Slope Steepness and Incorporated Residue Effects

ABSTRACT A controlled field experiment was conducted to determine the effect of slope steepness and incorporated residue on rill erosion. Duplicate rills were tested on slopes of 9, 18, and 23%, each with incorporated wheat straw residue of about 0, 4700, and 9400 kg/ha. Rill erosion was shown to vary directly with flow shear stress, but rill geometry depended on other processes. The medium and high residue rates reduced rill erosion to 40 and 15% of the no-residue condition, respectively, which provides guidelines for the USLE C-factor.