A New Approach for Controlling Rill Erosion in Two Typical Erodible Soils in Southern China

ABSTRACT Most soil erosion on slopes originates from rill erosion, and rapidly and effectively controlling rill erosion is key to the prevention and control of soil and water loss on slopes. We used a novel approach to control rill soil erosion for Quaternary red clay (QRC) and granitic red soil (GRS) in southern China using an ecologically friendly material (W‐OH) and verified the effectiveness of the approach using field‐simulated scouring experiments with different W‐OH concentrations (0%, 0.5%, 1%, and 2%). The results indicated that most of the hydraulic and hydrodynamic indices of runoffs for the two soils differed between sprayed and unsprayed W‐OH rills but differed less between the sprayed rills (0.5%–2%), indicating a similar draining effect of W‐OH on runoff in the rills. The concentration of W‐OH did not significantly affect runoff intensity or its yield but significantly affected sediment concentration and yield, with rates of decrease of 65.0%–99.8% and 43.4%–99.7% for QRC and GRS, respectively, indicating a good effect of W‐OH in preventing and controlling rill soil erosion. Pedotransfer functions were built for the two soils under W‐OH spraying based on the main hydraulic and hydrodynamic factors affecting rill erosion, which could explain the variabilities of 68.7%–73.8% and 55.0%–55.7% for QRC and GRS, respectively. This study provides a novel and effective approach for controlling erosion in erosion rills in southern China and a basis for predicting the erosion of slopes sprayed with W‐OH.