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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #421421
Research Project: Sustainable Intensification in Agricultural Watersheds through Optimized Management and Technology

Location: Agroecosystems Management Research

Title: Rye performance in central Iowa under different seeding and nitrogen fertilizer rates

Author
item CRESPO, CECILIA - Oak Ridge Institute For Science And Education (ORISE)
item Malone, Robert
item Radke, Anna
item Kovar, John
item Emmett, Bryan
item Feyereisen, Gary
item Thorp, Kelly
item RICHARD, TOM - Pennsylvania State University
item O'Brien, Peter

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/8/2025
Publication Date: 7/9/2025
Citation: Crespo, C., Malone, R.W., Radke, A.G., Kovar, J.L., Emmett, B.D., Feyereisen, G.W., Thorp, K.R., Richard, T., O'Brien, P.L. 2025. Rye performance in central Iowa under different seeding and nitrogen fertilizer rates. Agronomy Journal. https://doi.org/10.1002/agj2.70112.
DOI: https://doi.org/10.1002/agj2.70112

Interpretive Summary: Double cropping, when two crops are grown and harvested in the same field in one year, may be a useful way to increase crop production and green ground cover without negative effects to the environment. We studied a double cropping system using a winter rye cover crop and soybean for two years in central Iowa. We found that rye biomass production can be optimized with low seeding rates and without N fertilization, whereas higher seeding rates increase spring ground cover that may reduce erosion and weeds. However, soybean yields were lower than local averages suggesting more research is needed to balance double systems such as rye termination time and alternative soybean varieties. Our study shows some of the tradeoffs between crop production, green ground cover, and inputs such as seeding and fertilizer rates when double cropping. Our findings are important to producers, scientists, crop advisers, and policy makers trying to find the best agricultural management practices in the North Central U.S.

Technical Abstract: The inclusion of a harvested winter cereal in corn (Zea mays) – soybean (Glycine max (L.) Merr.) rotations can increase productivity and sustainability of these cropping systems. Still, management of the winter cereal must be optimized for efficient production of both crops in the rotation. A field study was conducted from 2021 to 2023 in central Iowa, USA to evaluate rye (Secale cereale L.) spring green ground cover, biomass production, and aboveground nitrogen (N) accumulation in a rye-soybean rotation, using three seeding rates (20, 40, and 60 kg ha-1) and three N rates (0, 30, and 60 kg N ha-1). Green ground cover was up to 42% higher in the highest seeding rates. Conversely, rye biomass production was not affected by seeding or N rates and averaged 3.0±1.1 and 4.9±1.3 Mg ha-1 in the first and second growing seasons, respectively. Rye N accumulation increased 0.13 and 0.51 kg N ha-1 for each kg N applied in the first and second growing seasons, respectively. Soybean yield was similar among treatments and lower than the county average production, especially in the second growing season due to limited precipitation. The results indicate that rye biomass production can be optimized with low seeding rates and without N fertilization, whereas higher seeding rates increase spring ground cover. However, because of its effect on soybean yields, further studies are needed to evaluate rye termination time and alternative soybean varieties to optimize soybean production after rye for central Iowa conditions.