Abstract Breeding has altered wheat physiology substantially. While physiological improvements boosted grain yields, there is still limited understanding of how this affected agricultural water use on a continental scale. We employed a crop model, calibrated for a historical (released 1895) and a modern (released 2002) German winter wheat cultivar, across Europe for a period of 30 years to compare changes in transpiration. Throughout all locations and the simulation period, the modern cultivar transpired significantly less water (−17%) than the historical cultivar. Cultivar differences in transpiration were more pronounced in southern Europe. Over the whole 30-year period, an upward trend in transpiration was observed for both cultivars. Transpiration between cultivars was closely linked to higher leaf area index values. Root physiology was crucial, especially in dry regions. The findings underscore the need to incorporate cultivar-specific water use characteristics into large-scale assessments of land-atmosphere interactions and water use projections of agricultural lands.
Behrend et al. (2026) studied this question.