Utilizing 4R-Nitrogen Management to Mitigate Winter Cereal Rye Cover Crop Effects Before Grain Corn: A Provincial Approach

Lead Applicant: Laura Van Eerd

Research Priority: Sustainable Production Systems

Program Type: Tier 1

Funding Cycle: 2026/2027

Research Centre: Ontario Crops Research Centre - Elora, New Liskeard, Ridgetown, Winchester

Research Summary: Cereal rye is the only reliable cover crop option in a soybean-corn rotation, but it suppresses early corn growth, potentially reducing yields. Adjusting nitrogen fertilization management can overcome rye limitations; however, the interactive effects of rye cover crop before grain corn with 4R-N strategies are largely unknown across diverse soil types and climatic conditions. With an outcome of provincial and regional BMP recommendations, the objective of this project is to quantify 4R-N with and without rye cover crop on corn grain yield, economics, nitrogen use efficiency and risk of N losses. Field split-block experiment (4 replicates) of +/- rye cover crop and 13 4R-N treatments at 12 site-years. Benefits to the Ontario agri-food sector include: consumers have protected soil/water/food; farmers have location-specific recommendations; and policy and farmers will have economic data to inform decisions.