Interrill erosion occurs as a result of detachment of soil surface particles caused by raindrop impact and their transportation by overland flow (drag and suspension), which contain the organic matter and nutrients that are essential for agricultural production. An experiment was carried out to evaluate the effect of different soil cover types on the overland flow in interrill erosion in an area of sugarcane cultivation. The following situations were evaluated: bare soil; sugarcane straw mulch; sugarcane canopy cover; sugarcane canopy cover + sugarcane straw mulch three and 12 months after sugarcane harvest. The laminar flow regimes were slow and interrill soil erodibility of the Red-Yellow Argisol was 1.87 x 10(6) kg s m-4 due to the occurrence of kaolinite and mica. Sugarcane straw mulch increased hydraulic roughness, while the standing sugarcane crop intercepted rain and delayed the start of overland flow, increasing water infiltration and decreasing interrill erosion rates.
water erosion; soil erodibility; flow regime; simulated rain
