Potassium Release Kinetics in Potato Growing Alluvial Soils of North Western India

Potassium (K) release and kinetics were studied in soils of north western India varying in soil properties. Mathematical equations were tested for their applicability to describe K release in the alluvial soils. The major portion of total K was released within 1 h of the reaction. The initial rapid K release was followed by a slower rate of K release. The linear equation adequately described the K release kinetics. The next best fit to satisfactorily describe the reaction rates of K release was the first order equation. There existed two separate first order equations indicating different rates of K release. Soils having higher native potassium and clay released higher amounts of K and at a faster rate. However, the first order equation showed that the faster rate of reaction might be inhibited by higher amounts of clay, probably because of the restrictive properties of illites.