Trends in Use of Cover Crops in the U.S.
It is well established that cover crops (CC) should be considered as an integral part of any cropping system that seeks to become more sustainable since CC’s provide documented environmental and soil health benefits. These benefits arise from:
• Providing soil cover to prevent erosion in the off-season between cash or forage crops;
• Increasing water infiltration into the soil;
• Reducing nutrient loss and leaching from the soil profile;
• Lowering residual nitrogen (N) content in the soil;
• Reducing herbicide runoff;
• Suppressing or reducing early-season weeds and weed biomass;
• Providing plant residues to increase soil organic matter; and
• Increasing the soil N supply for a following summer grain crop.
A publication titled “Cover Crop Trends, Programs, and Practices in the United States” by Wallander et al. of the USDA-ERS provides results from USDA’s Agricultural Resource Management Survey that was conducted to determine cover crop trends related to major commodity crops grown in the U.S.
• According to USDA, a CC may include grasses, legumes, and forbs that are grown for seasonal cover to provide erosion control, and soil health and water quality improvement. Cover crops may be grazed or harvested for hay or silage, but cannot be harvested for grain or seed.
• Use of CC’s increased by 50% between 2012 (10.3 million acres) and 2017 (15.4 million acres) on U.S. cropland. Financial incentives provided by federal (e.g. EQIP), state, and private organizations were largely responsible for this increase. These incentives somewhat offset the extra costs that are incurred when CC’s are used. However, CC adoption was still a very low 5.1% in 2017.
• Fields devoted to cotton and corn silage were more likely to be planted to CC’s than fields devoted to corn-for-grain or soybeans. In fact, the level of CC adoption varied substantially by the primary commodity crop that followed the CC, with CC adoption just over 5% on acreage used for corn-for-grain, 8% for soybean acreage, about 13% for cotton acreage, and about 25% on corn-for-silage acreage.
• Conservation tillage and testing for soil nutrients and organic matter were more often practiced by producers that used CC’s. This indicates that most CC use was part of a suite of conservation practices that make up a producer’s soil health management system. However, no-till (104 million acres) and conservation tillage (97 million acres, excluding no-till) were more widely used than were CC’s.
• Farmers have choices when choosing CC species to plant, and selecting the proper species or mixture of species should depend on the intended purpose of planting a CC. Costs associated with the selected CC species or species mix is also a consideration. When corn, cotton, or soybeans are the subsequent cash crop following a CC, small grains are most often used. Rye is the most used CC species before soybeans, and its seed was the cheapest vs. that of oats, winter wheat, and a mix.
• Just under 1/4 of soybean fields with CC’s were planted with a CC mix.
• In soybean, corn-for-grain, and cotton fields, herbicide termination of CC’s before cash crop planting was used on almost 2/3 of the acreage with CC’s. Tillage was used for CC termination on about 30% of the CC acreage.
• Surveyed soybean farmers who used a CC were more likely (72% vs. 36%) to use no-till as a conservation measure. No-till was more likely to be used with soybeans that with corn and cotton.
• Finally, the survey results showed that farmers who use CC’s are more likely to use other soil health-related conservation practices such as conservation tillage, conservation rotations, and nutrient management. However, since the survey results indicated that CC adoption was very low, the use of conservation management systems that include CC’s is being practiced on only a limited acreage in the U.S.
The following points are especially noteworthy. 1) These statistics regarding CC use are from several years ago. Thus, it is assumed that use of CC’s on U.S. cropland is increasing to this day. However, even a modest increase in the adoption of CC use on U.S. cropland since these survey numbers were obtained means that still only a relatively small percentage of cropland acreage has CC’s planted on it. 2) Since there is no financial incentive for a producer to use CC’s–i.e. extra cost with no immediate financial return–it certainly seems likely that CC use will stay low. That is why financial incentives that will encourage and support producer use of this conservation management practice will always be important. Such financial incentives will need to remain in place for the long-term since the benefits arising from use of CC’s generally require a long-term commitment for those benefits to accrue. And even then, such benefits may not result in an obvious financial improvement for the producer. It will be interesting to see if government programs that provide financial incentives to use CC’s continue for the long-term, and if so, what their impact on CC use will be.
Takeaway. Using CC’s to arguably improve soil health and crop yields is a noble undertaking, but they must be used long-term to achieve a projected/intended benefit. However, their use likely will not be adopted long-term if there is no financial reward in a time span that a producer can withstand financially.
Readers of this article are encouraged to access a Cover Crops White Paper and the various blog articles (click Articles, filter Sustainability, search Cover Crops) that have been posted on this website to learn more about the benefits that can be expected from using CC’s, and how they should be managed to achieve those benefits.
Composed by Larry G. Heatherly, Jan. 2023, larryh91746@gmail.com