Simulated effect of climate change on wheat production and nitrogen management at different sites in Germany

The impact of projected climate change for winter wheat production is simulated for 9 sites across Germany using the dynamic agro-ecosystem model HERMES and downscaled climate change scenarios of the GCM ECHAM5 output for SRES emission scenario A1B until 2050. Yield reductions between 2 and 11% were estimated for 8 sites for the period 2031-2050. One site at higher altitude showed an increase in,simulated grain yield compared to the reference period 1970-1989. Yield reduction Was strongest on sandy sites and the dry eastern part of Germany. Nitrogen response curves were estimated simulating different fertilizer levels. Response curves were altered by climate change, but no unique trend across the sites was observed. Decreasing summer precipitation led to a reduced efficiency of nitrogen fertilizers.