Techniques to Reduce Soil Erosion

Farming

• Reducing soil erosion in farming became a serious issue after the Dust Bowl of the 1930s. Conservation techniques developed using the topography of the land and variations in crop planting. Contour farming is practiced by planting rows along the natural lay of land; soil erosion is reduced because the natural barriers are in place to prevent soil from being washed or blown away. Terrace farming is similar in that it creates nearly level layers of cropland along hillsides.

  Keeping vegetation on the soil constantly reduces soil erosion by allowing root systems to remain in place and prevent soil movement. Planting grassy cover crops such as winter rye or fescue keeps soil in place between regularly planted crops. Allowing crop stubble such as corn silage or soybean to remain after harvesting keeps barriers in place for the soil to hold on to.

  Planting at right angles to prevailing winds controls wind erosion. Strip cropping and rotation of unused land also prevents erosion by avoiding constant tilling. No-till farming reduces the impact on topsoil, thereby allowing the soil to remain compacted.

Landscape Use

• Creating natural barriers to water and wind over soil controls erosion. Apply mulch over topsoil to retain moisture and keep topsoil in place. Plant fast-growing annual grasses such as fescues or rye as temporary ground cover. Use bushes and trees such as willow along hills to prevent water from carrying away soil. Set up winter fencing, stone or brick walls at right angles to prevailing wind or water routes. Use shallow, saucer-shaped cross sections and vegetation for waterways to control runoff. Creating pathways and access routes reduces the impact of traffic upon soil. Limiting soil disturbance within construction areas or during development allows the majority of soil surfaces outside the area to remain intact.

Windbreaks

• Planting fast-growing stands of trees such as Leyland cypress, Osage orange or other evergreens in dense groups creates a wind barrier stopping the force and flow of wind against the soil. Tall perennial grasses or sunflowers also provide windbreaks. Place windbreaks along northern and western edges of the property or field. This placement puts the windbreak perpendicular to wind direction.

Controlling Runoff

• Runoffs are the effect of unaltered rain flow on unprotected soil. Rain washes away soil by force as it impacts directly on the soil when hitting the ground. Trenches and artificial barriers are used to direct rainfall so that it impacts the least amount of soil. Retaining walls and contour farming also reduce runoff as a result of rainfall.

  Diversions are used to contain runoff heavy with soil. Two techniques are common: dikes and swales. Mounds built up to 3 feet high and 3 feet wide are called dikes. Swales are smaller mounds 1 foot high by up to 6 feet wide using sloping sides. These use combinations of secure matting and ground cover such as grass.

  Use of vegetation as ground cover for site control during construction is another technique. When needed, physical barriers such as straw bale, winter fencing or sandbag sleeves are used. Use physical barriers such as these when natural ground cover is not established or fails to establish fast enough.