Mapping the race between crop phenology and climate risks. A case-study for wheat in France under climate change conditions

Abstract

Abstract Climate change threatens food security by affecting the productivity of major cereal crops. To date, agroclimatic risk projections have focused on expected hazards exposure during the crop’s current vulnerable seasons, without considering the non-stationarity of their phenology under evolving climatic conditions. We propose a new method for spatially classifying agroclimatic risks for wheat, combining high-resolution climatic data with a wheat’s phenological model. The method is implemented for French wheat involving three GCM-RCM model pairs and two emission scenarios. We found that the precocity of phenological stages allows wheat to avoid periods of water deficit in the near future. Nevertheless, in the coming decades under the RCP 8.5 scenario, climatic conditions for wheat cultivation are projected to deteriorate over the French territory, due to the emergence of heat stress and increasing water deficit. Projections show the appearance of combined risks of heat and water deficit up to 4 years per decade. The proposed method provides a deep level of information that enables regional adaptation strategies: the nature of the risk, its temporal and spatial occurrence, and its potential combination with other risks. It’s a first step towards identifying potential sites for breeding crop varieties to increase the resilience of agricultural systems.