Perenniality and diversity drive output stability and resilience in a 26-year cropping systems experiment

Sustainable cropping systems should be both stable and resilient to erratic and extreme climate, while remaining profitable and providing critical ecosystem services. Stable cropping systems exhibit minimal interannual variability while resilient systems remain productive under disturbances. It is unclear however which cropping system charataristics (e.g., perenniality, diversity, management) contribute the most to stability or resilience. Using a 26-year experiment we calculated food-energy output from five cropping systems typical of the North Central U.S.: continuous maize, maize-soybean under minimum tillage, organic maize-soybean-wheat system, and two forage rotations including maize and alfalfa. We found that output was greatest for non-organic maize rotations, followed by the forage rotations and the organic grain system. Output improved in all systems over time and was more stable in systems with a greater degree of perenniality. Soil health indicators were positively associated with both stability and perenniality. More diverse cropping systems exhibited greater resilience in the face of drought, due in part to having less maize in rotation. Perennial and diverse cropping systems are critical to sustainable food production, especially under increasingly erratic climate patterns, and should be actively promoted by policy.