Soil Salinity and Sodicity Impacts on Soil Shrinkage, Water Movement and Retention

Saline, sodic, and saline-sodic ground waters are problematic throughout the Northern Great Plains and Red River Valley. High sodium adsorption ratio (SAR) and low electrical conductivity (EC) of soil solution and irrigation waters are known to create issues with saturated soil hydrologic conductivity. Our objective was determine the impact of saline, sodic and saline-sodic solutions on soil shrinkage and soil hydrologic properties. Soil shrinkage, water retention, and hydraulic conductivity were determined on a variety of soil textures following saturation with salt solutions of variable EC and SAR combinations. Data were fitted with simple theoretical models then model parameters statistically compared. Increasing SAR and decreasing EC of increased soil shrinkage, decreased hydraulic conductivity, and increased water retention near saturated conditions (i.e., > -100 cm H2O). Whereas saline-sodic waters resulted in the greatest rate of decline in saturated conductivity over time such as when salts would be managed without maintaining divalent cations