soil degradation in india: challenges and potential solutions

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WELCOME

DEPARTMENT OF SOIL SCIENCE AND AGRICULTURAL CHEMISTRYINSTITUTE OF AGRICULTURAL SCIENCES

BANARAS HINDU UNIVERSITYVARANASI-221005

Speaker Lokesh Kumar Jat ID.

No. PS-12098

Supervisor Dr. Y.V. Singh

DEPARTMENT OF SOIL SCIENCE AND AGRICULTURAL CHEMISTRYINSTITUTE OF AGRICULTURAL SCIENCES

BANARAS HINDU UNIVERSITYVARANASI-221005

Soil Degradation in India: Challenges and Potential Solutions

Course seminar ON

3

Contents

Soil Degradation : Extent and Distribution in India

Principle types and mechanism of soil degradation Causes of soil degradation in India

A case study on Cost estimation of soil erosion A case study on management of soil erosion in Rajasthan

desert Strategies to mitigate soil degradation

Research results documenting to soil conservation

Drivers of soil erosion

Conclusion

Introduction

4

Introduction• Of India’s (TGA 328.7 Mha), 304.9 Mha comprise the reporting

area with 264.5 Mha being used for agriculture, forestry, pasture and other biomass production

• Soil degradation in India is estimated to be occurring on 147 million hectares (Mha) of land (NBSS&LUP, 2004) out of which >94 Mha degraded by water erosion

• India suffers from deleterious effect of soil erosion with an average soil erosion rate was ~16.0 ton ha−1 year−1, resulting in an annual total soil loss of 5.33 billion tons throughout the country (Pandey et al., 2007)

• Nearly 29% of total eroded soil is permanently lost to the sea, while 61% is simply transferred from one place to another and the remaining 10% is deposited in reservoirs

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ABOUT SOIL DEGRADATION

“The nation that

destroys its soil

destroys itself.”

Franklin D. Roosevelt (1882 - 1945)

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SOIL DEGRADATION?

"Soil degradation, decline in its capacity to support

functions and provide ecosystem services, is caused by

erosion, salinization, elemental imbalance

acidification, depletion of soil organic carbon,

reduction in soil biodiversity, and decline in soil

structure and tilth” (Lal, 2012).

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Soil degradation refers to the processes,

primarily human induced, by which soil

declines in quality and is thus made less fit for

a specific purpose, such as crop production

(FAO, 2011).

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LAND DEGRADATIONv/s

SOIL DEGRADATION

“Soil is a part of Land, thus any deterioration in it’s quality, mass or volume

either singly or in combination, is also

deterioration of Land”

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SOIL DEGRADATION

“Soil degradation is closely linked to poverty in the sense that, as the

degree of degradation increases, crop and animal yields decline and people have both less to eat and less to sell

to support themselves.”Clark & Wallace,2002

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INCREASE IN RURAL

POPULATION

LIMITED LAND

RESOURCES

LAND SHORTAGE

LAND DEGRADATIO

NPOVERT

Y

NON-SUSTAINABLE

LAND MANAGEMENT

PRACTICES

CAUSAL SERIES BETWEEN LAND, POPULATION, POVERTY AND DEGRADATION

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Asia Africa South and central

America

Europe Oceania North America

0

500

1000

1500

2000

2500

3000 2787

1663 1714

796

644

1131

747

494

307218

10496

Total land Degraded land

Mill

ion

Hect

ares

Global estimates of soil degradation

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Table 1: Extent of land degradation in India, as assessed by different organizations

Organizations Assessment Year

Degraded Area (Mha)

National Commission on Agriculture, New Delhi 1976 148.1Ministry of Agriculture-Soil and Water Conservation Division, New Delhi 1978 175.0

Department of Environment, New Delhi 1980 95.0National Wasteland Development Board, New Delhi 1985 123.0

Society for Promotion of Wastelands Development, New Delhi 1984 129.6

National Remote Sensing Agency, Balanagar, Hyderabad 1985 53.3

Ministry of Agriculture, New Delhi (20th ed.) 1985 173.6Ministry of Agriculture, New Delhi (25th ed.) 1994 107.4NBSS&LUP 1994 187.7NBSS&LUP (revised) 2004 146.8National Remote Sensing Agency, Balanagar, Hyderabad

2006 47.22

ICAR, New Delhi 2010 120.4

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Andhra Prad

esh +

Telengan

aGoa

Karnata

kaKera

la

Tamil N

adu

Manipur

Mizorum

Meghalaya

Assam

Arunachal P

radesh

Nagala

ndSik

kimTri

pura

Himach

al Pradesh

Jammu an

d Kashmir

Uttar Prad

esh + Uttara

khand

Delhi

Haryana

Punjab

Bihar + Jh

arkhan

d

West Ben

gal

Union Territ

ories

Gujarat

Rajasth

an

Madhya Pradesh

+ Chhatti

sgarh

Maharash

traOris

sa0

10

20

30

40

50

60

70

80

90

100

15

0.2

7.62.6

5.31.9 1.9 1.2 2.2

4.61 0.20.600000000000001

4.27

15.3

0.1 1.5 1.36.3

2.80.2

8.111.4

26.2

13.1

6.1

54.5

43.939.8

67.1

41 42.6

89.2

53.9

28.2

53.8

60

33

59.9

75

31.6

5255.4

33.2

25.4

36.131

24.8

41.5

33.2

59.1

42.439.3

Total Degraded Area % of Degraded Area to TGA

Fig. State-wise extent of degraded area in India (Mha), Source: NBSS&LUP, 2005 on 1:250,000 scale

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Table 2. Estimates on the annual direct cost of land degradation in India

Parameters NRSA (1990)

ARPU (1990)

Sehgal and Abrol (1994)

Area affected by soil erosion (Mha) 31.5 58.0 166.1

Area affected by salinization, alkalinization and waterlogging (Mha) 3.2 - 21.7

Total area affected by land degradation (Mha) 34.7 58.0 187.7

Cost of soil erosion in lost nutrients (Rs billion) 18.0 33.3 98.3

Cost of soil erosion in lost production (Rs billion) 67.6 124.0 361.0

Cost of salinization, alkalinization andwaterloggingin lost production (Rs billion)

7.6 - 87.6

Total direct cost of land degradation (Rs billion) 75.2 - 448.6

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Area (Mha) affected by various erosion process in India

9416

14

9 67

Water erosionAcidificationFloodingWind ErosionSalanityCombination of Factors

Type of Erosion

NBSS&LUP, 2004 (Total 147 Mha)

ICAR, 2010 (Total 120.4 Mha)

94.9

0.9

3.717.9

2.70.3Water and wind erosion

Water logging

Soil alkalinity/sodicity

Soil acidity

Soil salinity

Mining and industrial waste

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Classes Codes Area (in Mha)Water Erosion

Loss of top soilTerrain deformation

WWt 83.31Wd 10.37

Wind ErosionLoss of top soilLoss of top-soil/terrain deformationTerrain deformation/over blowing

EWt 4.35

Et/Ed 3.24Ed/Eo 1.89

Chemical DegradationSalinizationLoss of nutrients (En) – (Acid soils)

CCs 5.89En 16.03

Physical DegradationWaterlogging

PPw 14.29

OthersIce caps/Rock outcrops/Arid mountain I/R/M 8.38

Total 147.75

Table 3: NBSS&LUP soil Degradation Classes, Derived From 1: 250,000 soil map (2004)

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“Perhaps the most dominant soil degradation processes are soil erosion and organic matter decline.”

B.A. Stewart, R. Lal, and S.A. El-Swaify. Sustaining the Resource Base of an Expanding World Agriculture. In: Soil Management for Sustainability. R. Lal and F.J. Pierce (eds.), 1991.

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SOIL DEGRADATION

NATURALHUMAN -INDUCED

URBAN LAND

•Pollution •Compactio

n•Erosion

INDUSTRIAL LAND

•Soil Compaction•Soil

Contamination•Acid Rain

AGRICULTURAL LAND

PHYSICAL• Pan

formation• Hard-

setting

CHEMICAL• Leterization•Calcification• Leaching/ Illuviation

BIOLOGICAL• Decline in

soil diversity

PHYSICAL•Compaction•Crusting•Water

imbalance•Impeded

erosion•Runoff

CHEMICAL•Acidification•Nutrient depletion•Leaching•Nutrient imbalance•Salanization/

alkanization

BIOLOGICAL•Decline in soil

organic C•Soil biodiversity

reduced•Decrease in biomass

C

Principal types of soil degradation: (i) natural (ii)Human-induced

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2 Primary drivers of soil erosion

Water : non arid areas

Gravity involved in both wind and water erosion (>94 mha area subject to wind and water erosion in India)

Drivers

Wind : arid and semi arid areas

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Process involved in erosion

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Forms of Water Erosion

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soil

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Table 4:Common soil stress and related degradative processes

Stress Principal degradative processes

Heavy load due to extensive mechanization (vehicular traffic)

Physical degradation, eg., crusting, compaction, structural decline and poor soil tilth

High intensity of rain and overland flow, high wind velocity Accelerated erosion by water and wind

High evaporation demand and high salt concentration in the profile

Drought, aridization or desertification, salinization or sodification

Poor internal drainage, and slow surface drainage Soil wetness and anaerobiasis

Intensive cropping Chemical degradation, nutrient imbalance and soil organic matter depletion

Intensive use of agrochemicals and monoculture

Biological degradation, acidification and reduction in soil biodiversity

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1.Overgrazing

2.Deforestation

3.Industrialization

4.Overpopulation (Land Shortage, Land Fragmentation and Poor Economy)

5.Over exploitation/Mining of land

6.Agricultural activities leading to soil degradationi. Low and Imbalanced Fertilizationii. Excessive Tillage and Use of Heavy Machineryiii. Crop Residue Burning and Inadequate Organic Matter Inputsiv. Poor Irrigation and Water Managementv. Poor Crop Rotationsvi. Pesticide Overuse and Soil Pollution

Causes of Soil Degradation

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Causes of Soil Degradation1.Overgrazing

Current position:

Cattle population: 467 Million

Area of pasture land: 11 Mha

Implying an average of 42 animals per hectare

Threshold level: 5 animals per hectare

(Sahay, K.B. 2000)

Too many grazing cattle, sheep, or goats, which can destroy vegetation and as a result, soil is exposed to erosion.

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Causes of Soil Degradation cont......

2. Deforestation

Current position: Per capita forest land in the

country is only 0.08 ha compared to a requirement of 0.47 ha to meet basic needs.

Average rate of soil loss due to wind and water erosion in India is 16.4 tons per hectare annually with an annual total loss of 5.334 billion tons [CSWCRTI Dehradun, 2010] and in US it was 1.725 billion tons in 2007.

Deforestation is both, a type of degradation by itself, and a cause for other types of degradation, principally, water erosion

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Causes of Soil Degradation cont......3. Industrialization

Underground tanks

storage, application of

pesticides, oil and fuel dumping,

leaching of wastes from landfills

or direct discharge of industrial

wastes to the soil.

In industrialized urban regions, pollution can harm the soil of farms and make the land unstable for farming

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4. Overpopulation

Current position: India has • Land area is about 2.5% of global

land• Supports 16% of global human

population and ~20% of livestock population• Average size of land holding

declined from 2.3 ha to 1.3 ha during 1970–2000 with per capita land of 0.32 hectare in 2001

The needs also increase and utilize forests resources. To meet the demands of rapidly growing population, agricultural lands and settlements are created permanently by clearing forests

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5. Over exploitation/Mining of land Negative effects of mining are water scarcity due to lowering of water table, soil contamination, part or total loss of flora and fauna, air and water pollution and acid mine drainage

Mineral Production (Mt) Overburden/Waste (Mt)

Estimated Land Affected (ha)

Coal 407 1493 10,175Limestone 170 178 1704

Bauxite 12 8 123Iron ore 154 144 1544

Others 9 19 -

Table 5. Mineral Production, waste generation and land affected in 2005-06 (Data source: Sahu and Das, 2011).

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Causes of Soil Degradation cont......6. Agricultural activities leading to soil degradation

Current position: India has • Imbalanced consumption ratio of (N:P:K fertilizers)• 6.2:4:1 in 1990–1991 has widened

to • 7:2.7:1 in 2000–2001 and • 5:2:1 in 2009–2010 compared with

• Target ratio is 4:2:1

Agricultural activities and practices can cause land degradation in a number of ways depending on land use, crops grown and management practices adoptedi. Low and Imbalanced Fertilization

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In India, ~500 Mt of crop residues are generated every year and ~ 125 Mt are burned. Crop residue generation is greatest in Uttar Pradesh (60 Mt) followed by Punjab (51 Mt) and Maharashtra (46 Mt)

Ministry of New and Renewable Energy (2009)

ii. Crop Residue Burning and Inadequate Organic Matter Inputs

Residue generation by different crops in India (MNRE, 2009)

Burning of rice residues, a prevalent practice in northwest India

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Excessive tillage coupled with use of heavy machinery for harvesting and lack of adequate soil conservation measures causes a multitude of soil and environmental problems

iii. Excessive Tillage and Use of Heavy Machinery

Less CO2 leaves soil when no-tilledCompaction due to use of heavy

machinery and others

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Expansion of canal irrigation (like the Indira Gandhi Nahar Project, for instance) has been associated with widespread waterlogging and salinity problems in areas, such as in the Indo-Gangetic Plains.

iv. Poor Irrigation and Water Management

Waterlooging and salinity due to poor irrigation management

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Improper crop rotation coupled with lack of proper soil and water conservation measures are important reasons contributing to soil erosion in lands under cultivation

v. Poor Crop Rotations

Table 6: Effect of crop rotation on soil organic matter in soils

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Overuse of chemical fertilizers and pesticides have effects on the soil organisms that are similar to human overuse of antibiotics. Indiscriminate use of chemicals might work for a few years, but after awhile, there aren’t enough beneficial soil organisms to hold onto the nutrients” (Savonen, 1997)

vi. Pesticide Overuse and Soil Pollution

Consumption pattern of pesticides (Aktar et al., 2009)

Once they has been sprayed, it does not disappear completely. Some of it mixes with the water and seeps into the ground. The rest of is absorbed by the soil and plant itself.

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The major outcomes of land degradations are as follows:

Decline in the productive capacity of the soil (temporary or permanent)Decline in the soil “usefulness”.Loss of biodiversityIncreased vulnerability of the environment or people to destruction or crisisAccelerated soil erosion by wind and waterSoil acidification and the formation of acid sulphate soil resulting in barren soilSoil alkalinisation owing to irrigation with water containing sodiumbicarbonate leading to poor soil structure and reduced crop yieldsSoil salinization in irrigated land requiring soil salinity control to reclaim the landSoil water logging in irrigated land which calls for some form of subsurface land drainage to remediate the negative effects.Destruction of soil structure including loss of organic matter.

Consequences of Soil Degradation

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A case study on Cost estimation of soil erosion and nutrient loss from a watershed of the Chotanagpur

Plateau, India (Area- 14 square km, slope - 1% to 5%, annual rainfall –

1300–1500 mm, soil texture -Sandy clay loam)

Gulati and Rai, 2014

1. It was observed that overland flow was greatest in orchard (30.73%) and lowest in vegetable field (15.84%).

2. Soil loss from the field plots ranged between 9 and 37 tonnes/ha during the monsoon months.

3. Nutrient leaching was highest in paddy fields. A strong positive correlation was observed between organic carbon and soil loss (P < 0.01).

4. On an average, 590 kg of macro-nutrients (N, P and K) were lost per hectare during the monsoon season. Approximately INR 8,893 ha–1 (US$ 137 ha–1) would be required to replace this loss through inorganic fertilizers.

5. Agricultural practices in mountain areas should be strengthened with more agroforestry components to promote conservation of soil, water and nutrients.

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Case study :Management of soil erosion in the Rajasthan Desert

What is the Issue?= Desert and semi-desert conditions occur in Rajasthan and there has been advance of the desert and encroachment of sand on fertile lands due to desertification and soil erosion.

There has been a programme of action which includes: 1. Creation of a vegetation belt—five miles wide—along the

western border of Rajasthan.2. Improvement of land-use practices, especially the creation of

shelter belts of trees by cultivators3. A Desert Research Station is being set up at Jodhpur to

investigate the problems of desertification. Research on soils, land-use and afforestation practices would be undertaken at this station.

Planning Commission, GOI

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•Soil Erosion•Nutrient runoff loss•Waterlogging•Degradation•Acidification•Compaction

Negative• Crusting• Organic matter loss• Salinization• Nutrient depletion by

leaching• Toxicant accumulation

• Conservation tillage• Crop rotation• Improved drainage• Residue management• Water conservation• Terracing Positive• Contour farming• Chemical fertilizer use• Organic fertilizer use• Organic fertilizer (Green

manure)• Improved nutrient cycling• Improved system to match

soil climate and cultivars

Soil Productivit

y

Soil Degradation Processes

Soil Conservation Processes

The relationship between soil degradation processes and soil conservation practices

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Soil Erosion Control Water Harvesting (Watershed Approach), Terracing and Other

Engineering Structure Landslide and Mine-spoil Rehabilitation and River Bank Erosion

Control Intercropping and Contour Farming Integrated Nutrient Management and Organic Manuring Reclamation of Acid and Salt Affected Soils and Drainage

(Desalinization) Water Management and Pollution Control Vegetative Barriers and Using Natural Geotextiles, Mulching

and Diversified Cropping Agro forestry Conservation Agriculture (CA) Disaster (Tsunami) Management

Strategies to Mitigate Soil Degradation

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Research results documenting both soil conservation and soil health improvement

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Figure 1. Soil organic C (SOC) stabilization in the 0 to 45 cm soil layer as affected by 32 years of continuous annual fertilization under soybean-wheat cropping in a sandy clay loam soil of the Indian Himalayas

Figure 2. Ratios of labile and recalcitrant pools of total SOC and applied C stabilized in soils by depth after 32 years of cropping with different fertilization (error bars indicate SEm

Integrated Nutrient Management and Soil Carbon Pools

Source: Bhattacharyya et al. (2011)

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Table 7: Effects of balanced fertilization (NPK and NPK + FYM or compost) on C build up

in soils under different cropping systems

Build-up = [(NPK//NPK + FYM – Control)/Control] × 100; Build-up rate = [(NPK//NPK + FYM – Control)/year]; R-M-S, rice-mustard-sesame; R-W-F, rice-wheat-fallow; R-F-B, rice-fallow-berseem; R-W-J, rice-wheat-jute; R-F-R, rice-fallow-rice, FYM, farmyard manure.

(Data source: Mandal et al. [2007]).

CroppingSystem

C Build-Up (%) in Treatments overthe Control Plots

C Build-Up Rate (Mg C ha−1 year−1 )over the Control Plots

NPK NPK + FYM NPK NPK+FYM

R-M-S 51.8 a 55.7 a 1.91 a 2.05 aR-W-F 16.8 c 23.4 c 0.27 b 0.37 c

R-F-B 9.3 d 24.7 c 0.13 c 0.36 c

R-W-J 14.9 c 32.3 b 0.11 c 0.25 d

R-F-R 33.5 b 54.8 a 0.28 b 0.45 b

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Table 8: Runoff and soil loss under different crops on varying slopes at research farm, Bellary (Karnataka)

(Source: CSWCR&TI Annual Report [2009])

Treatments

Runoff (mm) Soil Loss (ton ha−1 )

Sorghum Chickpea Sorghum Chickpea

0.5 1.0 2.0 0.5 1.0 2.0 0.5 1.0 2.0 0.5 1.0 2.0

Slope (%)

With fertilizer 52.3 66.78 94.8 48.71 64.45 84.56 2.45 4.04 5.67 2.01 2.72 4.79

Without fertilizer 63.16 66.85 101.79

49.06 65.64 92.99 2.72 4.79 6.08 2.19 3.31 5.35

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Year Rainfall (mm)Runoff (mm) Soil Loss (ton ha-1 )

BBF FOG BBF FOG

2003 1058.0 163.0 (15.4%) 214.9 (20.3%) 2.0 2.9

2004 798.2 124.0 (15.5%) 183.3 (23.0%) 0.7 1.5

2005 946.0 177 (18.7%) 246 (26.1%) 1.4 3.1

2006 1513.0 502 (33.2%) 873 (57.7%) 3.5 6.4

Table 9: Seasonal rainfall, runoff and soil loss from different land configuration,

broad-bed and furrow (BBF) and flat on grade (FOG)

Note: Values within parentheses indicate the percent of total rainfall

[Data source: Mandal et al. (2013)]

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Table 10. Ameliorative effects of tree plantation on salt affected soils of India

Region Tree SpeciesSoil

Depth (cm)

Original AfterReferenc

espH EC(dSm−1) pH EC

(dSm−1)

KarnatakaAcacia nilotica

(Babul)(age 10 years)

0–15 9.2 3.73 7.9 2.05Basavaraja

et al. [2010]

KarnalEucalyptustereticornis

(age 9 years)0–10 10.06 1.90 8.02 0.63

Mishraet al.

[2003]

Lucknow and

Bahraich in

north India

Terminalia arjuna (Arjun)

0–15 9.60±0.42

1.47±0.45

8.40±0.27 0.31±0.07

Singh andKaur

[2012]

Prosopis juliflora (Kikar)

8.70±0.33 0.42±0.06

Tectona grandis (Teak)

6.15±0.23 0.06±0.006

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Fig. Impacts of conservation agriculture (CA) on soil aggregation in the 0–5 cm

layer in the upper IGP(Source: Bhattacharyya et al. [2013])

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Patchwork ploughing: Australian farmer creates huge geometric artwork to fight soil erosion

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Contour Trenches in Himalayan region

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Appropriate mitigation strategies of the nearly 147 Mha of existing degraded land in the sub-continent of India are of the utmost importance

With changing climate, land degradation is expected to only increase due to high intensity storms, extensive dry spells, and denudation of forest cover.

Combating further land degradation and investing in soil conservation is a major task involving promotion of sustainable development and nature conservation

Sustainable agricultural intensification using innovative farming practices have tremendous potential of increasing productivity and conserving natural resources, particularly by sequestering SOC and improving soil quality.

Novel CA practices include: permanent broad bed with residue retention under maize/cotton/pigeon pea-wheat cropping systems and seasonal tillage alterations under rainfed and rice-based agro-ecosystems.

Conclusion

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For sure, the non-edible (to animals) agricultural residues must not be burnt and should be used for mulching along with growing of cover crops, preferably legumes.

Improved grazing practices, irrigation management, control on urban sprawl and control and management on mining are a few other solutions for preventing land degradation.

Domestic and municipal wastes, sludges, pesticides, industrial wastes, etc. need to be used if possible to close nutrient cycles, but with caution to avoid the possibility of soil pollution.

Future research should focus on enhancing nutrient and water use efficiencies and reduction in the pesticide use under CA.

A well-defined integrated land use policy to include rural fuelwood and fodder grazing is urgently needed at the implementation level

Cont......

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THANK YOU

soil degradation in india: challenges and potential solutions

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