Impacts of compound hot–dry extremes on US soybean yields

Abstract. The US agriculture system supplies more than one-third of globally traded soybean, and with 90 % soybean produced under rainfed agriculture, trade is particularly sensitive to weather climate variability. Average growing season conditions can explain about yield Additionally, crops be specific short-term extremes, occurring in isolation or compounding at key moments throughout crop development. Here, we identify the dominant within-season drivers that variability US, explore synergistic effects between lead severe impacts. study combines data from reanalysis satellite-informed root zone soil moisture fields subnational yields using statistical methods account for interaction effects. On average, our models two-thirds year-to-year (70 all years 60 out-of-sample predictions). largest negative influence on driven by high temperature low during summer reproductive period. Moreover, due effects, heat considerably damaging dry less problematic wet conditions. Compounding interacting hot (hot–dry) (defined 95th 5th percentiles respectively) reduce 2 standard deviations. This sensitivity 4 3 times larger alone respectively. Other relevant responses are lower temperatures early late season, excessive precipitation season. We note identified varies across spatial domain. Higher latitudes, thus colder regions, positively affected other hand, warmer southeastern regions Historic trends indicate production has generally benefited recent shifts except increasing rainfall Overall, warming have reduced risk frost seasons potentially allowed earlier sowing dates. More importantly, summers been getting cooler wetter over eastern US. Nevertheless, despite these positive changes, show frequency compound hot–dry events remained unchanged 1946–2016 In longer term, project substantially continental although uncertainty remains as whether this will accompanied drier highlights a critical element future studies focused agricultural change.