The most effective way to slow the effects of wind erosion is through the use of residue from the previous crop. According to Bob Durland, there are three management practices that can control erosion from wind. These are, reducing the wind velocity at the soil surface, trapping soil particles, and increasing the size of soil aggregates.
The Colorado State University Extension Service also offers publications on soil erosion. Their Crop Series "Controlling Soil Erosion From Wind," states that soil erosion involves the detachment, sorting, abrasion, avalanching, and deposition of soil particles. SDSU estimates that soil erosion begins when the wind velocity at a height of one foot off the ground reaches 12 miles per hour.
Reducing the wind velocity at the soil surface therefore, is a logical place to begin managing soil erosion. This can be accomplished by decreasing the distance across a field that can be affected by the wind. Successful management practices include planting windbreaks, stripcropping, using cover crops, leaving sufficient crop residue, and tilling practices that leave larger soil aggregates.
Trapping soil particles can occur with cover crops and ridge tilling, or by creating a rough soil surface to slow blowing soil. Increasing the size of soil aggregates may take some medium range planning. If a field has been tilled often in a corn-soybean rotation, it may be advantageous to include a grass or alfalfa crop in the rotation. This will do two things. First, it will return crop residue to the soil resulting in increased organic matter, and second, the extensive root systems of a grass crop will help hold soil together.
If a serious wind erosion problem exists on a particular site, emergency tillage operations can help by creating clods on the soil surface. Chisel plows were identified by Durland as being a good tool to use in roughening up the soil surface.
The Colorado State Extension service also reminds us that ridges formed during emergency tillage operations should be made at right angles to the prevailing winds. This will prevent soil particles from being blown straight down the rows, defeating the purpose of the tillage operation.
This is an important point, since 50 to 80 percent of soil erosion is caused when soil particles are lifted from the soil surface and impact in a different location, dislodging other soil particles.
Adequate control of wind erosion may be accomplished with a mulch of hay, cornstalks, or straw. It is recommended that at least 2,500 pounds of residue per acre needs to be present to control wind erosion.
Spreading manure may be an option, however, liquid manure application will do little compared to a manure mixed with some form of bedding.
Soil erosion by wind has become a problem in South Dakota. If it has been identified as a potential problem in a particular field, application of the management practices outlined here will be a step forward.