Effect of P Soueces on the Sulfur Sorption Behavior in Alfisols under Groundnut

Abstract

Sorption phenomenon plays relevant role in the estimation of the solubility, availability, mobility and tendency of ion pollution of the environment. A field experiment was laid out in RBD with three replications and seven treatments using soluble and insoluble sources of phosphorus at different combination and lime during 2014 and 2015 to study their effect on the silfur sorption behavior under groundnut cropping system in Alfisols. Sulfate sorptivity was studied with shaking three grams soil for 24 h with 15 ml solution of K2SO4 varying in SO4 –concentration from (0, 25, 50, 75, 100, 125 and 150 μg S g-1 of soil) in a 50 ml centrifuge tubes at 25oC for 2 h. Sorption data were fitted in linear, Langmuir and Freundlich equations and sorption parameters especially sorption maximum (b or Smax), affinity constant (k), maximum buffering capacity (MBC), distribution coefficient (kf), sorption intensity (n), S (kd) and Gibbs free energy (DG0) were calculated. In general, sulfate sorption process was favorable, spontaneous, exothermic and controlled by dissociative mechanism.