Co-Authors:
Frenkel, H., Division of Soil Physical Chemistry Division of Soil Organic and Residue Chemistry, Volcani Center, Israel
Gerstl, Z., Division of Soil Physical Chemistry Division of Soil Organic and Residue Chemistry, Volcani Center, Israel
van de Veen, J.R., Division of Soil Physical Chemistry Division of Soil Organic and Residue Chemistry, Volcani Center, Israel
Abstract:
A simple and direct method for the quantitative determination and removal of gypsum in gypsiferous soil samples was developed. This procedure incorporates a combination of Na- and Cl-resins to aid in the dissolution of the gypsum. The primary effect of the exchange resins is to buffer the composition of the solution and thereby keep the rate of gypsum dissolution high. The dissolved calcium and sulfate exchange with the sodium and chloride on the resins, resulting in a solution containing primarily Na and Cl. The electrical conductivity of the supernatant is directly related to the amount of gypsum dissolved. This method was used on samples of artificially prepared mixtures and naturally gypsiferous soils. Compared with results obtained by other methods, the resin method gave identical results, while requiring much less time and fewer calculations. The resin method was also used to remove gypsum from gypsiferous soil samples prior to CEC determinations to see if the presence of gypsum effects the CEC as determined by the Bower method. No significant effect was noted for soil samples containing less than 20% gypsum. © 1986.