Effect of treating soils of different clay mineralogy with solutions varying in electrolyte concentration and sodium adsorption ratio

The relative ionic concentration and the total ionic concentration of irrigation waters are two main factors affecting soils. The present study investigated variations in relative ionic concentration and total ionic concentration of solutions in equilibrium with soils contrasting in clay mineralogy to determine certain effects on their physical and chemical properties. Three soils were studied, namely: Victoria clay (montmorillonitic), Hoban silty clay loam (illitic), and Nacogdoches clay (B horizon)(halloysitic). The main objectives of the study were to determine the following for each soil: (1) the effect of solutions varying in SAR (sodium adsorption ratio) and concentration on the equilibrium-ESP (equilibrium exchangeable sodium percentage); (2) Gapon's constants of adsorption for a two cation system, namely Na and Ca; (3) the degree of dispersion of soil colloids in the absence and in the presence of equilibrium solution varying in SAR and in concentration; (4) changes in equilibrium-ESP by solutions of constant SAR but varying in electrolyte concentration. ..