Climate change has impacted winter wheat growth in several ways and precise modelling studies are required to understand difficulties in future crop cultivation. Using the WoFoSt crop simulation model and climate projections for the 21st century, this study estimated the impact of climate change on winter wheat growth for the locations Changins and Reckenholz in Switzerland under RCP 4.5 and RCP 8.5. In both locations, considerable phenological shifts were projected under RCP 8.5, with average heading dates shifting forward by 22.2 days in Reckenholz and 24.4 days in Changins at the end of the century. Average maturity dates in this scenario shifted forward by 24.4 days and 25.5 days respectively. Smaller forward shifts were projected under RCP4.5, where heading dates shifted by 9.8 days (Reckenholz) and 11.1 days (Changins), while maturity dates shifted by 10.5 days (Reckenholz) and 10.9 days (Changins). With regards to future yield levels, this study found larger decreases of winter wheat yield in the higher emission scenario (Reckenholz: -17.91%, Changins: -23.85%) than the low emission scenario (Reckenholz: -4.16%, Changins: -6.04%) at the end of the century. However, the modelled impact of higher ambient CO2 concentrations more than offset this yield reduction, resulting in increased yield levels of up to 26.51% (Reckenholz) and 43.95% (Changins). Impact estimates of climate change on drought stress experienced by winter wheat were insignificant but showed differences in drought stress levels depending on soil type. Our findings indicate that winter wheat cultivation in Switzerland is strongly impacted by climate change, with a strong dependency on which representative concentration pathway the world will follow.
