The Feasibility of Winter Hardy Legumes in the North Central Region

Commodities

Practices

In the North Central region (NCR), cover cropping is one of the most effective in-field methods to simultaneously reduce soil erosion, nutrient loss via subsurface drainage, and increase soil health through carbon sequestration. However, cover crop adoption is limited to less than 10% of row crop acres due to nutrient availability, plant disease and other yield lag barriers experienced with the inclusion of cereal rye before corn, which widens the financial risk of adoption. One potential solution is the inclusion of winter hardy legumes that have been selected to survive the winter of the NCR fallow period. Results of a recent NCSARE grant (LNC20-432) performed by the Armstrong Lab suggested that Balansa Clover (Trifolium michelianum Savi) has the potential to absorb its adoption cost and risk of yield reduction through generating a sizable N credit that reduces the optimum N fertilizer rate by 50-100 lbs/A at equal yields relative to the non-cover crop control and cereal rye treatments (Figure 1). Unfortunately, these favorable results were only experienced in Southern IN and IL and establishment of the clover did not occur in the central and northern portions of the NC region. Further, the experiments were limited to Balansa Clover, one of many new varieties. Thus, we are proposing to investigate the feasibility of multiple winter hardy clover varieties as covers across the NC region using planting date and cropping systems as critical treatment variables. Currently, there is a lack of research that investigates feasible planting dates for the inclusion of winter hardy legumes within a corn and soybean cropping system across the hardiness zones of the NCR. Further, there is a dearth of data that demonstrate the potential of small grain cropping rotations that allow for an early fall planting date (Early August), which could advance the growth potential of winter hardy legumes in the central to northern portion of the NCR. A healthy stand of winter hardy legumes in the NCR could allow for greater carbon and nitrogen capture, reductions in nitrogen applied in corn production, and a greater number of low carbon intensity cropping systems in the NCR.   This study has potential to increase cover crop adoption by equipping NCR farmers with data and advanced management that maintain cash crop yield, absorb adoption cost, while reducing nutrient inputs and environmental losses. Our educational approach will focus on conducting on-farm research, field days, online data visualization platforms, and scientific meetings.

Objective: To quantify the feasibility of multiple overwintering legume clover species across the NCR to generate N credits that influence synthetic N fertilization rates, corn yield, farmer economics and N fate.

Learning outcomes: The research project will generate knowledge and data on the performance range of overwintering clovers in multiple cropping systems across the hardiness zones of the NC region. The knowledge gained and research findings will be stored and shared in a public database and interactive web interface that allows self-exploration of experimental results by farmers and trainers and form an overwintering clover informational hub in the NCR.