Soil is the foundation of a healthy operation, but it can be easy to take it for granted. After all, it’s just dirt, right? Wrong. Soil is a complex ecosystem teeming with life, and it’s essential for growing healthy crops.
One of the best ways to improve soil health is to plant cover crops. Cover crops are grown to protect and enhance the soil rather than be harvested. They can help to reduce erosion, improve water infiltration, suppress weeds and increase soil organic matter.
THE SECRET TO SOIL
When coupled with reduced tillage, implementing cover crops can help farmers build a healthier, more productive soil profile. The first step when working toward improved soil health is to begin viewing the soil as the living ecosystem that it is. Many beneficial micro-organisms live in the soil that, when managed appropriately, can go to work for soybean producers across the state. Without getting too far into the weeds, these beneficial fungi and bacteria in the soil must eat. Cash crops and cover crops both exude starches consumed by these micro-organisms, so by adding a living root to the soil during the winter, farmers essentially provide those root exudates year-round. Then, when terminating cover crops and planting cash crops in the spring, these micro-organisms feed on the dead cover crop material. After consumption, this decayed plant material mixes with existing soil components, increasing soil organic matter.
It is crucial to acknowledge the importance of fostering a diverse and robust soil microbiome, as various species of bacteria and fungi flourish under distinct conditions. A strategic mix of cover crop species is paramount to creating an environment conducive to this diversity. Incorporating a blend of cereal grains, brassicas and legumes offers the optimal conditions for a thriving microbiome.
One fundamental aspect to grasp when striving to enhance soil health is recognizing that substantial changes don’t occur overnight. Rebuilding these microorganism communities and increasing soil organic matter demands a multiyear commitment. As our understanding of soil microbes and their symbiotic relationships with cash crops deepens, it becomes evident that cover crops serve a broader purpose than merely providing winter field cover.
BOOMING WITH BENEFITS
While the benefits of soil health improvements won’t likely be seen after the first year of cover crop implementation, there are several other benefits that farmers can take advantage of in Year One.
The first is nutrient management and erosion control. Cover crops do an excellent job of keeping things in the right place. With current fertilizer prices, nobody wants to think about that kind of investment leaving their field. Cover crops can significantly reduce the nutrient runoff a farmer’s field can experience, keeping those nutrients in place and available for next year’s cash crop. Their living roots and above-ground cover can also significantly reduce erosion problems.
Cover crops emerge as a cost-effective tool to mitigate such losses when farmers weigh the potential cost of replenishing lost nutrients and topsoil that would otherwise have been depleted from their fields. Here are some examples of cover crop species that can aid in achieving these objectives: winter cereal rye, winter triticale, winter barley and winter wheat.
The second benefit is improved water efficiency. Cover crops change the physical structure of a field in a way that creates a more porous surface and slows the water flow rate during a significant rain event. This allows the water a more susceptible surface to soak into, as well as giving it more time to do so. This helps store more water in the field for cash crops rather than just letting it run down a waterway. Also, after termination, the layer of dead thatch that the cover crops have left behind serves as a mulch layer to slow surface evaporation, which helps cash crops get through periods of hot, dry weather.
Cover crops also help with weed suppression. With concerns about the growing number of herbicide-tolerant weeds, farmers can turn to cover crops for some help. A few species do an excellent job of suppressing small-seeded annual weeds. Some species physically alter the growing environment and choke out weeds via shade or more aggressive water and nutrient uptake. Others actively release chemicals that kill or prevent weeds from germinating. Winter cereal rye is known for its weed-fighting characteristics.
Finally, legumes are plants that — because of a symbiotic relationship with a beneficial bacterium — can take atmospheric nitrogen, convert it to a form usable by cash crops and store it below the surface of the soil. This requires fewer nitrogen inputs to achieve your fertility prescription. The catch is that these plants don’t start producing a lot of nitrogen until they flower, which sometimes can conflict with the optimal planting time for a cash crop. Some examples of legumes that will provide free nitrogen are crimson clover, hairy vetch and winter peas. Many other species of cover crops can take in extra nitrogen that cash crops leave behind and store it over the winter. The nitrogen is then available for next year’s cash crop.
MAXIMIZING MANAGEMENT
While cover crops can provide a wide array of benefits, there are some management considerations to keep in mind to prevent learning curve-related headaches.
Cover crops are a complex add-on to a current operation. They can require changes in several aspects of the yearly management plan. For this reason, it is best to start small. Farmers don’t have to convert the whole farm at once. Instead, they can select portions of a farm that are generally easier to manage, more convenient to monitor and pose the least risk. Then, as the experience level and comfortability grow, farmers can expand practices working well to new areas. Also, deciding locations, species, seeding methods, termination methods and timing months in advance will pay dividends when it comes time to act.
One issue with using cover crops, specifically cereal grains, before corn is the potential for the cover crop to put on a lot of vegetative growth before conditions allow for termination. Cereal rye is known for its ability to grow rapidly in the spring when temperatures warm up and the ground is still moist. This leaves a lot of residues that can make it difficult to plant. It also leaves more than the ideal amount of dead plant material on which soil microbes feed. As these microbes break down the dead thatch, they also consume nitrogen, the same nitrogen intended for corn. This can cause slowed establishment, reduced stand counts. It also can require producers to apply more nitrogen fertilizer than initially planned. To avoid this issue, the recommendation is to use a cover crop that will winter kill, such as oats, or prioritize termination before the cover crops start growing.
CREDITS FOR COVER CROPS
As efforts in climate-smart agriculture and sustainability grow, so too do incentive programs for cover crops. Currently, three categories of programs can help farmers in Missouri offset some of the costs associated with cover crop implementation.
The first category includes government cost-share programs, which pay farmers a predetermined amount to implement cover crops on their row-crop acres. Incentivizing the environmental benefits cover crops can provide (reduced erosion, nutrient loss, better water infiltration, etc.). Federal programs including the Conservation Stewardship Program (CSP) and the Environmental Quality Incentive Program (EQIP) are lucrative options. CSP provides excellent financial incentives for producers to implement cover crops when coupled with other practices that address soil health, water quality, etc.
EQIP delivers a slightly more flexible option that can be tailored to the farmer’s operation, but it comes with similar federal government paperwork and some competition for selection. Another government-led option is the soil and water conservation cost-share practices under the Missouri Department of Natural Resources. This is the easiest of the three options but has a life-time producer cap of $20,000.
The second category includes grant programs for farmers. Missouri Soybeans has partnered on three projects that received funding via the United States Department of Agriculture’s investment of $3.1 billion into the Partnerships for Climate Smart Commodities initiative. The University of Missouri’s Center for Regenerative Agriculture administers the Climate Resilient Crops and Livestock (CRCL) grant with a firm cover crop component. An essential “soy-rye” initiative pays producers to use a cereal rye cover crop before their soybean cash crop. A diverse mix option is available, too. There are also stackable incentives for later termination and grazing cover crops. Farmers for Soil Health is an opportunity focused on increasing cover-cropped acres in 20 states. It provides $50 per acre over three years ($25, $15, $10) to incorporate cover crops on row -crop land.
The Soil and Water Outcomes Fund takes a slightly different approach to incentivizing conservation practices. With this program, farmers choose the conservation practices they plan to implement (cover crops, reduced tillage, etc.), and their payment is based on those practice changes.
The third category includes a market-based carbon programs. Large corporations are being pushed to meet sustainability goals by their shareholders. When cover crops grow, they capture atmospheric carbon in the soil. If these acres were enrolled in a carbon program, a third-party company would verify and quantify the number of credits a farmer produced, then sell those credits to corporations and send a particular portion of that money to the farmer. There are a lot of different carbon programs out there, all with unique requirements and financial agreements. Several can be “stacked” (or used on the same acres) with some previously mentioned programs, providing two revenue streams for the same practice. Regarding carbon programs, producers are encouraged to read the contracts carefully and do what they feel is best for their operation.
As agriculture embraces sustainability and environmental responsibility, cover crops emerge as a tool for building healthier soils and supporting a resilient farming ecosystem. This adoption safeguards the foundation of farming operations and paves the way for a more sustainable and productive agricultural future. When making decisions this December, consider cover crops — one of the best investments you can make in the family operation.
Visit mosoy.org to learn more about cover crops and how to get started.
