Soil Salinity and Sodicity Impacts on Unsaturated Hydrologic Properties.

Soil salinity and sodicity are problematic in North Dakota from ground waters and soil parent materials high in soluble salts and sodium. Unsaturated hydrologic properties are important in movement and fates of soluble salts and sodium in soils. Soils were equilibrated with salt solutions of varying EC and SAR values then the saturated hydraulic conductivity, unsaturated hydraulic conductivity and water retention was measured on the soils. Increasing SAR and or decreasing EC caused conductivity values to decrease until some negative potential in which the values became similar. As EC decreased and or SAR increased there was a decrease in pores that drained near saturation. Maintaining adequate EC reduced the adverse effects of sodium on soil properties.