Kinetics of Desorption of Ammonium Acetate Extractable Potassium in Entisols

Desorption of potassium with 1M NH₄OAc from four soils of Haryana representing four different geographical locations, namely, aeolian cover, Chautang river basin, and bagar river _basin, and Yamuna river basin, was investigated. Desorption was studied in both KCI treated and untreated soils. In general, the amount of potassium desoroed increased with increase in time of equilibration. The equilibrium in rate of NH₄OAc extractable potassium was attained in about 30 days. Sandy clay loam, having highest amount of non-exchangeable K, released the maximum amount of K, while sandy soil the mtnintiun. Amongst different kinetic equations, viz. Elovich, parabolic diffusion, zero order, first order, and complex first order tested, the complex first order equation was found to be the best to-describe the K desorption kinetics of the soils used. The values of rate constants (k₁ and k₂) were lower in untreated soils than KCI treated Soils.