Abstract
Two surfaces soils horizon from calcareous soils in Mosul city classified as calciorthid with semictite dominance were chosen to study the effect of wetting and drying cycles on release of native and added potassium.Potassium was added to soil samples at rate (0,100,200,and 400 mgk.kg-1) as potassium chloride. Potassium release was determined by using Ca-resin capsules for 10 cycles of wetting to F.C and drying. Results showed that flaccuted water conten drying wetting and drying cycles increased of K-release of pedogenic and K-added to Ca-resin capsules until the tenth of wetting –drying cycle.Fine texture release more pedogenic K than coarse texture, also potassium fertilization rates with wetting and drying cycles increased of K-release to Ca-resin capsules.
