Improved practices in the farming of wheat could lead to a dramatic reduction in its carbon footprint according to a study published in Nature Communications. The findings show that reducing the frequency of fallow periods (periods during which land is not planted), coupled with the inclusion of grain legumes in crop rotation, increases crop yield and reduces carbon emissions.
Wheat is the world's second most favoured food source and, by 2050, global demand for grain is expected to increase by 70%. Current farming practices involve growing wheat in monoculture or wheat-fallow cropping system, with two years of cropping and one year fallowing. During the fallow year, multiple operations of tillage (mechanical agitation of soil) keeps plots clear of weeds. However, due to the large amounts of fossil fuels required for tillage, and the resulting loss of soil organic matter, such a system has serious environmental consequences.
Yantai Gan and colleagues investigate the carbon footprint of different wheat production systems. They show that by reducing the fallow period frequency and increasing the inclusion of nitrogen-fixing grain legumes (such as lentils) the carbon footprint of wheat could potentially be lowered to the extent that it removes more CO2 from the atmosphere than is emitted during production.