MANHATTAN, Kan. - Even with recentprecipitation here and there throughout the midsection of the country, drought conditionspersist through several states, which could heighten prospects for winderosion once springtime winds kick in.
"There are several things farmers can do tomitigate damage from wind erosion and it's best to do them before the windreally starts blowing," said Kansas State University assistant professorDeAnn Presley. "Often, wind erosion will start in a small area of a fieldwhere soil texture, aggregation, or vegetation conditions are morevulnerable to wind than other parts of the field."
The vulnerable areas, or "hot spots" arethe areas that need control first, said Presley, who is a soil management specialistwith K-State Research and Extension. She, along with U.S. Department of Agriculturesoil scientist, John Tatarko, authored a publication "Principles of WindErosion and its Control," available through K-State Research and Extensionoffices or online at www.ksre.ksu.edu/bookstore. Search for MF2860.
Emergency tillage is tillage performed on anactively 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 temporarymeasure, however," she added. "First, because clods can disintegrate rapidly undersaltating conditions and second, because a change in wind direction canmean soil loss from untilled strips."
Saltating is sort of a chain reaction, where underthe influence of wind, small particles bounce or hop along the soilsurface, she said. As they bounce, they strike other particles, causing themto move. The higher the particles jump, the more energy they derive fromthe wind. Because of this wind-derived energy, the impact of saltatingparticles initiates movement of other grains and smaller dust particles that canbe suspended in the air and carried long distances.
An implement used for emergency wind erosioncontrol should gently lift the soil, creating as many large stable clods aspossible. Implements such as listers and chisels do a good job of rougheningthe soil surface and creating clods. Each has its own benefits,depending on soil type.
Adding crop residue to the surface reduces windvelocity and traps moving soil particles, Presley said. Almost any kind ofresidue, including straw, hay or corn stalks can be used. Approximately2,000 to 4,000 pounds of residue per acre is required, however, to controlerosion in areas that already have begun to erode. Normally the residue must be anchored in placewith a stubble puncher or disk, although long-stemmed residues such as cornstalks might not require anchoring.
Livestock manure also can reduce wind erosion, shesaid, particularly in growing wheat, fallow fields and row crops.Typically, six to eight tons of manure per acre controls wind erosion onvulnerable spots, but care should be taken when storing and apply manure, so as notto contaminate water sources.
Irrigation to control erosion is generallyimpractical and wastes water because the surface tends to dry rapidly underhigh wind conditions. However, if a high-value cash crop is at stake,irrigation might be a practical solution if enough water can be appliedto keep the surface sufficiently moist.
Temporary, artificial wind barriers, such as boardor snow fences or hay bales can be used if the eroding area isrelatively small, such as stock watering areas or knolls. Protection can beexpected for a downwind distance approximately 10 to 15 times the height of thebarrier.
Soil stabilizers are soil additives or spray-onadhesives, which bind soil particles together, Presley said. They aregenerally expensive, temporary and used only for high-value cash crops such asvegetables. While there are a number of materials available, they are notcompatible 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-AgriculturalResearch Service Engineering and Wind Erosion Research Unit and USDA-NaturalResource Conservation Service in conjunction with the Educational CommunicationsCenter at Kansas State University.