Kinetics of Potassium Release in Ammonium Acetate in Some Soils of Semi-arid and Humid Regions

Kinetics of K release by M NH₄OAc was studied with an alkaline soil (Ustochrept, Hisar) from semi-arid region and two acidic soils (paleudult, Bokajall; Ochraqualf, Titabar) from humid region. Kinetics of K release was described, using Elovich, parabolic diffusion, first order diffusion and zero order equations. The equilibrium of K release from these soils in NH₄OAc solution took about six weeks. The rate of release of K gradually decreased with time. The K-release data from these soils were best described by parabolic diffusion equations suggesting diffusion controlled release of K from soil minerals.