Abstract
Potassium supplying power by using Beckett approach to evaluate some criterias of potassium thermodynamics and their uses as indicators in evaluating of soil fertility in some arid soils, location of KIRKUK province in northern of Iraq. Forms of soluble, non-exchangeable and exchangeable potassium were determined. However the study involved the estimation of activity ratio intensity - quantity factor, labile, potential buffering capacity, molar free energy of potassium and Gabon selectivity coefficient. The results showed that all soil samples had alkaline reactions (7.4-7.9), and contain appreciable amounts of calcium carbonates (270-300), active calcium carbonates (93-137) gm.Kg-1 respectively with dominate semictite and illite clay minerals. Forms of water soluble-K (12-17) mmole.m-3, exchangeable and non-exchangeable-K ranged from (0.48-0.91), (0.9-1.8) C.mole.Kg-1 respectively. Regarding to Q/I ratios suggested by beckett, the values ranged widely from (70-128)×10-4 mole.L-1/2 , the labile pool of potassium values were ranged from (0.34-0.99) C.mole Kg-1 , while potassium potential capacity values ranged from (48.57-83.06) C.mole.Kg-1/mole.L-1. On the other hand Gibbs free energy -∆G values were negatively spontaneous reactions and ranged between (-2939 to -2581) colories.mole-1 and Gapon selectivity coefficient values ranged from (1.67-3.46) L.mole-1.
