A common set of questions raised at our field days this year seem to revolve the use of cover crop mixtures. For example: what are the advantages or disadvantages for my soil health and crop yield when using mixtures versus single species cover crops? The Iowa Cover Crop Working Group realized there was limited research to answer these types of questions for Iowa famers, so we have set forth with our own mixture cover crop research and demonstration plots at six farmer association research farms across the state in an attempt to provide some answers.
Plots have been established at the following sites: Northwest at Sutherland, Northern at Kanawha, Northeast at Nashua, Southwest-Armstrong at Lewis, Southeast at Crawfordsville, and McNay at Chariton.
The plots compare three treatments: no cover crop, a single species cover crop, and a mixture cover crop. Each treatment is replicated four times at each site, for a total of 24 plots at each farm. Preceding the corn crop the single species is oats and the mix contains hairy vetch, oats, radish. Preceding the soybean crop the single species is rye and the mix contains rapeseed, rye, radish. The sites were hand planted between August 20th and August 28th. Soil sampling for total nitrogen, total carbon, organic matter, pH and bulk density are scheduled to begin at the end of October or early November.
Be sure to subscribe to our blog for updates as this project moves forward!