Continuous living cover for the Upper Midwest: from hairy vetch nodules to the lanscape scale

Abstract

The work in this dissertation illustrates challenges and opportunities related to implementing continuous living cover across the Midwestern U.S. Chapter 1 and Chapter 2 exemplify the challenges specific to one crop, hairy vetch. Temperature constraints in the region limit the utility of hairy vetch as a cover crop relative to other regions of the U.S. However, with continued improvements in N accumulation, hairy vetch could improve soil N fertility with a much lower environmental burden than synthetic fertilizers. Chapter 3 illustrates that continuous living cover could improve environmental outcomes across the region, but there is tremendous uncertainty and variability surrounding those outcomes. The practices with the most power to improve environmental outcomes also come at the greatest potential financial cost. Continued research to improve these crops and to understand their environmental benefits and limitations will be critical in efforts to improve agricultural sustainability.