Effect of Slope Gradient and Plant Growth on Soil Loss on Reconstructed Steep Slopes

The objectives of this study were to evaluate the effect of slope gradient and plant growth on soil loss on steep slopes, evaluate the effect of coversoil thickness on plant growth, and determine if the Revised Universal Soil Loss Equation (RUSLE) version 1.06 computer model could predict soil loss on steep slopes. Four slopes, with different gradients (25%, 33%, 40%, and 50%) were constructed. Each slope was divided into four plots with different coversoil thicknesses (0 cm, 15 cm, 30 cm, and 45 cm). Soil loss increased with slope gradients up to 40% and decreased as slope gradient increased to 50%. During the first two growing seasons, plant biomass was significantly correlated (r=0.65 and 0.70, respectively) to increases in coversoil thickness; however, increases in plant production did not reduce soil loss. Results from this study indicated that RUSLE v. 1.06 was an effective long-term planning tool to use on steep slopes.