Oats Cover Crops and Corn Yield Findings

By Scout Nelson

A research trial conducted at the South Dakota Agricultural Experiment Station Northeast Research Farm examines how cover crop mixtures perform after oats and how they affect corn yield the following year. The study focuses on cover crops planted after oats during the 2024 growing season and evaluates their influence on soil conditions and corn production.

Results show that cover crop mixtures planted after oats produce about 2,400 pounds per acre of dry biomass. However, similar biomass levels are also observed in plots without planted cover crops because volunteer oats grow naturally. This suggests that much of the biomass in cover crop plots may come from volunteer oats rather than the planted mixtures themselves.

Weather conditions during September and October 2024 are dry, limiting cover crop growth. Due to low rainfall, the cover crops do not establish strongly, which reduces their potential impact on soil health and crop performance. Despite these challenges, corn yield in the following season does not differ between fields with cover crop mixtures and fields without them.

The study finds that residue management plays a larger role than cover crops in influencing corn yield and soil conditions. Corn yield is lower when crop residue is removed compared to when residue is kept. Researchers believe this may be linked to nutrient movement and soil activity associated with residue presence.

Soil testing shows that cover crop mixtures do not significantly change most soil properties measured during the study. In contrast, removing oat residue affects many soil health indicators. Soil water content generally remains stable whether residue is removed or retained, except during extremely dry periods in October 2024 and April 2025.

Throughout the corn growing season, soil moisture levels remain similar or slightly higher in plots where residue is removed. After one year, residue removal does not cause major negative changes to soil health.

Researchers emphasize that these results are based on a single year of data. Long-term studies are needed to better understand how cover crops and residue management affect soil health and crop yields over time.

Photo Credit: istock-rustic