Co-Authors:
Feigenbaum, S.
Bar-Tal, A.
Portnoy, R.
Sparks, D.L.
Abstract:
Potassium exchange with Mg plus Ca was studied in 2 calcareous soils with variable concentrations of Na, using batch and miscible-displacement methods. Preference for K over the divalent cations was found in both soils, regardless of Na concentration and the experimental methods. Modified Gapon (kG) and Vanselow (kV) selectivity coefficients were calculated for each cation pair in binary and ternary systems. In both soils, the kV and the kG decreased with increasing K fraction in the solution, but the kG value was less affected than the kV. The high correlation of predicted exchangeable K with the directly measured values shows that binary selectivity coefficients can be used in multicationic systems on calcareous montmorillonitic soils. -from Authors