Winter wheat–soybean relay intercropping in conjunction with a shift in sowing dates as a climate change adaptation and mitigation strategy for crop production in Germany

Given the negative impacts of climate change on crop production, it is vital to implement efficient adaptation and mitigation strategies. The diversification of cropping systems, particularly through intercropping combined with shifts in sowing times, could have the potential to offset such negative impacts. Yet, both experimental data and simulation studies are scarce to elucidate the intercropping performance under future climate change conditions, particularly for evaluating its potential to offset climate impacts on crop and protein yields in German wheat-based systems. This study aimed to simulate the grain yield and grain protein performance of winter wheat-soybean relay-row intercropping across Germany under future climate conditions, comparing it to sole cropping systems. We employed the MONICA agroecosystem model and its intercropping module to simulate the performance of an innovative winter wheat–soybean relay intercropping system. This was in combination with a wide range of shifts in sowing dates, and we compared it against standard sole cropping under low and high emission scenarios across Germany. The model projected a 15 % higher sole wheat yield under the future (2031–2060) high emission scenario than that of the historical period (1981–2020), while sole soybean yield increased by 8 % in the same case. Although the simulation of winter wheat–soybean relay intercropping across Germany indicated a 9 % yield penalty compared to sole cropping in the future, with a transgressive overyielding index of 0.91, intercropping emerged as particularly advantageous in terms of land-use efficiency and protein production. It saved 17 % of land compared to sole cropping, thus produced equal amounts of grain yield, and produced 16 % more protein than sole cropping in the high emission scenario. On top of that, shifting the sowing dates of the component crops to earlier times was found to substantially enhance the advantages of intercropping, resulting in a maximum of 44 % higher total yield production, and 47 % higher protein production than sole wheat without shifting sowing date in the future projection window. Our findings highlight the grain yield and protein production potential of intercropping versus sole cropping under futuristic high emission scenarios (RCP 8.5), and underscoring its potential to create a win-win situation of increased crop diversity and productivity. The results affirm the crucial importance of selecting optimal sowing dates for the component crops in intercropping, to maximize production and ensure resilience in the face of a changing climate. • Central Europe is seeking alternative cropping systems as an adaptation to climate change. • Wheat–soybean intercropping options for Germany have been explored using a modelling approach. • Intercropping emerged with a 9 % yield penalty compared to sole cropping under RCP 8.5. • With yield penalty intercropping saved 17 % of land and produced 16 % more protein. • Optimizing sowing dates in intercropping enhances bulk and protein yield by 44 % and 47 % compared to the sole wheat without adaptation.