Cover crops have been an accepted conservation, as well as agronomic practice for hundreds of years. In recent years, there has been a groundswell of promotion of cover crops due to their ability to build healthy soil. When I began my career nearly 40 years ago, it was difficult to sell the idea of planting cover crops due to the additional costs, time and labor. A farmer had to be really dedicated to the idea of reducing soil erosion and improving soil tilth.
Over the years, we have learned that the economic and environmental benefits of planting cover crops more than offset the cost and labor of growing them. Cover crops recapture excess nutrients, build organic matter, increase water infiltration, assist with weed control, suppress some crop diseases, reduce compaction, provide additional nitrogen where needed, and much more.
If you want to reduce nitrogen losses from leaching, cover crops may well be a tool. Winter grass cover crops, such as cereal rye, store up soil nitrogen in the fall and winter through fast root growth. Rye can be difficult to kill in the spring if it is allowed to grow too tall. Some cover crops are easier to manage than others. Typically, turnips, radishes, oilseed and oats require less management.
A major environmental benefit of cover crops is their ability to greatly increase carbon inputs into the soil. When combined with no-till, the additional residue increases soil organic matter. Carbon and nitrogen are both needed to form soil organic matter, which greatly improves the health of your soil. With the accumulation of soil organic matter, the water-holding capacity of the soil rises and nutrients are released for plant uptake more readily.
As mentioned in this column several times, Delaware County soils are mostly poorly drained. Adding a cover crop to the rotation, and managing it based upon weather changes, can help yield production by making soil moisture more or less available. While cover crops increase water infiltration, they also help remove soil moisture and dry out fields. In a wet spring, it is good to allow the cover crop to grow as long as possible, as it acts as a sponge, sucking up excess water from the soil. In a dry spring, it is better to burn down the cover crop early so it doesn’t rob soil moisture from the spring-planted crop.
While it takes a little more management to be successful using cover crops, the benefits can far exceed the extra time and attention it takes to include them in your crop rotation. Building the health of your soil, through increased organic matter, improving the water-holding capacity and reducing soil compaction, can have long-term benefits of higher crop production and improving water quality. Planning should begin today if you are thinking of planting cover crops this fall.
To find more information on cover crops, go to ohioline.osu.edu or simply Google “cover crops” in your browser.
Brad Ross is communications specialist at the Delaware Soil and Water Conservation District. He can be reached at firstname.lastname@example.org.