Cereal rye cover crop termination at or before soybean planting has minimal effect on soybean yield across the midwestern US

Authors: SEVERO SILVA, TATIANE - University Of Wisconsin; MOURTZINIS, SPYRIDON - University Of Wisconsin; MCMECHAN, JUSTIN - University Of Nebraska; CARMONA, GABRIELA - University Of Nebraska; POTTER, BRUCE - University Of Minnesota; TILMON, KELLY - The Ohio State University; Hesler, Louis; SEITER, NICHOLAS - University Of Illinois; WRIGHT, ROBERT - University Of Nebraska; Osborne, Shannon; HUNT, THOMAS - Retired Non ARS Employee; CONLEY, SHAWN - University Of Wisconsin

Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2024
Publication Date: 4/28/2024
Citation: Severo Silva, T., Mourtzinis, S., Mcmechan, J., Carmona, G., Potter, B.D., Tilmon, K., Hesler, L.S., Seiter, N.J., Wright, R., Osborne, S.L., Hunt, T., Conley, S.P. 2024. Cereal rye cover crop termination at or before soybean planting has minimal effect on soybean yield across the midwestern US. Field Crops Research. 312. Article 109393. https://doi.org/10.1016/j.fcr.2024.109393.
DOI: https://doi.org/10.1016/j.fcr.2024.109393

Interpretive Summary: Interest is growing among Midwestern farmers in the potential benefits of cereal rye as a winter-sown cover crop for soybean. However, they are concerned about the potential trade-offs of this practice. In response to the concerns, field experiments were conducted from 2019 to 2021 across 28 location-years in the Midwestern US to assess cover crop termination before, at, and shortly after soybean planting. Termination timing did not reduce soybean yield in 27 of 28 location-years compared to a no cover crop treatment, and cereal rye-biomass accumulation was not related to soybean yield. The results suggest that farmers who adopt cereal rye as a cover crop in the region of this study have a flexible management window for terminating cereal rye with regard to soybean yield. On the other hand, there were no significant soybean yield benefits that would justify the cost associated with the use of cover crops. Future studies are recommended to better understand how cereal rye-cover crops may influence other aspects of soybean agronomy and profitability and also soil quality.

Technical Abstract: Interest is growing among farmers in the Midwestern US region in the potential benefits of establishing cereal rye (Secale cereale L.) as a cover crop. However, they are concerned about the implications and potential trade-offs due to this practice. Field experiments were conducted from 2019 to 2021 across 28 location-years in the Midwestern US to assess the effects of cereal rye cover crop termination timing on soybean yield. Cereal rye was terminated before, at planting, and after soybean planting. Results showed that termination timing did not reduce soybean yield in 27 of 28 location-years compared to no cover crop treatment. There was no clear evidence indicating that a threshold level of cereal rye biomass accumulation reduced soybean yield. Our results suggest that farmers who adopt cereal rye as a winter cover crop in the examined region have a flexible management window for terminating cereal rye, as the timing of termination has minimal effect on soybean yield. However, there were no significant soybean yield benefits that would justify the associated cost with the use of cover crops. Therefore, conducting long-term studies in the future is highly recommended to better understand how cereal rye cover crops can influence soybean yield and soil quality properties over time.