Effect of Spentwash Application on Potassium Dynamics in Soil

Distillery spentwash contains all nutrients and organic matter and is used in agriculture as a source of plant nutrients and irrigation water. Besides all the nutrients, spentwash contains high amount of potassium (K) also. The effect of different levels and methods of spentwash application on soil potassium dynamics was examined through a field experiment with groundnut ( Arachis hypogea L.) as a test crop. At all stages of groundnut growth, the amounts of water soluble, exchangeable and non exchangeable potassium were greater in soil that received 120 m 3 of spentwash. Results shown that K added through the spentwash exceeded the crop removal (uptake); it initially increases solution K and subsequently increases the K concentration in the exchangeable and non-exchangeable forms through the shifting of equilibrium. The phenomenon of both the fixation of exchangeable K and release of non-exchangeable K play an important role in the dynamics of soil potassium .