The Drought Monitor, after an extended period of no precipitation and some unseasonably warm temperatures, now shows almost all of Kansas, including our area, as abnormally dry. Not bad for drying down summer crops for harvest but not good news for wheat establishment. The six to 10 day outlook (Oct. 7 to 11) indicates well-below normal precipitation and well-above temperatures for the region. Looking out eight to 14 days (Oct. 9 to 15) indicates more of the same. A good forecast for bringing in the fall harvest and planting the 2021 wheat crop but less than ideal for wheat establishment.
Last week we discussed the reasons why fallow was developed, its potential benefits, the potential problems, and the increased interest in cover crops. Today, a brief discussion of what a cover crop is and its potential benefits.
• SARE (Sustainable Agriculture Research and Education), part of the USDA, defines a cover crops as “A cover crop is a plant that is used primarily to slow erosion, improve soil health, enhance water availability, smother weeds, help control pests and diseases, increase biodiversity and bring a host of other benefits to your farm.” In English, a cover crop “covers” the soil to help prevent wind and water erosion. It improves soil health by improving soil structure and providing organic matter for soil microorganisms allowing them to produce stable organic matter and providing essential nutrients. They further improve soil health by providing a more stable soil environment in terms of temperature and moisture. By providing organic matter, they improve the water holding capacity of the soil. By covering the soil, they can smother out weeds. And finally, a well-designed cover crop helps decrease disease and insect pressure.
• What qualifies as a cover crop? Really anything planted to cover the soil qualifies. However, a good cover crop should help address any specific concerns of the grower. For example, if you want to provide nitrogen to the soil, you would select a legume such as a pea, vetch, or clover. Is your primary objective to cover the soil and protect it from erosion and smother out weeds? Are you looking to increase organic matter to improve nutrient and water holding capacities? Likely, a producer is looking for a combination of these factors.
• An easy way to look at types of cover crops is legumes vs. non-legumes. We mentioned types of legumes previously. The benefit here is that under the proper conditions the can fix over 100 lb/acre of atmospheric nitrogen. Non-legumes include cereal grains such as wheat and rye while broadleaf species range from buckwheat to brassicas and forage radishes. There are even tillage radishes designed to break up compacted layers of soil. The non-legumes are better when you want a great deal of ground cover to protect the soil surface, suppress weeds, and add larger amounts of organic matter to the soil as rapidly as possible.
• The cover crop selected is a function of the previously discussed considerations along with cost, the environment, length of production. Typically, it is recommended to plant several species to maximize the benefits.
Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207.