Cover crop can offset negative effects of corn silage harvest on soils in a corn silage–soybean rotation

Authors: Ruis, Sabrina; O'Brien, Peter; CRESPO, CECILIA - Oak Ridge Institute For Science And Education (ORISE); KASPAR, THOMAS - Retired ARS Employee; Kovar, John

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2026
Publication Date: 3/1/2026
Citation: Ruis, S.J., O'Brien, P.L., Crespo, C., Kaspar, T.C., Kovar, J.L. 2026. Cover crop can offset negative effects of corn silage harvest on soils in a corn silage–soybean rotation. Soil Science Society of America Journal. https://doi.org/10.1002/saj2.70211.
DOI: https://doi.org/10.1002/saj2.70211

Interpretive Summary: Harvest of corn as silage is a key component of many animal operations. The lack of residue cover following harvest often leads to degradation of soils. Pairing corn silage harvest with a cover crop could offset soil degradation, but long-term data are few. We studied the impact of corn silage and corn grain with and without a winter rye cover crop on soil health indicators and function after 21 years of management in a highly productive soil of the central U.S. Corn silage with a cover crop increased soil microbial biomass and activity and easily decomposed organic matter levels compared with silage without a cover crop. This increase in these soil properties was due to increased biomass input from the cover crop. Silage with a cover crop had soil property levels similar to corn for grain for about 75% of the measured soil properties. The cover crop did not affect crop yields across years. Higher crop yields were linked with improvements in soil microbial biomass and activity and organic matter level. Overall, a winter rye cover crop following corn silage can maintain soil health at levels similar to corn grain systems without reducing yields. This work highlights the long-term value of good soil health to maintain crop yields for stakeholders and the scientific community considering use of corn silage and cover crops.

Technical Abstract: Harvesting corn (Zea mays L.) as silage is an important component of many livestock operations but can lead to soil degradation without support practices like cover crops (CCs). However, long-term research investigating the effects of such combination on soils with comparison to a corn grain system is minimal. Thus, our objectives were to assess the 21-year impact of corn silage and corn grain with and without a winter rye (Secale cereale L.) CC on soil biological, chemical, and physical health indicators in a no-till corn-soybean (Glycine max L.) rotation and determine whether effects of silage harvest persist following the subsequent crop in a Mollisol of the central U.S. Silage with cover crop (SilageCC) increased soil biological (microbial biomass and activity) and related soil properties (labile and total C) compared with silage no CC (SilageNCC) due to the greater biomass input. In both rotation phases, SilageCC had no effect on 6 of 13 soil properties and affected 1 property compared with grain corn. As expected, SilageNCC negatively affected soil properties (8 soil properties), and such negative effects persisted following the soybean phase for 8 properties. Treatment effects on soil properties were few below 5 cm. The CC did not affect crop yields across years, but crop yields were positively correlated with some soil biological and related properties. Overall, a winter rye CC following corn silage can maintain many soil properties at levels similar to corn grain systems without negatively impacting yields, unlike corn silage without a CC, in the Midwestern Mollisol of this study.