CHANGES OF AGROCLIMATIC CONDITIONS AND ASSOCIATED CROP FAILURES OVER GLOBAL CROP LANDS

Shifts of daily and long-term climate in crop production regions may threaten global food security. While consensus results have been reached regarding the impacts of temperature changes on crop yields over these regions, it is unknown how agriculture-significant climate conditions, as derived from daily weather, are changing and how these changes impact crop failure risks. In this study, we analyze the changes in twelve agroclimatic indices, as indicators of agriculture-significant climate condition, for four globally important staple crops: maize, rice, soybean, and wheat, as well as contributions of these indices to the changes in crop failures over global crop production regions from 1981 to 2016. We derive the agroclimate indices for each crop growing season at each grid point over global cropland, including last spring frost, climatological growing season length, the start of field operations, field conditions suitable for planting, in-season maintenance, field conditions suitable for harvest, growing degree days, growing season stress, growing season total precipitation, growing season dry days, first fall frost, and accumulated frost days. Daily gridded temperature, precipitation, and soil moisture from climate reanalysis and remote sensing are used to calculate the agroclimatic indices. We analyze trends and variations of the agroclimate indices for different breadbaskets and food insecure locations over global cropland and their impacts on crop failures using machine learning models. We will discuss the implications of our analysis to management decisions and adaptation strategies.