Submitted to: Encyclopedia of Soil Science
Publication Type: Book / Chapter
Publication Acceptance Date: December 12, 2005
Publication Date: March 27, 2006
Citation: Lindstrom, M.J. 2006. Tillage erosion: Description and process. In: Lal, R., editor. Encyclopedia of Soil Science. 2nd edition. New York, NY: Taylor & Francis. p. 1776-1778. Technical Abstract: Tillage erosion is the downslope displacement of soil through the action of tillage. Evidence of the mass downslope movement of soil by tillage has been present for years. Soil movement by tillage is a function of slope gradient and characteristics of the tillage operation, including the tillage frequency, tillage intensity (speed and depth), and size of the tillage implement. Quantitative descriptions of tillage erosion have indicated that soil translocation by tillage is directly proportional to the degree and scale of topographic complexity. The mean soil translocation distance in the direction of tillage has been observed to be linearly related to the slope gradient. The product of the slope of this linear relationship, the depth of tillage, and the bulk density of the soil provide a tillage erosion coefficient (k) for a given set of conditions. The unit soil transport rate in the direction of tillage can be calculated at any specific point in a field using the tillage erosion coefficient (k) and the slope gradient. The rate of soil erosion by tillage depends on the unit transport rate and the degree of change in slope gradients. In effect, soil loss occurs on convex slope positions and soil deposition occurs on concave slope positions. Although tillage erosion can result in considerable soil loss and accumulation within fields, soil is not directly lost from fields. However, tillage erosion exposes subsoil material on upper slope positions that is dispersed and mixed into the tilled layer of adjacent slope positions, resulting in an overall decrease in soil productivity.