Resilience, Stability, and Productivity of Alfalfa in the Midwestern United States.

Climate change is a major issue for agriculture and food security. Productive, resilient, and stable forage systems are needed to endure increasingly frequent climatic crisis like drought. Historically, relatively little attention has been paid to maximizing the ability to recover after a major climatic crisis event (like drought) or minimizing long term variability of yields. Resilience was defined as the ability to recover from a crisis, and stability as the minimal long term variability in yields. The main goal of this paper was to study resilience and stability of various alfalfa cultivars in the Midwestern United States, in order to identify cultivars that optimize these features. The methodology for this study was to analyze historic data from alfalfa variety trials in the Midwest, over the last 20 years, using a mixed models approach. Mayor climatic events (like summer droughts) were identified from the meteorological record of the experimental stations. Quantitative measures for resilience and stability for each cultivar were calculated for those cultivars with longer historic records. Differences in resilience and stability were quantified for the few cultivars analyzed. This methodology allowed to identify cultivars with different long term features. This can be useful for farmers because it provides information to choose cultivars that can be more profitable over the long term. This results can be incorporated into plant breeding to develop materials more adapted to climate change.