Assessing the impacts of spatial shifts in grain production on agricultural vulnerability in China: implications for nature-based solutions

Against the backdrop of economic expansion and climate warming, spatial shifts in grain production in China have continuously moved toward relatively economically underdeveloped and climatically marginal regions. However, how these spatial shifts affect agricultural vulnerability and what underlying economic-geographical mechanisms drive these effects remain insufficiently explored. Using prefecture-level city data in China and applying a counterfactual decomposition approach together with nonparametric testing, this study investigates these issues. The results show that, during 2010–2022, spatial shifts in grain production in China exhibited a U-shaped relationship with both grain yield variability and the agricultural vulnerability index, with most regions concentrated on the right side of the turning point of the curve. In other words, many grain yield growth regions were areas with high agricultural vulnerability. Spatial shifts in grain production during 2010–2022 increased grain yield variability and the agricultural vulnerability index by 3.07% and 5.07%, respectively. Rapid grain yield growth areas (e.g., emerging grain-production bases) face relatively high climate risks, low crop diversity and multiple cropping index, labor outmigration and limited agricultural inputs, weak local fiscal capacity for agricultural investment, and low rural incomes, which are the key mechanisms through which spatial shifts aggravate agricultural vulnerability. Finally, this study proposes a “U-shaped spatial continuum model” to provide theoretical insights into the impacts of spatial shifts in grain production on agricultural vulnerability, and on this basis offers policy implications for governing agricultural vulnerability in China from a spatial perspective that integrates nature-based, engineered, and input-based adaptation.