How changes in soil hydraulic properties influence transpiration dynamics under climate change across Europe: A sensitivity study

In SoilX it was hypothesized that more sustainable soil management practices would increase the amounts of plant available water, concomitant to higher values of near saturated hydraulic conductivity. However, the benefits of these changes for crop growth and yield stability my vary in space and in time. It was thus the aim of this model-based sensitivity study, to explore systematically how changes in saturated water content and saturated hydraulic conductivity would affect crop growth of grain maize and winter wheat, respectively, depending on climatic conditions. To represent spatial variance in climatic conditions, we applied the model SWAP at six long-term experimental sites along a northeast-southwest gradient across Europe. Temporal variance was accounted for by applying the model based on locally downscaled transient climate projections from CMIP6. Our preliminary results suggest that drought limitations to both grain maize and winter wheat increase with projected climate change in all sites. Despite linear shifts in the combinations of soil hydraulic properties, the benefits of increasing soil hydraulic conductivity differ both in space and in time driven by opposing effects on drought vs. excess water limitations to crop growth.