Spring cereals as a cover crop to protect against erosion on fallow ground
Where the soil is vulnerable to blowing this winter and spring, producers have the choice of doing nothing or using emergency tillage or manure applications to control erosion. Another option would be to plant spring oats, wheat, triticale, or barley as a cover crop as soon as there is sufficient moisture.
Planting a cover crop will not provide immediate control of wind erosion. Even if there is enough moisture for the crop to germinate quickly, it will take at least a month or two of good growing conditions before the plants are established enough to hold the soil. A cover crop could provide some ancillary benefits, however. If a cover crop can be established, this will not only help protect against erosion, but will help increase water infiltration and reduce evaporation. Research has shown that water infiltration rates are increased with higher levels of surface residue present.
We caution you that the use of a cover crop to control erosion may have implications for crop insurance coverage of the subsequent crop. For 2014 spring-planted crops such as corn, grain sorghum, sunflowers, and soybeans, USDA-Risk Management Agency (RMA) has begun to implement new crop insurance rules based on USDA-NRCS Cover Crop Termination Guidelines. These new guidelines were released in December, 2013 and can be found at: http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/landuse/crops/.
RMA is currently in the process of developing crop insurance provisions for the 2015 crop year for winter wheat. However, those provisions will not be released until later this spring or early summer but not later than June 30, 2014, which is the last date that changes can be made to the crop insurance program for crops like winter wheat for the 2015 crop year. The RMA 2014 crop year provisions for winter wheat (released in June 2013) expressly prohibit the planting of a cover crop during the fallow period for wheat insured under the summerfallow (SF) practice.
From an agronomic standpoint, when cereal crops are used as an emergency cover crop to protect against erosion, producers should simply select the cheapest seed available. If spring cereal seed is not available, producers could seed their own bin-run winter wheat. Whatever crop is used, crop insurance regulations would not allow it to be hayed or grazed and still have the following wheat crop be eligible for fallow wheat coverage. The benefit of this practice would strictly be erosion control, so producers should weigh the cost of a cover crop against the cost of emergency tillage or manure applications.
When planting a cereal grain as a cover crop, seeding rates do not have to be as high as normal, although higher populations will do a better job of holding the soil. To save on costs, you could plant only in the areas of the field most susceptible to blowing.
Be sure the crop is terminated before boot stage or sooner. It would be best to terminate the cereal cover crop once it gets about a foot tall. The cover crop should be terminated after it has produced enough growth to cover the soil, but before it uses a large amount of water. The earlier a grass/cereal cover crop is terminated, the faster the remaining residue will decompose all other things being equal. Lignin content increases rapidly after stem elongation and heading, increasing the C:N ratio and resulting is longer-lasting residue.
As a final reminder, prior to planting a cover crop, producers should check with both the USDA Farm Service Agency, crop insurance actuarial documents for your county which can be found at http://webapp.rma.usda.gov/apps/actuarialinformationbrowser/ and your crop insurance representative.
All things considered, emergency tillage or applying manure may be more attractive options for controlling wind erosion at this time of year than planting a cereal grain cover crop, especially if immediate control is needed.
Jim Shroyer, Crop Production Specialist
DeAnn Presley, Soil Management Specialist
Rebecca Davis, Director, Topeka Regional Office, USDA- Risk Management Agency