Take steps to control wind erosion before springtime winds blow
Even with recent precipitation here and there throughout the midsection of the country, drought conditions persist through several states, which could heighten prospects for wind erosion once springtime winds kick in.
“There are several things farmers can do to mitigate damage from wind erosion and it’s best to do them before the wind really starts blowing,” said Kansas State University assistant professor DeAnn Presley. “Often, wind erosion will start in a small area of a field where soil texture, aggregation, or vegetation conditions are more vulnerable to wind than other parts of the field.”
The vulnerable areas, or “hot spots” are the areas that need control first, said Presley, who is a soil management specialist with K-State Research and Extension.
She, along with U.S. Department of Agriculture soil scientist, John Tatarko, authored a publication “Principles of Wind Erosion and its Control,” available through K-State Research and Extension offices or online at www.ksre.ksu.edu/bookstore. Search for MF2860.
Emergency tillage is tillage performed on an actively blowing field to provide a rough, ridged, cloddy surface. The idea, Presley said, is to reduce wind velocity and trap windblown soil particles.
“Emergency tillage is only a temporary measure, however,” she added. “First, because clods can disintegrate rapidly under saltating conditions and second, because a change in wind direction can mean soil loss from untilled strips.”
Saltating is sort of a chain reaction, where under the influence of wind, small particles bounce or hop along the soil surface, she said. As they bounce, they strike other particles, causing them to move. The higher the particles jump, the more energy they derive from the wind. Because of this wind-derived energy, the impact of saltating particles initiates movement of other grains and smaller dust particles that can be suspended in the air and carried long distances.
An implement used for emergency wind erosion control should gently lift the soil, creating as many large stable clods as possible. Implements such as listers and chisels do a good job of roughening the soil surface and creating clods. Each has its own benefits, depending on soil type.
Adding crop residue to the surface reduces wind velocity and traps moving soil particles, Presley said. Almost any kind of residue, including straw, hay or corn stalks can be used. Approximately 2,000 to 4,000 pounds of residue per acre is required, however, to control erosion in areas that already have begun to erode.
Normally the residue must be anchored in place with a stubble puncher or disk, although long-stemmed residues such as corn stalks might not require anchoring.
Livestock manure also can reduce wind erosion, she said, particularly in growing wheat, fallow fields and row crops. Typically, six to eight tons of manure per acre controls wind erosion on vulnerable spots, but care should be taken when storing and apply manure, so as not to contaminate water sources.
Irrigation to control erosion is generally impractical and wastes water because the surface tends to dry rapidly under high wind conditions. However, if a high-value cash crop is at stake, irrigation might be a practical solution if enough water can be applied to keep the surface sufficiently moist.
Temporary, artificial wind barriers, such as board or snow fences or hay bales can be used if the eroding area is relatively small, such as stock watering areas or knolls. Protection can be expected for a downwind distance approximately 10 to 15 times the height of the barrier.
Soil stabilizers are soil additives or spray-on adhesives, which bind soil particles together, Presley said. They are generally expensive, temporary and used only for high-value cash crops such as vegetables. While there are a number of materials available, they are not compatible with all soils and often made ineffective by rainfall, cultivation, or abrasion from untreated areas.
In addition to the wind erosion publication, information is available at www.weru.ksu.edu/ and from three videos at: http://www.ksre.ksu.edu/p.aspx?tabid=255. The videos were produced by the U.S. Department of Agriculture-Agricultural Research Service Engineering and Wind Erosion Research Unit and USDA-Natural Resource Conservation Service in conjunction with the Educational Communications Center at Kansas State University.