|Herrick, Jeffrey - Jeff|
Submitted to: Soil Quality Information Sheets
Publication Type: Government Publication
Publication Acceptance Date: 5/1/2001
Publication Date: 5/1/2001
Citation: HERRICK, J.E., TUGEL, A.J., SHAVER, P.L., PELLANT, M. RANGELAND SOIL QUALITY: WATER EROSION. SOIL QUALITY INFORMATION SHEET. 2001. RANGELAND SHEET 9.
Interpretive Summary: Interpretive summary not required for government publications.
Technical Abstract: Water erosion is the detachment and removal of soil material by water. The process may be natural or accelerated by human activity. The rate of erosion may be very slow to very rapid, depending on the soil, the local landscape, and weather conditions. Water erosion wears away the earth¿s surface. Sheet erosion is the more or less uniform removal of soil from the surface. Rill and gully erosion occurs when concentrated runoff cuts conspicuous channels into the soil. Deposition of the sediment removed by erosion is likely in any area where the velocity of running water is reduced: behind plants, litter, and rocks; in places where slope is reduced; or in streams, lakes, and reservoirs. Erosion is caused by the impact of raindrops on bare soil and by the power of running water on the soil surface. Each specific soil has its own natural erosion rate. A sandy or clayey texture generally is less erodible than loam or silt loam. Sandy soils that formed in material weathered from decomposed granitic rock, however, are highly erodible. Soils with rock fragments or biological crusts on the surface are protected from the impact of raindrops. Stable soil aggregates bound together by organic matter resist erosion, enhance infiltration, and result in less runoff. Bare soil between plants is most susceptible to erosion. The risk of erosion and the potential for recovery after erosion must be considered in any management plan. The risk of erosion is increased by a fire frequency or intensity that is either greater or less than is expected for the site; by disturbances, such as heavy grazing; and by the establishment of weeds. Areas with fertile topsoil are most likely to recover after a disturbance. In areas where much of the topsoil is lost, the site may no longer be able to support the historic vegetation. Management strategies include: Maintain or increase the cover of plants or litter on the soil through the application of good rangeland management practices. Reduce soil surface disturbances, especially in arid areas. Increase the rate of water infiltration and improve soil aggregate stability by improving or maintaining the quality of the plant community. Minimize grazing and traffic when the soil is wet and thus prevent the reduced infiltration caused by compaction and physical crusting. Build water bars and direct waterflow from roads, trails, or vehicle tracks across the slope or into existing drainageways. Maintain road surfaces and drainageways.