AgMIP-Wheat

Figure 1: Meetings times, location and start of new activities of AgMIP-Wheat. The idea of the AgMIP-Wheat team was conceived in November 2010 at the first Global AgMIP Workshop at Long Beach in California. The AgMIP Wheat Team is organised since 2020 in several specific activities (see table below) with focus on model improvement. AgMIP-Wheat meets regularly to discuss progress, to explore new ideas and to decide on new research agendas. 

Figure 2: Measured (orange) and multi-model ensemble simulated (green) wheat grain protein concentration under different climatic (dry/wet and moderate/hot) and elevated CO₂ conditions. After Asseng et al. (2019). Error bars show 1 s.e. of measured and simulated mean.

Figure 3: Cover page of Nature Plants publication on model improvement from AgMIP-Wheat. Temperature functions in models and derived from experiments after Wang and Martre et al. (2017).  

Figure 4: AgMIP-Wheat workshop, Beijing, China, July 2024.

References

AgMIP-Wheat Google Scholar

Recent Noteworthy Finding: “New wheat varieties can contribute to food security”

Martre et al., 2024. “Global needs for nitrogen fertilizer to improve wheat yield under climate change.” NATURE PLANTS 10. https://doi.org/10.1038/s41477-024-01739-3.

Wheat is the world’s most important grain. But it has high environmental costs due to the need to fertilize with nitrogen. The AgMIP-Wheat Team has now determined that new wheat varieties produce better crops with the same quantities of fertilizer. It is not always easy to find the right amount of fertilizer for wheat crops. If too little is applied, it is completely used up, but the harvest falls short of its full potential. And if too much is used, the harvest is good but the growing grain does not consume all of the fertilizer. The surplus nitrogen finds its way into the environment and damages ecosystems and the climate. But wheat is essential for satisfying the growing hunger in the world.

To overcome these challenges, we have investigated new wheat cultivars still in the experimental stages. Their results have been published in Nature Plants. The team used data from five experimental fields representing global wheat producing regions with particularly high yields. The fields were included into a simulation model with other fields and analyzed under three climate scenarios: the climate conditions of today and global warming of 1 degree Celsius and 4.8 degrees Celsius. The results show the yields that can be expected from the tested varieties when different quantities of nitrogen fertilizer are applied.

The research showed that the new wheat cultivars achieve 16 % higher yields under current climate conditions than those now used if the same quantities of fertilizer are applied. Through improved utilization of the nitrogen, i.e. greater nitrogen efficiency, the ecological footprint is reduced. However, the team also showed that overall nitrogen needs will increase in the course of global warming if the full yield potential of the plants is to be achieved – although the new cultivars will still use nitrogen more efficiently than current varieties.

We recommend the continued use of the cultivars tested in the model in breeding programs. With improved selective breeding we can close the food gap for the next 20 to 30 years. But new varieties alone will not be sufficient to reconcile the conflicting goals of global food security, environmental protection and cost-effectiveness. What we need is a systemic approach that takes into account agricultural science methods, environmental aspects, socio-economic factors and policy makers.