NATURE COMMUNICATIONS|5:5012|DOI: 10.1038/ncomms6012|www.nature.com/naturecommunications

Yantai Gan^1,2, Chang Liang³, Qiang Chai¹, Reynald L. Lemke⁴, Con A. Campbell⁵ & Robert P. Zentner²

¹Gansu Provincial Key Laboratory for Aridland Crop Science, Gansu Agricultural University, Lanzhou 730070, China. ²Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, Saskatchewan, Canada S9H 3X2. ³Pollutant Inventories and Reporting Division, Environment Canada, 9th floor, Fontaine Building, 200 Sacre ´-Coeur, Gatineau, Que ´bec, Canada K1A 0H3. ⁴Saskatoon Research Centre, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan, Canada S7N 0X2. ⁵Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, Ontario, Canada K1A 0C6. Correspondence and requests for materials should be addressed to Y.G. (email: yantai.gan@agr.gc.ca or ganyantai@126.com) or to Q.C. (email: chaiq@gsau.edu.cn).

Wheat is one of the world’s most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging 256kg CO2 eqha 1 per year. For each kg of wheat grain produced, a net 0.027–0.377kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production.