Forms of soil acidity and the distribution of DTPA-extractable micronutrients in some soils of West Bengal (India)

摘要

The distribution of the DTPA- (Fe~(2+), Mn~(2+), Cu~(2+) and Zn~(2+)) in different pedons under Terai situations of West Bengal (India) was found to be governed by the forms of soil acidity. The pH and the organic carbon in soils had the major contributions towards the variation in extractable cations. The exchangeable Al~(3+) and total acidity contributed to the variation of extractable Fe~(2+), Mn~(2+) and Cu~(2+), while all forms of acidity except non-exchangeable form accounted for the availability of Zn~(2+) in soil solution. The different forms of acidity of the soils were quite comparable, although, the contribution of exchangeable acidity to the total potential acidity was low. The availability of nutrients varied with the soil depth and with different forms of acidity under the Terai situations of West Bengal. Significant correlations of extractable acidity and total potential acidity with the extractable Cu~(2+) and Zn~(2+) were observed for the given soils. The distribution of the formsof acidity with depth of soils varied on account of the changing accumulation of exchangeable bases at different depths in soils.