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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #421510
Research Project: Enhancing Cropping System and Grassland Sustainability in the Texas Gulf Coast Region by Managing Systems for Productivity and Resilience

Location: Grassland Soil and Water Research Laboratory

Title: Corn responses to nitrogen fertilization as influenced by cover cropping: A meta-analysis

Author
item JUNEJA, PULKIT - Texas A&M University
item BAATH, GURJINDER - Texas A&M University
item BRAR, JAIVEER - Texas A&M University
item Flynn, Kyle
item Krecker-Yost, Jenifer
item RAJAN, NITHYA - Texas A&M University

Submitted to: Agronomy for Sustainable Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2025
Publication Date: 1/7/2026
Citation: Juneja, P., Baath, G.S., Brar, J.S., Flynn, K.C., Krecker-Yost, J.L., Rajan, N. 2026. Corn responses to nitrogen fertilization as influenced by cover cropping: A meta-analysis. Agronomy for Sustainable Development. https://doi.org/10.1007/s13593-025-01067-6.
DOI: https://doi.org/10.1007/s13593-025-01067-6

Interpretive Summary: Cover crops are increasingly used in U.S. corn production, but questions about nitrogen management have slowed adoption. A study reviewed how nitrogen fertilization affects corn yield and nitrogen content after cover crops. Results showed that cover crops can increase corn yield by 11% and nitrogen content by 22%. Legume cover crops were especially effective, increasing yield by over 50% without added fertilizer. Grass and brassica cover crops required higher nitrogen inputs (200 kg/ha) to match yields from fields without cover crops. Timing also mattered—terminating cover crops close to planting produced better yields than ending them earlier. Manure and ammonium-based fertilizers worked better than urea. This meta-analysis shows that selecting the right cover crops, managing nitrogen inputs, and timing termination properly can increase yields, improve soil health, and make corn-cover crop systems more successful.

Technical Abstract: Adoption of cover crops in corn producing regions of the United States (U.S.) has progressed at an uneven pace. Since corn is a nitrogen demanding crop, limited understanding of nitrogen fertilizer management for corn following cover crops is one among the major barriers to wide adoption of cover crops. To address this knowledge gap, a meta-analysis was conducted to examine the impacts of nitrogen fertilization on corn yield and nitrogen content following cover crops, considering various agronomic practices and soil conditions. Studies comparing corn growth with and without cover crops were selected for analysis, with 392 and 228 individual observations included for corn yield and corn nitrogen content, respectively. Results depicted that integration of cover crops tends to boost corn yield and nitrogen content by 11% and 22%, respectively. The type of cover crop species impacts corn performance greatly, with legumes improving yield by more than 50% in subsequent non-fertilized corn. Grass and brassica cover crops require nearly 200 kg ha-1 nitrogen to achieve yield comparable to fallow systems, likely due to nitrogen immobilization by cover crop residues. Timing of cover crop termination also plays a critical role in yield outcomes, with late termination (within one week of corn planting) producing greater corn yield than early termination. Additionally, manure and ammonium-based fertilizers perform presumably better than urea-based fertilizers in systems involving cover crops. Key considerations include the selection of cover crop species and nitrogen fertilizer types to maximize the agronomic, environmental, and economic benefits in cover crop-corn production systems. These findings suggest that a well-managed cropping system has potential to effectively integrate cover crops while achieving yield goals.