A research trial was completed at the South Dakota Agricultural Experiment Station Northeast Research Farm comparing cover crop mixture performance after oats and its effect on corn yield the following year.
Cover crops planted after oats in 2024 produced about 2400 lb./ acre of dry biomass, although volunteer oats in ‘check’ plots produced similar biomass to the cover mixtures. This suggests that biomass in the cover crop treatment plots could also be due to volunteer oats. The growing conditions for cover crops were poor in September and October of 2024 due to a lack of rainfall. Corn yield was not affected by the cover crop mixture planted, but was much less when residue was removed vs retained. This could have been due to more nutrient tie-up when residue was retained vs removed. Cover crop mixtures that were planted did not affect most of the soil properties that were measured. However, eliminating the oats residue affected many of the measured soil properties. Removal of residue did not reduce soil water content, except during exceptionally dry conditions in October 2024 and April 2025. However, throughout the corn-growing season, soil water content was similar to or higher when the residue was removed. Removal of residue did not negatively impact most soil properties after one year.
These results are from a one-year and will need to be explored in upcoming growing seasons to see consistent improvement in soil health indicators.
