College of Agriculture, O.U.A.T., Chiplima, Sambalpur, Orissa, 768025
*Corresponding author
1Present address: Department of Soil Science and Agricultural Chemistry, Orissa University of Agriculture and Technology, Bhubaneswar, Orissa, 751003.
Sulphate adsorption characteristics of the surface soils and sub-soils of five Alfisols of the state were studied. Adsorption of SO42− was higher in the sub-soils than in the surface soils which was attributed to higher clay, free Fe2O3, exchangeable Ca2+ + Mg2+ and lower organic matter contents in the former than in the latter. Free Fe2O3 had the dominant role in SO42− adsorption, followed by clay and exchangeable Ca2+ + Mg2+. These three factors alongwith free A12O3, pHw and organic carbon jointly contributed 99.2 to 99.9 per cent of variations in SO42− adsorption at different levels of SO42−-S added. Equilibrium buffering capacity and maximum buffering capacity for SO42−-S increased, whereas supply parameter of SO42−-S decreased from surface to the sub-soils.
Initial mass sulphate adsorption, Freundlich, Langmuir and Temkin constants, buffering capacity, supply parameter of sulphate
