Some Environmental Implications When Restoring Crop Productivity of Eroded Land with Manure

Soil erosion has been a problem in agriculture since ancient times. The main impact of erosion on the soil is a loss of soil productivity because of decreased capacities in soil biological, chemical, and physical properties. Various researchers have reported reduced crop yields in eroded soils (Frye et al., 1982; Olson and Carmer, 1990; Chengere and Lal, 1995; Shaffer et al., 1995). This loss in crop productivity is caused by the removal of the surface soil, or topsoil, where most of the soil organic matter is present. It has been shown that reduced crop production in eroded soils comes from reduced water holding capacity in the soil (Andraski and Lowery, 1992). In general, reduced yields are noted with erosion, but similar and greater yields have been reported in eroded areas when compared to uneroded soils. This largely reflects weather differences between years, especially rainfall (Swan et al., 1987). Therefore, the productivity of an eroded soil could be restored if its plant-available water holding capacity is increased.