Study of physiological lime requirement of acid soils / Derek Yule Pariat
Material type:
TextSeries: [Soil Science and Agricultural Chemistry, School of Natural Resource Management]Publication details: Umiam : CPGS,CAU, c2011Description: [24] , 75p.: ill., some colSubject(s): DDC classification: - 631.42 PAR
| Item type | Current library | Collection | Call number | Status | Barcode | |
|---|---|---|---|---|---|---|
MSc Thesis
|
CPGS | Natural Resource Management | 631.42 PAR (Browse shelf(Opens below)) | Not for loan | TH026 |
Abstract:
A pot experiment was conducted to study the physiological lime requirement of acid soils to eliminate the Al toxicity equivalent to extractable Al for the test crop wheat.Eight bulk soil samples representing the major landuses of hill agriculture of Ri Bhoi district, Meghalaya were used to grow the test crop. Soils were limed equivalent to Al removed by different extractants viz. 1 M KCI, 1 N NH?OAc (pH-4.8), 0.2 M LaC1?, 0.33M LaC1?, 0.2 M CuCl? and 0.5 M CuCl?. Among the extractants, 0.5 M CuC? extracted more quantity of Al as compared to other extractants. The best extractant which could predict the optimum shoot and root yield of wheat was found to be 0.2 M LaCl?. P content and uptake in wheat increased with liming but was depressed to some extent by the lime rate predicted by 0.5 M CuCl?. K concentration and uptake increased only in the treatments based on 1 M KCI and 1 N NH?OAc and decreased significantly with higher rate of lime additions based on other extractants. However, Ca content and uptake were augmented by increasing Iime rates. Soil pH, exchangeable Ca, ECEC, % base and % Ca saturations increased significantly with increased levels of lime, whereas exchange acidity, exchangeable Al and % Al saturation decreased drastically. The lime rates based on 0.2 M LaCl?and 0.33 M LaCl? increased soil pH to around 5.5 irrespective of soils and reduced % Al saturation to 2.56% and 1.62%, respectively. Soil pH reflected significant negative correlation with exchange acidity, exchangeable Al and % Al saturation but was positively correlated with exchangeable Ca, ECEC, % base and % Ca saturations. The critical limit of soil pH for shoot and root growth of wheat was found to be 5.3 and 5.2, respectively. The critical values of exchange acidity, exchangeable AI, % Al saturation and % base saturation of ECEC were 1.0 [cmol (p+) kg-�], 0.75 [cmol (p+) kg-�], 10% and 66%, respectively which can be used as lime requirement indices for the acid soils of Meghalaya to optimise wheat.
Includes bibliographical references.
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