Miller Magazine Issue: 152 August 2022

68 COVER STORY MILLER / AUGUST 2022 INCREASED ATMOSPHERIC CONCENTRATION OF CARBON DIOXIDE There is little clarity regarding the impacts of elevated levels of carbon dioxide on the yield and the nutritional attributes of wheat. However, some experiments under controlled environ- ments and modeling exercises, suggest that the increased con- centration of carbon dioxide in the atmosphere could increase photosynthesis rates and productivity in C3 plants (i.e. plants that produce a three-carbon compound during photosynthesis) such as wheat. This increase could partly negate the impacts of climate change on wheat production. However, the increased concentration of carbon dioxide in the atmosphere may reduce the nutritional quality of wheat. For example, when wheat is culti- vated under elevated concentrations of carbon dioxide in the at- mosphere, the grains may have less protein, zinc and iron. Crop response to elevated carbon dioxide will most likely depend on environmental and crop management factors. More research in this area is needed. IMPACTS OF WHEAT PRODUCTION ON CLIMATE CHANGE In addition to being affected by climate change, wheat pro- duction also contributes to greenhouse gas (GHG) emissions. In wheat production systems, the primary sources of GHG emis- sions are associated with conventional crop production practic- es. These practices include conventional tillage, which leads to a loss of soil organic carbon; the use of nitrogen fertilizers and pesticides, which contribute to emissions of non-carbon dioxide GHGs (e.g. nitrous oxide); and emissions from agricultural op- erations (e.g. electricity consumption for irrigation and fuel con- sumption in agricultural machinery). Wheat production systems need to adapt to ensure they continue to contribute to food security, rural livelihoods and sustainable food systems under a changing climate. The spe- cific adaptation and mitigation approaches will vary according to location. In the world’s wheat-producing regions, there are a wide variety of agro-ecological conditions, microclimates within the soil, climate risks and socio-economic contexts. It is crucial to collect data and information to determine the best course of action and adapt practices to local needs. This information al- lows for a continuous learning process and can feed into the improvement of future policies. Close coordination and collab- oration among stakeholders at all levels are needed to build an enabling environment that gives farmers opportunities to adopt targeted measures to enhance the productivity, resilience and sustainability of wheat production in the face of climate change. The precise challenges that will be created by climate change on wheat production systems remain uncertain. These challeng- es will vary from one farming communities to another, but it is certain that they will be especially daunting for countries already coping with high levels of food insecurity. However, there is a clear way forward to meeting these challenges. Options include the adoption of context-specific good agronomic practices, such as conservation agriculture; efficient water and nutrient manage- ment; and IPM. These options will complement the gains that can be made through the cultivation of improved varieties. REFERENCE: FAO. 2022. Crops and climate change impact briefs. Cli- mate-smart agriculture for more sustainable, resilient, and equi- table food systems. Rome. https://doi.org/10.4060/cb8030en