Currently, farmer surveys suggest that <5% of row crop acreage in the North Central region of the U.S. receives cover crops. Cereal rye is the most common cover crop in the region because it is winter hardy and provides several environmental ecosystem services. However, reduced yield for corn and occasionally soybean (in wet springs) following cereal rye has been well documented and widely attributed to reduced soil inorganic nitrogen (N) availability. The negative trade-off of reduced yield is a major contributor to the lack of cover crop adoption in the region. Thus, there is a critical need to develop cover crop management strategies that mitigate cash crop yield reductions, while maintaining effectiveness in mitigating nitrate loading through tile-drainage and other ecosystem services. Two viable solutions that we propose to investigate are (1) creating non-intersecting zones of cover and cash crops growth using Real Time Kinematics (RTK) gradience and (2) including a legume cover crop with no-intersecting zones as described in solution 1 to eliminate N immobilization during cash crop growth. Therefore, this proposal will focus on investigating precision planting winter hardy cover crops (WHCC), cereal rye and crimson clover, to minimize the interaction between cover and cash crops through non-intersecting zones established through RTK guidance precision planting of cover crops. The non-intersecting zones of WHCC could reduce N immobilization and cover crop seeding rates, while maintaining nitrate loss reductions and competitive corn yields relative to the no cover crop control. However, there is no research that quantifies potential N credits and the environmental and soil health trade-offs of reducing cereal rye planting density and the inclusion of a winter hardy legume, relative to the conventional density of cereal rye only. We will investigate potential N fertilizer credits and differences in tile-drainage water quality, short-term soil health dynamics, and profitability between the traditional and precision planted WHCC. This study has potential to increase cover crop adoption by equipping North Central region farmers with knowledge to build on common cover crop strategies toward advanced cover crop adaptive management that maintain cash crop yield, reduce nutrient losses, improve soil health with adjusted corn N need, while at potentially lower seeding rates and cost. Our educational approach will focus on conducting on-farm research and associated field days, extension meetings and augmentation of extension cover crop signature programs, develop curricula for training workshops, development of fact sheets and online data visualization platforms, and scientific meetings.
Project objectives from proposal:
Objective: To determine the impact of precision planted WHCC on crop yield, farmer economic risk, and nitrogen loss reduction.
Learning outcomes: The research project will generate knowledge on adaptive cover crop management that would allow WHCC to be precision planted ahead of crops in non-intersecting zones. Precision planted WHCC in strips could inform farmers to lower WHCC seeding rates, adjust the N need for corn crop, while improving soil health, maintaining significant nitrate-N loss reduction via tile drainage and crop yields.
Action outcomes: Increased adoption of WHCC before corn and soybeans due to competitive agronomic production and less economic risk.