Runoff on saline range soils is associated with transport of salts dissolved from the soil to the lowlands and surface waters causing water quality deterioration. In an attempt to quantify the amounts of salts leaving the soil profile, rainfall simulation experiments were conducted on saline sodic soils in the Upper Colorado River Basin. Four rainfall intensities on plots 2 m wide by 6 m long under dry soil moisture conditions was applied over a range of canopy cover and slopes in order to determine the effect of canopy cover and slope on the amount of salts transported with runoff. Three replications of each rainfall intensity was applied for a total of 12 plots. A plot was only evaluated under a specific rainfall intensity to avoid confounding effects of associated with multiple rainfall events and trying to associate salt movement into and through the soil profile from applied rainfall events. In this study, total salt balance was partitioned between that on the soil exchange sites and the soluble fraction in the saturated extract of surface soils. Salts were also quantified in the dissolved fraction in the runoff to calculate a total salt balance for the site. Canopy cover, slope and other experimental conditions influenced the salt partitioning processes via hydrology, erosion and soil property interactions. Results from this study will improve existing model such as Rangeland Hydrology and Erosion Model (RHEM) and others for predicting the possible deterioration of surface water quality as a result of rainfall on saline soils and suggest management practices of such soils in order to reduce their negative effect on surface water.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.