Effective diffusion coefficient of cations as influenced by physical and chemical properties of selected Indiana soils

Abstract

Abstract Ion diffusion through the soil matrix is dependent upon both the physical and chemical properties of the soil. Cation (K, Na, Ca and Mg) diffusion coefficients De, were determined for seven Indiana soils by using the ion diffuison flux to a hydrogen resin paper technique. Volumetric moisture, clay content exchange and solution phase ionic concentrations, buffer capacity and organic C content were variously related to the determined De values. The larger the diffusion coefficient of K, Ca, and Mg, the lower the clay content, and exchange capacity of soils, and the higher the concentration of these cations in the solution phase. From the present study, it was concluded that the De of these cations was affected by one or more soil physical and chemical property which must be considered if De is to be used to estimate supply rate of these ions to growing roots in soil systems.