The last few years there has been a major focus on cover crops here in southeast Nebraska as well as other parts of Nebraska. Cover crops have been used for a number of years particularly in organic cropping systems. They have been a source of nitrogen, organic matter and other nutrients when incorporated as green manures in these systems. Cover crops have also been planted as forage crops for livestock for grazing or hay for many years. In recent years there has been increased interest in the use of cover crops in conventional cropping systems. The USDA NRCS (Natural Resource Conservation Service) has promoted cover crops and provided cost-share programs for farmers to encourage their use to help improve soil health and reduce erosion and degradation of soils.
With crops just starting to come out and the recent rains last weekend, cover crops can be drilled in to provide much needed erosion control on highly erodible land. Many areas of southeast Nebraska received some torrential rains this year, and there has been extreme erosion in many areas. Check with your local NRCS about programs on the use of cover crops to control ephemeral erosion. Some producers have used cereal rye, wheat or triticale with success in controlling erosion. On highly erodible soil, a cover crop of rye following soybeans can be very beneficial, it is generally the most winter hardy of the cereal crops. Cover crops maybe used as an annual waterway that can hold the soil and prevent ephemeral erosion. Cover crops can also have the potential to provide other benefits as well; i.e. improve water infiltration, scavenge nutrients, weed suppression and forage for livestock.
If you need forage for grazing in late winter or early spring, either rye or triticale provides excellent forage for cows or yearlings. Either of these forages planted in corn stalks also provides excellent forage for grazing along with the corn stalks, and generally can be utilized longer in the spring for grazing if the field is going back into soybeans. These forages can provide excellent quality forage, lower hay and pasture requirements, and reduce soil erosion from springtime thunderstorms. A number of farmers in southeast Nebraska are making excellent use if cereal rye as a forage for their cowherds and also seeing some of the other benefits.
In research conducted in Illinois, rye has shown to be beneficial in suppressing some weeds (Marestail and Glyphosate-resistant Marestail) and also disease pests, i.e. SCN (Soybean Cyst Nematode), SDS (Sudden Death Syndrome) and other foliar diseases in soybeans. Research in Northeast United States shows that rye has an allelopathic (weed suppressing) effect on pigweeds, lambsquarters and crabgrass. Recent research at Kansas State University showed cereal rye was effective in suppressing growth of Palmer Amaranth, one of the most invasive weeds in the United States that has recently made its presence in southeast Nebraska. Research indicates cereal crops, such as wheat and rye can delay emergence up to 3-4 weeks and slow down growth of Palmer Amaranth compared to no cover crop. Farmers in Nebraska have also seen the benefits of cereal rye suppressing Marestail. A significant amount of research is currently being conducted in Nebraska to evaluate the impact of cover crops in cropping systems, although many farmers have been utilizing cover crops in no-till cropping systems for several years and also as forages for grazing. Research is indicating benefits of growing a cover crop by adding carbon and building soil structure, especially under no-till environments. If winter hardy cover crops like rye or triticale are planted, they are usually chemically killed prior to planting in the spring, although under intensive management some producers are planting green into the rye with success. If using a cover crop, be sure to check with your crop insurance agent on the rules for cover crop termination in crops. To find out more about cover crops in Nebraska, go to: https://cropwatch.unl.edu/cover-crops . You can also go to:
https://cropwatch.unl.edu/farmresearch/resultshome and find a number of on-farm research experiments that have been conducted across Nebraska with cover crops the past few years. If you have questions, feel free to contact me at (402) 274-4755.
Gary Lesoing
Extension Educator
Nemaha County
October 2019