Soil erosion is wearing away of soil particle due to action of erosion agents such as moving water, ice and wind.Erosion, whether it is by water, wind or tillage. Soil erosion involves three distinct actions – soil detachment, movement and deposition. Topsoil, which is high in organic matter, fertility and soil life, is relocated elsewhere “on-site” where it builds up over time or is carried “off-site” where it fills in drainage channels.
Soil erosion reduces cropland productivity and contributes to the pollution of adjacent watercourses, wetlands and lakes.
water erosion is the result of rain detaching and transporting vulnerable soil, either directly by means of of rain splash or indirectly by rill or gully erosion
The following are forms of water erosion
- Rain drop or splash erosion: Erosion preceded by the destruction of the crumb structure due to the impact of falling raindrop on the surface of soil is termed as splash erosion.
- Sheet erosion: It is the fairly uniform removal of soil in thin layers from the land surface, often scarcely perceptible, especially when caused by wind. Areas where loose, shallow topsoil overlies compact soil are most susceptible to sheet erosion.
- Rill erosion: A form of water erosion in which numerous very small and more or less straight channels are produced; the channels get obliterated by ordinary use. It can be removed by normal tillage operations.
- Gully erosion: A form of water erosion in which gullies are produced by combination of unattended rills.
- Stream bank erosion: Stream banks are eroded by water either flowing over the sides of a stream or scouring at the base. It is aggravated by removal of vegetation, over grazing or cultivation near the stream banks.