HYDRAULIC CONDUCTIVITY DISPERSION AND OSMOTIC EXPLOSION IN ARID-ZONE SOILS LEACHED WITH ELECTROLYTE SOLUTIONS

摘要

The maintenance of an appropriate soil structure and favorable soil hydraulic conductivity (HC) is critical for the sustainability of irrigated soils. Clay dispersion and/or swelling satisfactorily explain the observed reductions in HC at relatively low electrolyte concentrations (C) and/or relatively high sodium adsorption ratios (SAR). However, uncertainties still remain with regard to the mechanisms responsible for observed reductions in HC at relatively high C and/or low SAR values. Our objective was to determine the effect of a range of C and SAR values on clay dispersion and HC of four calcareous, micaceous, arid-zone soils and to ascertain the contribution of the osmotic explosion effect to the observed HC reductions at high electrolyte concentrations.