freshwater resources, anamplifying climate cycle, and concern for the environmental
impacts of agriculture (Foley et al., 2011). To make significant
strides in improving the production capacity and resiliency of
global agricultural systems, we must better understand the regional distribution
of factors currently limiting production: where crops are most
vulnerable to climate extremes, where expansion and intensification
can occur with minimal environmental costs, and where infusions of
technology in water and land management are likely to significantly improve
yields (Lobell et al., 2008; van Ittersum & Cassman, 2013; Zaitchik
et al., 2012). Robust early warning indicators highlighting regions with
developing crop stress and degrading canopy conditions due to drought