Effect of Water Ionic Strength on Potassium Desorption for Some Calcareous Soils in Nineveh Province

Abstract

A laboratory study was conducted to determine potassium desorption behavior from ex change- able and non-exchangeable phases by using miscible displacement technique for disturbed soil columns sampled from two locations in Mosul at northern of Iraq which were classified within soil great group (Calcid) for ten continuous irrigation cycles to study effect of flow time of two qualities of water differ in their ionic strength on rate and capacity of potassium desorption and diffusion from soils. Results showed higher values of accumulative desorbed K+ by sulfuric water, a high significant correlation of flow time on K+ desorption capacity R2 (0.79 - 0.98). Desorption process appeared two different pathways representing exchangeable and non-exchangeable K+ respectively. Also a graduate depression of desorption process is occurred by alternative irrigation cycles. Soils coefficient K+ desorption by low ionic strength waters were ranged from (0.048 - 0.146) , (0.125 - 0.256) C.mole.kg-1.mint.-½ for high and low ionic strength for both studied soils respectively.