Winter Cereal Rye Cover Crop Effect on Cash Crop Yield, Year 8
Winter Cereal Rye Cover Crop Effect on Cash Crop Yield: Year 8 is now available! This is a long-term project being conducted by Iowa Learning Farms and Practical Farmers of Iowa. Between 2009 and 2016, 12 farmer-cooperators have contributed to 59 site-years of on-farm research to investigate what effect a cereal rye cover crop might have to yields of corn and soybeans.
Over the course of this project, farmers reported that in 55 of 59 site-years, properly managed cover crops had no negative effect on corn and soybean yields. Of those 55 site-years, soybean yields were improved by cover crops in 7 instances and corn yields were improved in 2 instances (both occurring in 2016).
How the Study was Conducted
This long-term study employs a “paired strips” design. Cooperators established and maintained replicated strips of “cover” and “no cover” that run the length of their field for the duration of the study in corn-soybean rotations. Cooperators were allowed to manage their cover crops and cash crops however they saw fit. The table below shows how the six farmer-cooperators who participated in 2016 managed cover crops and cash crops during the growing season.
Corn and Soybean Yields 2015 and 2016
In the past two years, corn yields at locations have mostly been at or above 200 bu/ac (Fig. 1). In 2016, corn yields were improved by the cover crop at West Chester and New Market. At New Market, an especially wet year reduced corn yields overall but the cover crop appeared to soften that blow.
Figure 1. Corn yields in 2015 and 2016 as affected by the cereal rye cover crop.
Soybean yields have been near 60 bu/ac the past two years with improvements from the cover crop being observed at New Market, West Chester and Kalona in 2015 (Fig. 2).
Figure 2. Soybean yields in 2015 and 2016 as affected by the cereal rye cover crop.
Long-Term Trends
Over the course of this project, 34 site-years have been dedicated to determining the effect of the cover crop on corn yields and 25 site-years have been dedicated to determining the effect of the cover crop on soybean yields. In the majority of cases, yield were not affected by the cover crop. Read the full report here.
For more information on this study, contact Stefan Gailans at stefan@practicalfarmers.org.
This project has been made possible by funds provided by the State Soil Conservation Committee, the Iowa Department of Agriculture and Land Stewardship, NCR-SARE, the Walton Family Foundation and Iowa Learning Farms.