Soil Erosion By Water

When soil erodes, particles move from the place of origin and are deposited elsewhere. Most soil erosion on farmland is caused by water, wind or tillage. Generally, poorly managed and unprotected lands are most prone to erosion. However, local conditions will dictate the type and severity of erosion. When soil erodes from Ontario farmland it takes with it, the productive base and costly crop inputs.

Erosion by Water - How it Happens

The extent of erosion by water is affected by several factors: the length and steepness of slope, soil texture (silt loam, fine sand, etc.), the amount and timing of severe rains and field protection measures. The diagram is an unprotected, steeply sloping field with soil that is vulnerable to erosion.

Knolls with light-coloured subsoil at the surface are evidence of past erosion by tillage, wind and water. Soil loss can be accelerated when the forces of tillage and weather are both at work.

Steeply-sloping fields with silty soils are prone to erosion by water and tillage.  Properly managed, however, these fields can sustain yields with minimal erosion. Poor management will allow continued erosion, reduce returns and eventually, destroy the soil's ability to produce crops.

Large eroded channels, which cannot be crossed by farm equipment, are called gullies.

During a storm, rain can quickly form a thin layer of water on the ground which can flow together to cause channels, called rills, that can move soil downslope.

Best Management Practices: A First Look