Potassium release kinetics was investigated in soils drawn from plots of a long term fertilizer experiment that had been receiving different rates of K. Non exchangeable K release was higher in soils that were receiving organic and inorganic fertilizers than the soils not dressed with K. The amount of non exchangeable K release was faster initially and it slowed down afterwards. To understand the mechanism of K release, data were fitted to various mathematical models, out of these models parabolic diffusion equation was the best to describe the reaction rates of K release followed by Elovich equation. The initial curvilinear response suggested that film diffusion and latter linear response indicated that intra-particle diffusion were the rate controlling processes. The magnitude of K release rate coefficients suggested medium rates of non exchangeable K release.