ABSTRACT
Soil surface covers of crop canopies and permeable mulches are important in reducing soil erosion by water. Surface cover effects can be divided into three classes: canopy effects, ground-cover effects, and within-soil effects. Rainfall simulator studies show that interrill soil erosion varies with the square of rainfall intensity. The naturally occurring surface covers for the Badin, Georgeville, and Goldston were approximately 70%, 60%, and 20%, respectively. Agassi and Levy found that stone cover on a loamy soil located in Israel had significant effect on both the infiltration rate and soil erosion. The influences of rock fragments on soil erosion as they interact with soil physical and chemical properties are complex. Surface cover reduces soil erosion by water because it absorbs raindrop impact energy, reduces the area of erodible surface causing flow energy to be dissipated on nonerodible cover in contact with the surface, increases infiltration by reducing surface sealing, and slows the velocity of runoff.
