Soil erosion is a widespread and major environmental threat to our terrestrial ecosystems (Singer and Warkentin, 1996; Yang et al., 2003).
During the last 40 years, nearly one-third of the world's arable land has been lost to erosion, with loss continuing at the rate of more than 10 million ha per year (Pimental et al., 1995). Soil erosion is directly related to reduced agricultural productivity and to water pollution, and it may reduce the ability of soil to mitigate the greenhouse effect (Lal and Bruce, 1999; Nearing et al., 2005; Weltzin et al., 2003).
Soil erosion by water is considered one of the most severe types of erosion and has attracted considerable attention in the past, mainly due to its destructive effects, including eutrophication, non-point pollution and, eventually, land degradation (Asselman et al., 2003; Jin et al., 2008; Singer and Shainberg, 2004).