Interest in cover crops is increasing as a number of groups have demonstrated higher yields and improved soil health from incorporating them into an operation. But adopting cover crops is not a one-size-fits-all solution for growers and there many different options that may provide different benefits for different operations.
Cover crops have many potential benefits. Using cover crops with soybean can be helpful for:
- Reducing soil erosion
- Reducing soil compaction
- Increasing yield
- Controlling weeds
- Managing nitrogen
Many of these benefits are the result of a long-term investment in cover crops and likely not to be seen after a single year of use. The specific benefits of a cover crop depend on the species grown as well as the environment. Cover crops require management and planning, just as any farm practice does and before you implement them in your operation, consider these steps.
- Determine what you want to accomplish by planting a cover crop & what benefits do you want to work towards. This may be improving erosion, weed control, or increasing yields. You may have different goals for different fields or farms.
- Select the right species of cover crops to help you reach your goals. Each species has a distinct set of characteristics that make it useful for different goals. Selecting the wrong species can lead to more problems than when you started.
Grasses (including winter cereals such as rye, wheat, barley, triticale) are the most common cover crops in corn and soybean cropping systems. The extensive fibrous root system produced by grass cover crops make them well suited for stabilizing soil (preventing erosion) and building soil organic matter. These are typically planted through late fall and produce a small to moderate amount of root and above ground biomass before going dormant in the winter. Vigorous growth resumes in early spring.
Legumes (including hairy vetch, field pea, lentil. Crimson clover, red clover) are popular for their ability to fix N. The amount of N accumulated varies by species but is directly proportional to the biomass produced. Legumes typically need to be planted by early fall for them to survive the winter.
Brassica (including mustards, tillage radish) have grown in popularity for their ability to provide many of the same benefits as grasses but with residues that break down more quickly in the spring. Tillage radish is becoming known for its ability to produce a large taproot that is effective at breaking up soil compaction. Like legumes, brassicas must be planted by early fall to successfully establish and provide maximum benefits.
- Have a plan. Think about changes that need to be made to your current operation to successfully incorporate cover crops, including earlier maturing varieties, early harvest, labor requirements, seed acquisition, and herbicide programs.
- Think small when first starting out. Select a field or few areas that will benefit most from a cover crop and start experimenting with those areas first. Also, consider leaving a check strip for comparison. Side-by-side comparison makes a great way to evaluate progress made by incorporating cover crops.
- Make a commitment. Incorporating cover crops is a long-term investment, and you won’t necessarily notice the benefits after a single year or use.
As you think about incorporating cover crops into your soybean rotation, keep the specifics of your operation, climate, and location in mind. Talk to growers in your area who are successfully using cover crops and start small. By experimenting on a few fields to begin, with you can determine which practices work best for your operation.
References:
Heggenstaller, A. Managing winter cover crops in corn and soybean cropping systems. https://www.pioneer.com/home/site/us/agronomy/library/managing-winter-cover-crops/.
Wohltman, S. 2016. Planning for cover crops. Illinois Soybean Association. http://ilsoyadvisor.com/agronomy/2016/october/planning-for-cover-crops/.
