STUDY SHOWS COVER CROPS HAVE LITTLE EFFECT ON YIELDS
May 20, 2014
Source: Iowa Learning Farms and Practical Farmers of Iowa
Cereal rye cover crops added to a corn-soybean rotation seems to have little effect on yield, according to a five-year study conducted by Iowa Learning Farms and Practical Farmers of Iowa. Ten Iowa farmers have devoted part of their acres to conduct the study.
Between 2009 and 2013, the farmers established side-by-side strips of corn/soybean crops with a winter cereal rye cover crop, and strips using no cover crop, replicated at least two times. The cover crop was either drilled after harvest or aerially seeded into standing crops each fall. At each site, the cover crop was terminated the following spring by herbicide.
*When the project began, the farmers were concerned that the winter cereal rye would impact their corn or soybean yields negatively. But after harvest was completed each year, the farmers reported that this was not so. The properly managed cover crops had little to no negative effect and, in some cases, actually improved soybean yield.
"When I first started the trial, I thought the following crop would suffer because of the competition for water and nutrients," says Butler County farmer Rick Juchems. "That has been proven wrong with stronger yields and better soil quality." Juchems' corn yields remained steady and he saw a slight improvement in soybean yields on the cover crop acres last year as well as in 2011.
Proper management is a key issue when incorporating cover crops into a corn-soybean rotation. Knowing which cover crop to plant, when and how to plant and terminate the cover crop are the main components to successful management. There are many resources to help farmers with answers to these management details. Primary resources can be a cover crop farmer champion contacted through the ILF or PFI network, or a local Extension field agronomist or NRCS field specialist.
Cover crops provide numerous benefits to farm fields. They reduce erosion by holding soil in place, increase soil microbial activity and nutrient cycling, reduce excess nitrogen and increase soil carbon. The biomass from the plant helps to build soil organic matter as well. Cover crop varieties range from grains like cereal rye, legumes such as hairy vetch, and brassicas including radish and rapeseed. Winter cereal rye was the only cover crop used in this study.
The farmers in this study include:
*Bill Buman, Harlan;
*Jim Funcke, Jefferson;
*Rick Juchems, Plainfield;
*Whiterock Conservancy, Coon Rapids;
*Mark Pokorny, Clutier;
*George Schaefer, Kalona;
*Jerry Sindt, Holstein;
*Rob Stout, West Chester;
*Gary and Dave Nelson, Fort Dodge; and
*Kelly Tobin, New Market.
A four-page summary of the study is available online at the ILF website here.
About Practical Farmers of Iowa
Founded in 1985, Practical Farmers of Iowa is an open, supportive and diverse organization of farmers and friends of farmers, advancing profitable, ecologically sound and community-enhancing approaches to agriculture through farmer-to-farmer networking, farmer-led investigation and information sharing. Farmers in our network produce corn, soybeans, beef cattle, hay, fruits and vegetables, and more. For additional information, call (515) 232-5661 or visit www.practicalfarmers.org.
About Iowa Learning Farms
Established in 2004, Iowa Learning Farms is building a Culture of Conservation, encouraging adoption of conservation practices. Farmers, researchers and ILF team members are working together to identify and implement the best management practices that improve water quality and soil health while remaining profitable. Partners of Iowa Learning Farms are the Iowa Department of Agriculture and Land Stewardship, Iowa State University Extension and Outreach, Leopold Center for Sustainable Agriculture, Iowa Natural Resources Conservation Service and Iowa Department of Natural Resources (USEPA section 319), Conservation Districts of Iowa, Iowa Farm Bureau, Iowa Water Center and Practical Farmers of Iowa. For more information about Iowa Learning Farms, visit the website: www.extension.iastate.edu/ilf.