How Rain Intensity Affects Interrill Erosion

THE effect of rain intensity on interrill erosion was studied on crop-row sideslopes of farm fields using simulated rainfall. For a wide range of soils and cropping conditions, erosion (E) was related to intensity (I) as the power equation, E = aP. The exponent, b, decreased from slightly above 2.0 for soils of low clay content to about 1.6 for soils with about 50 percent clay. For the low-clay soils (silts, silt loams, loams and sandy loams), the power equation, E = cl2, fit the data well, and the ratios of the coefficients, c, then expressed the relative interrill erodibilities of the different soils. When a certain soil was studied at different crop stages, the c-values in-dicated the relative effect of different cropping condi-tions on interrill erosion.