Impact of cropland spatial shift on carbon footprint of agricultural inputs for grain production in China, 1990–2018

Cropland spatial shifts are occurring globally, potentially influencing anthropogenic greenhouse gas (GHG) emissions of agricultural inputs for grain production at different spatial scales. The extent of this impact and its regional variations are key questions. Taking China as the study area, we quantified the impacts of cropland spatial shifts on carbon footprints of agricultural inputs (CFAI) for grain production in China by integrating multi-source data during 1990–2018. Results revealed that cropland centroid in China moved 83 km northwestward from 1990 to 2018, resulting in a 2% increase in CFAI per unit cropland area at the national level. By region, the Northwestern arid region contributed the most to the increase in CFAI, about 9.2 Mt carbon dioxide equivalent (CO₂-eq), due to the dramatic cropland expansion and highest CFAI per unit cropland area. This study reveals the importance of considering the increase in CFAI resulted from cropland expansion when formulating land use planning and cropland protection policies.