Depth-wise fractionation of sulphur in cultivated soils of low and mid hills of Himachal Pradesh

Abstract

The current investigation was conducted to study the fractions of sulphur in nine districts of low and mid hills of Himachal Pradesh. For this purpose 31 representative soil sampling sites were selected from nine districts and the soil samples were analyzed for physicochemical properties and different fractions of sulphur (water soluble sulphur, exchangeable sulphur, available sulphur, non-sulphate sulphur, organic sulphur and total sulphur). The results indicated that the total sulphur in soils varied from 98.2 to 470.1 mg kg-1 in surface soil (0-15 cm) and 67.2 to 370.7 mg kg-1 in sub-surface layer (15-60 cm). The organic sulphur varied from 80.5 to 401.1 mg kg-1 in surface and 44 to 306.1 mg kg-1 in sub-surface layer. The water soluble sulphur, exchangeable sulphur, available sulphur and non-sulphate sulphur varied from 1.7 to 9.2, 2.7 to 18.4, 4.5 to 27.6 and 10.2 to 58.9 mg kg-1 respectively in surface soil and 0.5 to 5.4, 1 to 17.7, 3.7 to 23.5 and 12.5 to 50.2 mg kg-1, respectively in sub-surface soil. It was observed during course of study that with increase in the soil depth the content of different fractions of sulphur decreased. These soils had the major part of their total sulphur content in organic form followed by non-sulphate sulphur, available sulphur, exchangeable sulphur and water soluble sulphur. It can be concluded that the soil texture and organic carbon content played a major role in determining the quantity of different fractions of sulphur in these soils.