This study was conducted during August 2015 to June 2016, which included studying some physicochemical properties of the soils of 14 locations at Bewain plain. The main results were summarized as follows: The range of soluble, exchangeable, and total potassium were (0.04-0.38 mmol c .L -1 ), (0.03-0.11mmol.kg -1 ) and (0.59-1.28 mmol c .L -1 ) for the studied soils respectively. The values of potassium activity ratio ARK and potassium free energy (ΔG) were (0.001 to 0.002 mmol.L -1 ) 0.5 and

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... 142 to -6411 cal mol -1 ) respectively. The amount of adsorbed, desorbed, desorption index (DI) and hysteresis of K + for the studied soils were ranged between (594.4 -1081.2), (335 -738), (0.68 -0.99) and (344.6 -156.8) mg.kg -1 respectively. The ratio between (initial soluble K + concentration, total K + , Ca 2+ , Mg 2+ , Na + , HCO 3 -, Cl -1 , SO 4 2-, AR K , Exchange able K + , adsorbed K + , desorbed K + , K + Hysteresis, DI, pH, CEC, EC, ΔG, CaCO 3 and Organic matter) for irrigated soils to non irrigated soils were (