYrites and sulphllallon pressmud on SOil properties, Yield and quahty of sugarcane In calcanous salmB-sodlc SOil of Bihar J IndlM Soc Sol/ SCI VOl 34 152-54, 1986

Yadav, D V 1995 Recent trend-,n the ullhzallon of pressmud cake In Indian Agnculture In G B Singh and S Soloman (eds) Sugarcane Agro-Industanl Altemailes Oxford and IBH publishing Ltd N Deihl

ValdiVia, V S 1978. Effect of excess sodium on sugar.cane Yield Proceedings 16th Congress Intemallonal SOClety of Sugar Cane TechnologISts, Brazil 1977. 861-866

Zerega, M L, T Hemandez, and J Valladares 1995 Effect of three amendments on sahne SadlC SOil used to grow 9 sugarcane cultlvar Cana de Azucar 13 51-64.

229

Remote Sensing & ~IS for Delineation and Characterization of Groundwater Zones /

D,S, Bundels and C,K, Saxena DivIsion of lnigation & Drainage Engmesnng Central Soil Sa/imty Research Inslllule, Kamal-132001

Introduction \ Groundwater is a major source for imgabon and dnnklng water supplies in the country and occurs In

unconfined, semi-confined and confined aqu~ers of varying depths in different geographical setbngs The composibon of groundwater reflects inputs from rainfall, Irngatlon and seepage, from water-soil and rock mineral interactions in flow direction, as well as from pollutant sources such as agncunure, deforestatIOn, mining, domesbC and mdustnal wastes, The quality of groundwater is a measure of Its suitabIlity as a source of water for Imgatlon and dnnking purposes. Trad,Uonal methods of groundwater exploration by dniling has low success rate and even borewells have dried up In a short penod of Ume after successful drilling Of late, Significant progress has been made In application of remote sensing and GIS (GeographIcal Infonnabon System) techniques to groundwater resource mapping and management Exploration procedures can Ideally adopt remote sensing as the first step to be followed by field geological Studl8S, geophYSical prospecting and test dniling. ThiS helps In focusing the field efforts in areas where greater potential of groundwater eXIsts and in elrminaUng non-potenUal zones, Ihus recluclng the cost and lime Involvee in' exploration procedures GIS helps In the Integrabng remotely sensed denved data WIth ancIllary data to have more precIse and correct information In the groundwater prospecllng. Remote sensing and GIS techniques for groundwater exploration al district scale are qUick and inexpensIve techmque for getting 'nformabon on the occurrence of groundwater and for selecting promlsfOg areas for further groundWater explora~on thus reducmg field worl< and provides InfOrmation on prospects and depth In a SIngle map ThIS type of information is very helpful In the areas Where more emphaSIS IS on groundwater development for the Irrigabon and dnnklng purposes InclUSIOn of subsurface InformatIon Inferred from geoelectncal survey can gIve more realistIC pIcture of groundwater potentlalrty and quality of an area' This lecture attempts to delineate and charactenze the potential zones of groundwater on prospects, depth and quality using Integrated approach of remote senslOg, geoelectncal and GIS techmques. '

Approaches

Traditional approach of collection of groundwater informabon by drilling IS bme consumlOg and expensive Remote sensing can be explOJted to prOVIde bmely informatIon but II needs some form of ground data as a check to make It reliable Satell~e remote sensing WIth limIted field work lias been successfully used for groundwater mapping at a variety of spatial and temporal scales It is a cost effective alternative and major source of timely and reliable informabon, because of repeated observabons in rela~vely short penocJ and synopbc multispectral coverage. Munlsllectral claSSIfication techniques for ground surface feature mapping have been proved to be promising as a key spatial IOpUt data to several groundwater studies

Remote Sensing refers to the technology of acquiring Information about the earth's surface uSing electromagnebc rad,abon as a medIum of interaction (rom senSOrs onboard allPome or spacebome pratfonns Remote sensing employs passive or aC\Jve sensors, PassIVe sensors sense naturat radiations either reflected or emitted from the earth whereas active sensors emit their own electromagnetic radiation Remote sensing can be broadly claSSified as optical, mIcrowave and hyperspectral In optIcal remote senSing, sensors detect solar radiation In the viSible, near-, middle- and thermal-infrared wavelength regions, reflected/scattered or emitted from the earth, forming Images resembling phOtographs-taken by a cameral sensor located high up In space Different land usa and land C(lver features, such as water, soli, vegetatIon, nver and rocks reflect VISible and Infrared light 10 different ways Interpretabon of opbcal Images reqUires the knoWledge of the spectral reflectance pattems of various matenals (natural or man-made) covering the surface of the earth In case of green VegetatIon, there IS low renectance In the blue and red regIon and relabvely hIgh reflectance in green and a marked Increase of leaf reflectance '" the near mfrared region (Figure 1) In the VIsible and near Infrared regions, soli reflectance shows a generally Increasing trend WIth wavelength, Water absorbs most of the radiatIon In the near IR and mIddle IR regIons

Microwave remote senSing IS highly useful as it provides observation of the earth's surface, regardless of day/flJfjhl and the atmosphenc conditiOns. The microwaves have electromagnetic frequenCies betweenl0' and 10 H~ Radar IS an active microwave remote sensing system The Radar Illuminates the terrain WIth electromagnetic energy, detects the scattered energy returning from the terrain (called radar return)ilnd then records It as an \Illage. IntenSity of radar return, for both aircraft and satellite-based systems, depends upon radar system properties and terrain properties Hyperspectral remote sensing deals WIth imagIng at nanrow spectral bands over a contiguous spectral range, and produces the spectra of ali pll,els 1M

the soene Hyperspectral signature can detect the IndiVidual absorpUon features, since all the matenals are

Remote Sensing and GIS tor Dellneabon and Charactenzabon of Groundwater Zones

bound by chemical bonds, thus they can be Idenllfied by their spectral charactensllcs more accurately as compared to broadband multi-spectral ""agers. Hence, hyperspectral data IS being used 10 detect the subtle changes In water, SOil, vegetation and minerai reflectance.

Spacebome Sensors

Dala from spaceborne sensors are globally available for an area of Interest at a speCific time while data from airbome sensors are not available globally though they' have better resolu~on and geometnc accuracy Various spacebOme sensors have been launched In the country and world under vanous remote sensing missions Multispectral data can be selected and obtained for an apphcabon on the basis of spatial resolubon and swath of a satellite sensor (Table 1)

MulUspectral Sensors

Multispectral data from LlSS-1I1 &' IV camera IS Widely used for generating thematiC maps for groundwater' studies In the country It IS a multispectral high resolution camera with a spabal resolution of 5 B m at nadir. The sensor consIsts of three linear odd-even pairs of charge coupled detector (CCO) arrays, each With 12000 pixels The odd and even pixel rows are separated by 35 microns, which correspond to five scan lines Also the placement of the three CCOs In the focal plane IS such that their imaging strips on the ground are separated by 14 25 km In the along-track direction The camera can be operated In two modes Panchromatic and multispectral. In the mulb-spectral mode, data are collected In three spectral bands. a 52 to 0.59 mlcron'metres (green), 0.62 to 0.68 micron metres (red) and 0.76 to a 86 microns metres (near Infrared) These bands can be used for vanous pnnclpal applications (Table 2)

Table I' Spatial resolution and swath of various satellite sensors

Sensor Satellite ResolullOn (m) SWath (km)

'IndIan spacebome sensors PAN Stereo Cartosat-2 (IRS-P5) 08 96 PAN Stereo Cartesat-I (lRS-P5) 25 30 PAN IRS-Ie,IRS-IO 5.8 70 LlSS-IV (Multispectral) Resourcesa!-I (IRS PS) 58 239 LlSS-IV(Mono) Resourcesat-I (IRS-P6) 58 70 USS-III IRS-IC, IRS-I 0, IRS-P6 235 141 LlSS-JI IRS-lAo, IRS-IS 363 148

IntematlOnal spacebome sensors Pan & Mulnspectral IKONOS Pan & Multispectral QUickbird O.SI &266 160 High Re~olutlon VISIble SPOT-5 25,55.10 600 Pan & Mulnspectral GeoEye-1 041 and 165 152 Pan World View-I 055. 176 Pan & MultJspectral FORMOSAT-2 '2.0 and 60

(Note PAN stands for Panchromatl & LlSS Linear Imagmg self scannmg sensor)

In the mul~spectral mode, the sensor proVides data corresponding to pre-selected 4096 contiguous pixels, corresponding to 23 9 km swath In panchromatiC (mono) mode, the data of full 12K pixels of anyone selected band, corresponding to a swath of 70 km, can be transmitted. Nomlnally;'red band data are prefelTed In this mode. The LlSS-IV camera has the additional feature of off-nadir VieWing capability by lilting the camera by +1- 26 degrees for revI51bng and obtainmg a stereo pairs ThiS way, rt can provide a reViSit of 5 days for any given ground area

Table 2 PnJ1CJpat appJlCSbons of the LlSS spectral bands

Band

Pan

MSI

MS2 MS3

Wavelength (11m)

051-073

052- 59

062-68 0.76- 86

Principal applications

Fine geometncal detail mapping, cadastral and cartographiC mapPing. DEM generabon Cultural feature Identlfica~on Iron content In rocks and Salls, vegetabon dlscnmlnatlon, vigour assessment, Cultural feature Identification, plant species dlfferenbatlon. Water body dellneanon, SOil mOisture dlscnmlnatlon, vegetation type dlscnmlnatlon & Vigour assessment, biomass survey

231

Chemical Changes & Nutnent Transformation In SodlC/Poor Quality Water Irngaled Salls

Data Format and Product

Archive and planned satellite remote sensing data from venous sensors and platfonms are available on the country and abroad These data can be selected from vanous data sources given below for further processing for groundwater resource studies Field data from geophysical sensors can be collected Ancillary Information such as topographiC maps, SOils, groundwater depth and quality data can also be obtained from concerned agenCIes

Table 3 Data Fonmats and Products

No

2

3

Product type

Scene based

Mapsheet based

LlSS-III+LlSS-IV (Mono)

Level of correction

Standard

Georeferenced

Geocoded

Merged data

Geocoded

(Note Mx stands for multispectral)

Area covered (km x km)

23x 23 70x 70

23x 23 70x 70

75' x 7 5' 75'x75' 15'x 15'

15'x 15'

70x70

No of Output product bands

3 Mx PhotographiC/digital Mono Digital/photographiC 3Mx Digital Mono Digital 3Mx PhotographiC/digital

Mono PhotographiC/digital Mono PhotographiC/digital

3 PhotographiC/digital

3 PhotographiC/digital

Fig 1 Multiple sources of Image data from left to nght (aenal photo, multispectral Image, radar Image and DEM)

/

Integrated Approach of Groundwater Mapping

Field data are generally collected by ground suNey WIth a sampling scI1eme Area estimates by such survey are unbiased but suffer from high sampling errors due to small number of samples Area estimates by satellite Image classlficalion have no sampling errors but usually suffer from biased (mlsclasslficatlon) These two techniques complement each other and are, therefore, combined to obtain Improved estimates, which are more accurate than eother of the two approaches to be used (Fig 2)-

Unbiased but high sampling error

Fig 2 Integrated SUNeY methodology

232

Biased but no sampling error

Remote Sensing and GIS for Delineation and Characienzahon of GrounClwatef Zones

Analysis Techniques

Many further steps of digital Image processing and modelling are reqUired In order to extract useful information from the Image data SUitable techniques are adopted for a given theme, depending on the requirements of the speCific problem Since remote sensing may not proVide all the Information needed for a full-fledged assessment, many other spatial attnbutes from variOus anCillary sources are needed to be Integraled With remote sensing data This Integration of spailal data and their combined analysis IS performed uSing GIS A digital Image processing and GIS software can be chosen conSidering application and budget constraint (Table 4) Digital Image processing compnses the follOWing four baSIC steps

• Image correctIOn/restoratIOn' Image data recorded by sensors on a satellite contain errors relaled to geometry and brightness values of the pixels These errors are corrected uSing SUitable mathematical models, which are either definite or statistical models

• Image enhancement Image enhancement IS the modification of Image by changing the pixel bflghtness values to Improve Its Visual impact These techniques are performed by denvlng the new bnghlness value for a pixel either from Its eXlstIOg value or from the bnghtness values of a set of surrounding pixels

• Image transformatJon MultISpectral character of Image data allows It to be spectrally transformed to a new set of Image components or bands With a purpose to get some Information more eVident or to preserve the essenlial Informallon content of the Image (for a given application), With a reduced number of lransformed dimenSions The pixel values of the new components are related to the onglnal set of spectral bands via a linear operation

• Image classification The overall obleclive af Image classlflCBbon procedures IS to automatically categorIZe ali pixels In an Image Into land cover classes or themes A pixel IS characterized by ItS spectral signature, which IS determined by the relative reflectance In different wavelength bands Multi-spectral ciasslficatlon IS an Information extraction process that analyses these spectral signatures and assigns the pixels to classes based on Similar signatures

Table 4 Software and tools for dlgllallmage processIOg -.l __ , __ ,- _

Data source Optical remote sensing Radar Remote Sen Sing

Aenal Photography

GIS

GPS

...... , , ~, ~

Software available In the market ERDAS Imagine 9, PCI Geomatlca 9, ENVI 4 2, IDRISI Kilimaniaro ERDAS Imagine IFSAR module, ArcVlew-SARscape, Geomatlca Radar, PhoeniX SARIlnSAR Toolkit

ERDAS Imagine Photogrammetry SUite, PCI Geomatlca 9 OrthoEnglne

ESRI ArcGIS Arclnfo 8 x, ArcV,ew 32, GeoMedla Professional, PC Raster, GRAM" Trimble Pathfinder ProXRS With post processed phase dIIf correction, Garml" Etrex-Vista & GPS12

Delineation and Characterization of Groundwater Zones

• Preparation of hydrogeomorphological and other thematic maps

Groundwater can be distinguished In the near Infrared wavelength due to low reflectIOn of water Synoptic View, repetitive coverage and capability to view the scene In several spectral bands of VISible and NIR portions, are speCial characteristics that have made remote sensing an effective tool In groundwater exploration Spatia-temporal distribution of groundwater depends on the underlYing rock formations, the" structural fabnc and geometry, and surface expression The remote sensing data in coni unction With suffiCient ground truth Information proVides Information on the geology, geomorphology, structural pattern and recharge conditions which ultimately define the groundwater prospects The surface expressions of aquifers are the baSIS of clue to groundwater prospecting which can be diSCriminated by remote sensing techniques

A standard soene or geocoded data of false colour composite (FCC) Image of the selected sensor of the study area IS obtained on CD-ROM from the National Remote Sensing Agency (NRSA), Hyderabad In case of standard scene, the Scene IS to be rectified and georeferenced uSlrtg SUitable ground control pOints obtained from Survey of India topographiC maps or GPS survey Visual or digital interpretation of a FCC of mulb spectral data IS earned out by taking IOto conslderallOn vanous Image and terrain elements for the preparation of vanous thematiC maps Significant hydrogeomorphlc units are demarcated based on tone, texture, shape, Size, pattern, aSSOCiation, etc Delineation of all linear features on the FCC Image IS carned out and these hnear features are further claSSified Into fractures, faults, shear zones, straight hthocontacls With

Remote Sensulg ariel GIS tor DelIneation and Charactenzabon of Groundwater Zones

/

Analysis Techniques / .

Many furth.er steps of digital Image processing and modelling are required in order to exllact useful Information from the Image data SUitable techniques are adopted for a given theme, depending on the requirements of the speCific problem Since remote sensing may not provide ali the InformaUon needed for a full-fledged assessment, many other spabal attnbutes from vanous anCillary sources are needed to be

~ Integrated With remote sensing data Th.s integrabon of spatial data and their combined analysIs IS perfonned using GIS A digital Image processmg and GIS software can be chosen considering application and budget constraint (TabJe 4). Digital Image processing compnses the following four baSIC steps \

• Image correction/restoration Image data recorded by sensors on a satellite conta;" errors related to geometry and bnghtness values of the pixels These errors are corrected uSing sUitable mathematlcsl' models, which are Mher definite or statlsncal models. ~

• Image enhancement Image enhancement IS the modification of Image by changing the pixel brightness values to Improve lis Visual impact. These techniques are perfonned by denVing the new bnghtness value for a pixel either from Its eXIsting value or from the bnghtness values of a set of surrounding pixels

• Image transformation Multispectral character of Image data allows It to be spectrally transformed to a new set of image components or bands With a purpose to get some informabon more eVident or to preserva the essential Information content of the Image (for a given application), With a reduced number of transformed dimensions The pixel values of the new components are~ related'to the on9lnal set of speellal bands via a hnear operation

• Image classification The .overall obJective of' image classlficabon procedures, IS to~ automabcally categonze all pIXels In an Image Into land cover classes or themes A pixel IS charactenzed by Its spectral signature: which is determined ~by ~the relative reflectance in dllferent wavelength ,bandS Multi-spectral claSSification IS an Infonnabon'exllacton process that analyses these spectral~sl9natures and assigns the pixels to classes based on Similar signatures . .

Table 4:' Software and tools for digital Image processing

Data source Optical remote sensing Radar Remote' Sensin9 -- ~ - .

Aenal ~hotography

GIS

GPS

Software available In the market .ERDAS Imagine 9, PCI Geomabca 9, ENVI 4 2, IDRISI KlirrnanJpro ERDAS~lmagine IFSAR module, ArcVlew-SARscape, Geomatlca Radar, PhoenIX SARIlnSAR Toolkit

ERDAS Imagine Photogrammetry SUite, PCI Geomatlca 9 OrthoEnglne

ESRI ArcGIS Arclnfo 8 x, ArcView 3.2, GeoMedla ProfeSSional, . PC Raster, GRAM++ Tnmble Pathfinder ProXRS With post processed phase dlff correction, Garm," Elrex-Vista & GPS12

Delineation and Characterization of Gr,?undwater Zones

• Preparation of hydrogeomorphologlcal and oth.er themat)c mapa

Groundwater can be distinguished In the near Infrared wavelength due to low reHectlon of water Synoptic View, repebUve coverage and capability to view the scene In several spectral bands of ViSible and NIR porllons, are special charactensbcs thai have made remote sensing an effective 1001 '" groundwater explorabon Spatia-temporal dlsbnbutlon of groundwater depends on the underlYing rocl< formations, their stnJctural fabnc and geometry, and surface expression The remote sensing data In conjunction wllh suffiCient groiJnd truth Informallon proVides Information on the geology, geomorphology, structural pattem and recharge conditions which ultimately define the groundwater prospects The surface expressions of aqUifers are the baSIS of clue to groundwater prospecting which can be discriminated by remote sensing techniques

A standard scene or geocoded data of false colour compoSIte (FCC) Image of the selected sensor of the study area IS obtained on CD-ROM from the Nallonal Remote Sensing Agency (NRSA), Hyderabad In case of standard scene, the scene IS to be rectified and geore!erenced usmg SUitable ground control pOints obtained from Survey of India topographiC maps or GPS survey. Visual or digital interpretation of a FCC of multi spectral data IS camed out by laking Into consjderation vanous Image and lerraln elements for the preparallon of various thematiC maps Slgmficant hydrogeomorphlc units are demarcated based on tone, texture, shape, SIZe, pattem, aSSOCiation, etc Delineation of all linear features on the FCC Image IS carned out and these linear features are further claSSified Into fractures. faults. shear zones, straight Iithocontacts With

233

Chemical Changes ~ Nutnent Transformation In Sodlc/Poor Quahty Water Jmgated Sods

, 1 available Information Delineahon of landforms Including hydrogeomorphologlcally significant landforms VIZ valley fills, ,alluVIal fans, piedmont zones, alluVIal plains, braided channels, abandoned channels, palaeochannels, flood plain etc are carned out In the area covered by unconsolidated sediments All the delineated hydrogeomorphlc landforms are suffixed With lithology type On the baSIS of Image charactenstlcs, salls, hydrology, land use and land cover, etc maps are prepared through onscreen Interpretation of the Imagery using flow diagram (Fig 3) Land use and land cover map ,s prepared uslng multispectral claSSification technique Digital elevation model can be generated from the dlgltlzahOn and spatlallMterpolatlon of contour lines and spot elevation from topographiC map or uSing stereogrammet,y of satellite stereo data Slope and aspect maps of an area are" denved from a OEM whereas drainage map IS prepared from mterpretahon of the FCC and OEM The Interpreted all thematiC maps are checked dUring the ground truth colieChon Interpreted maps are mod,fied by taking Into conslderahon the ground observations to prepare a hydrogeomorphologlcal map at the study area. All maps are imported to GIS software VIZ ArcGlS 9 1 for integrating ancillary data tor further analYSIS Groundwater depth and quality data and maps are also digitized In GIS software After dlgltisatlon, error removal and attnbutahon of anCillary maps, groundwater prospects and quality maps are thus prepared to develop groundwater prospective zone map 'at dlstnct scale The groundwater prospeChve zone map IS draped on dlgllal elevation model (DEM) to develop a map of further groundwater development .

Remote Sensmg data r Toposheet Field Data I lISS IV -, 1 50,000 scale + +

~:Ih ,I DnUmg I Hydro-geomorphology PreparatJon Of Contour and Preparation of InterpretabOll of

& Irneaments maps drainage map spot elevation geoelectncaJ geoelectncaJ map soundmg map sounding

I I ,., CopverBlon to OEM Slope Map I GeoeIec:tncaIl---Digital formal parameter

I I -r CorrelaOOn cI geoe!ectncal parameter

+ GIS Dala base I 01 dnlled SItes With

......

I Inbsgraoon Into GIS I II Based on correlatIOn, lithOlogy IS Inferred at other sounding locations

'" I Modeling for ldentlflCatiOn of zones I r Infemd lithology sod \hlcmen frool geoelectncaJ

y parameters alre&peatve I~bon is

I Groundwater potenbal zone map I I PreparatIOn 01 overburden thickness and aqurt'er -r layer ~lCkness mapa uSing GIS

Fig 3 Flow diagram at locah ng groundwater potenll3l zones

• Oeline"tlon of groundwater potential zones based hydrogeomorphlc units

It IS necessary to carry out rapid geophYSical scannrng In an area by ground penetrattng radar, electncal reSistiVity, borehole logglOg, electncal reSistiVity, geoelectncal squndlng and groundwater quality sample Information to Integrate themahc maps With subsurface water quality data '" order to acqUire oomprehenslvEl knowledge on groundwater prospects and quality of an area The imperviOus clay thickness and aqUifer depth and quality information are Integrated to GIS In order to demarcate the groundwater potennal zones

, The hydro-geomorphologlcal, geology, slope and land use and lan'd cover maps are SUitably SUbdiVided into feature classes In GIS according to the Table 5 and are given score and welghtage A GIS based groundwater potenbal map IS thus prepared uSing an equatron given below The details of delineated geomorphic units WIth groundwater prospects In Haryana are grven In Table 6

234

Remote SenSing and GIS for Delineation and Charactenzabon of Groundwater Zones

Table 5- Fealure class WIth welghtage and score for groundwater prospecllng

Theme We'gntage (%) Feature class ResIdual hIli com plex ResIdual hili Residual mound

,. Pediment

Hydro- 45 Valley fill geomorphology "alley flat

FloodplaIn Water bodies

I J AllUVial plain

Sandy Silty allUVIum Co?stai sand Brown sand Lalente Llgnlteilrlt!y sandstone

Geology 35 Dolente Pegmatite and quarts veins Garnet biotite gneiss Cordiente gneiss Chamocklte Quartzite

0-7 8-15

Slope 15 16-25 26-35

>35

Paddy field Abandoned paddy field Mixed crop

Land useiland 5 Rubber plantabon

cover Reclaimed paddy field Urban area Industnal estate Water body

Groundwater potentlal map (GPM}

GPM = (Geomorphology! x 0 45 + (Lithology) x 035 + (Slope) x a 1

.. (Land useiLand cover) x a 05

Score 8 5 1

10 17 20 23 25 25

25 23 22 6 20 1 1 4 2 4 1

25 18 10 04 01 25 23 11 6 15 2 2

25

(1 )

VIBGYOR colour code IS used In denobng degree of groundwater prospect In GIS (Fig 4) \Mlile VIolet indicates high prospect for groundwater occurrence, red colour region shows no prospect for groundwater Groundwater prospect l)1ap shows probable regions where borewells can be dnlled These maps have faCilitated Identifying sources of dnnklng water for deprived Villages follOWIng national level hydrogeon'lOlphic mapping shOWIng groundwater prospect areas on 1 250,000 scale, more detailed maps for few prionty states on 1 50,000 scale are generated In GIS enVIronment under the Rajlv Gandhi Nallonal Dnnklng Water MiSSIOn The feedback has shown more than 90% success rate, when wells were drilled on the baSIS of groundwater prospect maps generated uSing Integrated approach of remote sensing and GIS (Table 7)

235

Chemical Changes &' Nutnent Transformation 111 SodlcJPoor Quality Water Imgated 501l:s

/

Table S' Groundwater prospects of vanous geomorphic units ~

Geomorphic Units Fluvial ongln Alluvial Plain Alluvial plain With· sand cover Palaeo channel IAbandoned channel Denuda~onal

ongm Pediment

Inter-montane Valley/Basin Valley Fill Residual hills

Structural ongin Structural Hills . Linear Ridges

Descnpbon Gently undulabng plams consisting of clay. Silt, fine to coarse sand of varying lithology With extensive Undulating plains comprising sand, slit and clay Sand IS \ dominant but stabilized \, Channels which are cut off from main course of the nver, buned, or abonded Comprises of flUVial deposits (sand, Silt and clay particles) Occumng near to structural hills gently slopping area compnslng collUVial matenal and medium to fine grained sand and Silt This Unit has higher thickness near ndges and laterally merge with allUVial plain DepreSSion between mountains, formed as broad baSin consisting of collUVial depoSits covered With allUVium Unconsolidated matenal coarse to fine sand, Silt and clay Isolated low relief hili formed due 10 differential weathenng conslsbng of metasediments Structurally controlled steep Sides hills associated With tolds, faults, fractures and JOints these are meta sediments of Deihl super group (moderate along fault planes) Long narrow low lYing linear to arcuate hills nSlng from allUVial plains acbng as bamers of ground water flow

Fig 4 Groundwater prospect map generated In GIS environment

Table 7, Success ,rate of remote sensing based groundwater prospect mapping under. RaJ'v Gandhi National Dnnklng Water MISSion (RGNDWM)

State

Andhra Pradesh Chattlsgam GUJarat Kamataka Madhya Pradesh Kerala

No of wells dnlled as per groundwater prospect maps

29,873 19,503

34 5213 7730

10,430

• Reproduced from Navalgund et al 2007

236

Success rate (%)

900 900 1000 930

920 900

Water Prospects Excellent

Good

Very Good

Moderate to good

Excellent

Good Poor

Poor to Moderate

Poor

Remote Sensing and GIS for Delineation and Characterization of Groundwater Zones.

Groundwater quality Information wrth tJiree quahty classes on the basIs of EC I e good (EC vanes from 0-2 0 dS/m), marginal (EC from 2 0-40 dS/m) and poor (EC > 4,0 dS/m) IS Integrated to GIS With other thema~c maps for preparabon With groundwater quality map With depth Groundwater quality map of three zones of HalYana With water table depth information IS prepared (Fig 5)

Concluding Remark

legend

0.,"" .... GWQuallty

!;Q """...,-

~""'-EilI .... __

Fig 5 Groundwater quahty of Map of Haryana

Integrated approach of remote sensing, geophYSical scanning survey'and GIS IS very useful for the preparabon of groundwater prospect mapping and poor quality groundwater zones on a sClenbfic baSIS The Information generated on prospects, quality and depth In a Single map Will help the planners and deCISion makers for,devls,",g sound and feaSible groundwater development and recharge plans for sustainable 'use

Bibliography

Campbell, J R 2002 Introduchon to remote sensmg, Third edlbon, London Taylor and FranCIS Gibson, P J a nd Power, C H 2000 Introductory remote sensing dlgtlal image processing and appiicatlons

London Routledge Jensen, J R 2000 Remote sensing of the environment an earth resource perspecflve Prenbce Hall Senes ,n

GIS, New Jersey- Prentice Hall Liliesand, T M , Kiefer, R Wand Chipman, J W 2003 Remote sensing and Image Interpretaflon Fifth Edition,

New York John Wiley & Sons Mather P.M 1999 Computer processing of remotely sensed Images an Introducflon. Second ed,llon;

Chichester. John INIley and Sons Navalgund, R R , Jayaraman, V and Roy, P S 2007 .. Remote sensing apphcatlOns An overview Current

SCience, 93 (12), 1747-1766

Richards, J A and Jla, X. 1999. Remote senSing digItal Image analYSIS an introduction Third edition, Berlin' Spnnger-Verlag

INIlhams, J 1995. GeographiC infoml8uon from space Processing and application of geocoded sat9111te Images, INIley Pra,xIS senes In remota sensing Chichester John Wiley & Sons and PraxIs Publishing

237

~ ,

Remote Se'!sing & Geographic Information System tor Appraising Salt-Affected Soils /

./ Madhurama 5e-thi D,v,s,on of Sot! and Crop Management C~ntra' Soli Salimty Research Institute, Kama'-132 001

Introductlon

Predlcfing and mapping salinity is a challenge oonsidenng the vast vanabon In the 'field and constraints that "anabillty presents Mapping opportunlfies for qualltafive and quanutafive changes In'infonnatlon COl/ecbon, storage and dissemination present constant reason for expenmentallon and Innovafion Dunng ths past two decades the availability of remotely sensed data, Improved hardware from Global POSitioning System (GPS) to high technology sensDls, and Improved sollware based on cartographic pnnClples mainly Geographic Infonnallon System (GIS) has enhanced understanding and management of agnculture, salls and other natural systems and now proVide updated and hi-tech maPPtng opportunrties Geographical data play a key role In den'llng Infonnalion on natural resottroeS and enVll'onment Ii'om aenal photographs and satellt!e data, and in the interpretation of spatial and attnbute data In a GIS environment for doosiOI1 making. Timely and reliable ,nfom1afion about the status of natural resources, espeCially solis WIth respect to their potentials and limitatiOns IS a pm-requlsrte for sustainable development Satellite remote sensing data by Virtue of synopbc coverage of a fairly large area at a regular IntelVal hold a great promise In prOViding qualltaWe and quanfitabve information In a fimely and sCienfiftc manner

Origin of Remote Sensing and GIS

Hlstoncally, the first photographs taken Ii'om a small rocket, from a height of about 100 m, were Imaged from a rocket deSigned by Alfred Nobel (of Prize fame) and launched in 1897 over a Swedish landscape Remote sensing from space received Its first Impetus through remote sensing from rockets As early as 1891, the Germans were developing rocket propelled camera systems, and by 1907 gyro-stablhsabon had been added to Improve picture quality Space remote sensing began In eamest In the pened 1946-50 when many cameras were earned on rockets and balhstlc mls~lles The development of meteorological .sateilltes prOVided the Impetus for most modem remote sensing TIROS-1 was launched In 1960 and retumed the first coarse Views of cloud patterns Wrth refinements in Imaging sensors meteorologists-began to collect informatIOn on terrestnal features as well and the concept of looking through the atmosphere evolved The manned spaceflightS of the 1960's and 70's Yielded spectacular photographs of the earth's surface and faCilitated the first use of mUlb-specbral and microwave Instruments from space FollOWing the success of Ihesa missions the firsl earth resources satellites were planned in 1967 and the ERTS-l satellIte was launched by NASA In 1972, in what was to beCOme the forerunner 10 the LANDSAT program The most important outcome of devetopments In space exploration and remote sensing has been the role of these technologies In conceiving of tile earth as a system Space remote sensing has brought a new dimenSion to our urlderstanding not only the natural wonders and processes operating on our planet but also the Impacts of humankind on earth's traglle and Interconnected reSOurce base Currently, the satellites in space VIZ the f'ranch SPOT, -The Indian IRS, The Ameflcan LANDSAT/NOAA snd other $steliites are Widely used for weather fOrecasting, agnculture, forestry, bathymetry. oceanography, fishenes a~d other applications

For map production, a new dlsdphne VIZ computer assisted cartography (automated Imodern) was &at up. Meanwhile sClen~sts, planners and policy makers have Increasingly become aware of the Importance of acquinny and using computer based systems that enable any type of environmental Information to be effiCiently and cost effectively handled, analysed. and displayed Consequently. pubhc and pnvate agencies and sCienliftc mSlttutlOOs made several attempts to extend to the realm of geographical data and the methods used in the processing of tabular (non-spabal) data through data management systems) DBMS These data were combined With new and Improved resolution satellite Images to produce updated multispectr"l, mulb temporal and mulb theme maps.

Remote Sensing

Remote sensing IS a technology used for obtaining Information about a target through the analYSIS of dam acqutred frOm the target at a dIStance It is composed of three parts, the targets-oblects or phenomena In an area, the data acquIsition - through certain instruments, and the data analySIS - again by soma deVices ThiS ciefinltion IS so broad that the vISion system of human eyes, sonar sounding of the sea floor, ultrasound and x-rays used In medlcsl SCiences, laser probing of atmosphenc particles, are all Included The target can be as big as the earth, the moon and other planets, or as small as biological cells that can only be seen through microscopes

Remote Sensing and GIS for AppraIsing Salt-Affected SOils

Remote sensing data acquIsItion can be conducted from vanous piatfOTms sucl) as alTcrail, satell~es, balloons, rockets, space shuttles, etc Inside or on-board these platforms, sensors are ~sed to collect data In the vanous parts of electromagnetIC spectrum (Fig 1) SensolS mclude aenal,photographlC cameras and nonphotographic instruments, such as radiometers, electro-opt,cal scanners, radar systems, etc Electro-magnetic ener9Y is reflected, transmitted or emllted by the tar'ijet and recorded by the sensor. BE!cause energy travels through the medium of the earth's atmosphere" It IS modified such that the Signal between the taiget and the sensor Will differ i ,

" ,~I"fle ,~;",.l~ I:n, Flg,_1 SensolS wlt~ different ~-V; le~gth~ of In electro~agn,etlc sPectrum • 91 ~,~",'" J .,t I! 12 firH fll Itl,Ni.:.1 ,t \" l ;.,,1'''' -w."" ,l\~" ,~\ ,,-,I,_, , ... , '_ _ .,

., .. h' ,>.OnceJm~ge,data ~re a.CQUlred;we ne€(j methodsior Interpreting and analYZing Images By KnOWing :'w~'!\~'!~\0'l!'alKl!, _we)e~ct ~o. <:len_va from remote sensIng followed by the how (metl\odology) and where ,(geog,\!ph!caJ .lcx;atlon),',and hoY', such data can: be tranM~rrned 'into valuable Infonmabon about the earth surface Remote sensmg Information is In raster format wM x and y coordmates

;_·r ........... "''""I'''I~ ..... '"'_ _ -,~. - ~ ,..-.. 1"1

, • I, ~. :.:[ "r:~.:l ,....!!.?:.rJr, 1~:J'19~-~ It b:...:;.~· E:~i"'~. ,~ L )1.[1,': II',,: • ~ ~. RasterDatahasthefoliowmgcharactensfiCS,,(," :_0"<'" f'c-S H,<N

• ..., •. ~ "'l', ..... '.:.'t-; ... ; ...... c ~. t.,'lr",~ l,.r.f.<i'lt'~I' v\.Jt.'rl"lIfClblfJ<.;.:;J .... ;1 , "0' 'Points; lines and polygons everythmg In the form ot pIXels (Fig 2a)' ,_, ,1, l l" r .1,.' .. - Pll' nl \.~~J..l -.J .. \~ \,.1 t.,~ ... l~, ,,,1.." • .II • ...J .... <..- .-

• Large file size • Networ1<S are not 50 well represented . • 1 Only one pixel value represents each glld'eell ( ':(jHl

n' ~ ,\'" " ~I~ft

• _ .,,~l "1 ~f ,.f IW~f1 .. 1'

• GeneralIZation of features (like boundanes) hence accuracy may decrease • SimulatIons and modeling IS easier (spabal analYSIS, teiraln-mOdeling etc) • Malntalnlng\ IS easrer r;rnul(.LV (.)1;:

• Excellent for representing data contalnmg contmuous values (lIKe land use, elevabon etc,) • -f ,... >,

., ,CoOrdinate-systeni transformations taKe-more time and con.sume a lot of mamOly

• Gnd cells or pixel makes SImpler data structure

A row of pixels (Fig 2b) rep~sents ,a ~~n hne coll,!:C!~d,as the sensor moves left to nght or collected through the use of a linear array' of photodetectors An Imag~-,s composed of pixels geographically ordered and adlacent to one another consisting of 'n' pIxels In the x direction and 'n' pixels In the y direction A satellite Imagery contains number of bands depndlng upon the sensors capblilty: for an example, LlSS-IV sensor dala contains three bands viz green, red and near Infrared bands.

a)

~ 25

b)

239

-' ;,"26~ ~i6 ,0--.,

Chemical Changes & Nutnent Transformatfon In SadiclPoor Qua.llty Water Imgated SOils

. ,~rf':~;;:~~~:·:=~~"=.",::-:c~,,,:::=· 'zn~

c) p)

~ ~. '7J

Fig 2 A satelhte Imagery of 7 bands With digital numbers a) a pixel, b) a scan line and c) an Image wilh rows and columns and d) an Image With 7 bands

Geographleallnfcirmation System'

A geographic Informallon system (GIS) IS an information system for capturing, stonng, analyzing, managing and presenllng data which are spatially referenced (hnked to location) In the stnctest sense, It IS any Information system capable of integrating, stonng, editing, analYZing, shanng, and displaYing geographically referenced mformalloQ In a more genenc sense, GIS apphcabons are lools that allow users to create Interactive queries, analyze spallal information, edit data, maps, and present the results of all these operallons, GeographiC Intormallon sCience IS the sCIence underlymg the geographic concepts, apphcallOns and systems, GeographiC Information system technology can be used for scienbfic Investigations, agncu~ure, land use studies resource management, asset management, environmental Impact assessment, urban planning, cartography, cnminology, geographiC history, marllellng, and logiStiCS 10 name a few GIS data IS stored and manipulated In vector format as well as vector fonmat data IS also used In the exchange of GIS data

Vector data IS spatial data stored as pairs of x and y coordinates, usually With 10 numbers, data typically stored In separate data tables and ha~ the follOWing charactensllcs'

• Represented by pOint. line and polygon • Relatively small file Size (small data volume) • Excellent representabon of networks • A large no of attnbutes can be attached, hence more information Intensive and a number of themallc

maps can be prepared from a Single layer .' Features are more detailed & accurate ., Creating, cleaning and updabng data is more time and labour consuming, • Topology-based analYSIS ~ operations are easier to perform (like network analySIS etc) • Cannot represent conllnuous values nke land use, elevation etc very welf • AsSigning projection and transformations are less time taking and consumes less memory of the

computer system '

GIS faCIlitates' , >

• The analysis of information & properties derived from such data

• ThiS can be done In a spatial manner,

• Allows the changes in pattem and somellmes process to be charactenzed

The good complimentary use of GIS reqUires that In thiS process InformallOn on data hneage and metadatasuch as data error, accuracy and preCIsion are retained and passed on

• Topology makes data structure complex

240

Remote Sensing and GIS for Appraising Salt-Affected Salls

I'~='-I ~.--

Fig 3 GIS data types WIth few Ihemabc maps in vector formats

Integrated Data Processing

Mosl of the geospallal data processing packages have attempted- to Integrate earth observallon data processing and GIS functIOnality For' example Ihrough Ihe use of map boundanes data to aid Image dassificalion-- so caITed per-field classification, through the use of GIS data sets to aid image classification In the form of extra discriminatory layers - e 9 , topography, SOil type etc, and/or, through the combmatlon of both map data boundaries and GIS data sets to aid Image dasslficabon - so called CLEVER mapping

Fig 4, Steps of CLEVER mappmg

Geospabal data processing has malar relevance IS In Inventorying (dellneabon and mapping), mOnltonng temporal change, and creation of spatal and non-spatal databases, evaluation of status/conditions of natural resources follOWing modeling approaches, Integrating analYSIS follOWing modeling approaches, EnVIronmental Impact Assessment, Cosl-benelil analysIS

Sources and Types of Soils and Crop Inventory Data

• Data sources

Generally, the sources of data can be broadly claSSified according to whelher Ihey are primary or secondary and digital or non-dlgltal (Table 1)

241

Che~TIIcal Changes & NLJtnent Transformation In SodlclPoor Quality Water Irngated SOils

Table 1 Data Sources for salt affected, watenogged SOils and ClOp Inventory ~some examples)

Non-<llgltal

Pnmary

Field mapping Field Hand-recorded data Laboratory analyzed soil and crop samples data, 5011 & Crop reflectance ground radiometry data

\

Secondary

\

Map

Tables

GPS (Global POslbonlngSyitem) Digital Field observatJon

Setecbon of Remote Sensing Oata

Field Instruments WIIh data logger Automabc weather sta~on meteorological data Remote Sensing data (CCTICD-ROM)

Selection of remotely sensed data for an appllcabon project depends on several factors SUch as

• scale of mapping (Table 2), • compleXity of spatlaJ dlstnbullon pattem of natural resources, • compleXity of the resource,

• frequency of temporal analYSIS, • extraction 3-<llmenslonallnfoll11atlon (elevabon/helght) of the terrain, etc

Table 2 Mapping scale 01 various sensor data

Mapping scale 1100,000 to 1 500, 000 or smaller 1 SO, 000 to 1 100,000

1 25,000 to l:SO,OOO

110,000 to 1 25,000

15,000 to 1 10,9000r larger

R S data reqUirements IRS-USS-I, LANDSAT -MSS IRS-USS-II & USS-III, LANDSAT-TM, SPOT·MSS, HYPERION, high ailitude aenal photographs (>12 km) IRS-USS-III, PAN, SPOT-MSS, medium altJtude aenal photographs (3 -12 km)

IRS-1 CI1 D-PAN, Cartosat PAN, SPOT-PAN, low ailitude aenal photograph Very low altitude ae~al photographs, very high spatial resolution satellite data (e g IKONOS)-

Hardware and Software Requ irements for RS a nd GIS

A robust computer system is a must for smoothly perfonmng all the requITed operations We can divide hardware In two categones- essential and opbonal The essential hardware Includes Computer monitor, CPU, keyboard and mouse ThiS is the basic reqUirement to start werning in GIS Op~onal hardware Indudespnnter, plotter, scanner, projector etc It IS good to have optional hardWare also but only If your budget permits, otherwise these can be outsourced Apart from these one should have storage and data transfer deVices also, Ilke- CDs (for transfernng & stonng data which IS small In volume), DVDs (for larger data sets), pen dnve, extemal hard disk etc

242

Remote Sensmg and GIS for Appraising Salt-Affected Solis

GIS software

• ArcGIS (PC or Wori<slat,on based) • ILWlS (PC basecl) • Maplnfo (PC based) • Geomedla Professional ,

Digiialimage processing (DIP) Software

• • •

ERDAS Imagine (PC based, Wori<stallOn based) Geomabca (PC based, Worl<statlon based) ER-MAPPER (PC ~sed)

• ILWlS (PC based) , I

Delineation a~d_ Mapping of Salt-Affected Waterlogged Solis

Image interpretation of remotely sensed cata can be attempted either by visual or digital techniques of analysIs The purpose of applYing either of the, above two techniques IS for feature Idenbficabon and classlficabon The methOdOlogy for conducting visual Interpretation of multl-date satellite Imagenes compnses the following SIX major steps

• Selection and acquisition of data, Standard FCC ImageI)' or raw Imagery of IRS data of Khan( and Rablseasons

• Preliminary visual interpretation. IRS FCC's of Khall' and Rabl seasons are Interpreted IndIVIdually making use of the Interpretabon keys The boundanes of land uselland cover classes are plotted onto transparent overlay, such as artlan or polyester traCing sheets

• Ground data collection and veriflcation FollOWIng the preViously drawn scheme and transverse plan, ground truth information IS collected as per specific performa to cover at least 80 percent of the dlstnct as a reconnaissance Inlbally In areas where no mapping has been conducted before~ 10 percent once the mapping has been established Areas of doubtful preliminary InterpretallOn are particularly verified

• Final interpretation and modification Based on the ground truth data, modifications are effectE'd and classes as well as their boundanes refined

• Area estimation Areas under different classes are estimated by computer for digital data/or plammetenc measurements for analog maps to complete dlstnct land use statistics

• Final cartographic map preparation and reproduction: Fair draWings of angina 15 are made as per predesigned speCifications and cartographiC symbols on the computer or manually

Land uselland cover maps have been completed follOWing the visual Interpretation approach for a large part of the country,

A number of factors determine the vulnerability of SItes to salinization and are as follows

• the position of a site within a landscape - generally the lower It IS, the more likely It IS that the water table Will reach the surface and cause salinization

• SOil type • management - such as the extent of cleanng

• rainfall

Combining infolTTlabon on these and other factors could alloW the predictIon of Slt~S vulnerable to the saline menace ThiS IS where a geographiC information system (GIS) takes on an Important role because the data are stored In digital form they can be analysed readily by computer In the case of salinity, sCientists can use data on rainfall, topography, soil type-Indeed, any spatial information that IS available electronically - to ~rst determine the combinations most susceptible to salinization, and then to predict Similar regions that may be at nsk

CSSRI has earned out the Important tasks of coll€ctlon of database, Inventory and information gathering for updabng the status of salt-affected waterlogged Salls USing multl-date Images, Image processing tE'chnlques, GIS and ground truth data, there IS a continuous effort to add to the detailed Informa~on on the status of salt affected Salls

243

Cherrlleal Changes & Nutnent Transformation In SodldPoor Quality Water, Irrigated SOIls

Mettemlcht & Zinck (2003) have Impressed the fact thai nearly 20% of all irrigated land IS saltaffected These lands tend to Increase In proportion despite considerable efforts dedicated to land reclamation and require careful monltonng of the SOil salinity status In some areas of the world where salinity IS a major problem; II is rather difficult to mOnitor the required ground infonmauon In the areas affected by salinity (Gates et al , 2002) therefore multltemporal Image analYSIS might be effective In detecting salt dynamiCS In a certain region and assessing the degree of damage on both crops and Yield Howan, (2003) has' indicated the capability of remote sensing data such as lANDSAT ETM+, airborne vlslble/mfrared Imagmg spectrometer (AVlRIS), colour mfrared aerial photos (CIR), and high-resolution field spectro radiometer (GER 3700) to extract surface Infonmatlon about 5011 sallmty, A quan~tatlve error assessment showed, that 75% of all saltaffected sites are being detected (Furby et ai, 1995)

On the baSIS of greenness and bnghtness, sallnlzed and cropped areas have' been Identified WIth classical false-colour composites of three selected bands or WIth a computer-assisted land-surface classlfica~on technique (Kauth and Thomas 1976, Hardlsky, Klemas and Dalber, 1983, Steven et ai, 1992, Vincent et al , 1996) RatiOS of ViSible to near infrared and between Infrared bands have proven to be better for Identifying salts In SOils and salt stressed crops than IndiVidual bands (Craig et al 1996, Hick and Russel 1990 and Hick et a11964) The accuracy of mapPing shallow groundwater depth and salinity uSing remote sensing data were studied A methodology was formulated Involving image processing and GIS·techniques uSing false colour compOSite, vegetation indiceS, denSity sliCing, overlaymg and supervised -claSSification and applied the methodology to IRS,1B USS-II data In their study: groundwater depth and salinity maps were based on refiectance vanatlons of vegeta~on above the ground surface, they assert that the speCies of vegetatJon found In the aTea and vegetaten dens~les can proVide eVIdence of shallow ground water conditions

Sethi, et al (1996) camed out an assessment of SOil salinity and waterlogging In the Ukai-Kakrapar command In GUlara! and Kanpur dlstnct In Uttar Pradesh uSing IRS data Sethi et al (2oo6r studied Shorapur Taluka, located between 76'15 and 76·56 E longitudes and 16'10 and 16°35 N latitudes ThiS area receives Imgatlon waters from the Knshna left vank canal 'under the UpPer Knshna Irrigalion Project In the dlstnct of Gulbarga, .n the state of Karnataka The SOils In Shorapur are extenSively affected by salimty and waterlogging problems Images from IRS ID-US5-1I1 for 27 March 1999 were Interpreted to assess the extent to which salt affected soils could be Iden~fied and InventOried and mapped NRSA reported 2mha In 1996 and reVised It to 1 2 million ha (NRSA 1996' and 2004) CSSRI has recently reported about '67 m ha -under salty lands

Future Prospects

The overall sltualion on the status of salt affected lands raises an Important question should greater efforts, including Investment, be made Immediately to combat salinity degradation, or should these await the acqulslbon of better data? Much mforrnahon IS already In a form that can be used In a GIS, and more IS being added continuallY-Including that produced by satellite data al'\d ground truth As the databases and prediction techniques improve, farmers and land management agencies Will be better placed to wage an assault on salt

Estimates of the extent of sallnlty/wate~ogglng, andlor Its effects on crop production, may be conSiderable Because the data arE! so uncertain, we need to clearly state the seventy of sallnrty decay and prOVide _a better foundation of eVidence, so thaI expenditure of scarce development funds are spent on measures to combat sallmty degradation,

ThiS view serves one Important purpose, In that It places emphaSIS on what are, Indeed, large uncertainties In estimates of the eldent of degradation and ItS effects_ Overuse of water, changing croPPing patterns, nSlng water tables In Imga~on commands and degradation from seoondary salinization are a reality Whilst It IS certainly true that some of the estimates are based on Questionable foundations the most certain reports indicate and pOint to the certain existence of two types of srtuatlons:

• Severe degradation in speCific areas, complete sallnlzabon • Light to moderate salinity degradation over extensive areas, e 9 the evidence for soil fertility

decline and reduced productiVity

It IS, therefore, apparent that, although m"ore precise data should be obta.ned Since the total eVidence IS suffiCient to call for Immediate aelion to map and re-quantlfy the areas under salinization The NBSS&LUP, Nagpur have made considerable effort over the yealS to delineate saU affected soils In different agro ecological zones, these are by far the most sCientifically accurate estimate we have so far, however there IS an urgent need for conducting a nationWide update on the status of sa~-affected SOils and updating the maps uSing satellite Imagery and limited ground truth A nodal agency must be Identified and all resources provided to proVide an updated accurate and Vitally essential database on the status of sail-affected SOlis In the country"

244

Remote Sensing and GIS for Appraising Sail-Affected Salls

Bibliography

Craig, J C, Shih, SF ,Boman, B J ,& Carter G A(199S) Deteclion of sahnlty stress In Cltru~ trees uSing narrow band multJpsectral Imagm9 ASAE paPer no 983076 ASAE Annual Intematnonlll Meeling Ortando, FL,USA, 12-16 July, 1998,10pp

Furby, S L, Wallace, J F., Caccetta, P. and Wheaton, G A. (1995) Detecling and mo,lItonng salt-affected , land Report to LWRRDC project 'DeteelJng and Momtonng Changes In Land COndrtlOfl Through

TIme USing Remotely Sensed Data . Gates, T, J. Bur1<halter, J. labadie, J. Valliant and I Broner. 2002 Momtonng and mocleiling flow and salt

, transport In a salinity threatened imgated valley J, of Imgatlon and Dramage Englneenng-ASCE 128. 87-99 _ -

Hlck,P T, and Russel, W G R (1990) Some spectral considerations for remote senSing, Austrahan joumal of 5011 research 28,417-431 I _

Hick, P T, DaVies, J RAND StecKIS, R A (1984) MapPing Dryland Sahnlty In West~m Australia uSing remotely sensed data Satellite remote sensing review and preview RemotE! Sensmg SOCIety, Readmg, UK, 343-350

Howari, F. M 2003 The use of remote sensing data to extract Information from a!Jrlculturar land with emphasis on soil sallmty Australian Journal of SOil Research 41(7) 1243 - 1253 Huete, A R, (19BS), A sOII-adJusted vegetation Index (SAVI) , Remote Sensing and the Environment, 2~, pp 53-70

Kauth, R J and Thomas, G S, (1976), The tasselea cap - A graphic aescnpbon 01 the spectral temporal development of agncultural crops as seen by Landsat, Proceedings of the SympOSiUm on Machlfle Processing of Remotely Sensed Data, Purdue UnlvelSity, West Lafayette, Indiana, pp 41-51

Hardlsky, M A., Klemas, V & Dalber, F.C 1983 Remote sensing saltrnalSh biomass arid stress detection Advances In Space Research, 2. 219-229

Kauth, R,J, & Thomas, 0 S 1976. The tasseled cap, a graphic descnptlon of spectral-ten,poral development of agncultural crops as seen by landsat In Symposium on machine processing of remotely sensed data, 41-5 1 New York, Insbtute of Electncal and ElectroniCS Engineers

Metternichl, 0 and ZIfIcK, J.A 1997. Spatial dlscflmlnatlon of salt and sodium-affected ~oll surfaces Int J .R S., 18 (12\. 2571-2586

Mettemfcht 01 and ZIfIck JA 2003 Remote sensing of SOil sallmty, potentials and constnl'ints Remote Sens . Environ 85 1-205ethl, Madhurama, Gupta, 5 K and Dubey, D D (1996) Assessment of 5011 salinity

and wateriogg'"9 in the Ukal-Kakrapar command area uSing remotely sensed dDta Proc Workshop on Ukai-Kakrapar Commana Area, Anana, Gujrat 21-33

Sethi, M, Dasog, G 5., van L,eshoul, AM and 5alimath, 5 B -2006 Salinity appraisal uSln9 IRS Images in Shorapur Taluka, upper Knshna Imgabon project, phase I, Gulbarga Dlstnct, Kam~taka. India In International JOurnal of remote sensing, 27 (2006}14, pp 2917-2926

Shrestha, D P 1991 Lecture notes on digital Image processing of remote sensln~ data. Enschede, Netherlands, ITC.

Shrestha, D P_ 1988 Remote sensing techmques for land cover and land use analyses. In Proceedlfl9s of the 14th UN/FAO '"ternatlonal training course on remote sensmg applications to land resources Rome, FAO

Steven, M.D .. Malthus, T J., Jaggard, F.M. & Andrieu, B. t992. Monllonng responses of vegetatton to stress. In A P Cracknell & R A. Vaughan, eds Remote sensing from research to operation proceedings of the 18" annual conference of the Remote Sensing SOCiety, p, 369-377, Nottlngpam, UK, Remote Sensing Society

Vincent, B, Vidal, A , Tabbet, D, Baqri, A. and Kuper, M 1996 Use of satellite remote sensing for the assessment of waterlogging or sallmty as an Indication of the performance of drained syslems In B Vincent, ed Evaluabon of performance of subsurface drainage systems' 16" co~gress on Irrgallon and dralOage, Cairo, p 20:>'216 New Deihl, ICID.

245

/

GPS Technology for Assisting Ground Truth for Salt-Affected Soils /

Madhurama Sethi and D.S. Bundela' DIVIS/on of Soil and ClOP Management 'D,v,s,on of ImgatlOn & Dramage Engmeenng Central Soil Salimty Research Institute, Kama/-132 001

Introduction

Global Pos/bomng System (GPS) is a space·based radiO naVIgation system t~ai provides reliable posltlomng, navigation, and timing services to CIvilian users on a continuous wo~dWlde basIs GPS provides accurate location and time Information for an unlimited number of people In all weather, day and night, anywhere In Ihe world The GPS IS made up of three parts satellttes, control and monitOring slatlons, and the GPS receivers GPS satellites broadcast signals from space that are picked up and Identified by GPS receivers Each GPS receiver then provides three-dImensional location (latitude, longitude, and altitude) and tJms Individuals may acqUire GPS handsets that are readily available through commercial retJaliers EqUipped WIth these GPS receivers, users can accurately locate where they are and eaSily navigate to where they want to go, whether walking, dnvlng, flYing, or boating Farmers, surveyors, geologists and countless others pelform their work more effiCiently, safely, economically and accurately uSing open GPS signals The GPS technology has tremendous amount of appllcatJons In GIS data collecbon, surveYing, and mapPlngGPS IS also widely used In transportation systems wo~dwlde

Geoposilionlng.Basic Concepts

By poslllonlng, we understJand the detennlnallcn of locatIOn of stationary or moving objects These can be determined as follows

• In relabon to a well-defined coondlnate system, usually by three coordinate values and

• In relation to other POint, taking one point as the ongln of a local coordinate system

The' first mode of positioning is known as POint positioning, the second as relabve poslbonlng If the object to be positioned IS statJonary, it IS termed as static posltlomng When the obJect,ls moving, It IS called klnematJc posltronln9 Usually, the StatiC positioning IS used In surveYing and the klnematJc posrtlon In navigation (Fig 1) .

Fig 1 Kinematic positioning of an object

Components of GPS System

GPS uses satellites and computers to compute pOSitIOns anywhere on earth The GPS IS based on satellite ranging That means the positJon on the earth IS detemllned by measunng the distance from a group of satellites In space The baSIC prinCiples behind GPS are really Simple, even though the system employs some of the most hlgh·tech eqUipment ever developed In onder to understand GPS baSICS, the system can be categOrized Into five steps

• . Tnangulabon from the satellites IS the baSIS of the system

• GPS measures the distance uSing the travel time of the radiO message for tnangulatlon

• GPS uses a very accurate clock to measure travel time

GPS Technology for Assisting Ground Truth for Salt-Affected Salls

• Once the distance to a satellite IS known, then we need to know where the satellite IS In space

• As the GPS signal travels through the Ionosphere and the earth's atmosphere, the signal IS delayed

I To compute a position In three dimensions, four satellite measurements are- required GPS uses a

trigonometnc approach to calculate the pOSlboris, The GPS satellites are so high up that their orbits are very' predictable and each of the satellites IS equipped Wlth a very accurate atomic clock The GPS IS divided Into three malor components I -

• Space Segment

• Control Segment • User Segment

Space Segment I ,

The space segment oonslsts of a constellation of NAVASTAR earth orbiting satellites It contains a full constellation_of 24 satellites (21 operational and 3 In:orbit spares) The satellites are arrayed In 6 orbital planes, Inclined 55 degrees to the equator (Flg- 2)" They Orbit at altitudes of about 12000, miles each, With orbital perrods of 12 sidereal hours (I e, determined by or from the stars), or approximately one half of the earth's penods, approximately 12 hours of 3-D poslnon fixes Each satellite contains four precise atomiC clocks (RUbidium and Cesium standards) and has a microprocessor on board for limited self-monltorrng and data processing The satellites are equipped With thrusters which can be used to maintain or modify their orbrts

Control Segment

(iPS Nllllllul ["1III~WIlatJoR u ... utI_Ja to nrbI .... f'la!,..

4!ooar11 ....... _..._

u,:_Jo.-. 4.kI ..... r 11.1 D:ot ..... IndI.....o.n.

Fig 2 A constellation of 24 GPS satellites In 6 Orbits

The control segment consists of five monltorrng stations (Colorado Spnngs, Asceslon Island, Diego, GarCia, HawaII, and Kwalaleln Island) Three of the stabons (AscenSion, Diego Garcia, and Kwalalern) serve as uplink Installations, capable of transmlillng data to the satellites, ,ncluding new ephemendes (sateUlte poslbons as a function of bme), clock correctIons, and other broadcast message data, while Colorado Sprrngs serves as the master control stacon The Control Segment IS the sale responsibility of the DOD who undertakes COnstruction, launching, maIntenance, and IIlrtuaUy constant performance monltonng of all GPS satellItes

The DOD (Department of Defence) monrtonng stations track all GPS Signals for use In controlling the satellites and predicting therr OrbIts Meteorological data also are collected at the monltonng stations, permitting the most accurate evaluation of tropospherrc delays of GPS Signals Satellite tracking data from the monrtonng stations are transmItted to the master control station for processing ThiS processing Involves the computabon of satellite ephemerrdes and satellrte clock correctons The master station controls orbital correcbons, when any satellite strays too far from Its assigned pOSition, and necessary repositioning to compensate for unhealthy (not fully functioning) satellites

247

Chemical Changes & N.utnent Transformation in SodlcJPoot Quality Water Imgated SOils

User Segment /

/

The user segment is a total user and supplier communl,ty, both cIvilian and military, The user segment consists of ,all earth-based GPS receivers, Receivers vary greatly In size and compleXity, though the basIc design Is rather simple The typical receiver is composed of an antenna and preamplifier, radiO Signal microprocessor, control and display device, data recording unit, and power supply The GPS receiver decodes the tmlng signals from the 'VISible' satellites (four or more) and calculates their distances and computes Its own latitude, longitude, elevation and time ThiS IS a continuous process and generally the poSItion IS updated on a second-by-second baSIS, output to the receiver display deVice and, If the receiver display deVice and, If the receiver-proVides data capture capabllll!es, stored by the receiver-logging unit

GPS POSitioning Types

Absolute Positioning

The mode of poslDomng relies upon a Single receiver stallon It is also referred to as 'stand-alone' GPS (Fig 3), because ranging IS camed out stnctJy between the satellite and the receiver station, not on a ground-based reference station that assIsts With the computation of error correcbons As a result, the posilions denved In absolute mode are sublect to the unmitigated errors Inherent In satellite posltlomng

Fig 3 Absolute poSItioning

Differential PosItIonIng

Relallve or dlfferenllal GPS carnes the tnangulatlon pnnClples one step further, With a second receiver at a known reference pOlnl To further faCIlitate determmabon of a pOlnfs poslbon, relabve to the known earth surface pOint, thiS configuration demands collection of an error-;:;orrectlng message from the reference receiver, Differential-mode pOSItiOning relies upon an established control pOint (Fig 4) The reference stall on IS placed on the control pOint, a triangulated poSillon, the control pOint coordinate ThiS allows for a correcbon factor to be calculated and applied to other roving GPS Units used In the same area and In the same time series InaccuraCies '" the control po",t's coordinate are directly additive to errors ",herent in Ihe satellite positioning process Error correcbons denved by the reference station vary rapidly, as the factors propagallng position errors are not static over time ThIS error correction alloWS for a conSiderable amount of error of error to be negated, potentially as much as 90 percent

248

GPS Technology for Asslsbng Ground TMh for Sall-Affecled SOils

Fig 4 Dlfferenbal POSitioning In CPS

Accuracy of GPS

There are four basIc levels of accuracy (Table 1) which can be With your real-time GPS mining system.

Table 1 Accuracy of GPS system

Mode Autonomous Differential CPS (DGPS) Real-Time Kinematic Float (RTK Floal) Real-Time Kinematic Fixed (RTK Fixed)

Accuracy 15 - 100 meters 05 - 5 meters

20cm - 1 meter

1cm -5 em

Factors Affecting GPS Accuracy

There are a number of potential error sources that affect either the GPS Signal directly or your ability to produce optimal results

Number of satellites required: You must track atleast four common satellites - the same four satellites - at both the reference receiver and rover for either DGPS or RTK solullons Also to achieve cenllmeter -level accuracy, remember you must have a fifth satellite for on-the fly RTK Initialization This extra satellUe adds a check on the Internal calculation Any additIOnal satellites beyond five proVide even more checks, which IS always useful

Ionosphere: Before GPS Signals reach your antenna on the earth, they pass through a zone of chargeci pamcles calleci the Ionosphere, which changes the speed of the Signal If your reference and rover receivers are relabvely close together, the effect of Ionosphere tends to be minimal And If you are working With the lower range of GPS precIsions. the Ionosphere IS not a major conslcieratlon However If your rover IS wOlKmg too far from the reference stallon. you may expenence problems, particularly With InitialiZing your RTK fixed solution

Multlpalh: Multipath IS Simply reflection of Signals Similar to the phenomenon of ghosbng on our teleVISion screen GPS signals may be reftected by surfaces near the antennae, causing error In the travel bme and therefore error In the GPS posibons. ,

Troposphere: Troposphere IS essentiallY the weather zone of our atmosphere, and droplets of water vapour In It can effect the speed of the Signals The vertical component of your GPS answer (your elevation) IS particularly sensitive to the troposphere

249

Chemical Changes & Nutnent Transformation In SodlclPoor Ouallty Water Imgated Solis

Satellite geometry Satellite GeometlY - or the dlstnbutlon of satellites In the sky - effects the computation of your position This IS often referred to as PosllIon Dilution of Precision (POOP) POOP IS expressed as a number, where lower numbers are preferable to higher numbers The best results are obtained when POOP IS less than about 7 POOP 15 deterrl1lned by your geographic location, the time of day you are working, and any site obstruction, which might block satellites You can use planning software to help you determine when you'll have the most satellites In a particular area \

When satellites are spread out, POOP IS Low (good)

When satellites are closer together, POOP IS High (weak)

Satellite health: While the satellite system IS robust and dependable, II IS possible for'the satellites to ocCasionally be unhealthy A satellite broadcasts Its health status, basad on Information from the U S Department of Defense Your receivers have safeguards to protect against uSing data from unhealthy satellites

Signal strength. The strength of the satellite signal depends on obstructions and the elevation of the satellites above the hOrizon. To the extent It IS possible, obstructions between ,your GPS antennae and the sky should be avoided Also watch out for satellites which are close to the honzon, because the signals are weaker

Distance from the Reference Recelver:_ The effective range of a rover from a reference statton depends pnmanly on the type of accuracy you aere trying to achieve for the highest real time accuracy (RTK fixad), roveres should be WIthin about 10-15 Km (about 6·9 miles) of the reference station As the range exceeds thiS recommended limit, you may fallto initialize and be restricted to RTK float solubons (deCimeter accuracy)

Radio frequency (RF) interference: RF Interference may somellmes be a problem both for your GPS recepbon and your radiO system Some sources of RF Interference Include

• RadiO towers • Transmitters • Satellite dishes • Generators

One should be part.cula~y careful of sources which transmit either near the GPS frequenCies (1227 and 1575 MHz) or near harmonics (multiples) of these frequenCies One should also be aware of the Rf generated by hiS own machines

Loss of radio transmission from base: If, for any reason, there IS an Interruption In the radiO ilnk between a reference receiver and a rover, then your rover IS left With an autonomous POSition It IS very Important to set up a netyvork of radiOS and repeaters, which can proVide the uninterrupted radiO link needad for the best GPS results

GPS Applications

,_ One of the most Significant and unique features of the Global Posilloning. Systems IS the fact thai the positioning Signal I' available to users In any POSition worldWIde at any time, With a fully operational GPS system, It can be generated to a large community of likely to grow as there are multiple appllcatjQns, ranging from surveYing, mapping, and navigation to GIS data capture Th~ GPS WIll soon be a part of the overall utility of technology

Remote Sensing and GIS

It IS also pOSSible to integrate GPS posltlomng Into remote-sensing methods such as photogrammetry and aerial scanning. magnetometry, and Video technology USing DGPS or kinematic techniques. depending upon the accuracy reqUlrad, real time or post-processing Will prOVide positions for the sensor which can be projected to the ground, Instead of haVing ground control projected to an image GPS are becoming very effecllve tools for GIS data capture .The GIS user commumty benefits from the use of GPS for locational data capture in various GIS applications The GPS can eaSily be hnked to a laptop computer In the freid, and, With appropriate software, users can also have all their data on a common base WIth' every little dlstort.on Thus GPS can help In several aspects of construcbon of accurate and timely GIS databases

Soil S un(ey Field Activities

A Significant part of the time spent In the productIOn of a SOil survey by Ihe SOIl sClenlists Involved In the prolect IS nol In an office but on-site There are new technological developments that may diminish the necessrty for as much on-site wor!( by ,nd,v,duals through prad,ct,ve models uSing remote sensing derivatives

250

GPS Technology for Assisting Ground Trulh tor Salt·Affected Sods

As effective as these new tools may prove to be, there Will always need'to be on-site work performed dUring the COurse of a sOil survey proJect, and it is In thiS area that mobile computing devICes are conSidered to Improve production, The two categOries of this on-Site work are field mapping and supporlmg documentation

Advantages of Using Mobile GIS

Real time mappIng < I ConSiderable production time IS saved when the mapper Is working on the digital version of the sOil map

rather than on a hardcopy map that would have to be converted to a digital forma! The number of errors that result from processing and converting the hardcopy map to digital are reduced However, thiS process needs to be taken out of the office and off the desktop computer and into the field on a mobile computer. Real-time mapPing enables the creation 'or modification of the dlQltal product on-site by the Individual who knows the most about that particular sOIVlandscape model used In the survey With an application such as ArcPad, that Integrates GPS position data Into the GIS, the mapper IS no longer constantly burdened With haVing to keep a running count of paces in order to locate the position on the map The Importance of the time savings that occurs cannot be overstated when the location on the aenal photo base can be observed by uSing GPS Integrated With the GIS TM GPS position IS Viewed on the map display that can Include the digital aenal photograph and the location of the SOil map untt boundanes The mapper can actually stand on the map unit boundary as It appears on the map display Other data layers may also provide the mapper WIth valuable Information while on-Site, such as the location oWinershlp boundanes

On-Site documentation

Use of a tablet or PDA mobile deVice would enable more documentation dunng field mapping Each location at which an observation IS made can be captured as a pOint feature uSing the coordinates obtained from the GPS Attnbute Information could include how well the predicted map unit corresponded With the observation. ThiS observation database would prOVide a clearplcture of which landscape components needed to be studied more Intensely, ThiS spatial database could also be quened and analyzed to determine map Unit com'posltlon and to proVide a recOrd of what areas have had on-site observations Use of a tablet mobile deVice would enable the mapper to capture detailed field notes In a digital lormat uSing the Windows Pedon Program or Similar data recording program ThiS would replace the handwntten form on p~per that would have to be input into the computer back in the office Data enlly in the field on a mobile device would save conSiderable time and reduce pOSSible errors dunng data entry An addilional funcbon that mobile deVices provide IS the capability to have dl9,tal reference matenal available In the field Informalion such as SOil descnptlons and standards and methods frequently reViewed, whIch would require thick cumbersome threenng binders, can be accessed digitally whenever needed on the mobile deVice

Mobile device solutions

A number of mobile deVices have been examined for their use In SOil survey applications and to Identify busIOess reqUirements needed to develop technical speCifications These deVices range from handheld PDA to tablet computers Potential users want a deVice that IS able to Withstand exposure to the elements Involved In field work, has a large display area Viewable In bnght sunlight to near darkness, has a long battery life, and IS small, IlQhtwelght, and easy to carry, A mobile deVice must have suffiCient data storage processing capacity and to handle GIS analYSIS and editing

Handheld PDA deVices With GPS Integration have been successfully used for Simple field data collection A disadvantage of handheld PDA deVices IS that they are not conSidered SUitable for field SOIl mapping because of the limited size of the display, There Is simply not enough area for the mapper to View the " area of Interest at a desirable scale The larger display size on tablet computers IS conSidered to be more SUitable 'Technology IS rapidly changing With new products constanlly being released Even Without the optimal display capability, the advantages to uSing mobile deVices In regard to time saved on editing map Unit line work, field note collection, and the positioning capabIlity prOVided by Wireless GPS Integration, Will result In a very e ffectrve tool for future SOil survey prOJects" '

GPS for ground truth data collection for salinity mapping

The high preciSion, of GPS carner phase measurements, together With appropnate adlustment algorithms, prOVide an adequate tool for a variety of tasks for surveYing and mapping Mapping of the land damaged due to salinization IS a frantiC task and requires lot of man power and time since It reqUires Identification, sampling and classlfylng,the land by conventional surveYing methods On the other hand advanced techniques like remote sensing (RS) and GIS can do thiS task more effiCiently The approach to the problem dealing With salt affectec! lanc! uSln9 RS anc! GIS has been proved In many recent stUdies to be the most effiCient Large coverage, good resolution In VISible and near VISible spectrum and repetitive passes are advantages of Indian Remote Senslng(IRS) satellites and advanced analytical techniques In GIS can be useful In detection and IOtenslty analYSIS of salt affected land Applications, such as cadastral mapPing,

251

Chemical Changes & Nutrient Transformabon In SodlcIPoor Quabty Water Imgated So~s

,. needing a high degree of accuracy also can be camed out uSing high grade GPS receIvers, Cont,nuous konematlc technIques can be used for topographIc surveys and accurate linear mappIng

/ '

'Ground truth data cotlecban for deloneatong sallnlty/alkallnrty as well aS,water loggIng are In the forms of sample cotlectoon based on GP13, morphological and chemical analYSIS data for salt affected 5011 profiles 5001 saturatoon extracts are prepaned 10 determIne Ion types and content EC and pH far representatIve 5011 samples of indIVidual salInity/alkalInIty classes Other ancillarY dala (ground cover type and percentage of organIC matter content, crust type and color also recorded For water loggmg the ground truth mformatlon normally includes extent of surface water loggmg, type of aquatic vegetation, slope gradient and Its direction and depth of standing water above ground surface

Training sets of Information dasses such as SOIl saltnlty/alkaltnlty or water logging are marked In the false color composite (FCC) of IRS 1C L1SS III In general training set should be homogeneous and composed of many pixels usually an average of 10 pixels of training data are collected for extraction

Future of GPS Technology

The development and Implementation of preCISion agriculture or site-specific farming has been made possible by combining the Global PositiOning System (GPS) and geographic informabon systems (GIS) These technologies enable the coupling of real-bme data collectoon With accurate posibon Informabon, leadmg to the effiCIent manipulation and analYSIS of large amounts of geospatlal data GPS-based applications In precIsion farming are being used for farm planning, field mapping, 5011 sampling, tractor guidance, crop scouting, vanable rate appllcattons, 'and Yield mapPing GPS allows farmers to work dUring low VISibility eondlbons such as rain, dust, fog and darkness '

In the past. It was difficult for farmers to correlate productoon techniques and crop Yields With land variability. ThiS limited their ability to develop the most effective SOIl/plant treatment strategies that could have enhanced their production Today, more precise appltcatton of pestICides, herbiCides, and fertlitJ;ers, and better control of the dispersion those chemicals are pOSSible through preCiSion agrtculture, thus reducing expenses, prodUCing a higher Yield, and creatong a more environmentally fnendly usage on the farm PreCiSion agrtculture IS now changing the way farmers and agrtbuslnesses view the land from which they reap their profits Precision agriculture IS about collecting bmely geospatlal Information on SOil-plant-animal requirements and prescnblng and apPlying site-specific treatments to Increase agncultural production and protect the enVironment \/\/here farmers may have once treated their fields uniformly, they are now seemg benefits from micromanaging their fields PrecIsion agnculture IS gaining In popularity largely due to the introduction of high teC/Jnology tools Into the agricultural community that are more accurate, cost effective, and user friendly Many of the new Innovattons rely on the integration of on-board computers, data collection sensors, and GPS tome and posllton reference systems

Many believe that the benefits of precIsion agnculture can only be realized on large farms With huge cap~al. Investments and expenenre With mformatlon technOlogies SUCh IS not the case There are inexpensive and easy-to-use methods and techniques that can be developed for use by all farmers Through tha use of GPS, GIS, and remote sensing, informabon needed for imProving land and water use can be collected Farmers can achieve additional benefits by combining better utilization of fertilIZers and other 5011

amendments, determining the economic threshold for treating pest and weed infestattons, and protecting the natural resources for future use

GPS eqUipment manufacturers have developed several tools to help farmers and agribuslnesses become more productive and effiCient In their precIsion farming activIties Today, many farmers use GPS-denved products to enhanC(; operations In their farming bUSinesses Location Information IS collected by GPS receivers for mapping field boundartes, roads, !rngatlon systems, and problem areas In crops such as weeds or disease The accuracy of GPS allows farmers to create farm maps With precise aCreage for field areas, road locations and distances between pOints of mterest GPS allows farmers to accurately navigate to speCific locations In the field, year after year, to collect 5011 samples or monitor crop conditions

Crop adVISOrs use rugged data collectoon deVices Wlth GPS for accurate positioning to map pest, Insed, ana weed Infestatoons In the field Pest problem areas in crops can be pinpOinted and mapped for future management deCISions and Input recommendations The same field data can also be used by aircraft sprayers, enabling accurate swathing of fields Wlthout use of human "naggers" to gUIde them Crop (lusters eqUipped With GPS are able to fly accurate swaths over the field, applymg chemicals only where needed, mlniml:ting chemical dnlt, reducing the amount of chemicals needed, thereby benefiting the environment GPS also allows pilots to proVide famners Wlth accurate maps

252

GPS Technol"llY ror p..slsbng Ground Truth for Sall-Af!9c1ed 50110

Farmers and agnculture servIce providers can e)(ped even further improvements as GPS conbnues to modernIZe In addition to the current CIVIlian selVlce proVided by GPS, the United States IS committed to Implemenbng a second and a third CIVil Signal on GPS satellites The first satellrts With the second ciVilian Signal was launched In 2005 The new Signals Will enhance both the qualrty and effiCiency of agricultural operations In the future '

Common GPS Tenns , , CoDldmate Systems - Such as latltudeJIongltude, represent your poslllon on the earth to a fiat surface like a

sale map , Declmal/Oll Settmg - GPS Units can be adjusted to the ~mount of magnetic declination In the area of use

Dlfferenllal GPS (DGPS) - An extension of !he GPS system that uses landbased radiO beacons' to transmit position corrections to GPS receiverS OGPS reduces the effect of seledive availability, propagation delay, etc and can improVe poSItIon accuracy to better than 10m.

Error - Measurement of hOrizontal pOSitIOn error In feet or meters based on a variety of factors IncludIng Dllutl09 of PreCiSion (DOP) and satellite signal quality

GOTO - The selected point you Wish to travel to or find, It may be a poslbon fix or part of a route or track.

Headmg - The dlTectlol] in Which you or your vehicle are moving For'boat or airplane operabons, thiS may differ from adual Course Over Ground (COG) due to Winds, currents, etc

Lalltude -'A posItIon's dIstance north or south of the equator, measuned by degrees from -zero to 90 One minute of latitude' equals one nautical mile

Longitude - The dIstance east or west of the pnme mend Ian (measured in degrees) The prime mendlan runs from the North Pole to the South Pole, through GreenWich, Englang 4

Magnebc Declmaflon - The dIfference between true north and magnetic north at a speCific locabon NAVSTAR - The offiCIal U S Government name gIven to the GPS satellIte system NAVSTAR IS an acronym

for NaVigatIon Satellite TIming and Ranging Poslbon fix - The GPS recelve~s Computed posItIon coordinates

PreCision - Measure of the 'repeatability" of the data Taking repeated readings from a point Will Improve the preCiSIon of the sample mean

Route· A group of waypoints entered into the GPS receiver In the sequence you deSire to navigate them Track - Your current dlredlon of travel relatIve to a ground poslbon (same as Course Over Ground) , WaypomflLandmarl< - WaYPoints are locations or landmarks worth recording and stoTing In your GPS These

are locatIons you may later want to return to or aVOid They may be check POints on a route or Significant ground features such as a campSite, the truck, a cultural resource, or a lavonte fishing spot WaYPOInts may be defined and stored m the Unit manually by taking coordinates for the waYPolnt from a map or other reference. ThiS can be done before ever leaVing home Or more usually, waypolnts may be entered dlTectly by taking a reading With the unIt at the locatIon itself, gIving It a name, and then saVing the pomt

Wide Area Augmentation System (WAAS) - A system of satellites and ground stabons operated' by the Federal AViation Authonty that prOVide GPS signal corrections for better posItIon accuracy for airplanes WAAS consists of approXImately 25 ground reference stabons posItIoned across the United States that monitor GPS satellite data Two master stations, located on either coast, collect data from the reference stallons and create a GPS correcllon message A WAAS-apable receiver can be adapted 10 ground , use and give you a POSitIon accuracy of better th"n three meters, 95 percent of the tIme

Bibliography

Tnmble Web sIte - GPS tulonal (http IlWwwtnmble com)

Garroi" webSite (www garroln com) GPS and OGPS Tutonal (http Ilwww colorado edulgeooraphy/gcrafllnoteslgpslgps html)

sClencellnks Jpi)-easVarllcle/1999181000019991899A0688537 php www navtechgps com/links asp https/lwww e-educatlon psu edu/geog862111_p3 html sopac ucsd eduiprojects/slollOi

wwwgnss umaine edu httpsllwww e-educatlon psU,edu/geog862113_p3 hbnl

253

r

Multi·enterp!ise Agriculture to Improve Nutrient and Water Productivity in Reclaimed Lands

/ AshokKumar DIVISion of SOil and Crop Management Central SOil Saftmty Research Institute, Kamal-132 001, Haryana

Introduction

The farm of Central SOil salinity Research Insbtute, Kamal was affected largely with sOil alkalinity (high pH) at the time of Its establishment In 19S9 Within few years of, Its establishment, a technolo9Y for redamatlon of alkali 5011 was developed, and now most of the crops except a few very senSItive ones can be groWl'l successfully Among crops, nee-wheat rotation was round more cost-effective but thiS rotation has led to depletion of water level and loss of SOil fertility Due to Intensive agriculture and climate change.In recent ,years the productJvlty of crops IS continuously gOing down Simultaneously, land holding IS diminishing continuously With consistent Increase In population OWing to reduced farm Size and Increased cost of cultivation farmelS are facing finanCial hardships From nee-wheat cropping system fannelS get Income only two times In a year when the crops are harvested dunng early summer or early winter but a farmer needs regular Income to meet out hiS day-to-day needs For thiS he has to borrow loan but when unable to repay back hiS economiC and mental sltuallon IS dlstUibed Because of above Cited reasons tIlere IS pressing need to reonent the present fanning systems and adopt those, which can Improve water productIVIty as well as proVide regular Income and employment Also, there IS need to revelSe natural resource degradahon trend and bUild the fannelS confidence In agriculture MU~I-enterprise agnculture (popularly called famlng system approach) seems to be a Viable solullon ·to these problems. By dOing'so, the cost of cultivation can be reduced to a large extent and the reslduesiby-productsl wastes of different kinds available wlthrn the system of various components may be recycled to Improve 5011 health and other shared benefits

Multi-enterprise Agriculture

A mulll-enterpnse agnculture project has been Initiated at the Central SOil sahnlty Research Ins~tute, Kamal since rabl season 2005-06 as a model for 20 ha land With the follOWing obJectJve~

• Comparative evaluation of crop enterpnse dlvelSlfica~on options ,n the reclaimed sodlc land

• To Increase water, nu!nent and energy use effiCiency through diversified agnculture systems

• To reduce cost of cuJtlvatlon for higher returns through recychng of residues Within the system

• Assess chemical, phYSical arid biological changes In 5011 under different land use optlonslsystems

• To Idenllfy profitabie, sustainable and eco-fnendly agnculture model for 2 ha land holding

, Main theme of thiS prolect 15 to find alternatives which use less water. The Idea behind Multlenterpnse agriculture IS that In conjunction With agnculture a farmer can adopt several related enterpnses such as dairying, hortJculture, flonculture, bee keeping, vegetables, fishenes, poultry, duckery, mushroom, gobar gas and verml-wmpost etc to Improve hiS family Income and generate employment each component IS monitored meticulously for SOIl phYSical, chemical and microbial properties and other parametelS The water use effiCiency and economiC productiVity are aJso being monitored The main enterpnses! components/capsules along With the" area those are being used In the model are as follows

A. Grain Product,ion (08 ha cropped area)

• 02 ha Rice-Wheat cropping • 02 ha Maize -Wheat- Moong croPPing

• 02 ha Winter Maize -Soybean • 0 2 ha Pigeon pea (SO) - Mustard-Fodder Maize

B, Floriculture (0 2 hal

Flowers like Mangold and Gladiolus etc are being groWl'l dunng rebl season and crops hke baby corn, sweet corn etc dunng khanf season,

C. Fodder productJon for 4 cross·bred cowslbuffaloes ad their heifers/calves (04 hal·

Fodder requirement 3540 kg/day/ammal (Sorghum/MaIZe) and 60 kg berseem/day/anlmal With feeding thiS fodder 7 to 8 htre/day/animal can be produced For every 2 5 to 3 0 liter milk one kg balanced

MulU-enterpnse AgnaJilure to Improve Nutrient and Water ProductiVIty in Reclaimed lands

concentrate Will be required Year round fOdder production IS maintained by adopfion of forage crop rotations uSing berseem, maize, malze+ cowpea and multl-cut sorghum

D. Horticulture and vegetables (0 2 hal

Seasonal vegetables are being grown In between the rows of guava and papaya trees

E.l'egetables (0 2 hal

The,approach IS to have green vegetables all the year round

F. Fish fanning, bee keeping, poultry, duckery and mushroom (02 hal

On the baSIS of 2 years average 'data, 19 2006'()7 and 2007-08, wheat gave a net Income of Rs 37109 per ha and B C ratio of 3 08 By contrast, berseem (fodder) and bottle gourd! Ghla (vegetable) proVided a net Income of 43542 and 56062, respectJvely With respective Be ratios of 4 99 and 2,95 Performance of soybean and pigeon pea was not sallsfactory and proved uneconomic While seeing comparatIVe economics of crop rotations It was found that malze-oat-berseem: sorghum-berseem and nee-wheat were the most remunerallve crop rotations amongst all the-cropping sequences undertaken ,n the selected plots On an average of the 2 years net income, these rotabons prOVided Rs 63656, Rs 59522 and Rs 53626 per ha, respectJvely The B-C ratio for these crop rotallons was 3 64, 2 34 and 2 15, respectively Bee keeping and fish production are also profitable enterpnses On the dyke of fish ponds (alkaline SOil With ImtlSl pH about 10) In the west d,recllon alkalr tolerant frUit trees Irke aonla, karonda have been planted and groWing well However, in the east and north dlrectJon where SOil rs almost normal banana and guava has been planted and banana and guava have already started frUiting and supplYing regular Income The growth and fruiting showed distinct effect of SOil alkalinity Se~sonal vegetables berng grown between the fruit trees are prOViding regular Income The dung received from cattle IS being used for making compost, verml-compost and gobar gas beSides some of It IS used as fish feed

Together With crop productron, bee keeping rs also a good enterpnse, wherein from 15 boxes 343 kg honey was been extracted and a net Income of Rs 17,000 was recovered Wlthln 6-7 months In the first year In thiS occupation there rs no need of much space but gives honey production starting from October to June From second year onwards there Will not be the cost of Infrastructure and only little management Will be required It IS an established fact that honeybees produce more honey and profit If grown where flowers are cultrvated For some crops like mustard, sunflower and fruit trees honey bees help rn pollination and thus Increasing their Yields In the second year 10 more boxes were added but due to Inclement weather dunng summer and winter, the honey bees could not produce enough honey thus gave a meager net Income of Rs 3432 Overall, honey bee keeping proved a benefiCial enterprise

Fish cultivation IS a valuable and economical enterpnse, particularly on those farms, which are located at the lower elevation From a 12 hectare of fishpond Wlth Investment of Rs 27,663 a net profit Rs Of 12,5281- can be obtained Within a year, and on the dykes of fishpond, fruit trees, like banana, guava have been already planted, which WIll gIVe additional Income In between the spaces of fruit tees One Side of the pond, where dug out SOil was placed even now the SOil pH IS more than 10 (Hrghly alkaline), so on that Side alkali tolerant frUit speeres like Karonda and Amla have been planted All these Will contnbute to the Income of the farmer When the pond IS emplled, the pond water that IS very nch In plant nutrrents can be used for ,"'gatron The dung from 4-5 animals rs suffiCient to produce gobar gas that can be used for cooking food of 7-8 family members and prepanng verm,-rompost The slurry removed after making gobar gas IS berng used for compostlng The compost and vermr-compost are being used for groWlng vegetables and fruit trees organically, Which fetches more Income to the farmer Apart from thiS, solar heater can be Installed to meet electnclty problem of the family

Thus, rt can be Inferred that by adopbng mUlti-enterpnse system by synergetic blending of different components, regUlar and sustainable Income can be generated and nsk of farlure of one crop IS covered With other component In-Situ recycling of reSidues has tremendous potenllal to Increase productIVIty, profitabllrty, water productiVity and livelihood secunty By follOWing thiS system, bummg of strawsistubbles can be aVOided which consecutively help In pollullon free enVIronment

255

Cultivation of N;n-ConventionaJ Crops of Economic Value unde(Saline Environment'

/ I

Vandana LOdha D,v,s,on of crop Improvement Central Soil Salinity Research Institute, Kamal-132 0011, Haryana

/

Introduction

PopulatJon In developing countnes IS growing so qUickly that the limited land and water resources are unable to sustain them, Although, irngation IS being provided to bnng land In and and semi-and areas Into production, It often leads to salinization and gOing out of productoon, Salt-affected salinization of the sOils In many parts of the wo~d is reduCing the acreage available for conventional agnculture Salinity, desertification and andlty have led to several famines in different parts of the wo~d Therefore, the need for salt-tolerant crops around the world Increases each year as a growing population seeks to feed Itself on ever decreaSing sOil resources and dWindling fresh water supplies, With the Increased demand of food, feed and raw matenals for Industnal use, more InvestlgatJons Into available resources JS necessary, espeCially In developing countnes where feed and food' shortages are more dramatiC With the increased demand of food, feed and raw matenals for, Industnal ~se, many agncultural products are available but not utilized effiCiently Therefore, Investigation of potential of such products IS essential to find out new outlets for utilization of the WOrld, 5 resources The trade in aromatic and herbal medicinal products IS estimated to Involve about Rs 600 crores per annum In India (Anonymous, 1996) To meet the Internal consumption and for eamlng foreign exchange, the productoon of these commodities IS reqUired to be Increased The main problem, however, lies In spanng fertile lands for cult,vabon of aromatic and medicinal crops due to the Simultaneous high pressure to produce more food fiber, fodder and other agncultural Commodl~es A Viable alternative could be the utilization of cuilivable wastelands Including the salt-affected 50115 to raise these crops. In and and seml- and areas where rainfall IS very lillie and SOils are problematiC In nature Good quality waler is also, not available and groundwater too, IS brackJsh In nature containing high salt levels which IS unSUitable for conventional crops The survey of groundwater quality has Indicated that the poor quality (saline and alkali) water constitutes a major percentage (32-84%) of total IrngatJon potential of groundwater, espeCially, In the RaJasthan, Haryana, Punjab and U P (Mlnhas and Gupta, 1992) In the states of Punjab, Haryana and Rajasthan haVing 22, 24 and 16 percent ground water are In the In saline category (Mlnhas and Tyagl, 199B) Therefore, the utilization of these types of lands and water can be promoted by raising plant species of aromatic and mediCinal value IS one of the emerging pOSSibilities for crop diversification espeCially, on lands where cultlvallon of arable crops IS not Viable (Patra and Singh, 1995, Tomar and Monhas, 2004 a, b) Naturally occurnng sail-tolerant plants of eoonomlc value may be SUitable altematlves for the successful rehabilitation of degraded salone wastelands after undertaking remedial measures and those that might make desirable crops With use of saline waters and In turn can prOVide food/fodder, edible! non- edible oils, fuel and other bio-actlve products Since, there IS a shortage of edJble and non-edlble Oils' in the country also, an Immediate need IS there to explOit renewable resources for meeting the demands and to save the valuable foreign exchange

Suitable Non-ConvenlJonal Crops

0111 (Anethum graveolens)

It belongs to family Ap,aceaa IS among ona of the unportant crop cultivated, parocularty in GUlara! for Its essential qll of medicinal Importance and used as major Ingredient In gtlpe water. The 011 and its emulSion In water are conSidered as stomachiC, diuretic, anathematlc and antlfiatulent It IS also, used as a potherb In soups, sauces, and seasoning and also, used In flavonng food products and alcoholic beverages Studies oonducted at Khanpur farm In GUjarat, Indicated that dill IS a most promising moderately salt-tolerant crop and oould give economic Yields up to EC,w 5 a d Slm Without any Irrigation and Yield may further be Increased With use of underground brackish water It is pOSSible to produce BOD kg seed ha" yea,' which gives gross and net returns of Rs 24, 000 and 16, OOO,'respectlvely (Nayak at ai, October 2000, Indian farming 40-41pp)

Palma Rosa (Cymbopogon martini) ,

Among other aromatic crops, wats var Motia) popularly known as rusa or rosha grass, the essential 011 of thiS grass is a rich source of geraniol that IS expensively used In perlumery parncularty for ftavormg of tobacco and blending of soaps, It performs well on saline 50115 With ECe of 8-12 dS m" (Patra and Dutta, 1979 and Singh and anwar, 1985,) Moderate salinity levels was rather Increased the herb and 011 Yields It could also successfully grow with saline water irrigation having EC,w of 16 dS m

O

' (Anonymous 1987) With herb and 'essenUal oil Yield Increased With saline waters haVing ECw up to 12 dS m" However chlonne dominated salinity was more deletenous over sulphates (patra el al 1992),

,

CulbvaUon of Non-ConventIOnal Crops of Economic Value under Saline EnVironments

Lemon glass (Cymbopogon flexuous)

, The plants of lemon grass (Steud) Wa~) have a strong lemon like flavor due to high content of cltral in essenllal Oils present In leaves The cltral IS Isolated from lemon oil IS used In the manufacture of the Vitamln-A Plant flounshes on a Wide vanety of 50115 ranging from nch loam to poor fate rite It IS handy crop and rose successfully without reduction In herb and essential all content In alkaline salls haVing pH 9 5 (Anonymous, 1992) and In saline salls With ECe up to 10 0 dSm" (Singh and Anwar, 1985) Its performance In tenns of herb and essential oif Yield was beHer when imgated With saline waters having ECW up to 4 0 dSm-' In companson to fresh water, and Yield started to decline beyond ECW 6 0 dS m"

Vetlvarfa zlzaniotdes (Vetfvar)

It IS locally known as khus, yield essenllal all Widely used In perfumery and cosmellc Industnes vellver all finds extensive use In perfumery as a fixallve and as an odor oontnbutor The crop IS IA:!ry hardy In nature and can Withstand penodlCaI water logging, alkaline 5011 conditions (Singh et af, 1987) It could be raised imgatlng With saline water up to 10 EC (Tomar at af , 1995,2003, 2004 a and b 2007)

Matricaria chamomile ( Gennan chamomile)

German chamomile IS one of the an JIJ1portant medICInal plant among the other medICinal crops cultivated Widely In east European countnes and have been found promising for cultivation With saline water Imgallon' In India, It IS cuilivated In Punjab, Himachal Pradesh and parts of Uttar Pradesh Its flower Yields an essential all, Which conta'"s anllspasmodlc, expectorant, carminative, anathematlc, sedative, diuretic and attenuate properties It IS also conSidered useful In the ailments of children such as teething problems, stomach disorders, eatache and neuralgiC pains and oonvulslons O,l,s used In flaVOring alcoholic and nonalcoholIC beverages, ICe cream, cheWing gums etc Since there IS great demand of chamomile all In European countnes, It has a great export potenbal Thus, forelgn-exchange eamer, It IS cun,vated In large area of saline sodle soils of country Eugoslovakla It IS also grown extensively In clayey loam soils In Hungry that are virtually waslelands It can tolerate salinity as well as sodlcdy_ to higher levels as compared to other medICinal crops Mlshra (1987) observed that 2. 6 Mg ha-1 fresh flowers are produced In alkali 5011 of pH 95 and gives higher net Income than wheat grown under same enVIronment (table 1) Similar results were given by Kapoor at af, (1963) ThiS IS a Winter crop and therefore fits well In crop rotation With nee It also helps Improve the alka" Salls by Its excepllonally higher sodium uptake It can be successfully grown In saline 50115 haVIng ECe up to 12 d Sm" (Anonymous, 1992): It gives fresh flower yields of 4 Mg ha" under salIne conditions (Thakur et af, 1989) It IS also grown successfully on partially reclaimed soils The flower and essential 011 Yield, Its composition was oomparable With production In normal Salls (Tewarl et 81, 1998)

Table 1. Effect of sa"mty on herb and oJ! Yield of Palmarosa

EClw(d S/m) Herb Yield Oil content (%) 011 Yield (kg/ha)

24 442 065 287 40 456 066 301 80 450 065 35 120 490 067 328 160 360 064 243 200 353 065 229 LSD (p=O 05) 26 004 18

Source Anonymous (1987)

Table 2. Content and Quality of essential 011 Palmarosa and Lemongrass Under varying salinity levels

EC (dSlm)

Palmarosa Control (05) 25-150

Lemongrass Control (0 5) 25-150

011 Content ('!o)

063 058-063

0.43 037-045

Source Singh and Anwar (1985)

257

011 quality GeramoVCltral (%)

886 892-920

77.2 760-782

Chemical Changes & Nutnent TransformatIon In SodlclPoor Quality Water Imgated SOIls

, /

Cassia ang"s~lfolla (Indian Senna, Sana I)

It is being cultivated successfully In Tamil Nadu, Andhra Pradesh, Maharashtra, Rajasthan, Gujarat and Karnataka, West Bengal and Tnpura In about 25000 ha under Irrigated and ralnfed cond,llOns India IS 'the largest producer and exporter of senna leaves and pods and sennoslde concentrate to the world market About Rs 300 million IS earned annually through export (Fig' 1) It IS a perennial erect, under shrub, 06-1 0 m tall Flowers are bright yellow In color Cassia angustdolla IS deSignated In commerce as Indian senna Sanal In Ayurvedlc mediCine Senna leaves and pods contain anthraqUinone glycosides as sennosodes (sennoslde A & B), which .contains laxative properties and used in Ayurvedlc, Unani medicines It also contains 0 33 % BSitosterol In modem medicme It IS used In the form of calCium sennoslde tablets as laxative In traditional medicine, an InfuSion of leaves In the form of tea IS used as laxafive (ShelvaraJ et al 1978, Shah, 8t al 1981) Senna is usually cultivated as rainf6d crop as it IS deep-rooted hardy plant and demands warm and dry conditions When there IS erratic rainfall, hfe saVing Imgatlons (one or two) IS required Looking towards low water requirement of cnop, Pot culture, mlcroplot and field expenments were conducted In sandy loam calcanous Salls of Bir Forest, Hisar With use 01 underground saline water for three years on Cassia senna cnop and at CSSRI, Kamal, Indicated that rts pertOimance In terms 01 hero yield and active principle was Increased when Imgated With saline waters havmg ECJW up to 10 0 d Slm compared With fresh water Sennoslde content under salt stress was 37 % higher than contnol conditions (Lodha, 2007) Moderate salinity levels (EClw 4.0) dSlm Results from greenhouse as well as field studies uSing saline water Irrigation Indicated that the salinity up to 8 0 dSlm did not have any detnmental effect on plant gnowth and quality Immature leaves contained more sennoslde content over mature leaves Senna leaves contains more sennosldes than pods Green pods are more active than npe. Percent Sennoslde was found more In rainfed crop over Ir"gated Quality of produce meets the speCification of Indian as well as Bntlsh Pharmacopla and therefore, could fetch very good export market and In turn eam foreign exchange At present wholesale market Price In India 01 senna leaves JS Rs 35/- kg The cathartiC properlJes of senna are not los! during five years If packed airtight

Table 3 Effect of Saline water imgation on Sennoslde content in mediCinal crop Cassia angustdolla

ECIW Acfive pnnciple (%) Soli EC after experiment' (d S m· )

Control 240 055

40 335 062

60 332 093

80 330 104

100 328 148

120 327 161

(1 2 rabol, Source Lodha, 2005.

Fig 1 Export trend of Senna

Lepldium species

Lepldlurn species IS another medicinal plant used as an ingredient of vanous preparabons In Indian mediCine System All plant parts are of therapeu"c value and used ,n the treafinent of asthma, coughs and bleeding piles Leave are mildly stimulant and diuretic and useful In scorbutiC diseases and liver complaints The roots are used In secondary syphilis and tenesmus Seeds are rubifaclent, galctogogue, emmenagogue, laxallve, tOniC, aphrodisiac and dlurebc They are also used in POUlticeS for hurts and sprams It IS a small, herlbaceous, annual, '15-45 em tall and belongs to Mustard family (Cruclfereae) Field expenments condUced

?oR

CultivatIon of Non-Convenflonal Crops of EconomIc Value under Saline EnVironments

at Blr forest, Hisar In sandy loam calcarious salls With use of underground saline water up to 100 dS/m revealed that salinity did not have any detrimental effect On plant growth and quality Specie has low water requirement and could be raised as Rabl crop In degraded lands With use of underground sahne water up to 100 d S/m Seed Yield per ha obtained was more under salinity stress over nonnal conditions Crop was found more SUitable tor and and semland areas Chemical analYSIS of leaves showed that these are nch source 01 Iron and ascorbic aCid (Vit C)' Seeds contains 011 01 high quality containing high amount of polyunsaturated fatty aCids (90%) over saturated fatty aCids (10%) Seed meal left after extraction of all was found nch source of proteins (24%) With good dl)l matter digestibility (69%) and therefore, could be used as protein concentrate along With main ralions 01 livestock, (Lodha, 2005-07) Animal nutnllonal studies are In progress At present wholesale market pnce of Lepidlum seed IS Rs 48 0 I-kg -

Withania somnifera (Ash_wagandha)

It IS another mediCinal plant of vel)l high repute In AyUlvedlc and Una", system and also, known as 'Indian Ginseng' It IS a perenOlal, 1 0-1 5 m tall, belongs to Solanaceae (Bnn)al family) It is mostly found growing on degradedJwastelands In drY areas It IS largely cuilivated as a cash crop In Madhya Pradesh, Maharashtra, Kamataka, Himachal, Uttaranchal, _Gu)ara!. Deihl and Rajasthan ( Nagaun Ashwagandha) Roots and leaves of AshWsgsndha are used mediCinally in vanous diseases mainly as sedabve Leaves are used '10 kill worms, cure abcesses Other uses are as' antiulcer, anbarthntlc; In debility, CNS diseases, enhances memol)l Decoction 01 roots IS conSidered as tOniC and IS given to pregnant women and old persons It also, contains galactogue properties, AshWagandha roots mainly contain alkalOids Main alkalOids

-present are somnllenn, wltha"'n, Wlthananin,tropln,cholln etc whereas leaves contain Wlthanone and wlthalerlne-A Withaferine IS anticancer, Withafenn-A, anlimlcrobal and wlthanlne IS sadabve ,n nature Total 13 alkalOids are found present In roots, Pot culture, mlcroplot and field experiments camed out on VVilhama somnifera (Ashwagandha) at Central SOil Salinity Research Insbtute, Kamal with saline water (artifiCially prepared) of different salinity levels to know the effect on Yield and quality of produce Studies Indicated that thiS crop tolerates saline waler up to EC,w 14 0 dS m "Wlthout any adverse effect on growth AlkalOid content, which IS the acbve Ingredient In Ashwagandha plant. however, Increased Significantly With salinity stress over control (Lodha, 2005) Results Indicated that Ashwagandha crop has very good potential lor degradedJwastelands particularly, In and and semland areas as crop has vel)l low waler reqUirement and could be taken as rainfed crop II rains are erratic, lives saving imgatlons are given With brackish water available At present market pnce of Ashwagandha roots are Rs 14501-kg Simillarly, expenments are being conducted on Ajoe vera (Ghnt kuman) and Asparagus recemosus (Satavar) With various levels of saline water' Irrigation at Central SOil salinity research institute are found promising At present markel pnce 01 Satavar IS Rs 225 Olkg whereas Aloe vera IS Rs 500l-per kg Further work is on progress, Aloe IS ranked as seventh medicinal plant'ol vel)l high repute in USA and Intemanonal market

Chatharanthus roseus (Periwinkle)

It IS popularly known as sadabahar and In anCient times IS grown In every house Active pnnclple In thiS speCies IS an alkalOid that IS being used as ant-cancerous agent. More than 100 alkalOids have been Isolated from thIS plant lInlil date Major alkaloid IS raubas," Leaves contain vlnblastln and ",ncnst,ne, which are of therapeutic Interest Root bark contains the highest alkalOid content 0 55 percent) Penwlnkle IS commercially grown on large scale In Tamil Nadu In mlcroplot studies stem and root Yield did not decrease when irrigated With saline waters of ECW up to 100 dSm-' (Anonymous, 1987) whereas II can be grown In sahne SOils ECe up to 8 0 dSm-' (Anwar efal 1968) The ergot of l)Ie IS grown on l)Ie inflorescence parasItically by inoculation 01 spores, produces the sceleroba, which are pOisonous In nature These sceleroba after defatllng could be used as abortifiCient and controlling hemorrhage caused dunng chIldbirth Ergotamine and ergoimitnne are two most Important alkalOids used for post-partum hemorrhage Serotonin used as a starting matenal for the chemical compounds generally used for cerebral and muscular disorders like Parkinsonism etc Ergot alkalOids are used mostly In obstetncs on the contractible effects on the utenne smooth muscle It IS mosl tolerant mediCinal crop towards sahnlty compared to others (Anwar et al 1986) Other Important medicinal plants

Hyoscyamus muticus (Egyptian henebene) and Plantago ovata (Isabgol)

These-crops are moderately tolerant to 5011 salinity, CommerCial cultivation oflsabgol IS restricted to some distriCts of GUjarat Small-scale cultIVation IS reported In Patlala district 01 Punjab, Hisar In Hal)lana and some places 01 Uttar Pradesh Both the seeds and husk are important parts contain astnngent, emollient, demulcent, lubncant and l<fIxatlve properties therefore, used In the treatment of chroniC constipation, amoebiC and bacillal)l dysentel)l and diarrhea The seeds haVing cooling effect and all prevent arterioscleroses Results from a study uSing saline water ImgallOn Indicate that salinity up to 6 d Sm-' did not have any deleteriOUs effect on Its grain and straw yield (Anonymous, 1967, Tomar et ai, 2005) Anwar et al , 1988 reported that Egypllan henebene could be raised up to SOil salinity 8 0 dSm-' Egyptian henebene IS a source 01 tropane alkalOids and are used as an active prinCiple In vanous Unanl preparations, Which IS used In COld, acute chromc cough, apoplexy, lal)logills, vertllago, phal)lngbs, liver pain etc Mint IS a malar essenllal 011

259

Chemical Changes & Nutrient TransformatIon In SodlrJPoor Quality Water Imgated SOils

,. , bearing crop of high Industnal value It IS a susceptible crop compared.to other medicinal crops Quality of all was enhanced/,n mint under salt stress over normal conditions Which could be attributed to decline In the pnmary metabolites due to ,salt stress, causing intermediary products to become available for secondary metabolite synthesIs? Threshold safe limit of 5011 sallmty for penwlnkle and German chamomile IS 100 and 120 dSm,l, respectively LikeWise, among the less tolerant medicinal plants the tolerance limit of sallmty for Isabgol and Egyptian henbene is 60dSIm Results from micro plot studies uSing saline Imgallon water up to BOd Sm" did not have any deletenous effect on straw and grain Yields of Isabgol S,m'ha~y Egyptian henbene can be grown up to SOIl sallnily BOdS m" Results from pot as well as field studies on C angustdolia, -Lepldlurn and W'ithama somndera uSing saline water lITIgation up to 100 and 140 dSm' respectively, did not have any adverse effect on their growth, Yield and quality parameters Active prinCiple in these species under salt stress was observed higher than that of normal conditions, which Could be attributed to the decline of pnmary metabolites due to salt stress, causing Intermedlatery products to become available for secondary metabolites Among the mediCinal crops, rye for ergot can be successfully grown In Salls haVing EC 160 dSm" and pH 100 Salinity or alkahnlty does not have any slgmficant Influence on all content and quality of the aromabc and medicinal plants With respect to prinCiple ingredients The all produced In USAR lands IS equally acceptable in the market Singh (1992) observed that quality of lemon grass all With respect 10 cltral content was not affected by salinity Singh and Anwar (1965) observed that higher salinity did not have any adverse effect on oil content and Its quality In lemongrass when compared WIth that under normal conditions The cl!re1 was somewhat higher In sodlc Salis con<ll!lons (Anonymous, 1992), Quality (active pnnclples) In lemon grass, Kalmegh, Ashgandha was slightly higher "i sadie SOils (lodha, 2003) Sennosldes content in Cassia senna anel all content In Lepidlum species was observed higher In saline SOil conditions With use of saline water ""gallon whereas saline water Imgallon did not have adverse effect on all quality remained unaltered (lodha, 2005) Moreover, all produced In stressed conditions was of supenor quality than that under nonmal SOil-water conditions Some other crops, VIZ, Bach (Achorus calamus L), Muskdana (Abelmoschus moschatus Medik), Brahml (Cenlella aSiatica (L), kalmegh (Andrographls pan/culala (Burn f») wall ces nees, may be cultIVated on salt-affected SOils However, there IS an immediate need to'develop the Improved cultivation practices for their large 'scale commerCially Viable cultivation Most of the medicinal plants are In great demand to meet ",ternal reqUirement and for export Since, these are minor crops, It IS not always pOSSible to be produced on fertile lands, which can be used to meet the requIrement of food, fodder and fiber. The marginal lands, speCifically the land affected by sodlclty and sahmty problems where profitable returns are not pOSSible from agncultural crops, could be utlhzed lor the cultivation of these high-value crops With marginal Inputs Further studIes on amehorallve potenbal of these crops for different kinds of saline and SodlC Salls and their efficacy to Withstand Imgatlon-water salinity and tolerance to SOil sallmty stress IS reqUired for their cultivation under speCific cond,llons,

Effect of Salt Stress on Quality Aspects

Sahnlty has sl9nlficant Influence wrth respect to active pnnclple m medICinal crops Lodha, 2007 observed that sennaslde content In senna leaves was slgmficantly Increased With Increase In salinity However, does not have any adverse effect on quality of Leprdlum 011 (Lodha, 2004-7) Singh and Anwar (1985) also, observed that the higher sahmty did not have any adverse effect On 011 content In palmarosa when oompared With that under normal conditions (Table 30 5) Chandra (1978) made Similar observations With respect to quahty of palmarosa all grown under saline conditions The geraniol content In palmarosa 011 and crtralln lemongrass oil was either Similar or higher in sodle SOil conditions (Anonymous, 1992) I Salinity did not have any deleteriOUs effect on the quahty of the khus oil (Chandra and Sharma, 1987; Singh et ai, 1987) Moreover 011 produced under salinity stress is of supenor quality than that under normal soli-water condlbons

Conclusions

India IS amongst the few ploneenng countnes In developing practice of well-documented Indigenous system of medicines for eg Ayurveda, S,ddha and Tnbal MediCines, About 200 native pLant species are ubl!zed Widely for the" curative properties (Ghosh, 1996) and most of the mediCinal and aromatIC plants are In great demand to meet the mternal reqUirement and for export But Since, these crops are minor m natllre, It IS not always poSSible to spare fertile lands, which can be used to meet the requirement of food, fodder and fiber The marginal lands, espeCially lands affected by sallmtylsodlclty alon9 With underground brackish water problems where conventional agriculture IS not economically VIable, could be utilIZed for the cuilivabon of these high value crops With marginal Inputs Further, studies on screening of more number of salt-tolerant plants ara reqUired to Identify new non-convenllonal crops of value In saline environments

260

Cultlvahon of Non-Conventlooal Crops of Economic Value under Saline EnVironments

Table 4 Saf\, hmils of sahnity for some Important aromatic and medicinal crops

Crop Aromatic

Palmarosa (Cymbopogan martinll) Lemongrass (Cymbopogan flexuosus)

, Vellvar(VellVar zizanioides) Cltroryella (Cymbopogan wlnterianus) Jamrosa

MediCInal

11.5(160) 100(100)

120 55 120

Penwmkal (Chatflaranthus ros(Jus) 10 a (8 0) Chamomile (Matncana chamomile 120(8.0) Rye for ergot (elsVleeps purpuna) 16 0 Isabgcil (Plantago ovata) 8 0 (8 0) Henbene ( EgyptIan henbenee . B 0 Senna (Gassla angusllfolla) 80 (10 0) Mulethl (Glyclf7tllza glabra) 60 (10 0) Ash~agandha( Withama somndera) 8.0 (12 0) Ghnt kuman (Aloe vera) 80(1200) Shatavar(Asparagus reC6mosus) 6 0(10 0)

Source. Singh and Anwar (1985), Anonymous (1967), Anwar et ai, (1996), lodha (2001-08), Tomar at al (1995-97 2006) ·Maxlmum sahriity that the yield and quality IS not effected Figures In parenthesIs Indicate

,water sahmty

Bibliography

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Chandra, V 1978 Cympobogon martim Roxb Var moba grown In sahn&-alkah soils' Indian perfumer 22(4), 244

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Chemical Changes r- Nutrient Translormat)on In SodlcIPoor Quality W~,ter Irrigated Soils

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262

Biomass and Biodiesel for Energy Production from Salt-Affected Lands

S.K. Sharma & N.P.S. Yaduvanshl" D,v,s,on of Crop Improvement 'D,vIs,on of Sot! and Crop Management , Central Soil Salmlty Resllarch Inslttute.,Kamal- 132001, Haryana

Introduction

Government of India has chosery blo-Olesel produced from oll-beanng seeds of Jatropha (Jatropha cucas) and Pongamla plnnala as a substitute for HSD (high-speed diesel) under the recently launched Nabonal Mission on Blo-Olesel (NMB) The challenge is to produce large quantltres of blofuels and at pnces competitive WIth those of currently used ,fOSSil fuel products on a sustainable and environment fnendly baSIS WIth particular emphaSIS on the under-utilized and less productive lands InitIal efforts In thIs direction. produced mIxed results due to lack of Information, systemabc research and lack of knowledge about SUItable and productIve lines and SIlViculture pracbces In dIfferent SOIls and agro-cltmattc sItuatIons In the present scenario, when most of the cultIvable area nas been OCCUPted by conventronal/cultivated crops. plant specIes havtng tolerance to dtfferent ktnds of stresses and havtng potentral to come up tn degraded land under less favourable envIronmental condlttons need to be promoted In VIew of the emerging nattonal pnonttes for achtevlng energy secunty and tndependence. studtes on Imgatton, fertrltzers, spactng for their optimum productiVity in salt-affected SOils (salinity, alkallnlty/sodlclty) and With poor quality water have been taken up at Central SOIl SalinIty Research Insbtute Karnal and lis regional research centres located In dIfferent agrocllmabc zones of the country The ultImate goal IS to develop site-speCIfic SUitable genotypes that are tolerant to adverse growing conditions such as salinity, alkalmlty, water-logging and frost, so as to promote their culbvatlon in such areas Jatropha curcas, known as Ratan Jyot or Vana Erand, IS fast growing speOles, prOVIde a source of renewable energy, produces useful all from Its seed and IS also a good SOIl conservatIon plant, adaptable as a wmd break and has other multIple uses Jatrropha, which already grows In several parts of India, IS domesticated all over India for more than 400 years, is moderately resistant to drought, and thnves In and and semi-and areas It IS a vIgorous plant and IS not eaten by animals It proVides environmental benefits such as protecbon of crops or pasture lands. as a hedge for erosIon control, or as a WIndbreak and a source of organic manure

Potential and Scope of Biofuels

India has 107 million hectares of wasteland and It IS pOSSible to bnng 10 to 20 per cent ot thiS under culbvatlon of plants that can Yield biomass for energy As per estimates of the International Energy Agency, farmers can supply 10 percent of gasoline requirement of the world by 2025 Blofuels can be produced from a WIde range of feed stocks, from tradltronal com or rapeseed 011, or the more unconventional used cooking 011 or cheese Edible Oils are used as blodlesel In Europe, USA and other countries, whereas for countnes like' IndIa which are short of these OIls. ose of non-edlble Oils IS the only option. Jatropha is a multIpurpose plant whose every part has some economical value It starts prodUCIng oil-bearing se"ds Within one or two years of plantIng and optimum yields are obtained by three to five years and plants continue to be productive up to 45-50 years The main economIC part of Jatropha IS ItS kernel 011 content vanes from 25-35% In the seeds and 50-60% In the kernel It contaIns 21% saturated fatty aerds and 79% unsaturated fatty aCids Jatropha all IS also used as an IlIumlnant as It bums WIthout emllling smoke Its latex contains an alkalOid knowQ as • Jatrophtne" which IS reported to have antt-cancerous propertres It tS also used as an external appltcatlon for skin dIseases and rheumatism and for sores on domestic livestock Roots are reported to be used as an antidote for snake-bites Its uses are summanzed In table 1.

Potential Areas for Cultivation

About 3 0 mIllion hectare of land under stocked forests out of total forest cover In our country, 20m ha of nOllOnal plantation IS expected by absentee landlords On wastelands under Integrated Watershed Development and other poverty alleVIation programmes of MInistry of Rural Development a potential of 2 m ha of plantatron IS assessed Notronal coverage With Jatropha on 10m ha vast stretches of public lands along railway tracks, roads and canals can also be planted Jatropha hedges around agncultural fields can amount to 30m ha plantation

Studies on Jatropha and Pongamla at CSSRI

Central 5011 Salinity Research InstItute, Kamal IS IdentifyIng and evaluatIng plant specIes and vanetles from different areaslsources to Increase genetic diverSIty SUitable for alkali, saline SOils and sallnevertisols Germplasm base of Jatropha and Pongamla to promote therr economiC productIon In saline agnculture (sallnefsodic Salls and water) IS also beIng developed Matenals are being screened for germination, propagation, seedling, vegetative and reproductive growth under salt affected conditions Studies

Chemical Changes & Nutnent Transformation In Sodlc/Poor Quality Water Imgated SOils

, I

on physlologlcal_mechamsms govemlng tolerance of different hnes and clones of Jatropha and Pongamla are monitored for/soil-plant interactions With focus on accumulation and tOXICity of salts and mlcroelements In plant parts and rhlzosphere Studies on water and nulnant availability, uptake pattern, utlhzatlon, processes of gas exchange, photosynthesIs and C-sequestration are also undertaken Orchards of tolerant and productive hnes of these speOles are under estabhshment stage Ultimate objective of these studies IS development of SUitable and productive genotypeslvarletles tolerant to advelSe growing conditions such as sahnlty, alkahnlty, water-logglng and frost so as to lnelreasa the range of growth and cultivation In order to achieve above , mentioned objectives and to Idenlify pOSSible untapped genelic diversity and enhance potential value through Increased use 01 available genetic diversity and optimIZing productIVity through proper silvlcu~ural practices, a senes of expenments have been Inlbated at CSSRI Kamal and Its regional research stations at Lucknow (UP), Bharuch (Gujarat) and Canning Town (West Bengal) to exploit the potential of two species for energy generation

Tabte 1 Uses of Jatropha and Pongamla multi purpose tree species

Part

Seeds 0,1 cake

Stem and CuttJngs

Leaves

Leaves, Latex & Rools

Plants

Products Age

Ongln & Populanty

Jatropha

Blodlesel, Glycenn

B,o Manure

Toothache, Gum bleeding, Pyorrhea Wood for fuel '

Aqueous Extract -Insecticidal properties, Fumlgabon of houses, As Tussar Silkworm feed, Leaf htter

MediCinal uses (Laxatrve, Arthntls, Gout and Jaundice, Anlldote for Snake bite, Anll-Cancer drugs, AnthelmInthIC Hedge, Tree & Plantation Crop

Starts 1-3 Years Up to 40-50 Years Ongln from MeXICO & S Amenca

Salient Research Findings

Pongamla

Blodlesel

Blo Manure, Pou~ry leed and Insecticide

Fuel, Timber for furniture and dlfferentlrnplements

I nsecliCidal propertles, Fodder

MediCinal use In Gout & Skin diseases

As Shade & Ornamental Tree on RoadSide

Starts 5 Years > 50 Years

On gin In South Asia

Preliminary obselValions based upon expenments conducted al CSSRI, Kamal and Its regional research centres are recorded, however, these results Will be confirmed over the seasons before making field scale recommendations

Characteristics of a semi-reclaimed alkali !!eld at Kamal

Expenments on Irnga~on,' fertlhzers, spacing, pruning requirements and practices have been laid In one hectare field haVing semi-reclaimed 50,1, One year old Jatropha plants were planted In July 2005 uSing auger-pit technology.

Field characterization '------ -So,l samples at the start 01 the plantation revealed tile follOWing charactenstlCJ5 of the field Surface

5011 pH ranged from 7 65 to 8 35 at 0-15 cm and 15-30 em depths, Wh,le lower SOil depths (60- 90 em and 90-120 em) had mueh higher pH up to 10 15 With Ihe range 805 - 10 15 (Tabla 2)

Hard calcareous layer was present at lower depths and vaned In depth across the field Lower organic carbon (060 % at surface and 0 20 % at lower depths), low nitrogen and medIum P levels occurred In all the profiles Lower concentra~on of DTPA Zn and higher concentrations of Fe, Mn and Cu In companson to cnticaillmits of these m,cro-nutrlents were observed

264

Biomass and Brodlesel for Energy ProductJon from Salt~Affected Lands

Table 2. Inlbal 5011 pH and EC In Jatropha expenment field at Kamal

Depth (em) Profile 1 Profile 2 Profile 3 Profile 4

pH2 EC2 pH2 EC2 pH2 EC2 pH2 EC2

CJ.15 - 820 1.85 8.35 037 813 030 765 040 15-30 600 184 900 044 920 056 770 030

f

30- 60, 795 195 956 085 990 1 25 760 026 6(). 90 BOO 2.75 980 1.12 996 130 765 024 90- 120 805 030 9,70 097 1015 161 850 041

Hard Pan layer (Kankar)

AlkalUlIOdicity tolerance of Jatropha and Pongamia , I Jatropha and Pongamla perform well up to pH 9 5 Significant reductions In growth of shoot and root

growth were observed beyond pH 9 5 In pots ThiS Indicates'lts moderate tolerance to alkali conditions However IIi field Situation, plants were able to tolerate relatively higher pH and observed reductions In growth were lesser than those observed In pots It was probably due to the fact that the 5011 In pots was haVing Similar pH throughout the profile as compared to the field where surface layers had lower pH than the deeper ThiS IS well corroborated by the presence of most of the roots In the upper 5CJ.60 em 5011 profile and hardly any roots gOing below this depth even though the plants were 30 months old Almost Similar moderate tolerance to sodlclty (pH 95) was indicated In case of Pongamla, Use of auger-pit and application of gypsum or other amendments along With fertilizers help in establishment and growth of plants In alkali SOils haVing pH 9 5 -100 and can be helpful In raising Jatropha plantallons on such SOils. ThiS technology developed at CSSRI has been successfully used In plantation of forest and other tree speCies for rehabilitabon and reclamation of

.alkall 50115 , .' ' ,

Response of Jatropha to salinity ami saline water Irrigation

Jatropha' performs weU In saline (10 dS m") Salls Similarly, Jatropha grown on Vertisols With subsurface salinitY and "ngated With saline groundwater (11 6 dS m") also recorded good growth, flowenng and seed production Plants lITIgated With saline water at three different mtervals I e once In 10, 20 and 30 days Indlcaled no Significant difference In growth and seed Yield between 20 and 30 days Interval ,mgallon (Table 2) ThiS suggests that marginal quality of saline groundwater can be spared If the crop IS Irrigated once In a month dunng hot summer Appllcallon of lesser quanbtles of saline water also reduces salt bUild up in the SOil

I

Table 2 Performance of 2-year Jatropha With salme (11 6 dS m") "ngabon on Vertisols

Irrigabon IrngallOn Plant height Seed Yield Seed Yield Seed all Seed all frequency, applied (m) (g pian!") (kg ha') content (%) Yield (days) (I pian!") (kg ha')

10 (6) 90 136 268 2977 352 1047,9

20 (3) 45 122 184 2044 362 7399 30 (2) 30 114 173 1911 363 6937

(Figures In the parentheSIS Indicate number of Irrlgallons)

Irrlgallona

. . lITIgation and fertility are important factors In determining opbmum,productlvity of Jatropha In saltaffected SOils of semi-and regions Crop performance as rain-fed, With 2 life savlMg Irrigations dUring May/June and pec IJan , 4 IITIgabons and 6 Irrigations was tested

Preliminary results over two years show that application of at least 2 crUCial irrigations I e dUring peak summer (May-June) and peak winter (Dec - Jan) seasons IS essential for optimum survJVal and' productiVity of Jatropha In the first two years (Table 3) An additional Imgatlon dunng flowering perIOd IS helpful, In case of errabc rainfall Applym9 Irngatlon before expected frost In winters IS helpful In overcoming Its inJUriOUS effects '

Fertilizers

Though Jatropha IS adapted to low ferbllty slles and saline SOils but It seems that better Yields can be obtained with application of ferllllzers Supply of Inputs In terms of organic and Inorganic fertilizers promote better establishment of plantation, plant growth and seed Yield as better growth and seed Yield was recorded With addition of 50 g urea + 1209 SSP + 20 g MOP per plant In companson to control Growth and Yield further Improved by supplementing above chemical ferllllzers With 20 kg FYM In addlbon to fertilizers,

265

Chemical Changes & Nulnent Transformallon In SodlclPoor Quahty Water Imgated Soils

-' / , application of mycorrhl<:a also helps Jatropha plantabons In better establishment, dlsease~ protection and Improvement)n Yield, thus giving higher vegetabve biomass and seed producbon MyCOrrhlza proVed eifecllve In,promobng plant establishment, plant growth under atkalll sodlc conditions and protection against Wilt and other fungal diseases

Table 3 Growth of Jatropha In semi-reclaimed alkali SOil With vanable no of Irrigations '.~ \

No of Plant ht Plant dis Branch Branch Frtultmg, branch f'rUits No Img (em) (em) dla (em) No PI" No. PI" PI'\.

a 292 19B 497 .27 10 72 , 2 275 212 '514 29 13 98 4 311 234 537 30 16 221

6 301 228 553 31 12 167

Genetic variability and plant Improvement

FrUit WI g pr' 352 457 670 639

Low yields and plant to plant vanabllity is a IImlbng 'factor In Jatropha Yield vanauon from a few hundred grams to 2 kg were observed In the first year and Yields up to 12 kg have been reported In 4-5 year old plants This confirms genetic diversity for seed Yield and IS a IImltahon as well as opportUnity for plant Improvement; as availability of'good matenal In~ terms of seed andlor nursel)' and related Infra-structure network for procurement and processing IS a pre-requiSite for success of such programmes More research IS reqUired to answer these questions and also come up Wlth SUitable provenances or lines to ensure proper Incomes to farmers and protect nabonal interestS •

Establishment of germplasm orchards at Kamal and Bharuch Will promote further efforts In plant Improvement CSSRI has already collected 36 hnes! seledlons of Jatropha lrem different areas and sources beSides idenbfylng 'candidate plus trees' for higher seed yield SCientiSts are trym9 to build up thiS collection and also procure non-toxic and edible hnes from MeXICO and Latin Amenca All these collections have been planted In the germplasm orchard at Kamal for further evaluation and salt tolerance Observations Indicate that ea~y flowenng vanetles I e July to first -half of September are su~able for north Indian conditions where night temperatures start failing tram Odober onward Flowers in the late flowenng vanetles or formed later due to Indeterminate flowenng are not able to develop properly because of short time available for development of frUits and lower temperatures prevailing dunng that phase Consequently, frUits developing out of the later formed flowers are relahvely much smaller thus leading to lower Yields Indeterminate flowenng over prolonged penods IS thus a limiting factor in the productivity of Jatropha -

Inter-cropplng

Intercropplng With other value-added crops, particularly low water reqUlnng crops Including "romatlc and mediCinal plants can be an option which prOVides addrtional income dUring the Initial years Optimum Ylelds'in case of Jatropha are reported from 3 to 5 years and IS longer In case of Pongamla where frurtlng starts around 5 years To evaluate thiS opllon, stUdies involVing mustard, dill, turmenc, tUISI, and matricana were earned out In different agro-cilmabc and 5011 cond,llOns Since Jatropha can be grown as block plantations, row fences, or In combinallon With the agncultural crops, we need to test such plantation models In field so as to optimize Yields for adaptation by the farmers and entrepreneurs SpeCific Intolerance of these crops was not detected when Intercrops were sown In Jatropha or Jatropha and Pongamla plantations On the contral)', the shade can be explOited for shade~ovlng hertJal plants, vegetables such as red and green peppers, t",matoes, etc Our studies show Indian mustard gave YIeld of 1 08 lIha prOViding Rs 26,0001 In addition to Jatropha Yield, when planted as an IOtercrop between Jatropha and Pongamla plantations on a saml-reclalmed alkali SOil Simlla~y, dill (Anethum graveolens L.), a moderately salt tolerant SPice crop fonns a good propOSition for IntercropP,ng with Jatropha on Vertisols With sub-surface salinity and Irrigated With sahne ground water, V\lhlle, Jatropha produced 2 45 qlha seed, dill produced 670 kg of seed/ha Gross returns from dill when mtercropped With Jatropha was Rs 230001- per hectare

Pruning

Pruning IS a useful practICe for obtaining better Yields In case of Jatropha It IS generally recommended to prune upper two-third of the branches ThiS was done In Feb -March after leaf fall and seed harvest In Kamal type conditIOns Newiy formed branches produce Side shoots for better sprouting, flowers and seed In GUlarat conditions, pruning needs to be done by mid-November The cleanly cut top produces 8 - 12 Side branches It IS a good pracbce and also helps In restncbng the plant canopy to heights of 2 5 meters for convenient seed harvesting In the subsequent years, the lateral branches are cut back dunng the dormant penod so as to give a bushy shape to the plant

266

BIOmass and Bloole5Ollor Energy ProdUc\lon !rom SaU-Alleded Lands

Spacing requirements

Expenments were conducted to work out optimum spaCIng requirements for Jatropha In a semlreclaimed field Row to row spacing of 3 m ~as tned In comblna~on With 2, 3 and 4 m spaCIng haVing 1666, 1111 and 833 plants per hectare Plant growth and biomass of two and a half years old plants are shown In

table 4 These resulls show that fresh biomass production per plant Increased two and four times at 3 and 4 m spacing over 2 m spaCIng Consequently, an Increase of 50 and 100 % In fresh biomass production per hectare was obtained despite haVlng 66 and 50 % plant population as cOmpared to 2 m spacing -

Table 4 Fresh biomass of Two and a half years old Jatropha piants

Spacing 3x2m 3x 3m 3x4m Plant WI (kg) 1379 3029 5646 No of Plants ha-' 1666 1111 833 Bloma~s (t ha-') 22 97 3365 4705

Water stagnation

Jatropha IS well known for its drought tolerance and can survive dry condl~ons_ It Will also stand for long penods Without water SUrviVing on whatever httle available rains However, In order to get optimum Yield, lITIgation IS reqUired Contrary to the general feeling that Jatropha cannot withstand water stagnation, observations of Bharuch in Gujarat indicate that the plants can also withstand 2-4 weeks water stagnaMn on sahne Vertisols without any mortality Further swdles to evaluate waterlogglOg tolerance 10 available gennplasm and the mechanisms govemlng the responses are underway

Limitations and cauUons

Despite these characteristiCS, the full potential of Jatropha IS far from being reahzed There are several reasons and Issues-techmcal, economiC, cultural and Institu~onal - that need further intenSive research, diSCUSSion, formulation of poliCies and crelltlon of proper Infra-structure by the government However, we need to be sure about all aspects of Jatropha, especially Its effect on enVIronmental ecology and humanity as some reporis Indicating pOSSible harmful effects have appeared AuthentiCity or validity of such reporis needs to be looked mto properly In a SCientific and ratIOnal manner_ Due to ~S Wider adaptability to different stress conditions Jatropha can spread as II weed raiSing possible environmental concerns Evaluation for vanous diseases and pests In large plantations or monoculture through higher Inputs like Imgatlon and fertilizers IS also a PriOrity

Salient Research Findings

• Imgatlon and ferlillty are Important factors In determining optimum productIVIty of Jatropha In semi-and and salt-affected SOils

• Application of at least 2 cruCial imgabons I a dunng peak summer (May-June) and peak Winter (Dec -Jan) seasons is essential In the first two years for optimum survival and productiVity An additional irriga~on dunng flowenng is helpful, if rams fad

• Jatropha plants have good potential to produce biomass for fuel and other purposes

• Pot studies on Jatropha and Pongamia Indicate moderate alkah tolerance up to pH2 95 We need to evaluate more gennplasm to Identify more promising I tolerant lines

• Field and other studies show good san tolerance of JatrQpha as not much reduction occurred ',n 5011 salinity of 10- 12 dS m-' and application of sahne waters

• Low Yields and plant to plant vanablhty IS a Ilmltatlon Y,eld vanatlOn from a f~ hundred grams to 2 Kg were observed In first year and Yields up to 12 Kg have been reported In 4-5 year old plants

• ThIS confirms genetic variability offenng scope for plant Improvement efforts Establishment of germplasm bank Will help further efforts In plant Improvement

• Earty flower Imt'atlon (Aug -Sept) IS a deSirable trail In the North Indian conditions as late formed flowers and late flowenng vanetles face low temperatures (Oight) thus hampering further seed development and matunly

• Pruning after seed harvest and leaf fall help promote biomass, flowenng and seed production In the follOwing season

• Plants raised through vegetative propagation show earty establishment, flowenng and are more Uniform than plants raised from seeds

• ApplYing irrigation before the expected frost helps overcome Inlunous effects of frost

267

Chemical Changes & Nutrient Transformation In Sodlc/Poor Quailiy Water Imgated Solis

/

Future Scenario /

It IS the timely and urgent national requirement to examine the potential of Jatropha In meeting some of the energy needs, creating avenues tor greater employment aDd Its overall role In the national energy seenano Keen Interest and Initiatives by central and state governments and some malor pnvate companies In taking up major plantations IS a good forerunner In thIS dlrecl!OI\ and holds much prOll)lse with lot of benefits for future Some vanetles of Jatropha from MexICO and laM Amenca are edible In nature as therr seeds are used for eaMg after roasbng and all IS used for edible purposes We are trying to procure such matenal. for Introduction and plantation In India. Proper planning and ooordinated efforts on the . part of governments, researchers and farmers might ensure that fields of Jatropha and other abundant all trees and crops Wlil stand alongside 011 fields In meeong the world's future energy needs-providing a much-needed boost to rural economies around the world The growing emphaSIS world over on renewable energy sources, accompanied by nSlng crude oil Prices which has touched 130$ per barrel and uncerlaln world supply pOSllton, are likely to proVide a favourable ScenariO to the benefit of Jatropha and other blo-dlesel crop growers

268

Breeding Wheat Varieties for Salt Tolerance in India: Present Status and Future Prospects

Neem} Kulshreshtha D,v,s,on of Crop Improvement Central Soil Salmlty Research Institute, Kamal- 132001

Introduction

In India 6 73 million hectare area}s affected by either salinity or SodlClty wheat IS one of the major crops grown In these salls Breeding wheat vanetles for salt affected 50115 may help to a great extent In stabilIZing producbon for the rapidly growing population of the country Wheat Yields, are very poor and uneconomical In Initial 4-5 years of reclamation and management practices Will continue to play an Important role In getting better Yields of wheat In such SOil However, salt tolerant varieties playa very Important role by' requlnng lesser Inputs In the form of cheriHcal amendments Moreover under situations where the poor quality water IS the- only source of Irrigation, salt tol~rant vanetias offer the best technology for the farmers to adopt Therefore It IS now a great concern to breed wheat vanelles for salt affected Salls, which may help to a great extent In stabiliZing production for tM rapidly groWing populatIon of the CClJntry In IndIa lot of work related to mechanisms of salt tolerance (Sharma, 1987) and screening and evaluation of genotypes under stress has been camed out and documented (Mlshra, 1994,1996, Mlshra at aI, 1997, SIngh, 1991,2005 and Singh at ai, 2005) Culbvar tolerance for salinity and SodlClty can be a substItute for amendments as moderately saline/alkali Salls and supplements to amendments in strongly salt affected Salls

Genetic Variability for Salt Tolerance

A large number of Indian and exotic vanetles have been screened at CSSRI, Kamal under SOdlClty and salinity These vanebes have been categonzed under lour categones tolerant, medium tolerant medJUm senslWe-and senSItive for the purpose of standardization and making compansons The I!stof some of the known vanetles belonging to different dasses has been given in table 1,

Table 1 Ctassificatlon of some of wheat vanetles/genotypes With respect to tolerance under salinity and sOO\Ot'i .

Tolerant' Kharchla 65 KRL 3-4 KRL99

\ Medium T oleran?

KRL19 KRL 1-4 KRL35

HD 2009 HD 2285 HD 2851 HD 2329 UP 2338 PBW343 PBW502 WH542

I, Grows well and sets Viable seed upto 5011 pH, 96 or ECe 8 5 dS m-' 2 Grows well and sets VIable seed upto SOil pH, 9 3 or ECe 6 5 dS m" 3 Grows well and sets VIable seed upto SOil pH, 9 1 or ECe 5,5 dS m-' 4 Grows well and sets VIable seed uplo SOil pH, 8 5 or ECe 5 0 dS m-'

HD 4502 HD 4530 Raj 911 Mob Hlra Mexlcalll 75 Altar 84

In wheat It has been demonstrated that dlvelSlty for salt tolerance was greatE'r among countries WIthin regions while diversity among different species of wheat was greater than among plOidy levels (Singh and Chatrath, 1993) Screening more germplasm from the and and semi and regions espeCially from salt affected Salls has been advocated (Sayed, 1985)

Breeding for Salt Tolerance

Genebc adaptallon of crops to salinity reqUires that suffiCient hentable vanability eXists Within species to permit selection of salt tolerant strains and those plant charactenstlcs which conler salt tolerance, be Idenllfied By explolung the Inherent vanability In Wild species such as crested wheat grass, It has been suggested that the production under saline condItions could be more than double, In case of salt reSistance, It would seem that It IS essential to wall< hand to hand With Ihe plant physiologists and SOil SCIentists to prOVide appropnate co_n\Jltlons for selection and development of effectIve selection parameters for salinity tolerance

Chemicar Changes &,Nutrlent Transformation In SodlcIPoor Quality Water Imgated SOlis

, /

Germplasm Collection and Evaluation /

The presenl day vanelles have a relallvely narrow genellc base and are poorly adapled 10 adverse enVIronments such as salinity, However, endemiC genolypes Irom problem envlnonmenls may prOVide Ihe baSIC germ plasm for breeding sail loleranl vanelles wllh acceptabla Yield polenllal Genebc resources collecled as populallons samples of speCific slress enVIronments should be maintained as population wllhoul the loss of their genetic mtegnly. The environments where itle genelle resounces are, 10 be reluvenated should proVide equal opportunrtles for all seeds 10 grow and produce progenies, olherwlse genellc doft may occur due to poor performance 01 certain portion of the populabon '.

, . The classlficabon of germplasm or genetic matenal Wllh respect to lolerance under stress is a very

Importanl task, It IS not pOSSible many limes to screen genetic malenal under dlfferenl 'salinity/stress levels 'under field condilions Nevertheless, a soil sCientist can descnbe preCisely what IS causing the stiess In terms of salinity, pH and minerai toxlcllyldeficlency It IS pOSSible 10 dupllcale the salt slress under laboratory conditions. Thus vanous levels of combinations can be expenmenlally constructed and screening 01 genotypiC can be done

Selection efficiency under lIall stress

The major concem lor breeding under stress IS to increas~ the selecllon effiCiency under stress Unlike breeding for normal enVIronments selection under actual field condition may not be rewardmg always Allhough the Ideal situalion Will be to screen lor grain Yield under actual slress envlronmenl but the level 01 5011 heterogenelly In such fields are very high, This results m the selecbon of some of the genotypes which are nol otherwise tolerant These genotypes get selecled due to normal 5011 palches In between stress Therelore there IS need to select genolypes unde, artificially created enVIronments along With target s~es

In situ field evaluation

The field gradient of soil sallmly 15 determmed by the 5011 tests at small mtervals of space and a long striP running full length across the sallmty/sodlclty gradlenl IS allotted 10 each genolype The plots generally measured 2 10 3 rows of each vanety, 2D-30m long ThiS allows exposure of all genolypes 10 a varying sail stress condlbons to a comparable degree The layout of such a test IS generally an augmented deSign In which a sel of check vanely IS replicated many limes or an Incomplele block deSign such as Simple lattice Wllh a sel of check varieties (both tolerant and senSitive) It IS further pOSSible to cut aenos. the long plots In several parts to oblaln vanetal performance at varying levels of SOil SodlClty There has thus been an overall Increase In selection effiCiency Vlthlle advancing the matenals to minimum numbers, the limited varieties are evaluated In randomized block deSign With 3-4 rephcabons InvolVing nabonal and local checks lor Inilial YIeld evalualron The Involvement of more number of checks has been found better In data processmg and finalllClng the lolerant lines Selected genotypes are further evaluated as slallon tnal on bigger plot basiS to evaluate Ihelr Yield polentlal

Screen~ng In Microplots

SOil heterogeneity and spabal vanabillty hinders Ihe reliability 01 the response of the genotypes In true and dependable way, At CSSRI mini field enVIronments have been developed With varying levels of controlled sallmty and sodlClty enVIronments 11'15 pOSSible 10 create and malnlaln deSired levels of salimly and sodlClIy In these mlcroplots simulatmg field conditions minus the SOil helenogeneliy Allhough the plot size IS very small but there IS good control over micro enVIronment

Screening In Pow

For more preCise study of Ihe tndlvldual plant response under a constanlstress, round porcelain pots 0120 or 3D ern diameter, With a capacity 018 or 16 Kg 5011 Wllh a provIsion to allow or plug oflleachmg from bottom, ar~ used

Screening In Irays

For large scale screening 01 vanel,es at germination and seedling stage, shallow-depth wooden germination Irays prOVided With pofythene sheet lIning on the Inner lace are being used They are very useful In control of salinity, sodlClty and mOisture They allow a slmulallon 01 germmatlon response of Ihe field These stUdy give mdlcallons about relabve gerrmnallon and survival rates These trays are used lor seedling stage studies only

Germination studies as a seleciion criteria

Large number of invesligatlons 0,\ dlfferenllal responses of.crops or vanetles has been reported al gerrmnallon stage and attempts have been made to utilize thiS mlonnallOn In extrapolatmg tolerance limits for Ihe final performance ollhose crops or vanetles More than often such attempts are likely 10 be lrustratlng

270

Breeding Wheal Varlelles for Salt Tolerance In India Present Status and Future 'Prospects

because' tolerance charactensbcs at the two stages may be qUiet unrelated, for example In our experiments, we have found that one vanety IS comparatively more tolerant at gemllnatlon but another vanety IS relatively better than that for grain Yield, Therefore, the tolerance of cropslvanetles has to be assessed In relabon to the speCific component and speCific sltuaMn ?t particular stage of plant development and traJ! which IS responsible for the economic yield Standardlzalion of screening techniques is an essenbal pre-requIsite before the screemng IS unoertaken and plant vanables are adequately mon~ored so that performance of a genotype IS suitable assessed The evaluation can be made by measuring different parameters like germination under salt stress, absolute yield under salt stress and Yield and growth under salt stress conditions compared to be performance under nonmal SOil condltJons

5011 salinlty/alkalimty may affect germinatIOn by (a) Increasing the osmotic pressure of 5011 soluMn to the pOint that Will restncl. the Intake of' water or by (b) causing tOXICity to the embryo Both factors retard/prevent the germination, resultmg In poor stand of the crop, Among the vegetative growth phase, seedling stage IS the. most efficient stage for screemng large number of genotypes for salt tolerance Germlnalion rate IS another. way to'dlstlngulsh between genotypes under stress For measunng genmlnatlOn rate/emergence rate countJng of germinated seeds starts _on 6th day when the first coleoptlles emerged and' continued until the 24th day, when data IS recorded on 6 aays Interval dunng the penod of observations for the calculatJon of germination rate Index, Total germinatIOn In case 6f different vanetles under study is expressed as percentage of germinated seeds Germlnalion rate or emergence rate IS calculated by a Slight modJlicatJon of the method suggested by MagUire (1962) Singh and Rana (1989) used thiS method In wheat and found It very useful for screemng of large number of genotypes for salinity and alkalinity conditions GenotypIc values of this index are calculated as follows'

L-' ._ J,. •

e8rcifnlage ofemeroeo seecUri1!lS '+ % of'addlUonallyemerged seedlings + % ofaddltlOnal emerged seedlings I. ,J - .. days 10 final count... ,I -, -days to first collnt" f"" days to second count

II ~11f" I ,"T "~J_ ..... I ... '_.,~ __ • ' ,_, I"~ -~jl' J.</,,,I

I,... ,The, values obtained at each count are summed up at the end olthe germinalJon test to obtain the emergence Index.'VVlth the help' of these values: It'IS poSSible to-dlfferentJate between two genotypes which are haVing some value of germination percentage under same sa~ stress conditions Means faster In genmJnalio~ IS conSidered to be better under salt stress condrtlons c

Thresh hold EC,IpH Value

Crop Yields are' generally not decreasec slgmficanU{untll the EC. or pH or ESP exceeds a speCific value for each crop ThiS value IS known as the threshold level for that crop which vanes WIdely for different crops However, the ralalive tolerance of a crop IS evaluated on the salimty/alkalinlty level at which 50% decrease In Yield may:be expecled as compared to Yleld.oil normal SOil under comparable growing condItIons, In wheat the threshold salinitY level IS 6 0 dS m" and 50% Ylelcfreductlon IS observed at 14 0 dS m",

'_' • I I J' "-" i

Metabolic Parameters'

Under saline soiution, the concentrabon of Iici,,-€ssentlal or tOXIC Ions are greater than that of essential elements, for example, Na concentration In saline SOil solutions may exceed that of K and yet the Na K ratio In plants groWing on these Salls may be near one or even less ThiS high speCifically for K uptake IS present In Wide range of plants, Higher KINa ralio would characlenze a tolerant variety and a low ratio value"the relalively susceptJble one The salt tolerant Kharchla materials of wheat have relatrvely low Na/K ratio In companson to susceptible varlellaS HD2009, or HD4530 Most of the vanetles encounter follOWing phYSiological and biochemical manifestation under high salt stress condlbons

• High Na' transport to shoot. • Prefemlial accumulation of Na In older leaves • High cr uptaxe • lowsr K' uptake • lower fresh and dry weight of shoot and roots • low P and Zn uptake

Yield Components, Character association and combining ability studies

Tolerance to salt stress conditions IS very complex genetic phenomenon Genmlnatron, plant stand, vegetative growth, ferillity and other .Yleld components are Important criteria for diversity of tolerance to salt stress conditions. Character assoclabon has been found to undergo changes (Inder the Innuence of SOdlClty and salinity SodlClty tolerance have been found to be correlated With tillers/plant and biomass per plant (Singh at aJ ,2006) IntenSive selection should be exercised In developing Improved vanebes for salt affected SOils based on the Yield attributing characters Singh and Rana (1987a), Singh 1988 and Singh and Chatrath (1997) reported combining ability of grain Yield and contnbutlng traits In dlallel sets of bread wheat vanet,es under salt stress conditions Both addrtrve and non additive gene effects were found Important for the

271

Chemical Changes 6. Nutrlent Transformation In Sadie/Poor QualJty Water Imgated SOlis

/ -' Inheritance of all the studied traits Best general and specific combl~ers were found as parents HD 2285, KRL 1-4, PBW65 and cross KRL 3-4 x KRL 1-4 respectIVely

/ Varietal Improvement for salt tolerance

Evaluation and breeding work starts With the Introduction, collection, evaluation and systemalic cataloguing of available Indian and exobc germplasm All the conventional breeding methods can be followed Ie Inlroducbon, selection, hybndlzatlon, mutaban and sbuWe breeding approach for the development of salt tolerant vanetles At CSSRI Kamal, two salt tolerant wheat vanetles, KRL 1-4 and KRL 19 have been developed by Pedigree method of seleellon and released through CVRC '

KRL 1-4

, KRL 1-4 was the first wheat vanety released for saline and SodlC sOils of the North Western plain zones of the country ThIS varlety \S highly Improved from Kharchla 65 (the most salt tolerant vanety) on ac;count of amber grains, dwarl plant type, lodging resistance, high yield and disease resistance to all the prevalent rusts ThiS vanety IS dwarf type With 145 days of matunty The grain texture IS hard, medium bold and amber In color With 12% proleln content, 79 7 Kg hectaWe weight and sedimentation value as 40 ThiS has good Yielding abIlity upto 4-5 t ha-' under normal 5011 condlbo[l and 2 5-3 5 I ha" under SodlC stress up to pH, 9 3 and salinity up to ECa 7 a dS m"

KRL19

KRL 19 IS the latest salt tolerant vanety and can tolerate sahne (EC. 5 -7 dS m") as well as alkaline sOil (pH, 93 - 94) conditions It also does well In areas where the soil is good but ground water IS either brackish or sahne (ECIw 15·20 dS m", RSC 12-14 meq 1"), The variety has amber grain color With good gram appearance, high protein content (12%), hectoliter weight (77.4 Kg) and sedjmentation value (47 4ml) Though KRL 19 has been specifically bred for adverse saline/alkali SOils, Its Yield potential under normal SOil condrtlons IS 4 5-5 2 I ha" The variety has the Yield potential of 2.5-3 5 t ha-' under sodlc stress up to, pH2 9 3 and salinity up to EC. 7,0 dS m-1.

Charactenstlc KRL 14 KRL19

Year of Release 1990 2000

Parentage KharchlaIWL711 PBW255/KRL 1-4 Plant height 70cm 96cm

DuratJan 142 days 136 days

Gram size Medium Medium Dale of sOWIng Normal Normal

Salinity tolerance Upt073dSm" Upto73dSm" Sodlclty tolerance Up to pH, 93 Up to pH, 9 3

Grain Yield (Normal SOil) 4-5 I ha" 4 5-52 t ha" Grain Yield (Salt affeeled 5011) 25-35 t ha" 2 5-3 5 the'

, KRL 1-4 and'KRL 19 have been well taken up by farmers through different seed agencies or directly of !-Iaryana, U P and Rajasthan CSSRI has been prodUCing and dlstnbubng nucleus, breeder and labeled seed of these vanetles So far more than 700 qUintals of breedernabeled seed has been distributed to seed agencies and falTTlers Farmers can grow KRL 19 and KRL 1-4 under salt slress and can generate additional Yields up to 7.0 - 8 a qtlha which may fetch higher economiC" returns In oompanson to tradilional wheat vanetles .

Two salt toleranl genetic stocks KRL 35 and KRL 99 have also been registered at NBPGR uSing thiS method In addition a modified bulk pedigree approach can be employed under stress conditions, where IndiVidual F, plants can be harvested, as bulk up to F. generabon followed by Individual plant selecban and handling the population as In pedigree method

In addition to these vanetles and genetic stocks, CSSRI has developed many other Improved genotypes which are being tested under All India Coordinated wheat and ba~ey Improvemenl program The red grain genotype KRL 3-4 has been found to be highly tolerant to salinity and sodlClty and IS being used as tolerant check In the Salinity/Alkalinity nursery of All India Coordinated wheat and bartey Improvement program ,Moreover thiS genotype has been found to be associated With very low sodium uptake under stress KRL 119 has been found as amber grained salt lolerant genotype associated with high K uptake under stress among amber grained genotypes (Fig 1)

272

Breeding VVheat Vanetles for Salt Tolerance In India Present Status and Future Prospe~s

E ., " 0 E

'"

1000 900 800

700 600 5'00 ~ 400 .:....=' 300 ~-

200 I-c 100 f-'

0 1 ..

," ~~

Effect of salinity on Ionic uptake In wheat

- -" .. ~

-c-- c- '-- -I-- I-- -----' -

i -

~

f-- c-~ --r'

.. Q

.' ~,

.. 0

.' ~.

Genotypes

" Na (ECe 0 5 dslm)

• Na (ECe 5 9 ds/m)

o K (ECe a 5 dslm)

D K (ECe 5 9 dslm) ,

Frg 1 GenotyprG response to salinity with respect to leaf Na and K concentra~ons

(Genotypes are arranged in order of their Increased Na concentrabons Vertical hnes are sems)

Non.convenUonal Breeding

Doubled haploid technique

ThiS technique has !WIn advantage of speed and effiCiency and due to thrs, It has become most effectIve tools of the plant breeders to attain homogygOSlty of recombmants In shortest pOSSible time ThiS technique has been used In one of the Indo Austrahan Collaborative Project on waterlogging tolerance under sodlc SOils and has Yielded doubled haplOids tolerant than both oltha parents These doubled haplOids can be produced by ferlllrzing wheat ears of cresses between two parents WIth maize pollens The maize chromosomes are subsequently eliminated dunng development leaVIng haplOid wheat embryo which IS rescued after 14-21 days and transferred mto nulne"l culture medium Plantlets later treated WIth colchlanes lor the doubling of the chromosomes to get 100% homozyyous hnes (Singh and Tyagl, 1998) , Marker asslsled selecllon

It IS the most robust tool which supplement the conventional breeding approach by Identifying the recombinants lor two or more tolerance mechanisms uSing molecular markers The efforts In thiS directIon are being made by developing dIfferent permanent mapping populations These populatIons can be used to Identify QTL,s for salt tolerance ThiS requires a multidisCiplinary approach InvolVIng SCientIsts from Breeding, molecular biology, phySiology and SOIl sCIence disciplines

Bibliography

MagUire, J D 1962, Speed of germlna~on Aid In selection and evaluation for seedlIng emergence and vigour Crop Sci 2176-177,

Mlshra B 1994 Breeding for Salt tolerance In crops In Rao et al (Eds) 1994 Salinity Management for Sustainable Agnculture-25 years 01 research at CSSRI, Central 5011 salinity Research Instrtute,Karnal pp 226-259

Mlshra, B 1996 HighlIghts of research on crops and vanetles for salt affected SOils Technical Bulletin published by C5SRI, Karnal28p

Mlshra, B , SIngh R K. and Senadhlra, D 1997 Enhancln9 genetic resources and breedmg for problem solis In' Online book-Using Diversity EnhanCing and maIntaining genetic resources on-farm Ed by L5perllng and M Loevlnsohn IDRC on Live Book Catalogue httpllwwW Idrc ca/Jlbraryjdocument/1 045821mlshra htmJ 13p

Sayeed, HI 1985 Diversity of salt tolerance In germplasm collectIon of wheat Theor Appl Genet 69 651-657

Sharma 5 K 1987 Mechanism of tolerance In wheat genotypes dlffenng In sodlcrty tolerance PI Physiol Blochem 14(1) 87-94

Singh K N 1988 Combining abilIty in wheat In normal and SadlC Salls Indian J, Genet 48(1) 99-102

273

Chemical Changes & Nutnent Transformation In SodlcJPoor Qlfa1ity Water Irrigated Solis

/ '

Singh K N 1991 Recent approaches to breeding for salt tolerance In crop plants i In G .. nebc Research and Educabon Current trends and the next fifty years (Eds' e.Sharma at al) Indian Society of Genetics and Plant Breeding, New Deihl' pp 490-499.

Singh K N '-2005 Breeding wheat vanetles for salt tolerance' In Crop Improvement for Management of Salt affected soils, Manual of lectures for the training program on "Method Of Screening and Development of Vanetles and Germplasm of various crops for salt affected sOils held at Central SOil Salinity research Institute, Kamal 132001 ,India Janaury 17-22,2005, 65-68 ,

Singh, K N ,and Chatrath, R. 1993 Genebc divergence I~ bread wheat (trrtlcum aestlvurr1 L ,em Theil) under SodlC sOil conditions Wheat Information service 76 35-38 .

Singh, K Nand Chatrath,R 1997 Combining ability studies In bread wheat (Tntlcum a@stlvum, L em Thall) under salt stress enVifonments, Indian J Genet, 57(2) 13-18

Singh K N ,Kulshreshtha,N and Mohan Surender 2005 Screening wheat and nce for ~alt tolerance under controlled conditions In Crop Improvement for Management of Salt affected SOils, Manual of lectures for the training program on "Melhod of Screening and Development of VanetleS and GelTTlplasm of vanous crops for salt affected SOils held at Central SOil Salinity researc;h Institute, Kamal 132001 ,India January 17-22,2005, 210-216

Singh K N, Kulshreshtha NeeraJ, Kumar Vinod and Seiter TIm, 2006 Genebc vanabillll' of wheat (Trrtlcum aestNum) lines lOr grain Yield and component characters' grown under sadlC and walerlogged conditions Indian Joumal of AgncuHurai SCIences 76(7) 414419

Singh, K Nand Rana, R S 1987, Combining ability for Yield components in bread wheat grown In salt affected soliS Indian J agric Sci 57' 771-773,

Singh, K Nand Rana, R S 1989 Seedling emergence rating' A entenon for differenbal varietal responses to salt stress In cereals Agric SCI Digest 9 71-73

Singh K Nand Tyagl N K 1997 Genebc Improvement for suppressIve/salt affected SOils In Proceedings of the Intemallonal Group Meeting on ''VVheat Research Needs beyond 2000 AD" h/3ld at Directorate of 'MIea\ Research, Kamal !Tom l'Iug 12-14, 19\17 (Ed by S Nagarajan, G'Ia1'endra Smgll and B S.Tyagl), Narosa Publishing House 199-207

274

Resilient Rice Varieties for Reaping Higher Productivity from Sodic Soils

R.K. Gautam D,v,s,on of Crop Improvement, I Central SOIl Salinity Research Insfltute, Kamal- 132001

Introduction

In the world soil salinity affeds about 1000 mIllion hectares land and therefore poses a challengIng task of takIng up agnculture and enhancIng produdlvlty In these areas About 100 mIllIon ha In South and South-east AsIa are covered by problem soils where rice is 'the staple crop StudIes on mappIng salt affected areas In IndIa IndIcate tMt about 6 73 m ha land area IS salt affeded out of whIch 3 77 and 2 96 m ha are afflIcted, respectIvely by sodlc and salIne. SOIls (NRSA and AssocIates, 1 996) Such areas If managed properly can playa SIgnificant role In sustaInIng our natIonal food secunty

Rice In Salt-affected Soils

The year 2004 was declared by UNO as IntematJOnal Year of RIce whIch was celebrated In dIfferent countnes to mark the Importance of the crop In meeting major food reqUIrements of the world populatIon Generally, In the coastal saline areas nce IS the only feaSIble crop Rice crop due to many advantages IS Ideally SUIted to start WIth the reclamabon of SodlC soils SInce the nursery IS grown In normal soils, rice planbng in sail affected Salls also pem"ts early stage stress escape. UnlIke other crops nce culture Involves water stagnatIon which allows the dIlutIon and percolatIon of excessive salts thus makIng hospItable SOIl enVIronment for other crops as well The recommended technology for amellorabng barren sodlc soils Includes nce as the first crop dUring redamabon process because continuous cultivation of nee under submerged water condItIOns Improves SOIl properbes BeSIdes, profuse root bIomass left over after the harvest especially of tolerant nee vanetles decomposes leadIng to formation of organIc aCIds to neutralize the alkalinity to some extent

GeneticTailoring of Sail Tolerant Rice

AmelIoratIng problem Salls by chemIcal amendments and draInage Interventions could be one optIon but It Invanably Involves hIgher costs whIch are generally beyond the economIc access of poor and margInal farmers Inhabrtln9 such areas Another approach could be genebc tallonng of the crop plants to surt these condItIons InvolVIng conventIonal plant breedIng and recent molecular techniques that offer several benefits The approach IS SImple and economIcal to adopt and also ensures eco-preservatJOn There could.be a thIrd approach Ie .comblnatlon approach, based on hamesslng the synergIes between the ,mvlfonment modIfying technologIes and genetIcally enhanced plant types ThIS IS perceIved to be more practIcal, economIcally VIable and effiCIent approach Wlth tremendous potential Generally a gypsum dose of 50% gypsum reqUIrement (50% GR) IS recommended whIch IS about 15 I ha' for startIng cultlva~on of barren sodlc SOIls, however recent studIes IndIcate that 25 % GR In combInatIon Wlth salt tolerant nce vanet,es can achieve almost the same level of YIeld at Just the half of gypsum cost

This IS more pertinent In view of resource poor SOCIa- economIc conditions of farmers particularly In

states like UP arid BIhar Enormous van abIlity WIthIn cultIVated nce (OtyZa satIva L) for tolerance to SOIl salinity has been explored and documented, Therefore, breedIng and use of,salt tolerant nce vanetles are very Important to sustaIn and Increase nce productIVIty and profitabIlIty In these fragIle ece-systems.

Screening and Evaluation Methods

A plant breeder reqUIres a homogeneous plot Of field for screemng the gerrnplasm to know their relabve performance However, salt affected fields often suffer from field heterogenlety or spabal variabIlity thIS hinders the reproducIble screenIng and response of genotypes In salt affected SOIls Therefore, making a homogeneous 5011 envIronment representatJve of parbcular stress sItuatIon IS a key to successful screening and breedIng process

There are dIfferent methods being used to screen nce germ plasm for the" performance under salt affeded condItIons at CSSRI, Kamal These Include salIne hydroponlcs/solut,on culture, sodlc/sallne trays, sodlc/sallne mlcroplots or Iyslmetrs and sodlc/sallne fields Each method has both advantages and dIsadvantages In terms of precIsIon and space Therefore a combinatIon of dIfferent methods depending upon the objectIve Wlil help In making a nght chOIce

Successful development of salt tolerant rice varieties at CSSRI, Karnal

The breeding efforts at CSSRI got Impetus Wlth the Idenbficatlon, selectIon and Introgresslon of salt tolerance from land races lIke Damodar (CSR1), Dasal (CSR2) and Getu (CSR3) whIch were natIve to the

Chemical Changes & Nutnent Transformation In SodlclPoor Quality Water Imgated Salls

/ coastal Sunderban areas In West Bengal These are traditional, tall and photo:sensilive selecl!ons which selVed as donors tor salt tolerance for developing high Yleldmg sa~ tolerant, seml-dwarf and early matunng vanebes wrth better grain quality eSSRI IS pioneer In developing follOWing 6 salt tolerant nee vanebe5 from time to time for vanous agno-edaphlc conditions In India These vanelles possess different agro-morphologlcal and grain quality charaetenslres which are presented In Tablel '

eSR 10 ThiS IS tiMe first salt tolerant, dwarf, high Yielding nce vanety released and notified In 1989 by the Central Vanety Release Committee for alkahne and mland sahne SOils of the cOuntry II takes about 120 days for matunty (seed to seed) With short bold grain type It can Withstand pH, up to 102 Therefore It IS tenned as biological redamant and gives economical Yield even Without applYing chemical ~mendment

eSR 13 eSR13 IS the first fine grained, high Yielding sail tolerant nce varrety released In 1998 for SodlC and rnland saline Salls 01 UP, Hal)lana, GUlarat and Maharastra It has long slender grams With better

'reported puffing ability (lor puffed/chilwa nee) -

eSR 27 It was released In 1998 for SodlC and coastal salrne Salls of country It possesses long slender grains With maturity duration of 125 days

Table l' eVRC released salt tolerant nee vanebes developed by CSSRI"Kamal and therr salient traits

Name of vanety

lET No Year 01 release Plant height (em)

MaturItY days Tolerance hmlts Salinity (dS ni-')

Sodrclty (pH2)

Yield ( tlha) Non stress Salt stress

Gram type

Recommended ecology

eSR10

M40-431-24-114/ JayaA

10349 1989

85

120

<110

<102

>60 >30

Short bold Acts as Biological amendment lor highly detenorated sodlc and Inland sahne Sal_Is

eSR13 eSR23

CSR1/ IR6411 Bas 370/1 I R4630-22-2-CSR5 5-1-3/IR 964-

45-2-2 10348 13769 1998 2004

115 115

145 130

< 90 <100

<100 <99

>80 >65 >30 >4,0,

Long Long slender slender Sodlc a-rid Sod,C Salls Inland of Haryana, salrne SOlis UP and of UP, coastal Haryana, salrne areas GUJarat and of Maharaslra Maharastra

GUlara~ Tamil Nedu, Kerala and West Bengal

276

eSR27 eSR30 CSR36

NONA BR4-10/ GSRl31 BOKRAI Pak Panllel 21/ IR565-33- Basmati IR36 2 13765 14720 17340 1998 2001 2005

11.5 155 110

125 155 140

<100 <70 <110

< 99 <95 <100

>65 "3,0 "65 >40 >20 >40

Long Basmati Long slender slender type

Sadie First salt SodlC SOils

and tolerant of Haryena, coastal basmab UP

sahne vari~ty and

Salls of developed Pondlcherry

India for sodle areas of UP, Haryana and Punjab DOing very well In normal SOils also

Resilient Rice Vanetles for Reaping HJgher ProduClJvlty from SodLe Salls

.New Salt Tolerant Rice VariQlies Developed

CSR30 (yamin I)-the first salt tolerant basmati variety

CSR30 IS first salt tolerant basmati nee vanety and releasea In 2001 for moderate SodlC salls (pH, 8 8-95) of North Western States of UP, Punlab and Haryana CSR30 was developed from the cross BR4-101 Pak Basmati It takes around 155 days for matunty It has long slender (712 mm), highly scented grains with good head rice recovery (59%), high kemel elongation on cooking (KLAC)/Intennedlate gelallnlzlng temperature

.(GT) and IntenneCilate amylose content (23%) which 15 at par WIth Taraon Basmati In the panel test, rt was rated as one of the best cultures on account of Its attractive flakiness, aroma and fine elongation of cooked nce

,. Dunng Khanf 2001, seven basmati nee vanetles were grown under two different 5011

enVIronments. One of the locations was the reclaimed SodlC 50115 of main Institute fann Kamal with 5011 pH, around 9 0 which is almost nonnal for nce Another location had moderate SodlC SOil (pH 9 5-9 6) at CSSRI Regional Research Station, Sh,vn Fann', Lucknow Though the nee vanelles did not differ slgnlficanlly at Karnallocatlon for grain Yield, 5011 stress at Lucknow could unravel the Significant hidden vanabllity among the varieties for grain Yield under SOdlClty stress (Table 2) Highest Yield reduction (88 %) was noticed In Pusa Basmati 1 followed by Desl Hansral. Basmati 370 and Kastun It clearly Indicates their higher senSItivity to SodlClty ~tress Least Yield reduction happened In CSR 30 (26%). Based on absolute Yield at both the locations, only CSR 30 could Yield more than 2 tlha

Table 2 Grain Yield of basmati nce varieties under salt-slress conditions

Variety

CSR30

Super Basmati Basmati 370 HBC 19

Desl Hansral , Pusa Basmati-I'

Kastun Locabon's mean CD (P=O 05)

Grain Yield (kglha) Reclaimed sod,c SOils at Kamal (pH,_ 90)

3,537

3,655 3,556 2,787

3,395

3,617 2,163 3,326 NS

Sadie Salls at Lucknow (pH, -9 5-9 6)

2,611

1,556 1,222

1,778

1.055 455

833 1,493 899

Adaptive trials and popularization of CSR30

Yield reduction under SodlC stress (%)

262 574

656 352

.699

877 61 5 551

CSR 30 was tested at fanners' field by Krlshl Vigyan Kendra, .Jind (Haryana) before Its release and It Yielded 3,737 kg/ha at pH 93. Before the release, CSSRI also conducted a large area demonstrations of CSR 30 dunng Khanf 2000 at' CSSRI outreach fann at Bhaln! .Malra, Kalthal ( SOil. pH,-9 3 - 94 WIth poor quality water of high RSC of> 10 meqll, the safe limit for Imgatlon being <25.meq/l) Until maturity. both CSR30 and HBC19 vanetles behaved almost Similar but at the lime of panicle Imtlatloniflowerlng, HBC ,19 expenenced heavy damage of about >75% while CSR 30 had hardly 20- 25% damage ThiS damage was In tenns of the almost burnt or chaffy panicles due to high sOlllwater stress ThiS demonstration clearly brought out the potenllal of CSR 30 over tradllional basmati vanety HBC 19 and was a breakthrough to the fanners and seed producers in lavor 01 CSR 30 After the release of CSR 3D, Fronllme Demonstrallons (FLDs) were als6 conducted In Uttar Pradesh. Uttaranchal and Haryana At all the locabons CSR 30 perfonned better than check variety The Yield advantage was recorded from 15-37% over the local check HBC 19 ThiS IS also perfonnlng exceedingly well In nonnal Salls and h-iis beCome' exceedmgly popular In commercial cultlvalion BeSides huge demand for lis seed from other state agencies in India through ICAR Indent, Haryana SeeCi Development COIporatlon IS prodUCing about 800 qUIQ!al seed of CSR30 every year

CSR23

ThiS IS a Widely adaptable high Yielding and salt toterant riee stram and IS derived from a three way cross IR64I11R4530-22-2-5-1-31IR9764-45-2-2 CSR23 IS recommended dunng 2004 for groWIng In the alkaline 50115 of Uttar Pradesh and Haryana, and coastal saline Salls of Maharasthra. GUlarat, Tamil Nadu, Kerala and West Bengal This vanerty has perfonned very well In UP Land Development Corporation (UPLDC) adoptive research programmes at fanners' field In different dlstncts of U P It has Intennedlate plant stature (115-

277

ChemIcal Changes & Nutnent Transformation In SodlcJPoor Quality Water Imgated Solis

• / j

120 em) With lully exerted pamcle, awnless, purple sbgma and takes 100'105 days lor 50% flowenng :Grams are medium slender type With length - 5 8 mm and L B ratio - 2 8 ThiS vanety gave good tolerance and performance under tsunami affected areas In India dunng 2006-<)7

/ CSR36

CSR36 IS the latest salt-tolerant vanety possessing lustrous long slender grams and high degree 01 , sodlclty tolerance (pH2 -9 9) ThiS has been developed through a three way cross CSR13/Panvel-21JIR36 and recommended dunng 2005 lor the sodlc Salls 01 Haryana, UP and Pondlcherry CSR36 has intermediate plant height (about 100cm), IS awnless With fully exserted panicles and takes about 140 days lor matunty, It has In-bUilt resistance to biotiC stresses like blast, nee tungre disease, and green leal hopper CSR36 possesses dark green leaves, erect flag leal, green coleoptlle and white sllgma It has extra long slender

,grains (6 76 mm) With good cooking quality charactenstlcs like high head nce recovery (67 5%), Intermediate amylose content (250%), better gel consistency and very occasional chalklness CSR36 also gave good tolerance and performance under tsunami affected areas In India dunng 2006-07

Salt stress-genetlcs and physiological responses

Major plant symptoms 01 salt inlury are white leal/pamcle bp followed tiy bumlng (sallnlty),leaf browning and ne,rosls (SodIClty), stunted growth, low tillenng, spikelet stenllty, jow harvest Index, less florets number ,low grain Yield, change In phenological traits, leaf roiling, poor root growth and patchy growth In field (Smgh et al , 2004a) Salinity leads to injUry on nce plant and manifests symptoms like stunted growth, tiP bumlng! white leaf tiP, leaf scorching from lamina to lower portion, low IIl1enng, spikelet stenllty and death of plant because It affects growth In varying degrees In SOdIClty, almost all the symptoms remain same except leaf browning and necrosIs In place of white leaf lip Rice IS tolerant dunng germination, becomes very sensilive dUring early seedling, gains tolerance at vegetabVe, reverts to being senSItive dunng anthesls and fertlllzabon, and becomes tolerant at matunty Genetics lor salt'tolerance at vegetallve and reproductive stages has been amply studied revealing the polygenic control 01 the tolerance Combining ability studies confinned the Importance of both additive and non-addilive gene actions, thE! fQ"!Iei shOWing rather more preponderance (Mlshra at ai, 1990, Flowers ,2004) Information on genetic components of salinity tolerance has been Incorporated In the breeding strategy Blumwald and Grover (2006) have reviewed the blo-chemlcal responses and synthesIs lor salinity stress Anther culture protocol for rapid development 01 salt tolerant recombinants has been standardized Inlormallon on malntalners and restorers status IS available for CSR germplasm/vanetles lor developing sallmty tolerant 'WA' nce hybnds (Gautam and Slngh,2004) ,

Table 3 Sail tolerance mechanism based grouping of nce genotype

Groupl

Tissue tolerance to Na'

SR26B, CSR21, CSR26, CSR27, pokkall, IR4630-22-2-1-3, TCCP266-2-4g:2B-3, G!,1,1

Group2

Na' excluder

CSR1" PAC-631, CSR8, CSR10, CSR13, CSRI9, CSR20, CSR22, CSR23, CSR24, CSR25

Group 3

K' miners

Hathwan,Swar ndhan,Achhl, CSR23, IR36,IR4630-20,22-2-5-1-3, CSR21, GR11, SR26B, CSR1, CSR10, CSR11, CSR20, Panvel23

Group 4

LowCI-Uptake

HKR128,J aya,CSRl 0,PR108, CSR19

Group 5

Low Na'/K' raM

PR10B, Achhl CSR1, CSR19, ADT36, IR4630-22-2-5-1-3, CSR18,

, SLR1214, CSR10,IR42

Group 6

Early vigor

CSR-92-5, 89-H1-1-3 (96389), 91-H2-6-B-2 (96529), 92-H54 (96228), 93122,KRI-24, CSR11, CSR1, CSR27

PhYSiological mechanisms confemng tolerance Indude vanous attnbutes like Na exclUSion, tissue tolerance, low NaiK rallo, efficl9nt salt partitioning ability WIthin plant to retain harmful salts In functionally less active organs like vacuoles and older plant parts (Yeo at aI, 1990) Negative effects of salts are also offset by higher uptake of K, Zn and P Since earlier results showed that no Single mechanism could confer the absolute tolerance, pyramiding genes for diverse physiological mechanisms Into one genetic background has been Initiated and good breeding populations have been generated Donors for vanous salt tolerant trarts are already Identified (Singh at aI, 2004b) A Wide spectrum of nce germplasm has been evaluated and categoriZed based on tissue tolerance, Na' exclUSion, K' and P uptake, Na / K' ratio and reproductive stage

, , '

ReSlrlent Rice Vanebes for Reaping H'gher ProdudlVlty from Sadie SQlls

tolerance (Table 3) Improvea screening techniques, InfrastruCture facility and selection critena have been developed

Recent experie~ces on farmers' partlcll't"tory trials of gennplasm in the sodic areas 01 Uttar Pradesh

The newly developed sail lolerani vanebes and mate(lals are being deployed In the target salt stress areas particularly In the state of U p, The supenonty of these recen~y released vanelles like CSR23 and CSR36

'\ IS also demonstrated and vafidated under natural sadie lands of farmerS" under on-golng CGIAR funded Challenge Program on water and ,Food Ie, 'Development of technologies to hamess Ihe productiVity potential of sa~ affected areas of Inde>-Gangebc nver baSin" In'the SodlC areas In the state of U P Besides gIVIng higher Yields In

salty lands these Vanelles also provide unique opportunity of water saVing due to their short matunty durabon than convenbonal vanelles ThiS also allows' bmely sOWIng and thus has a beanng on enhanced yields of the succeeding crops

Quantifying the scope of germ plasm intervention

Farmers' grown nce vaneties from sodlc Villages in the state of U P (Dlslt Kanpur, Unnao and Lucknow) were randomly collected dunng 2006'to know their tolerance levels and to quantify the scope of germ plasm Intervention ThiS aimed at to explore the extent of Yield gap between recommended and prevailing vanelles In the sodlc areas 16 lines Including tole",nt (CSR23 and CSR36) and senSitive (VSR156) cheCk vanetles were tested In thnce replicated RBD each under 3 levels of salt stress I e. moderate (pH,-9 5) and high sodlc SOils (pH,-99) and saline SOil (ECe-ll OdS/m) In the preCIsely controlled micro-plots at CSSRI, Karnal Under moderate sodlc stresss, CSR36 and CSR23 ranked first (3 57 t ha' ) and second (3 34 t ha" ), respectively followed by the best collection Swarna (272 i ha") and lal Mahal (2 20 t ha,1) AI high stress. CSR36 and CSR23 again ranked first (2 16 t ha") and second ( 1 80 t ha''l.respecbvely where as better collections Swarna and Lal Mahal yielded dismally lower than 038 t ha' Some,collectlons did not Yield at all under tested conditions ThiS Indicates vast scope of genmplasm InterventIOn In such problem areas to reap higher Yields

Gennplasm development and dissemination

Efforts were made to disseminate the benefits of newly developed salt tolerant vanetles over prevailing vanetles In the target stress areas In U P A pre-release culture of nce CSR89-IR8 selected by farmers themselves IS becoming very popular among fanners due to Its higher yields and early matunty. A promising culture of nee CSR-89-IR8 developed by CSSRI which IS In advance stage of All India Salinity/Alkalinity Tolerant Tnals was selecled by farmers tihemselves durmg prevIous Year for Its tesling In their sodlc fields ThiS vanety not only performed belter but also became ready for harvest about 30 days before the adjOIning late vanety Therefore use of such germplasm not only gives higher Yields but can Immensely save water otherwise reqUired for additional "ngatlons In late vane!les ThiS can also allow early field vacating for the timely sowing and thus higher yields of subsequent crops

Low cost bechnology

RedamatlOn of SodlC SOIls aiming at redUCing the gypsum reqUirement from 5D t9 25o/~ GR, adaptive tnals were conducted at farmer's sodlc fieldS In Villages Dhora and Matena, Dlslt Unnao dunng khanf 2006 The grain Yield of SodlClty tolerant vanety (CSR 23) grown In plots at Dhora where gypsum was applied @ 50% and 25% GR were 4 15 and :) B4 tlha respectively The grain Yield of ST vanety With recommended 25 and 50% GR was 2604 and 31 56% higher over farmer's practices With tradltlonaJ variety ThiS shows the technology gap for Intervention

Dunng 2007 an adaptive tnal was conducted at farmer's field In Village Ohara, D,slt Unnao dunng 'khanf 2007 to demonstrate the feaSibility of reducing dose of gypsum from 50% G R to 25% G R With the help 'of sail toleranl vanety for obtaining almost same grain Yield The grain yield of ScdlC11y tolerant vanety CSR 23 grown In plots where gypsum was applied @ 5O%G Rand 25% G R were 443 and 4 11 t ha,1 respeclively whereas, the traditional vanety Indrasan correspondingly Yielded 361 and 360 t ha' ThUs grain Yield of salt tolerant vanety (CSR 23) with 25 and 50%G R was 142 and 162 % higher than the Yield of traditional variety, ,Besides, salt tolerant CSR 23 also matured earlier by about 10 days than Indrasan for benefit to next crop

PartiCipatory variety selection (PVS) trials in fanmers fields in Dislt, Unnao

Dunng khant 2006 In Village Dhaura. 9 nee genotypes were evaluated on farmers' field haVing 2 environments (pH2 89 and 94) Narendra359 gave maximum g"'ln Yield (55 tlha) followed by CSR 36(54 :Uha), ,CSR 13 (5 1Vha) CSR 89-IR 8(5 1 t /ha) and CSR2K-239( 5 1t tha) In the field haVing pH 8 9 whereas, 'In field where pH was 9 4, the highest Yield of about 47 tlha waS exhibited by CSR13, CSR36 and CSR89-IR8 'followed by Narendra 359(42 I lha) In Village Matena. CSR23, CSR30, CSR36, CSR89-IR8, CSR2K-219. CSR2K-262 and NDR-359 under 25 % GR were compared In an RBD field tnal With 4 replications CSR89-IRB gave highest grain Yield of paddy (44 Uha) followed by NDR-359 (43 Uha) and CSR2K-219 (4.1 Uha) At

279

Chemical Changes & Nutnent Transformation In SodleIPoor Quallty'Water Imgated SOils

/ A

KYK; Dhaura, 9 vanelles were evaluated under reclaimed SodlC sOil In an RBD With 3 replications CSR2K· 262 produced highest nce grain Yield (5 9 tlha) followed by CSR36, NDR359 and CSR89·IR8 Yielding 57, 55 and 5 4 t/ha; respectively

, , ,

Similarly dunng khanf 2007, nine promising salt tolerant nce genotypes (CSR2K·219, CSRl 01·IR· 75, CSR 2K 262, 92063, CSR 89-IR 8,CSRl Ot·IR97, CSR·2K22S, CSR 23 and,CSR 36) alon9 wIth local

_ vanety Indrasan were evaluated and demonstrated on farmers' fields in Villages of Matana (Inlbal pH, 10 1 and after 25% GR reclamation pH, 945) and Dhaura (reclaimed sadie sOil pH, 92 ) In DIStt, Unnao At Dhaura, on overall baSIS of grain Yield and other traits, CSR S9-IR 8 got highest rank followed by CSR-2K2t9 and CSRl 01-IR97 BeSides, CSR 89-IR 8 matured about 12 days earlier than the other vanetles tested_ At Matana Village, highest grain Yield of 3 45 tlha was obtained With CSR 23 where as Indrasan yielded only 2 56

'tlha However, CSRS9-IR-B scored maXl/Tlum chOice of farmers followed by CSR 23 and CSR·2K·228

Farmers' tested lines either released varieties or In pne·retease stage In All India Salinity/Alkalinity Tolerant Trials

To enable the systematic dissemination of lines found promising under farmers' SodlC conditions through seed chain, these need to be released either by Central Vanety Release Committee (CVRC) or State Vanety Release Committee (SVRC) In view of this the above tested vaneties CSR23 and CSR36 have already been released by CVRC and there IS no problem of seed avallabihty for these vanetles The genotypes CSR·2K·219 and CSR·2K-262 are In the final stages of rele8se Similarly lines CSRl 01.IR.75, CSR 89·IR 8,CSRl 01·IR97 and CSR·2K22B etc are In dIfferent stages of All India Salinity/Alkalinity Vanety Tolerant tnals In different sahnlty locaMns In India These farmers' tested hnes might become Mure salt tolerant vanetles '

Future breeding strategies

Recombination breeding InvolVing, parents With diverse mechanisms of tolerance IS expected to enhance the tolerance levels for sahn,ty as well as SodlClty Pyramiding of vanous morphological attributes and phYSiological mechanisms Into a Single cu~lvar IS perceived to enhance the ceilings of tolerance Contrasting parents for these traits are also Identified The gigantic task of gene pyramiding and transfer can

. be_ greatly faClhtated by marker'assisted breeding for salt tolerance (Zhang et a/, 1995, Ren at a/ ,2005, ,Ammar et a/ 2006) MapPing populallons for dIfferent mechanisms are being developed Research work for 'mapplngltagglng the major aTls confernng tolerance traits through mlcro·sateillte/SSR markers IS already underway to achieve these goals

Cultivation methods for higher rice productivity from sadie solis

,Selection of rice varieties

Appropriate salt tolerant nce vanelles should be chosen for the cultivation depending upon the requirement of particular plant type, grain type and yield level for a particular sallmty stress SituatIon In a state (Table I) There are different sodlclty tolerant nce vanetles hke CSRIO, CSRI3, CSR23, CSR27, CSR30 (basmati type), CSR36, Narender Usar dhan 2, Narender Usar Dhan 3, etc which are commercially available for growing In sodlc areas

Seed soaking and treatment for sowing

Saline water treatment

10 % sodium chlonde solullOn should be used to screen healthy seed Ikg salt In 10 hire water IS good enough for ,1·2 kg seed screemng at a time Use the same solubon for more seed one by one Remove the floabng seeds and use the heaVIer seed which were settled down In the bottom, Rinse them In fresh water 2·3 bmes before sOWIng

Chemical seed treal!n~,nt

Soak 10 kg seed for 24 hours before sOWIng In the solubon of Amlsan (0 5 %) - 5g / 10 Irtre of water + Streptocycllne (01%) 19 /10 hire of water

Seed rate and preparation of nurseries

Transplanting of 35-40 days-old seedhngs are recommended be""use they relallvely aged seedlings attain the tolerance at late seedling stage Seedbed plots With an area of 600-700 m' are prepared 1·2 days before sowing 50 • 60 kg of seeds for a one·hectare field Higher number of seedhngs must be transplanted to compensate for reduced bllenng of older seedlings and also to compens~te the pOSSible morlallty Seedbed must be located In a salt·free area or raised area (so that salt should wash out dunng ram /Irngatlon)

260

Reslhent Rice Vanetu9S for Reapmg Higher Produdlvlty from Sadie Soils

As fertilIZer applicabon, 225 g urea or 500 g (NH,)2S0, and 506 g SSP IS reqUlned for 10m2 nursery area In case' of N defiCiency, 50g urea I ",2 could be additionally applied In Zn deficient 50115, 2 sprays of zinc sulphate ~O 5% ZnSO. + 0 25% Ca(OH)2 mixture) I e 50 g Znso, + 25 g Ca hydroXide mixed In 10 IItres of water for 100m area after 10 days Interval from ~OWIng ,

Land preparation and amendment

" Leveling of the field IS very Imporiant In management of sodlc Salls However, for the management of sodlc Salls, bes!des leveling, If SOil amendments are cheap and available then limited quantity of SOil amendment like gypsum @ 25% GR should be used along With the salt-tolerant nce vanety Alternatively,

, highly salt tolerant nee vanetles like CSRl a and CSR36 could be grown by resource poor fanmers to get some 'field without gypsum for at least Inlbal 3 y@alS

'fta!\t.I'\a!\tlWOI I The seedlings must be pulled ge~tlY to aVOid too much damage to the roots Long leaves must be cut

to prevent them from touching the muddy watet that leads to mfecuon The seedlings must be uprooted In standing Water In nursery field to get nO It of, bakanae (foot rot) disease which appears in later stages partlCula~y on basmati vanetles Straight row planting IS recommended over random planbng to ensure a spacing of 15x15 ern In order to opbmlte plant populabon and faCIlitate the application of fertilizers and weeding operations and for getting higher Yields About 3-4 seedlings per hili are recommended for planting to compensate for the reduced bllering capaCity of older seedlings Transplanbng must be done at a depth of 2-3 cm to aVOid delayed tillenng. After transplanting, excess seedlings should be placed along alleyslbunds for replanhng MISSing or dead hills must be replanted Within 10 days

Weed Control

Weed control is very Important In noe dunng early seedling establishment Usually Butachlor (available With many trade names) IS used as weedlClde which is available In two Ionms

Solid granules broadcast gran ulSS 12kg I aCire or 30 kg I ha after 2-3 days of transplanllng In standing water

LIqUid (50EC). 1 2 Irtre I acre or :; litre I ha after 2-3 days of transplanbng In standing water after miXing In sand (5Okg/ha) or through a boIIIe With hole on ,ts lid

Fertilizer management

Split application of nlbrogen IS more benefiCial to nee plant under salt-affected conditions Three to four equal splits of total N fertllsers @ 150kglha should be applied at basal, ea~y tillenng, late tll/enng and pamcle inItiation Since salt-affected SOils are usually high In P and K, hence these fertilizers are not required However, 40 kg P,O, per hectare is reco~mended Zinc defiCiency IS very common In sodlc and saline Salls ThIS can be addressed by applYing 25 -30 kg Znso, per hectare

Plant protection:

Generally same plant protection measures for controlling diseases and Insect pests as recommended for nee culbvabon In normal SOils should be followed

To sum up, follOWing management strategy IS summanzed below to properly manage salt-affected Salls and to reap higher productIVIty • Provide surface drainage In areas prol1e to flooding, • Leach the salts out of the root zone, • \'<!R,!\'I>~ 'dt.tt>m?"a!\'1\'"'9 !lrom"'~\m\\\!\!l ~~ ~ ~~ (oe~'!1.-r). WR.a~s, • Use salt-tolerant nces of Intenmedlate stature With submergence tolerance, and • Use Improved crop and natural resources management (CNRM) practices

Conclusion

RICIa IS the most SUitable crop to start With reclamation and cultivation of sodle SOils due to different advantages ThiS IS also Inherently adapted crop for the coastal saline Salls However, screemng and breeding salt tolerant cult,vars With higher Yielding ability under such agro-ooaphlc conditions have paid rich diVidends CSR10 was the first seml-dwalf, photO-lnsenslbve sodlclty tolerant nce variety bred In India by CSSRI, Kamal ThiS was followed by the development of other fine grained vanet,es CSR13, CSR23, CSR27, CSR30 and CSR36 mostly for Inland saline ana sodlc Salls of the country Other successful vaneties for coastal saline 50115 developed at CSSRI, Regional Research Station, Canning Town (West Bengal) are CSR4 (Mohan), CSTI-l, CSR5 (Vikas), Sumab and Bhutnath ThiS was the outcome of systematic efforts on germplasm collection, hybridIZation, shuttle breeding, extensive evaluabon of segregabng matenal under target stress conditions which were supplemented by novel breeding techniques from time to time National sallmly

281

Chemlcal Changes & Nutrient Transformation In SadIe/Poor Quality Water Imgated Salls

networks and Jnt~matlonal programs mainly WIth IRRI, Phlllppinas accelerated the overall vanetal Improvement program Therefore perpetual development of salt tolerant vanebes possessing ,higher Yielding abllrty, resistance to emerging diseases and pests and their cultivation through recommended agronomic practices WIU reap higher productiVity from salt affected 50115 '

Bibliography ..-' '

Ammar, M H M , Pandll, Awadhesh, Tyagl, Kuldeep, Khandelwal, Vikas, Rai,Van~na, Galkwad, K. Singh, AK, Singh, R,K, Gautam, R K and Singh, N K 2006 Mapping of OTLs for\ salt tolerance traits In Indica nce vanety CSR27. In Proc 2nd Intematlonal Rice Congress held at New Deihl dunng Oct 9· 13,2006, Abstract (Id 5315) 300 ,

Blumwald, E and Grover, A 2006 Salt tolerance In Plant Blc-technology (Editor Nigel'Halford) John IMley and Sons Ltd 206-224

Flowers,T J 2004 Improving crop salt tolerance Journal of Expenmental Botany 55 307·319 Gautam, R Kand Singh, R K (2004) Identification of salt tolerant vanetles as restorers and mamtalners for

cytoplasmlc-gemc male stenhty for developing salt tolerant nce hybnds In Proc International Symposium on Rice From Green Revolution 10 Gene Revolullon held al Hyderabad dunng Oct 4-6, 2004 109-110

Mlshra,B, Akbar,M ancl Seshu, 0 V 1990 Genebc studies on salinity tolerance in nce towards belter productIVIty In sa~ affected soils Rice Research Seminar International Rice Research Institute, Philippines, July 12, 1990

NRSA and AsSOCiates, 1996 Mapping salt affected SOils of India, 1.250,000 mapsheets, . Legend, NRSA, Hyderabad '

Ren, Z H , Gao, J P., LI, G , Cal, XL, Huang, W, Chao, D.Y , Zhu, M Z, Wang, Z Y, Luan, S and Lin, H X. (2005) A quantitative trait locus for salt tolerance encodes a sodium transporter Nature Genebcs, 37(10) 1141·1146,

Singh, R K. Singh, K N, Mlshra,B, Sharma, S K and Tyagl, N K (2004) HarneSSing plant sail tolerance for overcoming SadlClty constraints an Indian expenence In Advances In SadlC Land Reclamation InternatIOnal Conference On Sustainable Management of Sadic Lands held at Lucknow dunng Feb 9'14,81·120

Singh, R K. Mishra, Band Gautam, R K 2004 Recomblnallon stralegy to enhance the level of salt tolerance in nce In Proc International Symposium on Rice From Green Revolution to Gene Revolution held at Hyderabad dunng Oct 4-6, 2004 pp 69-70.

Yeo, A R , Yeo, ME, Flowers, SA, and Flowers, T J 1990 Screening of nce (Oryza sabva L) genotypes for phYSiological characters oontnbuting to sallmty resistance and thelf relationship to overall performance Theor Appl Genel 79 377·384

Zhang, G, Y , Guo,Y , Chen, S L and Chen, S Y (1995) RFLP tagging of a salt tolerance gene In nee Plant SCience 110227·234.

282

Physiological Mechanisms of Salinity and Sodicity Tolerance in Crop Plants

S.K. Sharma . DIVIsion of Crop Improvement I Central SOIl SaliMy Research Institute, Kamal- 132001, Haryana

·Introductlon

Salinity and sodlclty stresses are ever-present threats to crop Yields, especially In ccuntnes where Imgatlon IS an essential aid to agnculture. Although the toterance of plants to saline condllions IS variable but crop species are generally Intolerant of one-third of the seawater salinity. Salt tolerance IS genetically and phYSiologically a complex mechanism In halophytes and relatIVely less tolerant crop plants shOWing a wide range. of adaptations Plants glOWl')(1 under salme and sodlc condlfions Inv.lnably face Increased concentrations of tOXIC Ions In their bssues resulbng from Increased uptake of Ions mainly Na and CI under salinity, and Na under sodlclty. Three majOr hazards aSSOCiated With salinity are, osmotic (water) stress anslng from more negative osmotic potential (higher osmotic pressure) of the rooMg medium, speCific Ion tOXICIty _ excess of Na', cr, S04·2 or other Ions, and'nutnconallmbalance

Glycophytes and Halophytes

MajOrity of plants are relatively salt sensitive and almost all crop plants are unable to tolerate persistent saline and sodlc ccndltlons Depending upon their responses, plants can be categorized Into glycophytes and halophytes The term halophyte literally means salt plants, but is used speCifically for plants that can grow In presence of high concentrations of sodium salts and are deSCribed as native flora of saline soils Examples of halop~ytes are Atnp/ex. Sueda, Sa/iearnla and Artemesla species. On the other hand. the plants that can not grow In presence of salts are called Glycophytes or Sweet plants (Sharma and Goyal, 2003) Almost all crop species are glYCOPhytes Glycophytes have a selecbve advantage In non-saline Salls over halophytes, because their growth rates are generally faster. In addition to the level of salinity, nature of salt responsible for salinIZation also has an important role to alter growth and development of plants

Effect of Salinity on Plants

Salts In SOil water may Inhibit plant growth through two ways. First. the presence of salt In SOil solution reduces the ability of plant to take up water, and leads to reductions In growth rate ThiS IS referred to ·as osmotic or water-deficlt effect of salinity Second, excessive amounts of salt entering plants' transpiration stream can Injure cells of transplnng leaves and may cause further reductions In growth ThiS IS called the salt-speclftc or lon-excess effect of salinity (Greenway and Munns, 1980, Sharma and Gupta, 1986). The definition of salt tolerance IS usually the percent of biomass production In saline 5011 relative to plants In nonsaline SOil, after growth for an extended penod of time. For slow-growing, long-lived. or uncultivated species It IS often difficult to assess the reduction In biomass productIOn, so percent sUlVlval,s often used As salinity IS often caused by rising water tables, It can be accompanied by water-logging Water-logging Itself Inhibits plant growth and also reduces the ability of roots to exclude salt, thus Increasing uptake rate of salt and Its accumulabon In shoots

Variability In Salinity and ,Sodiclty Tolerqnce of CropsiSpecles

Another crltenon of salt tolerance of crops IS their· Yield In saline versus non-saline conditions EvaluatIOn of salt tolerance of crops, vegetables and flUlt trees have been made by the USDA Salinity Laboratory (Fig 1) and Central SOil Salinity Research Institute, Karnal (Tables 2 and 3) According to these evaluations each species has a threshold salinity below which there IS no reduction In Yield. and thereafter Yield reduction fallows a particular trend With increasing salinity Within crop speCies there eXists a great vanatlon In the ability to grow and Yield under salinity or SodlClty In 5011 and poor quality water Even within a crop, different vaneces or cultlvars may differ Widely In their tolerance to salinity or sodlclty stress Crop species like lenlll, green gram, chick pea and other pulses are very senSitive to these stresses Their growth IS affected even at soli salinity of EC 4 dS m" or ESP 15 Wheat. rice and cotton are tolerant to moderate levels of salinity Beet, bartey and spinach can Withstand high levels of these stresses

Growth suppression IS typically ,n,uated'at some threshold value of sahnlty, Which vanes With crop tolerance and extemal enVJronmental factors which influence the need of the plant for water, espeCially the evaporative demand of the atmosphere (temperature, relative humidity, Wind speed etc) and the watersupplYing potential of the root zone; and Increases as sahnrty Increases unt,1 the plant dies The salt tolerances of vanous crops are conventlOn~lly expressed (after Maas and Hoffrran 1977), In terms of relative Yield (Y,), threshold sallmty value (a), and percentage decrement value per Unit Increase of salinity In excess of the threshold (b), where SOil salinity IS expressed In terms of EC., (dS m") as follows.

ChemIcal Changes & Nutrient Transformation In SodlcJPoor Quality Water Imgated Soils

,00 ~R"IN CAOPS

80

~ ;;

:. 60 ~

U e 40 > ,

<0

SEfoISITnIE

00 ,

Fig 1 Salt tolerance of grain crops (after Maas and Hoffman 1977)

Y, = 100 - b (EC. - a)

Where Y, IS the percentage of the yield of crop grown under sahne conditions relative to that obtained under non-salme, but othelWlse comparable, conditions ThiS use of EC. to express the effect of salinity on Yield Implies that crops respond pnmanly to osmotic potential of the SOil

Culbvated crops can be categorIZed Into sensitive, moderately-tolerant and tolerant speCies according to their Specific salt tolerance and these ratings are different tor sahne SOil, SodlC SOil and saline water Irngated SOil conditions The order of resistance IS not the same In all SOils and this IS at least partly due to the ,fact that relative rankmg of a given SpeCies IS not the same for different salts_ Most plants are less resistant to NaCI than to Na2S0., but some show the reverse relationship Sodium carbonate IS almost always more tOXIC to crop plants than NaCI and Na2S0. Relative tolerance of major crops to sahnlty and SodlClty stresses are presented In tables 2 and 3. Growth of some plants may be stimulated at low levels of salts even For example, growth of cabbage, spmach, wheat and turnip may be sbmulated In slightly saline enVIronments

Assessment of Tolerance

Ultimately, salt tolerance of crops IS tested as Yield from fanners' fields However, evaluabng field perfonnance under sahne conClibons IS notonously difficult because olthe variability of salinity Within fields and enonnous potential for Interactions With other enVIronmental factors, rangmg from gaseous pollutants, 5011

ferliltty and drainage to temperature, light ftux denSity and transplratlonal water 1055. Consequently, predlCfion of 'field' perfonnance IS commonly carned out In tnal plots. or uSing a solution-based method where salinity of medium can be readily adlusted to reqUired values (Maas and Hoffmann 1977) The latter often precludes measuII\'9 ~Ield through lacl< of space and estimates of tolerance obtamed {<om such expenments ma~ not always be borne out by response of plants," the field Evaluating tolerance IS made more complex by vanatlon In sensItivity to salt dunng the life cycle For example, It has long been known that grain Yield In nce IS much more depressed by salt than IS vegetative growth (Khatun and Flowers 1995) and gennlnatlon IS relatively salt resistant In tomato, tolerance at gennlnatlon IS not correlated With the ability to grow under salt stress because both are' controlled by different mechanisms, although some genotypes have Similar tolerance at gennlnation and dunng vegetative growth These e~mples suggest that while the assessment of tolerance IS complicated by changes occumng dunng the ontogeny of a plant and may be technically difficult under field conditions There IS evKfence of a genetically complex trait (Shannon 1985),'showmg heterOSIs, dominance and additive effects

Slmllal1y, there IS phYSiological eVidence to support the view that salt tolerance IS a complex trait Halophytes show a Wide range of adaptations from the morphological to the biochemical adaptabons that Include the ability to remove salt through glandular actIVIty Although control of ion uptake IS exercised at the root. the ability to secrete Ions has evolved Into a successful strategy for salt tolerance Some halophytes utilize salt-secreting glands to remove excess Ions from thelf leaves, redUCing the need for \/el)l tight balanCing of Ion accumulation and growth (Flowers and Yeo, 1988) Within less tolerant speCies, mtra-speclfic vanatlon In toterance IS also assOCiated With vanallon m a Wide vanety of phYSiological traits

Growth Reduction under ~allne ConditiOns

Effects of saline SOil are two-fold I.e effects outside roots, and effects of salt taken up by plants Salts in 5011 solubon (osmollc stress) reduce leaf growth and to a lesser extent root growth, thus decrease stomata conductance and thereby phOtosynthesIs (Munns, 1993) Rate at Which new leaves are produced depends largely on the water pptentlal of the soli solution In same way as for a drought-stressed plant Salts

284

Physiological Mechanisms of Sahmty and SodlClty Tolerance In Crop Plants

themselves do not bUild up In the grOWlng tissues at concentratons that inhibit growth This IS because menstemabc bssues are fed largely by phloem from which salt IS effectively excluded, and rapidly, elongatrng cells can accommodate the salt that amves In the xylem Within therr expanding vacuoles So, the salt taken up by the plant does not directly Inhibit growth of new leaves Salt wIThin the plant enhances the senescence 01' old leaves Continued transport of salt Into iransplnng leaves over a long paned of time eventually results In very high Na' and cr concentrations, and they die The rate of leaf death IS crucial for survival of the plant If ne)\' leaves are continually produced at a rate 'greater than that at which old leaves die, then there might be enough photosynthesIzing leaves for the plant to produce some flowers and seeds However, If the rate of leaf death exceeds the rate at which new leaves are produced, then the plant may not survive to produce seed For an annual plant there is a race agamst time to Initiate flowers and form seeds, while the leaf area IS stili adequate to supply necessary photosynthates Perennial speCies enter a state of dormancy and survive stress, however, retabva sahnlty tolerance of plants IS given In table 1 '

Table 1, Relative sahnity tolerance of different plants z 1

Tolerant is -10 dS m") Medium Tolerant (3 - 5 dS m")

Barley, Sugarbeet, Rice, Sugarcane, Cotton, Wheat, Ground nut, Maize, Sunflower, Guar, Safflower, Sorghum, Tobacco, Castor, Bajra, Rape, Mustard Soybean, Oat Sugarbeet, Amaranthus Tomato, Bnnjal, Cucumber, Spinach, turnip Cauliflower, Cabbage, Knol- Khol,

Potato, Sweet Potato, Peas, CUCUrblts, Carrol Onion, Lady finger, CUCUrblts

Sensitive (1 5 - 3 dS m")

Linseed, Sesame, Cowpea, Gram, Pea, Bean, Mung, Pigeonpea, Black gram

Radish, Beans

Two responses occur sequentially, giving nse to a two-phase growth response to sahnlty The first phase of growth redudlon IS qUickly apparent, and IS due to the salt outside the roots It IS essentially a water stress or osmotic phase, for Which there IS surpnslngly little genotypIc difference Then there IS a second phase of growth reducbon, which takes bme to develop, and results from mtemallnJury (Fig 2). An expenment was conducted With two genotypes of contrasting Na' uptake rates and known differences In salt tolerance After SOlt salin/zanon dunng first 3-4 weeks, there was large growth reducbon In both genotypes, called 'Phase I' response, and it IS due to osmotJc effed of the salt Genotypes differed after 4 weeks, one Wlth low Na' uptake rate continued to grow, although shll at a reduced rate compared to tine controls In non-saline solu\lon, but the other With high Na' uptake rate produced hltle biomass and many Individuals died ThiS IS 'Phase 2' response, and IS due to genotypIc differences In coping Na' or cr Ions In 5011, as dlslinct from osmotic stress

,~ Phase 1 Pnase2 -> • ,

§

" ~ i " i; , 'iii'

" • l-

• • ,. 20 >D, 4 •

Tline A.ftftr N ... CI added_ (d)

Fig 2 Two accessl0ns of dlplO1d wheat progemtor AB, tauschli grown In hydroponiCS (control solullon - closed symbols, 150 mM NaCI - open symbols, Circles denote tolerant acceSSion, tnangles tine senslbve one Arrow marks time where salt injUry symptoms seen on senSitive acceSSion, at the pOint, proportJOn of dead leaves was 10 and 1 % in SenSITiVe and tolerant acceSSIOns, respectively, Munns at ai" 1995)

PhysiologIcal MechanIsms of Injury to Plant under Salt and Water Stresses

The Interadlon of salts Wlth plant phYSiological processes IS ObV1ously complex There are many salt speCies, many mechanisms, and many organs, tissues and cells involved Reasons for the observed reduced growth and damage to \Issues Include, reduced water uptake I e phYSiological drought, Injury to cell membranes due to Na' to J\ selectiVity, Ca" to Na' selectiVity, transport and leakage Osmotic adjustment

285

Chemical Changes & Nutnent Transfonnatlon in SodlcIPoor Quality Water Irrigated Sods

, / ,

through solute accumulallon m symplast, or apoplast (cell wall) resuiling in cell dehydration, damage to developed tiSSUe, decreased photosvnthellc surface and lack of suffiCient metabolites for groWing IIssue. Cost of osmotic/adJustment, . compartmentabon and exclusion, horm~nal balance. In the plant and nutrient

,defiCienCies, especially Nand K are also equally Important . \

Plants growing under saline condlDons 'lnvanably face Increased concentrations of tOXIC Ions In their tISsues ThiS results from Increased uptake of Ions' mainly like Na: and cr under'salinlty, and Na' under sod ICily. Concentrallon of salts accumulallori IS higher In sensllive crops than the resistant ones In chickpea salt tolerance depends on "xcluslOn of Na' and cr from shoot, Na' was more "xcluded than CI' as d concentrations were 2-4 times higher than Na (Shamla and Kumar, 1992, Sharma, 1997), In wheat, Na' was more than cr In the top and also more In shoots of sensitive than resistant genotype (Shamna, 1996) indicating that concentraliOns of Na' and cr detemnlne relauve salt resistance. Lots of eVidences correlaling reduced Na' With salt tolerance are available (Jeschke, 1984, Schachliman et 81, 1991, Sharma, 1996) In wheat grown under saline condluons, lower Na' and cr levels are malntamed In apical bssue by preferenbal exclUSion of Ions, othelWlse leaf to leaf gradient In Na' and cr became steeper With, Increase In external salinity Correlation analYSIS On Individual plants Indicate that excluding Na' at low salinity, and Na' and cr at high salinity, were Significant wlt~ growth performance

1115 difficult to distinguish between Na' and cr tOXicity, but data on chickpea indicated that Injury was more With cr than Na' Increase In accumulation of chlonde with longer duration of salt exposure has been observed at second and third samplmg stages In older plants DecreaSing rates of plant growth and Increasing concentrations of Ions with prolonged exposure to salmily suggest their failure to adapt to salinity. more so In the salt sensitive genotype (CSG 8890) Chickpea plants showed higher salt senslDvlty despite negligible effects on their K' concentrations Chlonde IS the prevalent anion accompanYing Na' and K' and Its concentration was In the same range as the sum of Na' and K' There is suffiCient eVidence that salt tolerance IS a multl-gene trait Plants differ markedly Within and between species In their salt tolerance. Depending on the source of salinity and pattem of rainfall or Irngalion In fanner's fields, crop plants may experience salt stress transiently at different stages of the growth cycle, or confinuously throughout the season, however, Impact depends on Intensity and purabon of stress and stage of the crop resulting In short and long term responses

Short-Tenn Growth Responses

Earliest response of plants after exposUre to salinity IS reduCbon In leaf growth because of water defiCit the response IS very rapid (Within minutes, Matsuda and Rlazi, 1981), and IS usually proporoonal to the osmotic potential of the external solUtion, and IS rapidly revelSible (Munns at 81 1981; Rawson anq Munns, 1984) The rate of leaf area expansion IS a short- term response I a It IS set Within a day of exposure to salinity Plants exposed to salinity show Immediate cessation of growth and loss in water status, and may be followed by recovery If the stress IS of a moderate level (Table 2) Plants may suffer severe Inlury and morta~ty If the stress IS of a higher level

Table 2 Plant fresh and dry weight. leaf diffuSive resistance (LDR), transpiration rates and leaf water potenllal (LWP) of third fully expanded leaves

Days after sallnlZStron Fresh wt (g) Dry wt (g) lOR (S ern,l) Transplrabon (wern'/s) LWP(-MPa) Nomnal 478 82 1.7;!:0 2 11 7::,2 1 08::,02

2 433 87 158:!:22 12::,03 18~3

4 532 90 60;!:06 51;!:16 16::,02 6 574 96 53;!:06 70::,11 14~2

9 669 121 37;!:O4 79;!:10 14+02

Therefore, It should tie a standard practice when applYing saline solubons to plants In pot culture to minimize osmotic shock by increasing salinity concentrabons In gradual small Increments over a penod of several days unless the expenment IS speCifically aimed at determining the effects of sudden osmotic shock to th" plants

Long-Tonn Growth Responses

In longer- term, being weeks for a short-lived a,mual to months or yealS for a long-lived speCles, prolonged transplrabon Will cause salts to build up In the leaves. Thus a speCific effect of Ions on leaves and parts Will occur Salt concentrations In plants usually conUnue to increase With time In non-halophytes the fully expanded leaves are adversely affected long before the young leaves, as salt concentrations at a given bme of exposure to salinity are always higher In the oldest leaves, and the oldest leaves die long before the effects on younger leaves bec;ome apparent. The higher salt concentralions In the older leaves may result entirely

286

Physiological Mecf1anlsms 0' SalinIty and Sodlcrty Tolerance In Crop Plants

froll') a'prOduct of time by transpiration rate o'r at least partly from exclusion of speCIfic Ions from xylem suPl?lyjng to younger leaves (Yeo and Flowers, 1982)

Sail concentrations In Individual leaves usually Increase With ~me Glycophytes show no signs of regulabon of the sa~ concentration In their 'leaves unlike many halophytes which can maintain constant salt concentrations (Flowers and Yeo, 1986) Thus, for non-halophytes It IS Inevrtable that Ion concentrallons Will eventually bUild up in the older leaves, and they Will die Concentrations at which thiS cecUIS Will depend upon the ability of the species to compartment salts in the vacuole, and the time It takes to happen will depend mainly on the salinity level, the ability of roots to exclude salt, and the amblsrt condlbons affecting rate of transpirabon Salt bUild up In the cytoplasm Interferes With metabOlism, a-nd In cell wall causes loss of turgor and then excessive loss 01 waler Death of many older leaves limits producllvlty due to decreased photosynthetic leaf area Tlus resu~ In the decline In the production of ealbohydrate and ulbmately produCbon per plant falls below the levels that plants are not able to sustain growth '

Under saline. conditions, water defiCit IS usually expenenced first, followed by tOXICity effects, and then nutntlonal effects However, the temporal separation of'these effects and their relative severity are determined by genotype and enVironment. Plants growing under saline rondltlons are Invanably faced With the Increased concentrations of tOXIC Ions In thE'" tissues. ThiS results from Increased uptake of Ions like mainly Na and CI under salinity, and Na under sodlClty Concentrations of salts are higher In the sensrtlve crops than the resistant ones

Because of the differences In the effect of Salinity on varIOUS enzymes, cells and organs It IS difficult to distinguish between the osmollc and lomc effects of salinity on vanous plant processes The most common method available for distingUishing between secondary osmotic and primary salt Inlury IS to compare the effects of Isotomc solubons of salts With those of orgamc substances Organic substances hke mannitol, sugars and preferably polyethylene glycol (haVing molecular-weights In the range of 6,000 to 10,000) are used

Crop Improvement for Salinity and Alkalinity-Stresses"

The genetic Improvement of salt tolerance In crops can be achieved both by uSing tradlllOnal breeding methods as well as modem tools of genetic engineering and molecular biology The prereqUisites for genetic or breeding approaches are eXistence of suffiCient hentable vanallon In a particular character and a means by which genetic Information can be transferred In a stable form Measurable differences must eXlsl between indiViduals that can produce Viable offspnngs so that stable transfer of sail tolerance can be demonstrated, Promising stUdies have been undertaken With nce, wheat, wheat grass, barley, gram, mustard and tomato Generation of stress-tolerant and high Yielding breeding hnes/vanetles In crops and phYSiological indices and field evaluation of SUitable crop vanet,es for use In biological reclamation technology IS essential.

Genetic Improvement of salt tolerance of crops can be achieved by selection among agronomic cultlvars, evaluation of germplasm collected from areas haVing Similar stress sltuabons, use of vvld germplasm sources to develop new cuillvated speCJes, hybndlZation and plOidy changes, cell culture, and somaclonal vanatlon, somallc hybndlzatlon, molecular biology and recombinant DNA etc

Future developments In genetic englneenng may prOVide useful tools for speeding up the breeding programme as some genes responSible for tolerance' traits have been Idenbfied In some crops Better underslandlng of the phYSiological mechamsms governing plat responses to sahnlty, alkalinity and other ablobc stresses vvll help In further enhancement of tolerance of crops thereby Increasing the prOductiVity of these Salls

Bibliography

Sharma, S K, and Goyal, S S 2003 Progress In Sahnlty Resistance Research Integration of PhYSiOlogical, Genetic and Breeding Approaches In . Crop Production In Salme EnVironments S S G9yal, S K Sharma and 0 W Rains (Eds) Haworth Press, New York, USA Pp 387- 407 ..

Sharma, S K 1997. Plant growth, photosyntheSIS and Ion uptake In chickpea as Influenced by salinity Ind J Planl PhYSlC1 2(2) 171-73

Sharma, S K 1996 Significance of rates of uptake and dlstnbubon of Na+, " and CI' In governing plant salt tolerance In genotypes of wheat dlffenng In salt tolerance Blologla Plant 38(2) 261-67

Sharma, S K and Kumar, S 1992 Effect of salinity on Na+, " and cr content In different organs of chickpea and the baSIS of Ion expression BIOI Plant 34(3-4) 311-17

Sharma, S K 1991 EffeCt of exchangeable 'sodium on growth, Yield and IOniC relabons In wheat genotypes diffenng In sodlclty resistance Indian J Plant PhYSIOlogy 34(4) 35~2

287

, ,- I

Screening and Crop Physiology for Waterlogging Tolerance in Salt-Affected Soils "

S.K.Sharma ,/

DIVISion of Crop Improvement. Central Sot! Saltm/y Research Institute. Kamal- 132001. Haryana

Introduction •

Salrnlty and alkalrnlty are major world-wide Increasing problems In Irrigated areas ,From 34 3 m ha of Irrlgallon potenbal created In India by end of 1990,~ 33m ha. Ie 10 % IS suffenng from imgatlon Induced salinity (CSSRI, 1997) Twin problems of waterlogging and sOil salinity are threatening sustamability of agricultural production ,n the Irrlgated~areas parbcularly In large parts of Norlh-West (Punjab, Haryana and Rajasthan) and many other areas of the country Development of waterloggmg and 5011 salinization IS common due to injudicIous use of canal water for imgatlon and Inadequate drainage In old systems like Western Yamuna and new ones like Bhakra or the Ukal,Kakrapar project A second major cause of waterlogging In some areas IS the use of poor quality groundwater containing high carbonate and bicarbonates, which Induces sodlclty In salls India has made huge Investments In developing Imgatlon.potenllal and can not afford to detenorate the Imgated lands Therefore, the problems of waterlogging and salinity in India need ImmedIate attention to secure food secunty and achieve the target of 109 m tons of wheat produc!lon by 2020

To Improve and sustain production In salt affected and waterlogged areas, It IS necessary to prevent further detenoratlon In soil productivity and reclaim already detenorated sOils Reclamation of waterlogged sahne sOils IS though cost effeClive but sull the Inrtlal Investments are beyond the reach of poor .fanners. Solution to the problem thus lies In reclamation of waterlogged, areas, Integrated water management and Introduc!lon of appropnate less water reqUlnng, salt and waterlogging tolerant croppmg systems However, there IS little Infonnatlon on SUitable vanebes of the main crops for these stress situations A good amount of Infonnauan IS available on salt tolerance and inlury or adaptatIOn mechanisms of plants. espeCially crop plants Some tolerant lines have been Idenufied and ,n some cases tolerant matenals have also been developed and released in some countrieS (Flowers and Yeo, 1996 and Shanna and Goyal, 2003) The hmlted success in developing salt-tolerant vanetles IS to a large extent due to lack .of conSideration of waterlogging In programmes deSigned to breed for sahn<ty and alkalinity tolerance Hollington (2000) Most of studies have focused on saliOlty, alkalinity or waterlogging stresses IndiVidually. Hardly any effort has been made to see thel( combmed effects Studies on salinity/alkalinity - watertogglng Interactions enn elUCidate the problem of breeding cereals capable of higher Yields on such problem Salls There will be little Improvement unul culuvars are developed WIth tolerance to Simultaneous sallnlty/alkalinlty and hypoXia, which causes very large Increases In salt uptake (Barrett - Lennart, 1986) However, very few studies reporting the combined effects of salinity and waterloggmg stresses, mechanisms of Inlury or adaptation and screening of genotypes of wheat and other crops are there In the literature, moreover, such studies should be location and crop speCific Akhtar et al (1994) also showed strong posSibilities for IITlprovmg the perfonnance of cereals In sahne and ·waterlogged enVifonments by Simultaneously Inserting genes for salinity and waterlogging tolerance.

Characterization of Wa~rlogged Environments

Timing and duration of waterlogging ~

Exact information about the bmIOg and durabon of waterlogging In the field along With the type of 5011 IS essenbal to have accurate estimate of the loss to crop Timing of waterlogging IS usually concurrent With Imgabon schedules and high rainfall. Problem assumes severe proportions In heavy or SodlC Salls than light and neutral SOils Measurements of reduced oxygen flux and redox potenllal of the soli, percentage of SOil saturation or alf-filled porosity In SOIl surface layers are also useful to charactenze the durabon of waterlogging m SOils The timing and~ duration of waterlogging can be measured In the field uSing Simple, inexpenSive equipment consisting of 40 mm diameter slotted PVC tubes (piezometer tubes) or Similar deVIceS which measure when and at what depths water saturates SOil profile The depth to water In many cases prOVides a usefullndlCStlon about the aerobiC or anaerobiC nature of the SOil

Waterlogging Intensity

Measurements of intensity of water-logging relate to tlie chemical changes which are associated With OXidation and reduction status of SOil enVIronment With lime of water-logging, 5011 loses much or all of Its 02, concentrabons of other gases Increase, certain mlcroelenients are reduced and Increase In SOil solution, and phytotoxlns accumulate In addition, energy defiCiency or JlmltaUons fac¢ by the plant causes changes In root penneability are Important factors Most Important change under water-logging IS tha gas concentrallon Gases diffuse 10 000 bmes more slowly In water than In alf (Armstrong. 1979) Oxygen IS rapidly depleted, whereas gases like COiand ethylene accumUlate rapidly approaching gradual anaerobiOSIS In hours or even

Screening and Crop Physiology for WaterloGging Tolerance In Salt-Affected Solis.

-days The term 'water1ogglng' IS defined as a condition of the 5011 where excess water Inhibits gas

exchange of roots With the atmosphere water10gglng IS distingUished from 'flooding' because the latter results In additional factors of parbal or complete submergence of the shoot Redox measurement IS ana of the three Important charactenstlc of the current state of oXldallon-reductlon In a 5011 In addition to the 0" concentration and 0" flux Redox potemalls measured uSing bare platinum electrodes Redox measurements relate to SOil matnx - an enwonment of plant roots, and are partlrularly Important III Indll;atm9 f,?tenbal adverse effects

'from mlcroelement toxlcrues In absence of oxygen at 350 mV, Man:!lanese (Mn ') Increases and nitrate disappears (N03'1 when redox beoomes 250 mV LikeWise iron (Fe ') Increases at 150 mV (Setter and Waters, .2003) SodlC Salls are very slow In reoovery of redox potential even after drainage of water from the SUiface and tend to suffer from waterlogging and lower redox values for much longer periods as oompared to normal SOils. This_aggravates the effects of water10gglng under.sodlc condlbons as compared to neutral and light textured SOils It IS generally lower In sodlc SOil and reduCes further With duration of water-logging, the reduction being more In sodlcsoll (Fig 1)

. I Mechanisms 9f Plant Tolerance

To develop wheat vanet,es tolerant to salimty and water1ogglng, rapid methods for screening large segregating populations of young plants are needed ThiS may be achieved by selecting plants With the abllrty to maintain deSirable levels of growth and metabolism, uptake of nutnents, preventing bUild up 'of higher ooncentratlons of Na' and cr, leakage of cell metabolites and Ions BeSides these, continued uptake of 0, by developing aerenchyma-like tissue In the root cortex and stem base, and development of nodal roots under these stresses are very Important In addition, the ability to deal With the oonsequences of re-exposure to O"n the m()dlum IS equally important Cultlvars With some or most of these deSirable charaClers need to be Identified either for direct cuilivalion or pOSSible use as tolerant donor parents

500

'" ;; .00

i 350

1i '00 .. • 0 '" "il a: 200

'50

100

_ pH 78+WL --0- pH 9 2+WL

Anoxic

\WL Removed

o 1 2 3 • 5 15 7 8 90 10 11 13 Ie 15 11 20 :13 27

OaysofWL Recovery from W L

Fig 1 Redox potential in neutral and alkali Salls dunng 10 days water-logging and recovery

Changes In Concentrations of Toxic Elements

Water-logging Interacts With sallmty and sodlclty to mcrease concentrations of Na' and cr In plant shoots The Increases are caused Inl~ally by an Increase In net rates of transport of Na' and cr to shoot, and later on by decreased shoot growth Increased ooncentratlons of Na' and cr In shoots adversely effects plant growth and sUlVIVal Further, interaebons of sallnlty/sodlclty and water-logging have major Implications for management of these Salls and chOice of SUitable crops and vanetles for cultivation Water-logging In reclaimed SOil do not cause any major changes In sodium concentration of the upper 3 leaves of wheat plant at 22 and 90 days after sowing (DAS) In all wheat vanetles Na concentrations were higher In alkaline SOil, compared to reclaimed SOil, With different vanetles shOWing a wide range of response (083-206 % dry weight of Na) Na ooncentratlons In the leaves Increase further Wlth water-logging In alkali 5011 and concentration beoomes more (086-5 14%) when water-logging IS imposed at 90 than (064-2 72%) at 22 DAS stage Increased accumulation of Na In alkali 5011 exacerbated With water-logging IS pOSSibly due to reduced oontrol over Na uptake With less 0" accompanied by reduced conditions and energy restnctlOns to roots

Salient Experimental Findings

• Waterlogging In alkali Salls IS more harmful than In normal Salls • Increased uptake of Na, Mn, decreased concentrallons of Ca, lower redox potential and Ion tOXICity cause

269

Chemical Changes 8. Nutnent Transformation In SoolclPoor Quahty Water Imgated Sol/s

/ higher reduction in plant growth and Yield In water ~ogged alkali soils

• Oucula-4 acCumulate maximum Na, and mucl1lower accumulation IS observed In 0 4-20, 05-8, KRL 3-4, NW 10Wimd Perenjon.

• Significant genotyp'c dIfferences 'r tolerance of wheat genotypes are found In reclaimed and alkali Salls • Na concentration Increase In different plant parts VIZ upper three leaves, remaining lower leaves, -stem

and ear-heads under sodle and SodlCJty associated WIth waler-Iogglng Overall mean Increase aftenO days of water-logging IS found In order of remaining 10War leaves> upper three leaves> stem> earheads With dry weight baSIS percent concentrabons of 4 04, 338,245 and 114~respectlvely Contents Increase With water-logging duration Irom 0 to 5 and 10 days '"

• Increase In Na IS accompanied by decrease In K concentration under sodle, waler-Iogging and sadie + water-logging treatments However, the degree of cI1anges In K is lower than for Na -

• Upper three leaves have higher K than ear-heads = stem > remaining lower leaves With mean concentrations of 1.9S, 1 71, 1 70 and 1 24%, respecIJvely

• Waterlogging and SodlClty lead to reduced KINa ratios

Plants of four wheal vanellas grown In neutral and sadie Salls (pH 7 8 and 9 2) exposed to water-logging for 10 days were sampled at 0, 3, 6 and 10 days of WL, and after 10 days of removal of water stagnation Increasing durations of water-logging led to-higher concentrabons of Na In all the varieties and the highest Increase was observed In HD 4530 (Fig 2) HD 2189, KRL 19 and Ducula-4 showed Similar Increase In their leaf Na concentrallons No or negligible reduction In leaf Na was observed In any vanety even after 10 days of draining' off water thus ,"dlca~ng absence of recovery of plants from water-logging under SodlClty due to higher concentrations of sod,um_

Boron

6

5

i 4 ~

;; J

! • 2 z

o

pH 9_2+W L at 25 OAS

Na Lethal Level

HD 2189 KRL 19 Ouculs 4 HD 4530

Fig. 2 Time course In [Na+] of shoots for 0, 3, 6 and 10 dafter watenogglng and sodlelty treatment, ,additional treatments induded a 10 d recovery penod after surface water was removed from waterlogging treatments (pH 9 2). Plants were grown In pots and treated at 25 days after sOWIng (OAS) Lethal dose concentration of Na IS based on data of ShallTla (1995)

AnalysIS of plant top three leaves samples of seven genotypes of wheat grown In" alkal,,"ty (pH 9 1 and 9 4) and salinity (ECe 70) showed Increased concentrallOns of B well above the ooncentrabons conSidered tOXIC to wheat plants I e. 1-3 ppm Conoentra~ons of B Increased With Increase In alkalinity and were higher than salinity (Table 1) -

Wheat Varieties Screening for Waterlogging and Alkalinity

Laboratory Studies

Most of the results of effecIJs of waterlogging are based on laboratory studies InvolVing abrupt cI1anges In 0, supply to the plants (where anoxia treatment IS created by N2 flushing of the medium or uSing chemical compounds) Use of such artifiCial systems IS based on the premise that O2 shortage IS the primary factor In flooded SOil to which plants respond Use of sucl1 Simplified systems, overlooks the resistance mechanisms functiOning In natural enVIronments VIZ, protecbon against free radicals Under natural condl~ons of flooding or waterlogging, oxygen dissolved in SOil water IS, however, gradually depleted over a period of hours to days, the duration depending on SOil temperature and resp"atory aclJvlty of roots and microorganisms Roots invanably experience hypOXia before anoxia in nature, whlcl1 Improves the" performance under anoxIc COnditions, faced subsequently We, therefore, need to conduct these stUdies under natural salinity-waterlogged I submergence situations or try to Simulate these SitU allons In laboratory making roots hYPOXIC before anoxic, that IS, by exposing them first to sub-ambient 02 concentrations

290

Screening and Crop Physiology fOf Wate~ogglng Tolerance In Salt-Affected SOils

Table 1 Boron contents (ppm) In shoots of ten selected wheat vanetles In neutral and alkah sOil

Vanety pH 82 pH 8 2+\M_ pH 94 pH 94+\M_

Mean se Mean se Mean se Mean se HD 2189 5 05 19 3 19 2 20 2 KRL19 5 0:47 25 6 49 10 56 21

~ NWl014 5 049 19 3 49 17 48 15

Schomburgk 45 052 19 3' 49 10 71 16 BT -Schomburgk 4 05 17 2 48 22 45 6

HD 2009 35 05 15 2 61 24 63 5

Ducula4 6 1 24 3 65 12, 38 2 HD2329 5 ,046 17 3 39 6 44 10

Brookton 35 05 22 9 43 15 80 15

KRL3-4 4 0,5 38 3 58 25 44 6 Mean 5 06 22 48 51

Max 8 38 65 80

Min 35 15 19 20

WL stands for wate~ogglng

Pot Studies

Evaluation of different genotypes by sublectlng them to water-logging for different durations and stages of plant growth is a useful technique It has the additional advantage to ensure better control over treatments and Simulation which gives results nearer to natural situations those can be repeated and compared over different sites Significant genotypIc vanation has been observed for grain Yield and biomass under stress treatments of alkalinity, water~ogglng and therr combined effects HD 2189 gave best overall performance across all stresses, whereas HD 2009 was poorest (Table 3) All the three stress treatments caused Significant reduction In grain Yield of all the ten vanetles of wheat over control WIth maximum reduction In combined stress Perfomnance of most of the vanebes to water-logging dlffened In neutral and alkah conditions, which confirms our earher observabons regarding the level of alkahnlty and duration of waterlogging In governing vanetal tolerance MaXimum deletenous effects (631% reduction) on grarn yield were observed when water-logging was supenmposed over SOdlClty, followed by SodlClty alone (54 6% reduction) and water-logging alone (42 8% reduction), whereas the relative per cent reductions for biomass were 736, , 554 and 306, respectrvely Plant grarn Yield was thus' more reduced by waterlogging than biomass under neutral and alkali conditions, whereas sodlaty caused Similar reduction In both the parameters ThiS Indicates that water-logging cause relabvely mone severe effects on grain Yield processes as compared to those of biomass accumulabon It might be due to eddloonal detrimental factors affecbng conversion of biomass to grain Yield (source to sink) like translocabon of aSSimilates SodlClty+ waler-Iogglng had the most detrrmental effects on the harvest index, number of gralns,100 grain weight and number of green leaves In all the varretres

Micro-Plots and Field Studies

We now know that wheat genotypes differ In ~tolerance to salinity or alkalinity and some tolerant genotypes have been developed and released Secondly, cereals vary In tolerance to hYPOXia (o~ waterlogging) Some reports show varrability In tolerance to waterlogging In wheat genotypes (Thomson et 81, 1992), salinity and wate~ogglng (Akhtilr at 81, 1994), and alkalinity and waterfogglng (Gill et 81, 1992, Shamna, 2003) Shamna and Swarup (1988, 1989) reported that subjecting wheat crop groWing In alkali fields (ESP 11 and 32) to waterlogging for 1, 2, 4 and 6 days at 25 days stage, reduced plant growth and yield by 6, 17, 27 and 39 %, respectively Waterlogging decreased oxygen diffuSion rate (ODR), restncted root growth and reduced Ion uptake, espeCially of N, P, K, Ca, Mg and Zn, and led to higher absorption of Na, Fe and Mn Aimost Similar results were reported for barley,

Studies at CSSRI have revealed that water stagnation (for 4, 6, and 10 days) of already sahnlzed plants, reduced plant growth and Yield In wheat genotypes and was accompanied by reduction In net aSSimilation rates of CO, whereas stomata conductance was not affected Reduction In photosyntheSIS was accompanied by Increased concentrations of Intercellular C02 and increased uptake of No' and cr Two genotypes differed In these responses Genotype KRL 3-4 proved to be more tolerant to salinity, wate~ogglng and combined sallmty and waterlogging than PBW 343 Gill et 81 (1992) reported that floodrng an alkali field for 4, 6 and 12 days proved more detnmental at flowerrng stage than at tillering stage Out of 25 wheal vanetles tested, CSW 540-1, CSW 540-2, and CSW 538-2 were found more tolerant to the combined flooding

291

Chemical Changes & Nutnent Transformallon In SodlcJPoor Quality water Imgated Sods

, /

and alkali stresses This provides good indication that some range of vanability to'these stresses IS already present In wheat germ plasm This vanability needs to be Identified and exploited for Improved production of wheat In saline waterlogged SItuations

/' These genotypes dlffenng In salinity and waterloggIng tolerance prOVide a good tool for

understaridlng phYSiological mechanisms responSible for tolerance to saline and waterlogged stresses For agncultural crops, after screening the available commercial vanelles, further enhancement of tolerance requlles e1<pansloro oi 9'lrmp\asm base l<lerolll)im9 a\\ema\>ve vanallon In cases where little or flO vanauon eXIsts between vanelles, the alternallve approach to diversify the range of tolerance Will be to 'generate divergent populations In these crops uSing modern tools of genetic and molecular biology. Attention Will alSO have to be paid to screening ecotypes or explOiting plant to plant vanatlon for tolerance Within vanetles,

Waterlogging of SOil causes 0, defiCIency, Which becomes particularly severe when temperatures are high and promote rapid respiration (Jackson and Drew, 1984) The main effects are (a) Substanbal reduction In net transport to the shoot of a large range of nutnents N, P and K (Trought and Drew, '1980), (b) DUrln9 Q, defiCiency, seminal root growth ceased, While nodal root growth continued, nodal roots subsequently develop substantial aerenchyma (Barret-lennard et ai, 1988 and Trought and Drew, 1980) The Importance of aerenchyma and assoCIated oxygen movement to plant growth In waterlogged 5011 IS well documented (Armstrong, 1979) Aerenchyma !ormatlon, an adaptation to hypOXia in the crown rools at cereals, IS assoCiated With mcreased diffuSion of 0, to root lips (Thomson et ai, 1992) In stagnant nulnent solullon, tntlCSie cv MUIr had twice the aerenchyma percentage of wheat (Thomson et ai, 1992), and In field expenments waterlogged for 30 days, II out yielded 6 wheat cultlvars and another tnllcale (Hollington, 2000)

Germination Screening

Identification and! or development of crop vanetles tolerant to saline, alkali and waterlogged conditions and their culllVatlon can prevent loss In productiVity of the pnme agricultural lands In highly productive Ir"gatlon command areas faCIng the problems. Improved genotypes can help ,n complete Yield recovery In most of transient and margmally waterlogged areas However, in severely affected Situations, these can partially help III reducmg the yield losses. ldentlfica!!on and! or development of wheat vanetle" tolerant to saline and waterlogged conditions Will be an asset In nee-wheat areas, where after vacation of field from nce, espeCIally m low lands, prepanng the wet and heavy 5011 IS difficult ThiS often leads to under preparation of the fields leading, to poor stand or delay in sowing of wheat resu~ing in crop matunng under high temperature condlbons leading to Yield losses ThiS problem IS encountered In many areas of the ncewheat belt of the north India and IS frequent In eastern part also (Nagarajan, 1998). Identification I development of wheat lines tolerant to waterlogging and salinity can ensure higher YieldS by enabling timely sOWIng of wheat, development of proper crop stand and aVOiding the heat stress dunng grain filling stages,

Plants are least tolerant to waterlogging at pre-emergence, seedling growth and reproductive stages as compared to other stages (Setter and Waters, 2003) These results demonstrate the Importance of evaluatIng waterlogging toleraMe at different stages of de'Xllopment, paltlcu\aoy at stages which reffect the InCidence of waterlogging In the target environment A laboratory method to screen waterlogging tolerance of wheat genotypes dunng germination under normal and alkali conditions was standardised (Fig 3, Table 2)

Table 2 Redox potential (mV) In normal (pH 7 8) and alkali soils (pH 9 1) on water-logging

Wl Treatnnent N+Wl pH 9,1 + Wl

1 Day 3640+57 329,0 + 4 5

2 Days 3288+28 3075+ 171

4 Days 289,5+73 202 5 + 9.6

6 Days 2326+49 1003+ 7 6

BDays 1190+29 798 + B 2

Plot of germination percentage With bme showed that approximately 60% reduction In germination IS obselVed at 4 days water-logging and was used as the standand treatnnent duration for screening of other genotypes

292

Screening and Crop Physiology for w.te~ogglng Tolerance 10 Salt-Affected Sa,ls

100

80

60

40

20

a

.r.

,

,

1

I

,rl; ,

2

_, T :!'" J

~ -, -[ 1\ , , -_,

4 6 8

Days of Waterlogging

Fig 3 GelTTlinatlon percent of HD 2329 after 7 days of Wate~ogglng

GeJl7l1natlon of different vanetles was reduced to varying degrees by water I<Jgglng under neutral and sodle conditions and the reductIon in germinallon percentage vaned from 5-84% (Table 3) Ducula-4, the most'water loggIng toleront wheat genotype (vanGlnkle et al 1992), proved to be a poor performer In terms of Its germination In water.logglng under normal and alkalinity (pH 9.1) Its germination was reduced by 84 % and 76 %, when watMogged in neutral and alkali conditions The results of tested 200 vanetles have provided good eVidence for the presence of genetic differences In the gennplasm Tolerant and non-tolerant checks were also Idenllfied from these results Vanety 0 2-13 and Knchauff were the most tolerant and Ducula-4 and HD 2009 were the most sensItive genotypes dunng germlnabon These tolerant lines/ vanebes can be useful' for planting under waterlogged conditions and as tolerant donors for Improvement programmes

Table 3 Effect of water· logging on germination of wheat genotypes In normal and alkali SOlis

Vanety 4 Days Water-logging 7 Days Water-logging

Normal pHS 1 Normal pHg 1

Amery 600 + 9.9 755 + 22 0 610 + 96 755+220

Brookton 550+104 665+82 585+ 7.7 660+91 BT -$chumburgh 645+ 62 690 + 120 67 5+ ~8 705+124

Camamah 610+ 5 3 765+ 14 7 625+53 770+140 01-55 525 + 122 420+ 105 57.5+ 108 455+98

D2-13 950 + 76 800+136 980+ 2.3 810+116

04-20 495 + 41 320+ 44 480+49 320+44

D5-8 510 + 7.6 390+ 9 9 510+ 76 465 + 8 3

D 5-16 460+ 13 190+ 5 1 510+116 235 + 6 3

D5-34 695+159 715+180 715+124 49.0 .. 124

Ducula-4 160 + 2.8 240+ 95 165 .. 3 4 21 5 + 6 6

Gutha 315+8.1 205 + 4 5 355+25 410 + 8 9

HD 2009 19.0 + 3 8 250 + 84 190+ 38 265 + B 4

HD 2329 270+6.2 28_0 + 6 7 285 + 6 6 395 + 6 7

Kallanle 180+ 6 9 500+ 13 7 185+ 6 4 475.132

Kharchla 65 275+ 34 305+75 260 + 2 6 240+ 7 3

KRL 1-4 240+7.1 360+70 260 + 4 9 420-.106

KRL3-4 225+62 365+68 230 + 6 2 350 + 6 8

KRL 19 375+ 90 490 + 7 2 390 + 7 6 630 .. 109

Knchauff 925+97 635+59 930 + 8 7 445-.130

293

Chemical Changes 8: Nutrient TransformallOn In SadlclPoor Quahly Water Imgaled So'"

Bibliography /

Akhtar, J , Gorham, J and Qureshi, R H 1994 Combined effect of sallOity and hypoxta In wheat (Trrtlcum a8stlvum L. ) and wheat-Thlnopyrum amphlplOids Plant and Soli 166 47-54

, ,. , Barrett -Lennard, E G, Leighton, Armsstrong, W, Thomson, C, J, and Greenway, H (1988) Growmg wheat

In hypoxIc nutnent solubons and subsequent transfer to aerated ,soluuons, I Growth and carbohydrate In shoots and roots Australian',} Plant Physio/. 15. 585-98

Blemelt, S, Keetman, U, Albrecht, G 1998 Re-aerabon follOWing hypoxia or anoXia for acbvatlon of ~ntloxldatlon In wheat seedllnngs roots Plai\t PhyslO/ogy, 116 651-658 '

CSSRI, 1997 Vislon-2020 CSSRI Perspective PIan. Indian Council of Agncultural Research Director, Central $011 Salinity Research Institute, 95 pp

Goyal, S S, Sharma, S K and Rains, D W (Eds) 2003' Crop .Productlon In Saline Environments - a Global Prospective. Special issue J Crop Prod Haworth Press Inc New York, USA

Hollington, P. A 2000. Technological breakthroughs In screening wheat for salt ·tolerance Salimty Management In AgriCUlture Gupta, S K. Sharma, S K and Tyagl, N K. Eds. 273 - 89

Nagarajan, S. (1998) Perspedlves on wheat demand and' research needs In /l\lheal R9search Ne9ds B9yond 2000 AD Kamal, India Pp 13 - 28

Ram,. PC, Singh, A K, Singh, V P, Singh, H P .. Setter, T. L and Singh R K 1998 Environmental charactensatlon of floodwater In Eastem India Relevance to submergence tolerance of lowland nee ExpMmenfal Agnculturo 35141-152

Sayre, K D. Van GIOkel, ,M , RaJaram, Sand Ortlz-Monasterio, I 1994 Tolerance to wate~gglng losses In spnng bread wheat effect of time of onset on expression pp 165-171 In Annual /l\lheat Newsletler 40 Colorado State Umverslty

Sharma, S K and Sham S. Goyal (2003). Progress .n Plant Salinity Resistance Need for Integrabve Paradigm In Crop Production In Salme EnVironments - a Global ProspecfJV9 Ed5 Sham S Goyal, Sharma, S K and Rams, D W Haworth Press Inc New York, USA

Sandhi, S. K and Khepar, S D. 2000 Management of waterlogging and soli sahnrty of South-West Punlab In Salinity Management in Agnaulture. Gupta, S, \(., Sharma, S K and Tyagl, N. K Eds 125- 142

29

Physiological and Biochemical Roles of Micronutrients under Salt Stress

Ali Qadar D,v,s,on of Crop Improvement Central Soil SailmtyResearch Institute, Kamal-132001, Haryana

, Introduction

Mlcronutrtents, compnslng zinc (Zn), copper (Cu), Iron (Fe) manganese (Mn), boron (8), molybdenum (Mo) and chlonne (CJ), thpugh required by plants In much smaller amounts, yet are as essential for crops as the macronutnents nutnents Amongst these, only Fe occupies the fourth poslUon 19 50 % (by mass) In the earth crust after oxygen (46 6 %), SIlicon (27 7 %) and aluminum (8 1 %) Remaining ones are In

traces in most of the Situations. The availability of the mlcronutnents depends on a number of factors like pH and pE of the SOil solution and nature'of binding sites of organic and Inorganic particle surfaces Solubility as' well as avallablhty of mlcronuments (Cu, Fe, Mn, Mo and Zn) IS particularly low In saline and SadlC Salls and crops growing may show defiCiency symptoms for these nutnenls, but nolln all cases ThiS could be because 01 level of salt slress, nature and composition of sab present In the SOIl, micronutrient concentratJon, type of crop and Its vanety, grOWing condition and duranon of study The reqUirement of mlcronUtnents IS Increasing wo~d Wide as a result of mtenslve culbvabon pracbces Growmg high Yielding crop vanetles results In removal of high amount of mlcronutrlents from the SOil

Crop RequlremenUS

Goad crops of paddy (6 t ha') and wheal (4 t grain ha") remove on an average 350, 50, 3000, and 550 g ha' of Zn, Cu, Fe and Mn respecTIvely Typical removal of these elements by crops. content range In SOlis and plants are shown in table 1. As such, the replenishment of the mlcronutnents used by the crops grown therein IS Indispensable to sustain the high level of crop Yields and deSirable quality of the produce rallure In replenishment has resulted In micronutnent defiCiencies In many countnes including India The defiCIenCies of ln, Mn and Fe have been found to limit crop Yields in sates of India albeit to different extent depending on the degree of deficiency The defiCienCies of Zn and Mn are reported In wheat follOWing nee In highly permeable coarse-textured normal Salls In Punjab According to general standards, so,ls can be rated as defiCIent In ava,'able Zinc, copper, !fan and management if their available contents In the SOil fall below 0 6, 02, 4 5 and 3 5 mg kg" 5011, respectively DefiCienCies of Zn, Fe and Mn are generally encountered In coarse texture SOils; poor organic matter, high calCium carbonate, high pH (sodlc SOils) as well as flo~od plam, exposed sub-surface Salls and sod,c water imgated Salls

Table 1 Removal of some trace elements by crops and typical SOil cQntents

Elements Kg ha" Typical SOil content (mg kg") Concentration in Range Mean plants (ppm)

Molybdenum 001 007-5 19 015-15 Copper 01 25-60 26 2·80 Boron 02 09-1000 38 02·80 Zinc 02 15-2000 60 10-100 Manganese 05 <1-18300 76 10-400 Iron 05 001·21% 32% 20-800

The defiCienCies of ZinC, manganese and Iron have been found to limit crop Yields In sates of India albeit tD different extent depending Dn the degree of defiCiency The defiCienCies of Zn and Mn are reported In wheat follOWing nce In highly permeable coarse-textured normal SOils In Punjab According to general standards, 50115 can be rated as deficient In available zinc

j copper, iron and management If their available

contents In the SOil fall below 06, 0 2, .4 5 and 3.5 mg kg' 5011, respectively. DefiCienCIes of zinc, Iron and manganese are generally encountered In salls With coarse texture, poor onganlc ~alter, hlgh~ calCium carbonate, high pH (sodlc 50115) as well as flood plain, exposed sub-surface SOils and the SOils Imgated With SadlC water.

Essenbahty of Zn was first proposed by Ma~e In 1914 for higher plants and demonstrated by Sommer and Lipman (1926) for sunflower and ba~ey Amongst all the micronutrient, defiCiency of Zn and Fe are most common It is esllmated that Fe defiCiency occurs ,n aboul 30 % of cultivated Salls wo~dWlde and that about 50 5 of the Salls cultivated for cereal producTIon have low levelS of available Zn Aboul 46 % of 5011 sample tested In India were found low In Zn Its defiCiency IS known by different local names like Khalra disease In India, Agakare type II of Japan, Taya Taya and Apaya Pule of PhiliPPines, Hadda of PaKistan, and

Chemical Changes & Nutrient TransformaUon In SQchcIPoor Quality Water Irrigated Solis

J Bronzing and Alkali disease In USA. Zinc IS an Integral component of a large number of enzymes structure (Zn enzyme) In these enzymes, Zn has three functions' . ,

I , a) Catalytic (e g Caroonlc anhydrase and cart>oxypepMase) b) CocatalytiC (coactl<::e) (Copper-Zinc superoxide dlSmutase) c) Structural (Alcohol dehydrogenase)

Other Zn containing enzyme includes alkaline phosphatase, Carboxy peptidase and RNA polymerase

CartJonic anhydrase contains Single Zn atom, which catalyses the hydrabon of CO,

CO, + H,O CA o

Cu·Zn Superoxlde Dismutase

There are different isoenzymes of superoxlde dlslmutase, which differ in their metal component that might be iron (Fe SOD), manganese (Mn SOD) or Cu + Zn (Cu-Zn SOD) In later, most likely the Cu atom represents catalytiC metal component and Zn the structural Superoxlde dlsmutases (Fe SOD, Mn SOD, CuZn SOD) are present In all aerobiC organisms and play essenbal role In the ·survival of these organisms In the presence of 02 They protect from deletenous effects of oxygen free radical O· fonned In vanous enzyme reaction In which a Single electron IS transmitted to O'

+ o . (superoxlde, Reactive oxygen species)

Superoxlde dlsmutase O· +0 . + 2H+ H,02 + 02

Catalase and peroXidase are Fe containing enzymes Catalase lac.lltates dlsmutabon of H,O, to water and 0,

Catalase 2H,O, 2H,O + 0,

Peroxidases of vanous types (Isoenzymes) are abundant In plants and catalyse the follOWing reacllons

Peroxidase a) x + 2H,O, x + 2H,O

Peroxidase b) XH + ' XH + H,o, X--x +2H,O

a) e g AscartJate peroxidase detol(lfy H202 ,n chloroplast b) Cell wall bound peroxidases catalyses polymenzabon of Phenol to ligmn

Reactive Oxygen Species

0," (super oxide), ROO (LIpid perOXide), H,O,.OH (Hydroxyl radical) are highly reactive The actIVIties of Catalase and Peroxidase decline under Fe defiCienCY. This IS parbcula~y the case for Catalase actiVity In the leaves. The actiVity of Catalase IS indicator of Fe nutribonal status of the plans

Antioxidants

As~orbate, Alpha tocopherol, Glutathlones, Carotenoid.

As mentioned above, the availability of mlcronutnents to plants depends on a number of factors Including sallmty and SodlC.ty, for example, Mn defiCiency in barley In salme nutnent solution, (salmlty Induced defiCiency) and Bddlfion of Mn Improved growth, uptake of Mn, RGR (relative growth rate, NAR (net assimilation rate) and net photosynthesIs (Fig 1,2, and 3). Reduction In Mn conc;entrabon In com has been reported regardless whether these were eamed out in soil or salme solution Central)' to these, 10 tomato and sugarbeet either no change or Increased Mn concentrabon In leaf and shoot IS found 'The uptake of Fe, Mn, Zn Bnd Cu generally increases In crop plants under sallmty stress The detnmental effects of NaCI stress on the nu!nllon of bean plants are reflected in higher concentrations of CI and Mn In roots and CI, Fe and Mn I~ leaves and CI and Fe In fruits Bnefly, It IS reasonable to believe that numerous sallmty·nutnent interacbons are occumng at the same time but whether they ulbmately affect crop Yield or quality depends

296

PhysiolOgical and Biochemical Roles of Mlcromrtnents under Salt Stress

upon the salimty level and composluon of salts. the crop speCIes, the nutrient In quesbon and a number of enVIronmental factors

.8

. " Control

• • :SaIine NutrHnt folutlon

o .1 - 2 3 4

Mn m:Nulrleni Solution (mmo! m-3)

FIg 1. Growth of salt stressed ba~ey WIth supplemental Mn. 0_ control nutnent solubon .• - saline nutnent solutIon (N S +125 mol m" NaCI+ 9 6 mol m" CaCI2)

Salinity stress (150 mM NaCI) adversely affected growth and dry weights of dIfferent soybean culbvars namely (Omaha. A-3127, Mancon, Stresland, LN-69-3264, NE-3297, Ap-2292. Although, Inglous. 5-4520. Amsoy-71 and CIsne) and the extent of effects vaned dependIng on the salt tolerance of the culbvars The concentrabon of Fe. Mn, Cu and Zn were hIgher In roots compared WIth those In leaves and shoots In saR applied samples. Some vanabons are also found In the mlcronutnent contents in dIfferent organs of soybean cultivars as a resun 01 salt applIcatIon to groWIng envIronment Iron (Fe). manganese (Mn) and copper (Cu) content Increased In the samples WIth salt appllcabons except In some culbvars On the other hand. when mean data of cultovars are consIdered and compared. ZInc (Zn) content was not signIficantly affected by salt stress. In case of strawberry, applIcabon of 500 and 1000 m9 L" NaCI treatments dId not change total chlorophyll content IMth the salt applicatIons, iron (Fe) and manganese (Mn) content increased. whIle copper (Cu) content did not change in the aerial part of plants In both vaneues On the other hand. zinc (Zn) content Increased In the TIoga strawberry variety In the root part of plants. Fe. Zn. Mn and contents dId not change accordIng to salt apphcabons In both strawberry vanebes However, 2000 mg L" NaCI applIcatoons has been found to SignIficantly increase Cu content In the Camarosa strawberry vanety.

3: 25 0 _g 2 "0 E

.=0 '5

~ '" " c

'" 5

~ ~

4 ~ '8 a: -9',

§ ~

~ g - 5 6 10 12 14 16 16 20 22 24 c

B

:::0;.. T..ne (day)

FIg 2 The effect of supplemental Mn on A. Mn concentration In shoot. and B Mn uptake of sail stressed barley over bme (0- control .• -<:cntrol + Mn 0 sallmty •• SalInIty + Mn)

The foliar concentratIons of CI. Fe. Mn and Zn Increased In Zucchini plants (Cucurblta papo L var Mo~chata) grown ,n pots under greenhouse condItIons supplIed WIth dlffenng amounts of NaCI (0. 20. 40,

297

Chemical Changes & Nutnent Transformation In SodlcJPoo( Quality Water Irrigated Solis

/' , and 80 mM) The actlVlties of catalase and ascorbic aCid oXidase assayed In fruits showed an Inverse relationship with the sail concentrations applied In thiS context, It IS useful to determine the effect of NaCI on the mlcr'1nGtrlent ooncentrabon, given that the Improvement of crop watered with saline water enhances \he mlcronutnent profile Thus, at 80 mM NaCltreatrnent improved the mlcronutnent levels In the shoot, and slgnificanUy Increased the mlcronutnent denSity In the edible part of this crop ,

'\

,zs ,

',_ .2

'" :g 0:

.15 "" IX

1 gi ~ ~ ~ ~ iii

.0016'

~ '" -0

"l' ·.0012 5

.E) a: ,OOOa <to :z

,0004 -.;,

·c iC)',

,E <> 15 E a '" .:g~ ·~o

",,s' " , , ,C ,_" , , ~ 5 :; -= a..t m ,0 z

8 10 12 14 16 18 20 22 24 26

Time (day)

Flg3 The effect of supplemental Mn on A, the growth, B NAR, C net photosynthesIs of salt stressed barley over time

(0- control, .-control + Mn 0 salinity, • Salinity + Mn)

. To gain a beHer Insight Into long:term saft-Induced oXldabvEl stress, some phYSiological parameters in marigold (calendula officlnalls L) under 0, SO and 100 mM NaCI were Invesbgated Salmrty affected most of the conSidered parameters High sall~lty caused reduction in growth parameters, lipid peroxldatlon and hydrogen perOXide accumulation Under high salinity stress, a decrease in total glutathione and an Increase In tetal ascerbate (AsA + OHA), accompanied With enhanced glutathione reductase (GR, EC 1 64.2) and ascorbate peroxidase (APX, EC 1.111.11) activlbes, were obselVed In leaves In addlbon, salinity induced a decrease In superaxide dlsmutase (SOO, EC 11511) and peroXidase (POX, EC 1.111 7) actIVIties The decrease in monodehydroasoorbate reductase (MOHAR, EC 1 6,54) and dehydroascoroate reductase (OHAR, EC 1 B 5 1) actIVIties suggests thaI other mechanisms playa maJer role In the regenerahon of reduced ascorbate The changes In catal~se (CAT, EC 1 11 1 6) actiVltles, both In roets and In leaves, may be important In H20, homeostasIs Fohar appllcaoon of mlcronutnents on tomato IS reported to alleViate \he adverse effect of salt stress Increases tolerance to Sahmty In cereals and leguminOUs plants

Avallablilly of Zn In sodlc 501115 a major problem leading to VISible symptoms of Zn hunger and lis appllca~on has been reported to Improve the both growth and yield of the plants as well as uptake However, thiS may nal necessanly be we With increasing salinity The maJonty of studies 11\ the literature have shown sallmty to Increase Zn concentration In shoot such as in bean, Citrus, maize and tomato In other cases, It was not affected er actually decreased Zn concentration as In cucumber leaves Zinc applications have also been reported to Improve growth In salt stressed plants Infonmabon available on the Influence of salinity on the Fe concentrabon In plants are as mconslstence as those that concern sall",ty on

298

Physiological and BtochemlC?1 Roles of MIC"onutnents under Salt Stress

the Fe and Mn, The concentration of Fe IS reported to Increase In shoots of pea, tomalo and soybean and decreased Its concentration In the shoots of barley and Com, An Increase In Fe concentration In rice leaves IS also noted under SodlC condlbon that IS most likely, a result of concentration effect due to reduced growth Very little well< has been done on effect of slat stress on Cu and Mo uptake and accumulation In crops In studies With maize, It IS reported that Increased Mo concentration In plants when grown In saline, but some woll<ers have found no effect of salinity on Mo uptake when maize was grown In saline nutrient solution

,The effect of salimty stress on Cll conceptraIJons In salt stressed plants was also vanable In case of salt stressed maize, Cu concentralion decreased both In SOil and saline solution culture, but NaCI-sallnlty substanbaJJy Increased Jeaf Cu 1M hydroponically grown tomato,

Boron (B) defiCiency is more-Wide spread than 'B tOXICity particularly In humid Climates, but B tOXICity is of more of a concem In arid enVIronment where salinity problems also eXist Although It is conSidered on the baSIS of,experimentai"evldence that plants absorb B passively as H,BO" contradiction between expenmental resuns and obserVations In the field indicate that other factors, yet unknown may affect B uptake Vliheat responded to B'm sand culture expenment independently of NaCI and CaCl, saliMy Contrary to thiS, soluton, others have found that,a mlxed'salt'solutJon (Na, Ca CI and SO.) reduced B concentrallon in chickpea grown in pots filled wrth loamy 5011. Salinity (of mixed sallsO was noted to reduce the negative response of many field grown crops to high levels of B In imgatlon 'water Sallnrty compnslng of ·CI and SO. sans'reduced B uptake and accumulabon In stem of several Pnunus root stocks there by decreaSing B tOXICIty symptoms They also found' a nEigabve relationship between Band 504 concentration In tissue suggesting thai SO. could be responsible for the salinlty.induced reductJon In tissue B High concentraliOns of substrate calCium particularly In calcareous Salls decreased B absorption and can Induce B defiCiency

299

, Transfer of Technology Approaches In Management of Alkali S~ils in Uttar Pradesh , RarnA}ore7 DIvIsIon of Technology Evaluation anrJ Transfer Central SOIl SalInity Resea/Gh instrtute, Kamal- 132001

Introduction , Over 14% of the total salt affected salls are met within the Uttar Pradesh State alone Alkali' 5011

reclamatIon is the only way to Increase area under cultivatIon Singh etal (1990) reported that the alkali Salls of the Indo-Gangatlc plain offer enormous scope for extending agnculture Over mora areas, and thereby help meet the Increased demand for toad in the future The package of practices for amelioration of alkali Salls and crop productIOn advocate<:! by the Central Soil Sallntty Research Institute (CS~RI) Include proVISiOn of suffiCIent assured supply of good quality irngatlon water, as It was one of the major constraint In reclamation and management of alkali Salls (Ajore, 1991 and Alore & Singh, 1997) In order to cOpe w,th thiS constraint, the Uttar Pradesh Land Development Corporation (UPLDC) planned for reclamation of alkali SOIls alongwrth ensunng constitution of Water Users' AsSOCIations (WUAs) for each command of 4 ha Reclamation of alkali Salls undertaken by the UPLDC In two projects areas (Hardhandpur and P.uraon '" Sakeet block of Etah dlstnel) showed that the entire area had not been put under reclamation after ensunng Imgation water availability through WUAs and soli amendment (gypsum) Farmers have not adopted the reclamation of alkali Salls due to several problems/dlfficulbes II was, therefore, felt necessary to find out the problems faced by the farmers and suggestions In adoption of reclamabon of alkali Salls

The study was undertaken in two purposively selected villages I e Harchandpur and Puraon In Sakeet Block of Etah dlslnet as these IIIlIages could be accessed With ease A proportonate sample of 70 percent of the Water User ASSOCIations (WUAs) was drawn randomly from each of the village Thus, 13 WUAs from Harchandpur and 11 from Puraon were seleeted SIXty-five farmers from the WUAs formed In Harchandpur and 62 farmers from WUAs formed In Puraon were selected Data were collected by personally Intervl9WJng the benefiCianes With the help of a well-struclured inteMew schedule under the reclamation work undertaken by Uttar Pradesh Land Development Corporabon dunng 1994-95.

Extent of Adoption of Alkali 5011 Reclamation Technology

Though the CSSRI recommends package of practices for alkali SOIl reclamation, yet the farmers often selectively adopted the components of the package About 85% of the alkali area in Harchandpur and 89% area In Puraon were found to have been reclaimed by use of gypsum Nearly 87% of the area had been under reclamallon, Nearly 40% farmers adopted full use of amendment as per recommendations In Harchandpur and 32% In Puraon by bnnglng under reclamabon, 36% and 42% area under reclamation In these two villages, respecbvely. It was found that nearly 17% farmers in Harchandpur and 14% larmers In

Puraory did not imtlate reclamabon activities in Harchandpur and Puraon respectively About 48% of the farmers adopted only parIJal dose of gypsum I e below 12-15 ton/ha. In response to question about reasons of non-adoption of the package of practices of alkali SOil reciamaUon, 4ll% farmers mentioned that it was due to several reasons like non-receipt of gypsum and tear of recovery dunng later peneds. The Cited reason for parMI adoption was' partial (belOW recommended dose) receipt of gypsum from thel( group leaders and/or State Departments of Agnculture

Table E~nt of adoption of gypsum as SOil amendment for reclamatIOn of alkali Salls (N=127)

Adoption Level % Total S Village/Nos of Total alkali Full Partial Non Adopter area No farmers area (ha) Nos AC Nos AC Nos AC covered

(%) (%) (%)

1 Harchandpur 451 26 362 28 494 11 144 855 65 (40.0) (431) (169)

2 Puraon 405 20 42.1 33 474 9 105 695 62 (323) (532) (145)

Total 127 856 46 390 61 465 20 126 674 (362) (480) (15 B)

Figures In parentheses represent percentages AC = Area Covered

Transfer of TechnQlogy Approaches m Management of Alkali Salls m Uttar Pradesh

Constraints Experienced by the Farmers

About half of the sampled farmers reported that they received below the recommended dose of gypsum, there was Inadequate supply of imgatlon water In the command area (40%), non-availability of loan for purchase of engine/motor (38%), large size of WUAs (33%), group leaders don't allow use of engine by paYing diesel charges (28 35%), timely p~ssesslon of land not given (27%), and non-receipt of gypsum due to fear of mora recovery (16%) ,

. I

Table Constraints/problems expenenc9cl by farmers In raciamabon of alkali SOils (N=127)

S No

1 2 :3

4

5 6 7

Reasons

Not receIVed gypsum due to fear of more recovery. Received gypsum below the recommended dose No supply of suffiCient ~ater as per demand In 4 h. of command area Group leader do not allow to use tubewell water on Diesel payment or use of others' engine Water is cosily through pumpsets No possession of land In time Size of member In assocI anon IS large

Frequency

20 61 51

36

44 34 42

The sum of percentage IS more than 100 due to multiple response of the respondents

Fanners' Suggestlons for Boosting up Land Reclamation Programme

%

1560 4800 4015

2635

3464 26.77 3310

,Around 84% of farmers mentioned that demonstrations on full package pradlces should be oonduc!ed to oonvlnce and motivate them and to facllrtate assessment of the recommendations as per local CircUmstance Nearly 56 percent opined that command area should be reduced to :3 ha to faCilitate availability of suffiCientlmgatJon water About half of the sampled fanners suggested that there should be 3-5 members In each assoClalion to reduce local conflicts or sharing of Imgatlon water Diesel should be available at cheaper rate (40%), drainage work i e construction of link drainage be got done through concerned department (28%) A Sizable percentage (25%) deSired that the department of agnculture be made accountable for timely availability of loan for purchase of pumping sets 'and allocation of palta to farmers In oonsul!<ttlon ,WIth the Site Implementabon Commlltee (SIC) to keep the group homogeneous, which IS an essential reqUirement for eftedlve ImplementatJon of WUAs

Table Suggesbons offered by fanners for eftecbve reclamalion of alkali SOils (N=127)

S No

1.

2 3 4 5 6

Suggeslions

For motivating the farmers the demonstration on full package be laid out Command area should be 3 ha Members In assoCialion sould be 3 to 5 In numbers Agreement on bond paper of common prope!1Y nght of WUAs Diesel should be available at cheeper rate Drainage work be got dona through concerned department

Frequency

107

71 62 56 50 36

%

8425

5591 4882 44 10 3937 2834

7 Department be made responSible for timely availability of loan 32 2520 8 Patta be allotted In consultation With SIC group to maintain 10 7,87

homogenous group

The Sum of percentage is more than 100 due to multiple response of the respondents

FollOWing extension approaches for transfer of technology for management of alkali SOils are suggested

• In-seMce training to subled-matler-speCialist of the state department of agnculture

• laYing out demonstnltlons • Organlsabon of Agnllcultural Exhlbllion

• Organisation of fanners' Days • Publlcabon of literature

• PartlClpabon In Mass media programme • Arrang In9 Visits of the farmers & Extension wOlkers

301

Chemical Changes & Nulrlent Tran$formatlon In SodlciPoor Quality Waler Img.ted sons

r r ,

The research or Innollatlon system deals With the generation or communiCation of the technology, the extension system deals with the interpretabon and dissemination of the technology Under research sySlemlmnOllabon system, sClentlst of the Institute (CSSRI) Imparts training to subJecl-matter-speClalislS of the state and' under the extenSion-system these trained SMSs Impart training to grass root level extension funcIJonanes.

\ The efficiency and effectiveness of the work largely depend on both the extension workers and

fanners who have to carry the work of transfer & adopbon of the improved technology in reclamation and management of salt affected soils. On the quality and Willingness of these people depends the success 01 the programme The quality of extension personnel can be Improved through conbnuous training and those of fanners can be motivated to absorb the advances of reclamabon technology of salt affected SOils

Extension and Management Strategies for Transfer of Reclamation Technology of Alkali Salls

A number of strategic steps are essential for successfully transferring Alkali SOil reclamation technologies are given below

o Demonstration on full package of practices of the reclamatIOn technology at the few farmers' fields o Organisation of training programmes to extension workers & famter5 o Arranging field tnps of fanners to reclaimed area to convince and motivate the farmers o Arranging meelrng well in advance of reclamation programme to clarify doubts & making aware to the

farmers o Dlstnbubon of literature on the technology among lIterature fanners & extension personnel o Motivation camp be organized In problemabc areas of alkali soils o Inputs availability on subSIdized rate to landless/marginal & small fanners. o Installation of tubewall or ensure availability of canal irrigation o ProVision of timely availability of credrt faCility WIth low Interests o All Inputs shaUll:! be available before season at nearby places o Palta should be of at least one hectare. o Patta should be given at one place preferably In own village o Demarcation of patta well in advance of the reclamation o Work responSibility of reclamatIon With one InsbMlon. o ProViSion of electnc connecbon In Villages to run tubewells o Avoid frequent transfer of extension workers o Good irnkage between Research, Extension & Farmers.

Bibliography

Ajore, R 1991 A study on participation of farmers-in-centrally sponsored scheme for reclamation of sadie SOIls In UP, unpublished Ph D, theSIS, I A R I , New Delhi

Ajore, R and Singh, K. 1997, Making Re>clamabon of Alkali 50115 In UP, a success Wasteland Ne>ws, XII (3) 53-55

SIngh, K , Parshad, R & AJore, R. 1990 Want more land for crops & reclaim alkali Salls - Risk-Free, Intensive Agncutlura, XXVIII (6) 25 - 27

302

Financial Appraisal and Socia-Economic Benefits of Salt Affected Soli Reclamation

R,S, Trlpathl , DIVision of Technology Evaluation and Transfer Canttal SO/I Salinity Research Institute: Kamal- 132001

Introduction

Soil salimtY and sodlcdy have direct Impact on growlh and development of agncultural economy. The consequences of degrading land resources due to salinity and sodlcity are witnessed at fanm level, regional level and n9tlon,,1 level At the fanm level adverse effects are (I) threat to the susta,nab,lity of land resources and (II) decrease fanm production by (a) decline In resource productiVity, (b) abandon crop production and (c) cut-back In resourca use Studies have shown that the Yield and Income effects of sail affected Salls are qUite high. The land degradation severely affects the productJon of important crops like nee, wheat, cotton, sugarcane, groundnul, etc At the regional level, consequences are (I) displacement of labour from agnculture, (II) Widen Income dlspantles and (III) affect the sustainabllity of secondary and tarnary sectors At the national level, consequences are (I) declIne in agncultural production, (Ill affect gross domestic product, (in) bnng down export potential of Important crops and (IV) increase Import bIll

The brief deSCription of sgro-physical, socio-economlcal and enVironmental Impact of soil salInity and sOdici!y are as follows

Impact on Crop Production

Vanous degrees of sallmty and SodlCrty can cause senous and severe decline in SOIl productiVIty and crop yields (Table 1)

o To overcome reductIon in YIeld fanmers Increase mputs such as seeds, fertIlizers, etc • In salt-affected SOIls, response to any Input is low e 9 , crop YIeld response to fertl!lZer appllcabon IS less

9S sallmty IS a limItIng factor. o Less passlbUlty for altemahve land use. e g., farmers are forCed to cultivate only salt-tolerant crops, whIch

mIght not always be high-income cash crops. • Salinity and sodlcity reduce effiCIent use of water (I e crop yield per unll water) causing reductIon In

return from capitallnvestmen! and laboUr inputs • Salt-affected soils are more fragile WIth greater risk and always subjected to other tonms at degradabon

e g, salinIty and SodlClty reduce land green cover and SOIl becomIng subject to other degradatIon processes such as wind and water erosIon

o In salt-affected soil enVironment, saline watertable can enhance sallmty of fresh waters in nvers and other water sources through seepage.

o The rehabilitabOn programmes requIre hIgh Investment cost In reciamabon of salt-affected SOIls as compared to other types of degraded lands, in general

Table 1. Grain YIeld of major crops under vanous environments (tJha)

Crop Nonmal Salt affected SOIls Waterlogged SOIls SOils

1. RIce 399 218 (45) 230 (42)

2 lMleat 2.59 1 57 (40) 185 (38) 3 Cotton 163 061 (63) 037 (77) 4. Sugarcane 63.66 3302 (48) 24.74 (61)

FlQures in parentheses IndIcate percentage loss over nonmal SOIls

Impact on Socia-Economic Conditions

• Abandonment of the land where severa salinity and sodlClty degradatJon occurred whIch mcreased the number of landJess fanmers

o Low food security due to low food production and supply. o Reduce labour use effiCIency. e g, reclamatIon of salt-affected soils needs more labour, crop YIeld

declines and input requirement reduces whIch uttimately would reduca labour use effiCIency In these soils ReclamatIon programmes and Improved farrmng systems often Involve hIgh costs beIng capital investment of the Govemment

303

Chemical Changes &INutnent Transformation In SadlclPoor Quality Water Imgated Solis

; • Lower farm, Income of resource poor small farmers e g, as a consequence of salinity and SodlClty

farmel5 ,force to work on land of others or migrate to outside the area In search of other sources of, livehhooa ,

Impact on Environment

Most sludies of long-term expenments provide information only about biophYSical Impacts of SodlClty and ssliMy at the site of the expenment There are also off-srte environmental lnipacts of salinity development These may be at least as Important as those on-srte Chemical effects contribute because nutrients are leached from the SOil dunng leaching processes of salt-affected Salls and contaminate water supplies Biological effects because of the loss of organic matler, which weaken the strength of SOil aggregates, Increase the loss of nutnents In run-<>ff, and Increase carbon diOXide and methane released to the atmosphere Nutnent losses by leaching are most often Observed where nitrogenous fertrllZers are being used InJudlcioualy and where organic manures are concentrated and the effluent anslng IS allowed to reach streams or nvers

Washing of 5011 nutnents, organic matter and even nutrient nch topsails In to streams and nvers IS a senous cause of eutrophication The nutnents and organic matter cause a prolifera~on of water borne organisms, which use oxygen In the water and deplete It, at the expense of fish Until now there have been few studies In which a comprehenSive attempt has been made to quantify fully the off-site effects of saltaffected SOil development on environment Where Irngation systems are estabhshed it IS necessary that proper attention be given to inclusion of adequate drainage systems to dispose of the saline drainage waters so that salinIZation does not become an environmental hazard

FInancial Appraisal of Land Reclamation Projects

The finanCial appraisal of sallnrty and sodlClty management projects IS aimed to find out whether the proJect, IS economIcally reasonable and able to prOVide Justified return on the Investment made on It The finanCial feaslblirty Involves detail, analYSIS of the capital requirement for Installa~on of the systems, annual operational and maintenance cost of the project and benefits generated by the project In the land reclamation projects, the Initial Investment IS made once for Installa~on of the system whereas the returns obtained from the project IS spread over several years In future

The financial appraisal of project mainly Includes costs and benefits analyses for estimation of economiC parameters The cost-benefit analYSIS IS a deClsion-maklng tool for Investment chOice WIth respect of total costs and total benefits It helps In companng the cost and benefit of alternative technologies, Nevertheless, 'all the Costs and benefits are difficult to quantify In ~nancral terms because a new technology may have negative and pOSitive Side effects on the life quairty of society and accordingly required to be accounted for the assessment When Side effects of a technology are accounted both direct and Indirect benefits and costs, It IS called SOCial cost-benefit analysis Generally, for the financial feaSibility we consider only ta,nglble direct benefits and costs VIewing the slmpirClty of esomabon procedure,

There are many tools and measures to evaluate the feaslblirty of the land reciamabon technologies Some Important cost-benefit analYSIS measures are described here which are used W1~ely to find out the finanCIal and commercial viability of the technologies,

• Pay Back Pened • Simple Rate of Return • Net Present Worth • Present Worth of Benefit-Cost Ratio • Internal Rate of Retum

Pay Back Period (PBP)

The pay back penod measures the number of years It WIll take for the net undlscounted benefits to repay the Investment If the payout period IS longer than some arnltrary limit (say five years) the project IS rejected II shorter, It IS accepted Thus, the pay back IS the time penod for an Inveatmant to generate suffiCient Incremental cash to recover lis mitlal capltaJ outlay In full The fOllOWIng formula IS used to calculate the pay back pened, if the cash flows are uniform

I p =

E Where P = Number of years reqUIred for pay back the rnvestment,

I " Initial capital Investment, and , E = Annual net earning (benefits)

304

Financial Appraisal.net SOCIa-Economic Benefns of San-Affected 5011 Reel.matron

If the cash flow IS not unlfonm per year the payback penod IS detenmined by calculabng the cumulallve proceeds in suCGElSSlve years unbl the total IS equal to the anginal outlay It IS computed to supplement the other measures used to judge the deSirability of the projects The shorter pay b8Ck penod provides the greater profitability of Ihe project

, The payout period entenon is jusbfied for the IndiVidual's pomt of view In the short run but for

aggregate purposes such as a nation as a whole, some times II misleads the results The crucial draw back of , thiS measure IS that It rejects all projectS whose benefits take long time to matenahze and favours only good

short-teom prospects There IS no reason to beheve that all QUick Yielding projects are superior projects

Simple Rate of Re1um (SRR)

The Simple rate of return of a project IS used to compare With the rate that has been detenmlned to cut off entenon or the minimum rata of return. The follOWIng fonmula IS used to calculate the SSR of a prolect

I : E - D r=---

~ ,.-lMlere r = Simple rate of return on the InVesllment made for the project.

E = Annual net benefits expected from the prOject, o ; Annual average depreCiabon on the fixed assets, and ! "'""ial capital Investment on the project.

Net Present Worth (NPW)

The wailing has a'cost and the longer you walt the larger the cost If money and other assets are more productive, as reflected In the higher discount rate, the waiting IS cosHler ThiS raises the Question as to which mterest rate should be used m project appraisal Generally the discount rate should reflect the cost of capital to the Investor The net present worth method IS based on three Important features of the present value

• The present value IS always less than the nominal value that occurs In the future • The longer the delay, the less is the present value • The highest the Interest rate, the lower the present values

In the esbmallOn of NPW, the return achieved at different future dates IS made commensurable by asslgmng to them eqUivalent present values ThiS IS an expressIOn of net revenues from the crop production discounted ti> a common lime point for. ensunng costs and returns comparabihty, which occur at different penods of bme. The NPW can be calculated by taking \he difference between present worth of benefits and present worth of cost The POSitive values of NPW reflect Viability of the project whereas negative NPW Indicates economic loss In the project. Once future benefits and costs have been expressed In terms of present values, we add them to find out the NPW of the project General fonmula used for estimation of NWP IS.

NPW= n Bt - Ct !: --t=l (l+l)t

Where Bt = Benefit received each year, C = Cost incurred each year, t = Time In yealS (With present difference as 0), n = Number in years oftha prolect durabon, and i" Rate of interest for discounting the cost or benefit

Present Worth of Benefit-Cost Ratio (BeR)

Beneftt-cost rallO IS the most popular enterion in SOCial prolect appraisals It IS calculated by dlVldmg the total discounted benefits by totat discounted costs The project IS accepted If the BCR IS above 1_ The projects With the highest rabOs are given higher ranking It IS the ratio of present worth of benefit and present worth of cost expected at different pOints of time for a particular project The ratio more than 1 reflect economiC viability of the project whereas less than 1 mdlcabng loss In taking up me prolect The BCR can be calculated With the help of the follOWIng fonmula.

n Bt L

t=1 (1 +1)1 BGR=

n Ct L t=l (1 +1)1

305

Chemical Changes & Nutnent Transformation In SodldPoor Quality Water Irrigated Solis

/ j

The benefit-<:ost ratio is a ratio of PVB to PVC of a technology under assessment. In other words, It IS retum to one ,rupee Invested on the project Therefore, at the economic feaSibility level of the project the BCR, should be more than Unity

, " JntemaJ Rate of Retum (IRR)

The Internal rate of return IS used to find out the rata of return, which a project IS likely to earn over liS useful Life, ThiS measure IS practicaLly used for aLI economic and finanCial analyses of prOjects by the Internabonal financing agencies When the Intemal rate of return IS used In economic analYSIS, It IS called Internal economic rate of return (ERR) whereas~on the financial analYSIS It IS called Intemal rate of return (lRR) The IRR IS the discount rate at which the NPW IS equal to zero In calculabng the NPW, we Independently chose a discount rate based on the opportUnity cost of caprtal and then found the differences between discounted benefits and costs The IRR calculation reverses the procedure as we use for NPW Instead of seleCilng the discount rata, we set the NPW at zero and try to solve for the discount rate, which finally gives results Since higher discount rates reduce the present value of future ca~h flows, the higher the discount rate, the lower the NPW The process of finding the IRR Involves Inal and error method An arbllrary dlsoount rate is used to find NPW If the result IS POSitive a higher rate IS used to find the NPW, If negatIVe a lower rate IS used and the process IS repealed until the NPW IS~ reduced to zero At thiS discount rate, benefitcost rallO IS equal to one The IRR IS compared with the minimum acceptable rate of return and If It is either higher than or equal to the minimum acceptable rate of return, then the technology IS assessed to be deSirable Suppose, IRR IS 18% thiS means that a discount rate of 18% the project Just breakS even, Ie, It Will earn bacK all the capital and operatmg costs extended upon It and pay 18% for the use of money m the mean ume ~

The Internal rate of return or discounted cash flow rate of return IS the margmal effiCiency of capital or dIScounted cash flow of the mvestment on a project It IS the rate at Which the discounted cash flows are equal to the investment outlay of the enterprises So IRR IS ~that rate of Interest, which applies to expenditures Incurred at different times for findlng~compounded sums equal to, revenues compounded at the same lime The rate of discount, which makes Net Present Worth of the IIlvestment exactly equal to zero, IS known as Internal rate of retum of a project Thus IRR IS that rate of dlsoount, which makes present vaJue of benefits zero.

The IRR IS a tnal and error solution in which we choose a discount rate at random The mvestment is conSidered to be deSirable If the IRR IS hlghe(than the cost of caprtalln a project If NPW >0, we choose a higher discount rate (accept the project, Vlablhty) and NPW<O, we choose lower dIScount rate (reject the proposal) The rate of discount at which the NPW IS equal to 0 IS the actual IRR and at thiS stage the procedure is completed The IRR can be expressed In algebraiC form as:

n Bt-Ct

IRR = ~ = ° 1=1 (1+I)t

In the estlmabon of IRR, the first step IS to discount the cash flow at the cost of capital If the NPW IS negative, we know the project cannot pay such a high rate of Interest It means that we have chosen a high discount rate Now, choose a discOunt rate (lower rate), which Will give a POSitive NPW If m the first step, NPW is positive we should choose a new discount rate (higher), which will decrease the NPW and make It negative The real IRR lies between these two rates, and we can successively nalTow down the limits The easier and Widely adopted method employed for estimation of tnue IRR IS the Interpolation formula The InterpolatiOn formula IS as follows

NPW at lower discount rate IRR = Lower discount rate + Difference between X

the two discount rates Difference between NPWs at the two discount rates

It IS very Important to note that Interpolation should not be camed out between a Wider spread of discount rates (not more than five per cent) Since interpolation IS a higher hnear algebraic technique ancl the changes In IRR, NPW do not follow thiS pattem In reality, the IRR reCilfied by actual verification and by narrowing down the limits between the two discount rates

Socia-Economic Benefits of the ReclamaUon

There are numbers of socio-economlc and envIConmental benefits of the sodlc land reclamallon, which have changed the face of Villages and scenano of rural development In many states of India like Haryana and Punjab where almost all the problematic lands have been reclaimed 8I\he' completely or partially The most sodiclty' affected states Haryana and punjab alone contnbute nearly 50% food grains to the central pool every year after getting their SodlC lands reelalmed The SodlC land recJamatlon has direct influence on poverty and livelihood of the rural poor, The Impact of sodic land reelamabon IS qUite VISible in

306

Fmanc.al Appraisal and SOCiD-Economlc Benefits ot Salt~Affected 5011 Reclamation

terms of additional food production, employment, farm Income, resource-use, farm assets, capital formation, land value, sOil health and quality of life and environment It helps In ellmlnallng poverty and IneqUity amongst the rural SOCIety The sOCIal Impact can also be seen as mcreased literacy level, declined birth and death rates and high life expectancy of the affected people Sodlc land redamatlon has emphaSIZed social aspects to ensure stakeholders commitment In sustaining the actiVities to manage SodlC lands The major SOClO

enVironmental Impacts of SodlC land reclamation are discussed m the followmg paragraphs

, Food Production

A rapid Increase in foOd grains produClion was Witnessed In the northem states of India dunng sixties and seventies mainly due to mtroductlon of high yielding venlles of nce and wheat, on one hand and acreage expansion under these crops by reclamation of sodlc lands, on the other The addlbonal annual production of nce and wheat on SodlC lands after reclamatIOn IS esbmated to be 5 and 3 t he-I, respectively, after 3rd year of reclamation under farmer's resource constraints The Yield of nce and wheat due to adopllOn of reclamation technology at full eldent In Haryana IS presented in Table 2 It mdlcates that reclamation of sodlc land played Important role In augmenting the agncu~ural production and food secunty of the country Estimates are that, If 1 mlillor, ha SodlC lands have been redal/ned for crop' production so far, about B million tonne food grams are being added annually from thesa lands to the food basket of the country It IS reported that the sodlc land reclamabon has contributed 27% to the total Increase In nce and wheat production In Punjab, 14% In Haryana and 12% In Uttar Pradesh It clearly highlights the Importance of SodlC land reclamation In food grains production of the country

Table 2 Yield obtained In SodlC land after redamation In selected farms of Haryana

Rice Yield Wheat Yield Total yreld Reclama~on year (t he" ) (t ha' ) (t ha" )

1st year 4.0 20 60 2nd year 50 25 7,5 3rd year 50 30 BO

Employment Generation

One of the Important benefits from the sodlc land reclamation is employment opportUnity to the marginal farmers and landless labourers in rural sector Roughly 165 man-days ha' employment could be generated In the first year of reclamation The employment potential through reclamation of sodlc lands IS estimated to 30 man-days ha" In bundlng, levelling and gypsum appllcabon and 94 and 41 days ha" In nce and wheat cultivation, respectively In subsequent years, nearly 135 man-days ha' would be employed for nce-wheat cropping system at farme~s field The potential and achieved labour employment due to reclamation of SodlC land In Haryana farming situation 'IS shown In Table 3 The total employment potential In the 1st year of reclamation at full-fledged level of technology IS esbmated to 214 man-days ha-l Including nce and wheat cultivation whereas 160 man-days ha-' employment could be generated dunng the SUbsequent years In areas With high degree of mechamzauon of agncultural operatlOns at Haryana and Punjab Muatlons It ranges between 207 and 237 man-days ha" In areas With low degree of mechanization of Uttar Pradesh The rough estimates revealed that reclamabon of alkali lands 's annually generating Jobs for about 181000 farmers and landless labourers In Punjab and Haryana whereas nearly 78000 people are getting employment per annum In Uttar Pradesh because of SodlC land reclamation In case of afforestation of alkali lands, roughly 213 man-days ha-' employment can be generated In the form of In,ual establishment work It 's Indeed encouraging that the land once characterIZed as barren and lYing uncultivated because of sodlclty would generate remarkable productive employment after reclamation

Table 3 Potenllal and achieved labour employment due to reclamallon of sodle land

Parbculars

I, Labour demand for reclamation 2 Labour demand for nce cultivation 3 Labour demand for wheat cultivation 4 T oal employment In 1 st year 5 Employment In subsequent years

Estimated man-days ha-l) Potential at full-fledged level Achieved at farmer's of technology field

307

54 30 99 94 61

214 160

41 165 135

Chemical Changes & Nutnent Transformation In SodldPoor Quality Water Imgaled Salls

Family In come /

, f

The,progresslve Improvement of sa~ affected lands has contnbuted significantly to the agncultural development Among the multiple benefits of land reclamation, one of the Important sOeJal benefits IS a continuous Income generation and war against poverty In rural areas The land reclamation programme has not been limrted to merely treatment of salt affected SOils but also emphaslzE.d on proper 5011 and water management pracbces WIth the objective to develop 'a sustainable reclamation and production system It has been reported In a sample survey that before adopting the reclamation technology, the boltom 50% farmers had only 30% share of the lotal Income, wlllch rose to 36% after land reclamallon It Indicates the fact that dissemination of such programmes In a state like Uttar Pradesh IS Important for raising Income and purchaSing power of the rural poor who own salt affected lands and lives In abject poverty Post-project changes triggered significant InCJreases In family Income Annual household income of erstwhile landless households (now marglnaj farmers) has Increased more than 100% Income from reclaimed land constitutes about 44% of Incremental Income for those households who did not have access to a productIVe land before reclamation Due to project intervention, C-class barren lands have come under double crop from no-crop level and B-class mono-cropped lands turned to double cropped nie erstwhile landless labourers are enabled to eam on an average Rs 17,600 per annum from their owned land because of sodlc land reclamation programme Their non-farm Inrome confined mostly to wages, which has also gone up due to combined effect of nse ,n employment days and wage rate The Impact studies showed that after the land reclamation, Sizable growth has been noticed in many agro-based and aUXIliary Industnes such as poultry, dairying, farm machinery workshops, etc these rural Industnes are prOViding a good amount of Income ,to those who are associated WIth these Units dlnectly or Indirectly

Farm Assets and Capital Formation

The farm assets and capital formation Increase remarkably even on parlial adoption of the reclamabOn technology The studies show that farm assets and gross capital formation at different levels of technology adoption In Haryana are qUite encouraging (Table 4) The total capital formallon on technology adopter farms, on an average, was Rs 4,71,000 per farm, out of which 46% was on farm building, 28% on farm machinery, 14% on Irrlgatlon'structures and rest on livestock The gross capital formation was highest on high level of technology and lowest on the low level of technology adoption The capital assets showed an increasing trend WIth Increase In the level of technology adoption, The farm machinery got maxImum emphaSIS at high-level tec/hr\ology adoptIOn, It indicates that SodlC land redamal/on has remarkable favourable Impact on farm assets and capital fonnation, which ultimately enhance the Investment capaCity of the farmers

Table 4 Capital formation at different levels of reclamation on selected farms of Haryana

Technology Levels Gross capital Percentage of total capital (Based on gypsum use) (Rs lfarm) BUilding Machinery Irrigation Livestock

VeryJow «5,75 tha' ) 3,52,000 49 25 15 11 '

low (575-9501 ha' ) 4,73,000 47 28 15 10 Medium (95-1325 t ha") 4,94,000 47 28 14 11 Hrgh (>13251 ha" ) 5,03,000 48 31 13 08

Overall average 4,71,000 48 28 14 10

Resource-~se

The use of Inpul resources Increases tremendously in' the SodlC lands after reclamation The' time seTies analYSIS during sodlc land neclamatlon showed that the use of all the cruCial farm Inputs such as labour, machine, Imgatlon, fertlilzers, etc. Increase slgmficanHy on farme(s endowment (Table 5) The consumption of nitrogenous fertilizer Increases between 77 to 66%, Imgatlon hours 66% In nce and 12% In wheat cultlvatlo~ after land reclamation Machine power Increases between 92 to 117% wheneas human labour ~use nses to 19% In nce culbvation It could be altnbuted to anbcrpated higher productlvily and profitability of the crops despite high Input costs In the later panod Farm production and profitability of the crops could be Increased further through reallocation of the nesources partlcyla~y fertilizer and machme use In nce and wheat crops

land Value

The value of land IS a symbol of prestige In the society to the owner, deCides CJredlt worthiness of the farmer and plays an Important role In decislOn-makmg processes of the farm, The reclamabon of sodlc lands substanbally Increases value of the land due to Increased production potential and source of Income to the

'owner It IS estimated that the average value of sodlc land Increases from Rs 1D,OOO to Rs 2,OD,OOO'ha-l depending on the location and availability of Infrastructure In and around the area The UP Sodlc Lands Reclamabon Project showed tremendous Increment in value of land over a penod of 7 years The value of B+

306

FinanCial Appraisal and Socia-Economic Benefits of Sact·Affected 5011 Redama1lon

class land has Increased from Rs 1,15,000 ha" before reclamation to Rs 1,70,00 ha" after reclamation whereas value of Band C class lands Increased from Rs 55,000 and Rs 30,000 ha" to Rs 1,55,000 and Rs 1,25,00 ha' after reclamation, respectively It shows that value of reclaimed land has gone up by about 46% In case of B+ dass land, 106% In B class and 317% In C class land The reclamation enhances not only the

'value of land but also the SOCIal status of the landowner

Table 5 Changes In resource-use on nee and wheat after SodlC land reclamation (per hal

Rice Crop Wheat Crop Input

Resources

Labour (days) Maclhlne (hours) Irrigation (hours) NItrogen (kg) Zinc (kg)

Poverty alleviation

Inilial . stage

reclamation

69 6

101 64

After 5 years of reclamation

62 13

190 113 24

Imllal reclamallon After 5 years of stage Reclamabon

45 44 12 23 67 75 52 98

4

The sadlC land reclamation programme proVIdes umque opportumty to the rural people for alleViation of poverty, parIJcularty for marg,"al and small fanners, who are bound to struggle for their livelihood and delimited by the ViCiOUS Circle of poverty, i e low Investment" low output - low savings. Project intervention In Uttar Pradesh resulted In decline of partiCipant households below poverty line from 60% to 55 % dunng a short period of 7 years (Table 6) Thus, the SodlC land reclamation programme proved exemplary model for poverty alleViation in the sodiclty..affected areas

Table 6 Status of households before and after SodlC land reclamation

Pre - project status Post - prOJect status Households

Bellow poverty line (%) Above poverty line (%J Landless labourers 88 76 Marginal fanners 84 67 Small fanners 72 33 large fanners 69 26 Overall average 80 55

Qua lity of Life and Literacy

The intervention through land reclamation Increases cropping intensity, crop Yield and employment opportunities. These all have POS~lve Impact on household economy and quality of hfe of the benefiCianes The literacy Improves remarkably over the years in the areas where sodlc land reclamation takes place It has been proved In the selected Villages of Uttar Pradesh after execution of reclamation project The male literacy was Invartably more than female literacy In the project area Irrespective of the category of households The project has provided mIDClmum benefits to schedule costs and erstwhIle landless labourers Male literacy Improved by 7% and female literacy by 9 percent It IS attnbuted to the Increased awareness among people about education The number of clhlldren enrolled at school registered remarkably high as compared to the number registered before reclamation 1M those areas where reclamabon project has launched These facts reflect Impact of land reclamation on vanous important aspects of dally life and deCislon-making capabll~les of the rural people, whlclh have direct poslbve correlabon With the standard of liVing

Envlronmentallmpact

The Important SOCIal Impact of the sodlc land redamatlon IS Improved quality of enVIronment Utilization of rainwater by reducing surface runoff and SOil erosion during rainy season IS the bnghter aspect of reclamabon as about 40% of the totallmgatlon reqUirement of the newly reclaimed areas of nce and wheat IS met from the rainwater conservation, It is ultimately result'"9 to Increase In ground water reclharge and Improvement In the SOil quality II further helps In controll'"9 flood hazards by reducing peak runoff dunng the heavy ralnslonos. Thus by adoption of the sodlc land reclamation technology, the flood hazards minimIZe, recharge to ground water ,"creases and wate~ogglng reduces The combined effect of all these are resulting to considerable environmental Improvement In the area Another Important enVIronmental benefit IS the clhange In landscape after reclamallon of unproductive barren, undulated and unmanaged lands The prope~y managed SOil, water, road, path, vegetation and landscape Improve the overall microclimate of the area

309

11 11 U ~ I II 11 II

~ II -II II

chemical changes & ,nutrient transformation in sodic/poor quality water irrigated soils

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