Cover crops manage soil fertility and quality as well as pests and diseases.
Photo by Fotolia/oleksajewicz
The U.S. Department of Agriculture’s Sustainable Agriculture Research and Education (SARE) program has published the results of a nationwide survey that assesses the benefits, challenges, yield impacts, and scale of adoption of cover crops. The SARE program worked with the Conservation Technology Information Center (CTIC) to survey more than 750 farmers who have grown cover crops across 36 states. The results of the survey confirm that farmers are seeing multiple advantages of cover crops, including increased yields of corn and soybeans following the cover crop.
According to SARE, key findings of the survey include:
- During the fall of 2012, corn planted after cover crops had a 9.6 percent increase in yield compared to side-by-side fields with no cover crops. Likewise, soybean yields were improved 11.6 percent following cover crops.
- In the hardest hit drought areas of the Corn Belt, yield differences were even larger, with an 11.0 percent yield increase for corn and a 14.3 percent increase for soybeans.
- Surveyed farmers are rapidly increasing acreage of cover crops used, with an average of 303 acres of cover crops per farm planted in 2012 and farmers intending to plant an average of 421 acres of cover crops in 2013. Total acreage of cover crops among farmers surveyed increased 350 percent from 2008 to 2012.
- Farmers identified improved soil health as a key overall benefit from cover crops. Reduction in soil compaction, improved nutrient management, and reduced soil erosion were other key benefits cited for cover crops.
- Farmers are willing to pay an average (median) amount of $25 per acre for cover crop seed and an additional $15 per acre for establishment costs (either for their own cost of planting or to hire a contractor to do the seeding of the cover crop).
Most farmers (72 percent) choose to plant winter cereal grains as a cover crop, while 62 percent choose brassicas and 58 percent choose legumes. Roughly one-third of respondents plant multi-species mixes, which can fix nitrogen, scavenge nutrients, and break up hard pan. Most of the producers surveyed plant cover crops because they reduce soil compaction and erosion. Over 40 percent of respondents plant cover crops primarily for the nitrogen scavenging benefits.
Perhaps most importantly for producers, the survey results note:
- Respondents reported increases in 2012 cash crop yields in fields where they used cover crops – an average corn yield of 126.2 bushels per acre after cover crops vs. 115.1 bushels per acre without cover crops. It is important to note that the 2012 drought had a profound impact on corn yields across much of the country [...]
- Proponents of cover crops point out that water held in the soil by the shading action of cover crops, and the additional moisture-holding capacity of soil in which long-term cover cropping and other conservation practices have increased soil organic matter, likely accounted for much of the yield gain where cover crops were planted.
- Producers saw a similar yield increase with soybeans. Increases in yield were even greater in seven states severely impacted by the 2012 drought – Illinois, Indiana, Iowa, Kansas, Missouri, Nebraska and South Dakota. The increasing popularity of cover crops points to the great work that SARE and groups like Practical Farmers of Iowa (PFI) have been doing for many years to assess, demonstrate, and publicize the benefits of cover cropping. Nonetheless, significant barriers to cover crop adoption remain.
The new survey results clearly demonstrate that cover crops are increasing rather than decreasing cash crop yields. This information should help USDA’s Risk Management Agency assess the risk of adopting cover crops. The survey results also provide a great opportunity for USDA’s Natural Resources Conservation Service (NRCS) to increase outreach to producers through its Soil Health Initiative.