Novel cropping-system strategies in China can increase plant protein with higher economic value but lower greenhouse gas emissions and water use

Farming activities are a major source of greenhouse gas (GHG) emissions in China. Altering cropping practices is considered a potential emissions reduction route, but the extent to which GHG emissions can be mitigated without compromising other important aspects of food production (e.g., productivity, economic profits, water use, nutrition) remains unclear. Here we fill this knowledge gap using a state-of-art optimization model to quantify the net GHG emissions (NGEs) reduction potential of 17 cropping systems at the prefecture and province levels in China during 2014–2018. We find that increasing planting areas of soybean and winter wheat-summer maize and also decreasing those of single rice and single winter wheat across China could reduce the total NGEs by 7.4%–16.0% without compromising food security, farmers’ income, plant protein, or freshwater use. Our findings illustrate the importance of strategic cropping, e.g., altering crop distribution patterns and areas, in optimizing multiple objectives for low-carbon agriculture systems in China.