influence of lime and phosphorus application rates on growth of...

Research ArticleInfluence of Lime and Phosphorus Application Rates onGrowth of Maize in an Acid Soil

Peter Asbon Opala

Department of Soil Science Maseno University PO Box 3275-40100 Kisumu Kenya

Correspondence should be addressed to Peter Asbon Opala ptropalayahoocom

Received 24 October 2016 Revised 16 December 2016 Accepted 22 December 2016 Published 11 January 2017

Academic Editor Tibor Janda

Copyright copy 2017 Peter Asbon Opala This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The interactive effects of lime and phosphorus on maize growth in an acid soil were investigated in a greenhouse experiment Acompletely randomized designwith 12 treatments consisting of four lime levels 0 2 10 and 20 t haminus1 in a factorial combinationwiththree phosphorus rates 0 30 and 100 kg haminus1 was used Maize was grown in pots for six weeks and its heights and dry matter yieldwere determined and soils were analyzed for available P and exchangeable acidity Liming significantly reduced the exchangeableacidity in the soils The effect of lime on available P was not significant but available P increased with increasing P rates Therewas a significant effect of lime P and P by lime interactions on plant heights and dry matter Without lime application dry matterincreased with increasing P rates but with lime dry mattes increased from 0 to 30 kg P haminus1 but declined from 30 to 100 kg P haminus1The highest dry matter yield (138 g potminus1) was obtained with a combined 2 t haminus1 of lime with 30 kg P haminus1 suggesting that limeapplication at low rates combined with moderate amounts of P would be appropriate in this soil

1 Introduction

The problem of acid soil infertility in the tropics has beenrecognized for a long time [1 2] In acid soils with pH lt55 the solubility of aluminium increases to toxic levels thatseverely restrict root systems and reduce plant growth [3 4]In addition phosphorus reacts with iron and aluminiumin soil solution under acidic conditions to form insolublephosphates hence reducing its availability to plants [5] Phos-phorus deficiency often therefore occurs simultaneouslywith aluminium toxicity in these soils [6] Efforts to amelio-rate the deleterious effects of soil acidity must therefore beaccompanied by measures to increase available phosphorusin soils

Addition of lime to agricultural acid soils has been widelyadopted as an amelioration strategy for many years as ameans of improving crop production [7 8] but is rarelyused in western Kenya Failure to use lime together withthe increased use of acidifying fertilizers such as urea anddiammonium phosphate which are used to correct N and Pdeficiencies has resulted in a marked increase in acidity ofmany of these soils [9] Changes in soil pH brought aboutby liming may have profound effects on the availability of

many elements absorbed by crops Liming increases soil pHand therefore eliminates aluminium toxicity at pH gt 55 byprecipitating Al thus making it unavailable for plant uptake[10] It also improves Ca supply and Mo availability andensures optimal bacterial nitrogen fixation [11] But its effecton availability of P is controversial [12]

Conflicting reports suggest that the prior liming of highlyweathered acid soils can result in an increase a decrease or nochange in the availability of applied phosphate These effectsappear to be dependent on the rates of lime and P fertilizerapplied and their interactions [13] For example at high limerates the soil pH increases to gt6 and the soluble P forms acomplex with Ca and consequently P availability is decreased[14] while low lime rates are insufficient to eliminate solubleAl and Fe which fix P at low pH Appropriate combination oflime and P is therefore an important strategy for improvingcrop growth in acid soils [15] There is however paucityof information on interactive effects of lime and phosphatefertilizers on crop performance in western Kenya and thislimits the ability of farmers to make informed decisions onthe appropriate rates of lime and P fertilizer to be combinedThe objective of this study was therefore to investigatethe interactive effects of lime and phosphate fertilizer on

HindawiAdvances in AgricultureVolume 2017 Article ID 7083206 5 pageshttpsdoiorg10115520177083206

2 Advances in Agriculture

Table 1 Initial soil physical and chemical characteristics (0ndash20 cm)at Maseno University

Soil parameter ValuepH (H

2O)

Exchangeable acidityTotal NOrganic CBicarbonate extractable PExchangeable KExchangeable CaExchangeable MgClaySandSilt

5304 cmol kgminus120 g kgminus1168 g kgminus135mg kgminus103 cmol kgminus142 cmol kgminus114 cmol kgminus1

365422213

Table 2

Treatmentnumber Treatment combinations

123456789101112

0 t haminus1 lime 0 P kg haminus10 t haminus1 lime 30 kg P haminus10 t haminus1 lime 100 kg P haminus12 t haminus1 lime 0 kg P haminus12 t haminus1 lime 30 kg P haminus12 t haminus1 lime 100 kg P haminus110 t haminus1 lime 0 kg P haminus110 t haminus1 lime 30 kg P haminus110 t haminus1 lime 100 kg P haminus120 t haminus1 lime 0 P kg P haminus120 t haminus1 lime 30 P kg P haminus120 t haminus1 lime 100 kg P haminus1

exchangeable acidity P availability and maize growth in anacid soil of western Kenya

2 Materials and Methods

21 Experimental Site and Soil A greenhouse pot experimentwas conducted from March to April 2016 at Maseno Univer-sity (0∘001015840173610158401015840S and 34∘361015840016210158401015840E) in western Kenya Thesoil used in the study was a Ferralsol whose initial propertieswere determined before the establishment of the experimentand are presented in Table 1 The soil was generally welldrained clay loam acidic and low in available P

22 Experimental Design and Management The soil (0ndash20 cm) used in the studywas collected randomly fromvariousspots at the Maseno University farm and bulked It was air-dried sieved through a 4mm mesh and applied in all thepots at a rate 4 kg of soil potminus1 These pots consisted of theexperimental units There were twelve treatments consistingof four levels of lime (0 2 10 and 20 tonsha) in a factorialcombination with three rate of P (0 30 and 100 kg P haminus1)(Table 2) replicated thrice in a completely randomized design

A burnt lime material with 925 calcium carbonate(CaCO

3) equivalent and ground to pass through a 025mm

sieve was used in this study Triple superphosphate (46P2O5) was used to supply P Calcium ammonium nitrate and

muriate of potash were applied to all the treatments at therate of 60 kg haminus1 to supply N and K which are often limitingin these soils All the fertilizers and lime were incorporatedand thoroughly mixed with the soil at the time of plantingTwo maize seeds were planted per pot and later thinned toone at one week after emergence Soil moisture content wasmaintained at around field capacity by regular watering

23 Data Collection Soil was sampled six weeks after plant-ing (WAP) from each treatment and analyzed for exchange-able acidity and available phosphorus using standard pro-cedures as described by [16] Exchangeable acidity wasextracted using unbuffered 1MKCl In brief 25ml of 1MKClwas added to 10 g of air-dry soil and shaken for 10 minuteson a reciprocal shaker and then allowed to stand for 30minutes The contents were filtered and the soil leachedwith 5 successive 25ml aliquots of 1MKCl The filtrate wastitrated with 01MNaOH to determine the exchangeableacidity (H+ and Al3+) in the extract [16] The available Pwas determined by the Olsen method [17] which has beenreported to correlate well with maize yields in similar soilsin western Kenya [18] The method consisted of extractingsoil P with 05MNaHCO

3(pH 85) using a soil extractant

ratio of 1 20The samples were shaken on a reciprocal shakerfor 30 minutes and filtered through a Whatman number5 filter paper and the P in the filtrate was determinedcolorimetrically at 880 nm Plant heights were determinedat 4 and 6 WAP while the dry weight was determined afterharvesting at 6 WAP by oven drying at 70∘ Celsius to aconstant weight

24 Statistical Analysis All the generated data were subjectedto analysis of variance (ANOVA) using Genstat statisticalprogram and the least significant difference between means(LSD) used to separate the treatment means at statisticalsignificance level of p le 005

3 Results and Discussion

31 Exchangeable Acidity There was no significant inter-action between lime and phosphorus application rates onexchangeable acidity (Table 3) The effect of phosphorus wasalso not significant This is inconsistent with other studiesthat have reported that P can reduce exchangeable acidity byprecipitating the Al in solution [19] The rates of P used insuch studies were however much higher than in the presentstudy where the rates of P used are likely to have been toolow to achieve this effect Application of lime irrespective ofthe rate used significantly reduced the exchangeable aciditycompared to the control This is to be expected because limeis known to increase the soil pH hence precipitating Al asAl(OH)

3[20 21]This has the effect of reducing exchangeable

aciditywhich comprisesAl3+ andH+ However exchangeableacidity among the lime treatments did not differ significantlyIt is likely that all the Al was precipitated with application oflime even at the lowest rate and the exchangeable acidity that

Advances in Agriculture 3

Table 3 Exchangeable acidity (Cmolkgminus1)

Lime rate t haminus1 Phosphorus rates kg haminus1 Means0 30 100

0 042 038 043 0412 015 016 013 01410 014 012 012 01320 015 012 013 013Means 020 020 020 020F probabilities for ANOVA for phosphorus and lime ratesLime lt0001Phosphorus 0873Lime times phosphorus 0996LSDLime 00924Phosphorus 00800Lime times phosphorus 01600

Table 4 Available phosphorus (mg kgminus1)


0 370 411 878 5532 792 818 942 85110 336 649 1377 78720 497 683 1262 814Means 499 640 1115 751F probabilities for ANOVA for phosphorus and lime ratesLime 0239Phosphorus lt0001Lime times phosphorus 0389LSDLime 3210Phosphorus 2780Lime times phosphorus 5561

wasmeasured was therefore due to only H+ Hence theremaybe no need to apply lime at rates higher than 2 t haminus1 in thissoil

32 Available Phosphorus The available P ranged from 370(control with no P and lime input) to 1377mg kgminus1(10 t haminus1of lime combined with 100 kg P haminus1) (Table 4) There wasno significant interaction between lime and phosphorusapplication rates on available PThe effect of lime was also notsignificant but available P increased with increasing P ratesfor a given lime rate Generally the available P levels werelow even after application of fertilizers and lime thereforeconfirming that P was deficient in this soil and that some ofthe applied P could also have been fixed since most of thesoils in western Kenya are known to have high P fixationcapacities [22 23] It was only at high rates of P application

Table 5 Plant height (cm) at four weeks after planting


0 501 727 826 6852 793 921 519 74410 889 645 733 75620 610 683 679 657Means 685 744 689F probabilities for ANOVA for phosphorus and lime ratesLime 0032Phosphorus 0188Lime times phosphorus lt0001LSDLime 739Phosphorus 640Lime times phosphorus 1280

Table 6 Plant height (cm) at six weeks after planting


0 633 956 1031 8742 993 1144 643 92710 1101 836 956 96420 807 876 887 857Means 884 953 880 905F probabilities for ANOVA for phosphorus and lime ratesLime 0040Phosphorus 0068Lime times phosphorus lt0001LSDLime 800Phosphorus 693Lime times phosphorus 1385

(100 kg haminus1) with high lime rates of 10 or 20 t haminus1 that theavailable P exceeded the critical value of 10mg kgminus1 that hasbeen reported to be adequate for maize production [24]

33 Plant Heights and Dry Weight Plant heights at 4 WAPranged from 501 cm (no lime no P) to 921 cm when 2 t haminus1of lime was applied with 30 kg P haminus1 (Table 5) There wasa significant interaction between lime and P When no limewas applied plant heights increased with increasing P ratesbut when lime was applied plant heights increased from 0 to30 kg P haminus1 but declined from 30 to 100 kg haminus1 P A similartrend in plant heights was observed at 6 WAP (Table 6)

The results of the effects of treatments on dry weight ofmaize plants are presented in Table 7The effect of lime P andPby lime interactions on dryweightwas significant Averaged


Table 7 Dry weight (grams potminus1)



across all lime rates the highest drymatter yield was obtainedwith 30 kg P haminus1 while averaged across all P rates the highestdry matter yield was obtained with 2 t haminus1 of lime Thetrend in dry matter yield was similar to that of plant heightsat 6 WAP whereby when no lime was applied dry matterincreased with increasing P rates but when lime was applieddrymatter increased from 0 to 30 kg P haminus1 but declined from30 to 100 kg haminus1 P Application of lime at 10 and 20 t haminus1could have resulted in overliming which has been reported toreduce crop yields due to lime induced P and micronutrientdeficiencies [15 25] In the present study however high ratesof lime did not decrease the available P compared to controlwith no lime input and hence the likely cause of the lowyields at high lime rates was micronutrient deficiencies Thisis likely to have been exacerbated at high rates of Pwhich havealso been reported to aggravate Zn deficiencies in maize [26]The observed increase in dry matter yield with increasing Prate in treatments with no lime application confirmed thatP was limiting factor to maize growth in this soil Similarresponses to application of P fertilizers on P-deficient soils inwestern Kenya have been reported by other researchers [27ndash29] thus making the region ideal for P replenishment [22]Aluminium toxicity is however not likely to have been amajorproblem because the exchangeable acidity of the soil wasbelow the 100 cmolkgminus1 critical level for soils to have acidityproblem according to [30] The observed positive effect oflime on maize growth was therefore likely due to its effectin increasing the pH and therefore increasing availability ofmost nutrients to maize rather than its ability to amelioratealuminium toxicity

4 Conclusions and Recommendations

The exchangeable acidity levels in the soil were low and Altoxicity is therefore unlikely to be a major factor limitingmaize growth in this soil However liming is likely to haveincreased the pH to levels conducive for availability of most

nutrients and hence its positive effect on maize growth Theavailable P was also low and was likely a limiting factor formaize growth in this soil The effect of lime P and P bylime interactions on dry weight was significant The highestdry matter yield was obtained with 2 t haminus1 of lime appliedwith 30 kg P haminus1 The trend in dry matter yield was similarto that of plant heights whereby when no lime was applieddry matter increased with increasing P rates but when limewas applied dry matter increased from 0 to 30 kg P haminus1 butdeclined from 30 to 100 kg haminus1 P Lime application at lowrates combined with moderate amounts of P is thereforerecommended for soils in the study area

Competing Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The author thanks Mercy Korir for the management of theexperiment and data collection and Dickens Ondigo forassisting in soil analysis The author is grateful to MasenoUniversity for providing the greenhouse and laboratoryfacilities

References

[1] P A Sanchez Properties andManagement of Soils in the TropicsJohn Wiley amp Sons New York NY USA 1976

[2] A Wild ldquoPlant nutrients in soil phosphaterdquo in Russellrsquos SoilConditions and Plant Growth A Wild Ed pp 695ndash742 JohnWiley amp Sons New York NY USA 1988

[3] H Marschner Mineral Nutrition of Higher Plants AcademicPress London UK 1995

[4] H Matsumoto ldquoCell biology of aluminium toxicity and toler-ance in higher plantsrdquo International Review of Cytology vol 200pp 1ndash46 2000

[5] P A Sanchez and G Uehara ldquoManagement considerations foracid soils with high phosphorus fixation capacityrdquo inThe role ofP in agriculture F E Khasawneh C R Dinauer E C Sampleand E J Kamprath Eds pp 471ndash514 American Society ofAgronomy Madison Wis USA 1980

[6] H Liao H Wan J Shaff X Wang X Yan and L V KochianldquoPhosphorus and aluminum interactions in soybean in relationto aluminum tolerance Exudation of specific organic acidsfrom different regions of the intact root systemrdquo Plant Physi-ology vol 141 no 2 pp 674ndash684 2006

[7] R J Haynes ldquoLime and phosphate in the soil-plant systemrdquoAdvances in Agronomy vol 37 pp 249ndash315 1984

[8] B J Scott A M Ridley and M K Conyers ldquoManagement ofsoil acidity in long-term pastures of south-eastern Australia areviewrdquo Australian Journal of Experimental Agriculture vol 40no 8 pp 1173ndash1198 2000

[9] P A Opala J R Okalebo and C Othieno ldquoComparisonof effects of phosphorus sources on soil acidity availablephosphorus and maize yields at two sites in western KenyardquoArchives of Agronomy and Soil Science vol 59 no 3 pp 327ndash339 2013


[10] C Merino-Gergichevich M Alberdi A G Ivanov and MReyes-Dıaz ldquoAl3+-Ca2+ interaction in plants growing in acidsoils Al-phytotoxicity response to calcareous amendmentsrdquoJournal of Soil Science and Plant Nutrition vol 10 no 3 pp 217ndash243 2010

[11] S Bambara and P A Ndakidemi ldquoThe potential roles of limeand molybdenum on the growth nitrogen fixation and assim-ilation of metabolites in nodulated legume a special referenceto Phaseolus vulgaris Lrdquo African Journal of Biotechnology vol9 no 17 pp 2482ndash2489 2010

[12] R J Haynes ldquoEffects of liming on phosphate availability in acidsoilsrdquo Plant and Soil vol 68 no 3 pp 289ndash308 1982

[13] M E Sumner and M P W Farina ldquoPhosphorus interactionswith other nutrients and lime in field cropping systemsrdquo inAdvances in Soil Science vol 5 pp 201ndash236 Springer NewYorkNY USA 1986

[14] N K Fageria ldquoResponse of rice cultivars to liming in certadosoilrdquo Pesquisa Agropecuaria Brasileira Brasilia vol 19 pp 883ndash889 1984

[15] N K Fageria F J P Zimmermann and V C Baligar ldquoLimeand phosphorus interactions on growth and nutrient uptakeby upland rice wheat common bean and corn in an OxisolrdquoJournal of Plant Nutrition vol 18 no 11 pp 2519ndash2532 1995

[16] J M Anderson and J S I Ingram Tropical Soil Biologyand Fertility A Handbook of Methods CAB InternationalWallingford UK 1993

[17] S R Olsen C V Cole F S Watanabe and L A DeanldquoEstimation of available phosphorus in soils by extractionwith sodium bicarbonate USDA Agriculture United Statesdepartment of agriculture in cooperation with the Coloradoagricultural experiment stationrdquo Circular vol 939 pp 1ndash191954

[18] R O Nyambati and P A Opala ldquoThe effect of minjingu phos-phate rock and triple superphosphate on soil phosphorusfractions and maize yield in Western Kenyardquo ISRN Soil Sciencevol 2014 Article ID 920541 8 pages 2014

[19] T Iqbal P Sale and C Tang ldquoPhosphorus ameliorates alu-minium toxicity of Al sensitive wheat seedlingsrdquo in Proceedingsof the 19th World Congress of Soil Science Soil Solutions for aChanging World pp 92ndash95 Brisbane Australia August 2010

[20] N V Hue ldquoResponses of coffee seedlings to calcium andzinc amendments to two Hawaiian acid soilsrdquo Journal of PlantNutrition vol 27 no 2 pp 261ndash274 2004

[21] E F Caires I C Feldhaus G Barth and F J Garbuio ldquoLimeand gypsum application on the wheat croprdquo Scientia Agricolavol 59 no 2 pp 357ndash364 2002

[22] G Nziguheba S Zingore J Kihara et al ldquoPhosphorus in small-holder farming systems of sub-Saharan Africa implications foragricultural intensificationrdquoNutrient Cycling in Agroecosystemsvol 104 no 3 pp 321ndash340 2016

[23] P O Kisinyo C O Othieno S O Gudu et al ldquoImmediateand residual effects of lime and phosphorus fertilizer on soilacidity and maize production in Western Kenyardquo ExperimentalAgriculture vol 50 no 1 pp 128ndash143 2014

[24] J R Okalebo K W Gathua and P L Woomer LaboratoryMethods of Soil and Plant Analysis A Working Manual TSBF-CIAT SACRED Africa KARI SSEA Nairobi Kenya 2ndedition 2002

[25] D K Friesen A S Juo and M H Miller ldquoLiming and lime-phosphorus-zinc interactions in two nigerian ultisols I Inter-actions in the soil1rdquo Soil Science Society of America Journal vol44 no 6 p 1221 1980

[26] S Drissi A Houssa A Bamouh J Coquant and M BenbellaldquoEffect of zinc-phosphorus interaction on corn silage grown onsandy soilrdquo Agriculture vol 5 no 4 pp 1047ndash1059 2015

[27] J S Ademba J K Kwach A O Esilaba and S M Ngari ldquoTheeffects of phosphate fertilizers and manure on maize yields inSouth Western Kenyardquo East African Agricultural and ForestryJournal vol 81 no 1 pp 1ndash11 2015

[28] P A Opala P O Kisinyo and R O Nyambati ldquoEffects ofTithonia diversifolia farmyardmanure and urea and phosphatefertiliser application methods on maize yields in westernKenyardquo Journal of Agriculture and Rural Development in theTropics and Subtropics vol 116 no 1 pp 1ndash9 2015

[29] F L Ahmat J N Mugwe S K Kimani and J P Gweyi-Onyango ldquoMaize response to Tithonia diversifolia and rockphosphate application under two maize cropping systems inKenyardquo Journal of Applied Biosciences vol 79 pp 6983ndash69912014

[30] A Mohammed A U Dikko M Audu and T MohammedldquoEffects of organic and inorganic soil amendments on soilreaction exchangeable bases and cation exchange in sudansavanna soils of Nigeriardquo Nigerian Journal of Agriculture Foodand Environment vol 12 pp 95ndash103 2016

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Table 1 Initial soil physical and chemical characteristics (0ndash20 cm)at Maseno University

Soil parameter ValuepH (H

2O)

Exchangeable acidityTotal NOrganic CBicarbonate extractable PExchangeable KExchangeable CaExchangeable MgClaySandSilt

5304 cmol kgminus120 g kgminus1168 g kgminus135mg kgminus103 cmol kgminus142 cmol kgminus114 cmol kgminus1

365422213

Table 2

Treatmentnumber Treatment combinations

123456789101112

0 t haminus1 lime 0 P kg haminus10 t haminus1 lime 30 kg P haminus10 t haminus1 lime 100 kg P haminus12 t haminus1 lime 0 kg P haminus12 t haminus1 lime 30 kg P haminus12 t haminus1 lime 100 kg P haminus110 t haminus1 lime 0 kg P haminus110 t haminus1 lime 30 kg P haminus110 t haminus1 lime 100 kg P haminus120 t haminus1 lime 0 P kg P haminus120 t haminus1 lime 30 P kg P haminus120 t haminus1 lime 100 kg P haminus1

exchangeable acidity P availability and maize growth in anacid soil of western Kenya

2 Materials and Methods

21 Experimental Site and Soil A greenhouse pot experimentwas conducted from March to April 2016 at Maseno Univer-sity (0∘001015840173610158401015840S and 34∘361015840016210158401015840E) in western Kenya Thesoil used in the study was a Ferralsol whose initial propertieswere determined before the establishment of the experimentand are presented in Table 1 The soil was generally welldrained clay loam acidic and low in available P

22 Experimental Design and Management The soil (0ndash20 cm) used in the studywas collected randomly fromvariousspots at the Maseno University farm and bulked It was air-dried sieved through a 4mm mesh and applied in all thepots at a rate 4 kg of soil potminus1 These pots consisted of theexperimental units There were twelve treatments consistingof four levels of lime (0 2 10 and 20 tonsha) in a factorialcombination with three rate of P (0 30 and 100 kg P haminus1)(Table 2) replicated thrice in a completely randomized design

A burnt lime material with 925 calcium carbonate(CaCO

3) equivalent and ground to pass through a 025mm

sieve was used in this study Triple superphosphate (46P2O5) was used to supply P Calcium ammonium nitrate and

muriate of potash were applied to all the treatments at therate of 60 kg haminus1 to supply N and K which are often limitingin these soils All the fertilizers and lime were incorporatedand thoroughly mixed with the soil at the time of plantingTwo maize seeds were planted per pot and later thinned toone at one week after emergence Soil moisture content wasmaintained at around field capacity by regular watering

23 Data Collection Soil was sampled six weeks after plant-ing (WAP) from each treatment and analyzed for exchange-able acidity and available phosphorus using standard pro-cedures as described by [16] Exchangeable acidity wasextracted using unbuffered 1MKCl In brief 25ml of 1MKClwas added to 10 g of air-dry soil and shaken for 10 minuteson a reciprocal shaker and then allowed to stand for 30minutes The contents were filtered and the soil leachedwith 5 successive 25ml aliquots of 1MKCl The filtrate wastitrated with 01MNaOH to determine the exchangeableacidity (H+ and Al3+) in the extract [16] The available Pwas determined by the Olsen method [17] which has beenreported to correlate well with maize yields in similar soilsin western Kenya [18] The method consisted of extractingsoil P with 05MNaHCO

3(pH 85) using a soil extractant

ratio of 1 20The samples were shaken on a reciprocal shakerfor 30 minutes and filtered through a Whatman number5 filter paper and the P in the filtrate was determinedcolorimetrically at 880 nm Plant heights were determinedat 4 and 6 WAP while the dry weight was determined afterharvesting at 6 WAP by oven drying at 70∘ Celsius to aconstant weight

24 Statistical Analysis All the generated data were subjectedto analysis of variance (ANOVA) using Genstat statisticalprogram and the least significant difference between means(LSD) used to separate the treatment means at statisticalsignificance level of p le 005

3 Results and Discussion

31 Exchangeable Acidity There was no significant inter-action between lime and phosphorus application rates onexchangeable acidity (Table 3) The effect of phosphorus wasalso not significant This is inconsistent with other studiesthat have reported that P can reduce exchangeable acidity byprecipitating the Al in solution [19] The rates of P used insuch studies were however much higher than in the presentstudy where the rates of P used are likely to have been toolow to achieve this effect Application of lime irrespective ofthe rate used significantly reduced the exchangeable aciditycompared to the control This is to be expected because limeis known to increase the soil pH hence precipitating Al asAl(OH)

3[20 21]This has the effect of reducing exchangeable

aciditywhich comprisesAl3+ andH+ However exchangeableacidity among the lime treatments did not differ significantlyIt is likely that all the Al was precipitated with application oflime even at the lowest rate and the exchangeable acidity that



























Competing Interests


Acknowledgments


References


































Journal of




Agronomy





Microbiology




Volume 2014


















































Competing Interests


Acknowledgments


References


































Journal of




Agronomy





Microbiology




Volume 2014
















































Journal of




Agronomy





Microbiology




Volume 2014
























influence of lime and phosphorus application rates on growth of...

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