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Ten-Year Iowa Cover Crop Study Shows No Yield Decline

Iowa Learning Farms (ILF) and Practical Farmers of Iowa (PFI) have published the final results of their 10-year field-scale study of the effects of winter rye cover crops on corn and soybean yields. With consistent results across the full decade of recording and measurements, the final report notes no significant improvement or decline in cash crop yields attributable to the use of cover crops. “The cooperating farmers in the study were asked to plant full field length contiguous strips with and without the cover crop to provide a valid comparison at field scale,” said Jaqueline Comito, director of ILF. “While five farms stayed the course for the full 10 years, other participants saw enough value or improvement to convince them to plant cover crops in the entire field, thereby removing themselves from the study.” Stefan Gailans, PFI project lead, adds, “While the yields did not show significant changes, the cooperating farmers noted significant increases in biomass and reduced erosion and washouts in fields with cover crops.” The final report from the study is available online.