Looking beyond the short term in cover cropsBy Jim Isermann on Thursday, 20 June, 2019
No matter the region, farmers are always looking to give back more than what they reap from the soil. By reducing soil erosion, adding biomass, sequestering carbon and improving nutrient cycling, cover crops can be a huge benefit to farmers.
Cover crops are not a new idea, but best practices have to be determined for each farm and each farmer. Much depends on the risks each farmer is willing to take and the time they can dedicate to managing a cover crop. A sustainable adoption strategy requires a full understanding of potential risks.
At SHP we like to refer cover crops as a tool in a farmer's toolbox; however, even the same tool can be used differently depending on your end goal. Your reason for using cover crops matters, and you need to determine what is right for each piece of your farm. Whether you are aiming to reduce erosion, to reduce compaction, trying to get better yields, reduce your inputs, or improve your overall agronomic management systems, a cover crop can be part of the solution.
Cereal rye is a very common cover crop and can be managed in several different ways. For beginners, cereal rye can be planted ahead of a soybean crop without too many management concerns. It is best to terminate Cereal Rye at about 12 to 18 inches and then plant 2 weeks later. However, even in years when planting or termination is delayed due to weather, soybeans can still be planted into tall rye or even planted green without too much concern.
Cereal rye used ahead of corn should be for more advanced users ready to take additional management steps with their fertility, planting and termination systems. Less available nitrogen, cooler soils and increased pest pressure as a result of the cereal rye can have a negative impact on corn yields if not properly managed. Farmers working with cereal rye ahead of corn need to be prepared to work through these issues to provide their corn a good start.
Each application carries its own risks that vary across soil types. Certain soils with a lower organic matter and that are drought-prone will see some advantages much faster than a heavier, higher productive soil. Generally, short-term risks of using cover crops include cooler, wet soils in springtime resulting in delayed planting or emergence and increased insect pressure. These risks can be reduced by reducing seeding rates, earlier termination, and precision planting. The long-term benefits can yield strong attributes for soil health: building biomass, an aggressive approach to deterring invasive weeds, increased soil organic carbon, increased water filtration, and improved nutrient cycling.