Optimization of Starter Nitrogen Fertilizer Application for Corn Planted into a Cereal Rye Cover Crop

View the project final report

Commodities

• Agronomic: corn, rye

Practices

• Crop Production: cover crops, fertilizers, nutrient management

Problem and justification: Inclusion of cover crops in conservation tillage crop production systems in the Northeast has centered around erosion control and nutrient management. In particular, cereal cover crops are used after corn harvest to scavenge residual nitrogen (N). Since interest has grown in producing more cover crop biomass for soil health, forage, water and N management, and weed suppression, producers are now delaying cover crop termination prior to corn planting to take advantage of these benefits. This trend poses a challenge in corn production as producers have increasingly switched to split-N applications (i.e. starter and sidedress) to improve N use efficiency for both optimal yield and environmental stewardship. The combination of management changes poses a challenge in corn production. More mature cereal cover crops have greater C:N, which can significantly decrease N availability due to immobilization for early season corn growth and development. As a result, producers at cover crop extension events routinely inquire about the need to adjust N management to compensate for early corn N needs. Further, these producers are concerned as to whether they need to increase the total N application rate. Such N management decisions present both production and environmental management challenges for producers and the public.

Solution and approach: There is a critical need to examine both early-season N management in field corn production as well as the overall fertilizer rate needed across a gradient of cereal rye biomass. To address these concerns, we will conduct field studies across the Northeast region from MA to DE to characterize cover crop-based no-till field corn performance. Field studies will establish gradients of starter and sidedress N rates at standard and high total N application rates across a range of cereal rye biomass (Attachment 1). Our research, in combination with a strong Outreach and Education program, will provide sound management and environmental solutions addressing the needs of producers and the public. The education component, which complements the research component, will be carried out through presentations at meetings and conferences and on-site field days, articles for in-season newsletters, and updating written extension publications. Outreach efforts feature the support of project personnel to assist farmers who wish to experiment with delaying cereal rye termination. Outreach goals will be met using traditional approaches and in conjunction with Northeast Cover Crops Council activities and events

A total of 60 farmers in DE, MA, MD, NY, and PA will terminate cereal rye 2-4 weeks later than they usually would (April vs. early March) on 2,400 acres, doubling the average amount of cereal rye biomass produced and preventing the leaching of 45,000 lbs N into local watersheds.