11. March 2025
A new study by the Leibniz-Centre for Agricultural Landscape Research (ZALF) shows that the combined cultivation of winter wheat and soybean in Germany could be a sustainable alternative to conventional cultivation. By adjusting the sowing time, both yield and protein content of the crop can be increased. With mixed cropping, protein-rich soybeans for animal feed could be produced regionally. The researchers modelled yield development under different climate scenarios based on results from field trials with soy and wheat in relay intercropping systems. The results have been published in Field Crops Research.
Extreme weather events such as drought and heat are putting increasing pressure on agriculture, while demand for food continues to rise. One way to make more efficient use of arable land is to intercrop winter wheat and soybean: wheat is sown in the autumn, and soybean follows in the spring between the wheat rows. This cropping system could stabilize yields, improve soil fertility and make agriculture more resilient to climate change. By covering the soil year‐round, water is better retained and nutrients are more efficiently utilized due to the staggered development of the two crops.
“Our simulations show that intercropping winter wheat and soybean not only allows for more yield per unit area, but can also increase the protein content of the crop by up to 16%,” explains Jing Yu, lead author of the study. “By adjusting sowing times, we were able to observe higher yields of up to 44% in some climate scenarios.” A higher protein content makes the crop more economically attractive, as protein‐rich soybeans are particularly sought after for animal feed. Much of this is currently imported – growing it locally can reduce dependence on imports, long transport distances and CO₂ emissions.
How the research was done
The researchers used the agro‐ecosystem model MONICA to simulate intercropping of winter wheat and soybean at different sowing times and under different climate conditions (comparison periods: 1981–2020 and 2031–2060). Results from a field experiment in Müncheberg, Brandenburg, and long‐term climate data for Germany served as the basis. In addition to yields, land use efficiency and protein content were also analyzed.
More protein, less land
The simulations showed:
- Compared with conventional cultivation of wheat and soybean in separate fields, mixed cropping saves 17% of land.
- Wheat grown alone could become 15% more productive by 2060, while soybean cultivation would increase by 8%.
- Intercropping leads to a slight reduction in wheat yield (-9%), but this is offset by the additional soybean yield.
- Total protein yield increases by 16% as soy increases the overall protein content of the crop.
Practical solutions for sustainable farming
The researchers emphasized that choosing the right sowing time is particularly important: earlier sowing can further enhance the benefits of intercropping. Planting the wheat earlier gives it more time to develop before the soybean plants are added. This allows the wheat to grow more vigorously while ensuring that the soybeans have enough space and light, reducing competition for nutrients and water.
“Our results show that combining crop diversity with smart adjustment of sowing times creates a win‐win situation: we can achieve higher yields while reducing environmental impact,” says Prof. Claas Nendel, co‐author of the study.
What happens next?
Further research is needed to ensure that winter wheat and soybean can be successfully intercropped in practice. For example, additional work is required to develop harvesting techniques that account for the different maturation times of wheat and soybean. Moreover, further field trials are necessary to better understand the long‐term effects on soil fertility and nutrient cycling.
Policy measures could also support the adoption of mixed cropping. For instance, targeted support programs could provide financial assistance for the purchase of specialized machinery for mixed cropping. At the same time, adjusting agricultural subsidies to better integrate mixed cropping as a sustainable farming practice into the EU's Common Agricultural Policy (CAP) would be beneficial.
Project partner:
- Leibniz Centre for Agricultural Landscape Research (ZALF)
- University of Potsdam
- Swedish University of Agricultural Sciences (SLU)
Funding:
The work was funded by the Leibniz Centre for Agricultural Landscape Research (ZALF) as part of the project “Cropping system diversification to increase the resilience of farming systems (divCROP)” for the period 2021–2024.
Further Information:
Link to the original publication: https://www.sciencedirect.com/science/article/pii/S0378429024004489?via%3Dihub
Text disclaimer:
This is a summary of the original text created with the help of artificial intelligence: Yu, J., Rezaei, E. E., Reckling, M., & Nendel, C. (2025). 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. Field Crops Research, 322, 109695. DOI: 10.1016/j.fcr.2024.109695. Published Open Access under the CC BY 4.0 license.
The text has been carefully reviewed and revised in light of AI regulations at ZALF.
