The demand for food is rising, and with a growing global population, this trend shows no signs of decreasing. To meet the needs of the world's population, it is essential to produce more food without using additional land or depleting the planet's limited resources. Researchers from institutions all over the world have investigated genetic and agronomic methods to maximize wheat yields on a global scale. 

Their findings based on testing the models on five locations with reported yield potential ranging from 5 t o15 t ha-1 and then evaluated on 34 representative locations across the world which represent about 70% of the current global wheat production area. The field experiment were from New Zealand, France, and South America.  

After the global evaluation, the team (made of breeders, wheat physiologists and modelers) analysed the genetic variability and phenotypic space of sink-source traits driving high yields for a population of double haploids obtained from a cross between Bacanora and Weebil which are two high-biomass elite spring wheat cultivars.  

The high-yield wheat varieties have untapped potential. By fully exploiting these varieties, potential yields could increase to 18 tons per hectare, compared to the 8-10 tons per hectare for the current highest-yielding varieties.  

Professor Davide Cammarano from the Department of Agroecology at Aarhus University, a participant in the study, explains, "These high-yielding varieties exhibit substantial genetic potential. When combined with appropriate agronomic practices, we can significantly enhance global wheat production." 

Nitrogen fertilization: the key to higher yields 

One of the study's critical discoveries is the importance of nitrogen fertilization. Researchers found that high-yielding wheat varieties utilize nitrogen much more efficiently than standard varieties. These new varieties have a nitrogen use efficiency that is 17% higher, producing up to 42 kg of grain for every kg of nitrogen used, compared to 36 kg for standard varieties.  

"Optimizing nitrogen use is a significant step towards more efficient and environmentally friendly farming practices," says Davide Cammarano, “In our study, the collaborative work among breeders, physiologists, and modelers, helped to evaluate what happens when the improved sink and source traits increased yield by 16% with current nitrogen fertilizer applications under both current climate and mid-century climate change scenarios. The high nitrogen use efficiency of these high-yielding ideotypes would reduce the environmental footprints of wheat management.”   

Climate change impacts on wheat yields 

The study also focused on climate change and its impact on global wheat production. The results show that climate change can have both positive and negative effects, depending on the region. For instance, some areas in Northern Europe might experience increased yields due to longer growing seasons and higher CO2 concentrations. Conversely, parts of Africa and South Asia may see declining yields due to higher temperatures and water scarcity.  

Davide Cammarano emphasizes the importance of developing regional strategies that consider local conditions: "A thorough analysis of nitrogen needs must take into account agronomic, genetic, environmental, and socio-economic factors at the local level to find sustainable solutions." 

Innovative solutions for a sustainable future 

To meet the increasing demand for nitrogen fertilizers without exceeding the planet's limits, the researchers recommend that those high-yielding genotypes need to be combined with several innovative farming practices. Some suggested solutions include: 

• Biological nitrogen fixation from legumes 

• Use of nitrification inhibitors 

• Improved access to resources and markets for farmers in nutrient-limited areas, such as Sub-Saharan Africa 

"Improving resource access and implementing innovative methods like biological nitrogen fixation can help balance high yields with environmental sustainability. These are key elements in meeting the rising global demand for wheat," says Davide Cammarano. 

The study, published in the journal Nature Plants, provides insights into methods that can enhance global wheat production and manage future nitrogen needs. By focusing on genetic improvements, innovative methods, and the impacts of climate change, the researchers believe that sustainable higher wheat yields can be achieved.