Spatial agglomeration patterns of grain production in China and its sustainability risk assessment

China’s significant differentiation in grain production patterns highlights the complex and urgent challenges to achieving sustainable food security that it faces. Standard deviation ellipse (SDE) and gravity center (GC) methods were employed to analyze the spatial agglomeration patterns of grain production in China. A combination of the entropy weight technique for order preference by similarity to the ideal solution method and an obstacle degree model was used to identify the key risk factors affecting food security. The results revealed that while China’s overall food security index showed an upward trend, the production system exhibited significant sustainability vulnerabilities. The GC of grain production consistently moved northeastward within Henan Province, with the northern region undergoing a particularly high growth momentum. The GC and SDE of rice production moved and expanded significantly northeastward, but the middle and lower reaches of the Yangtze River remained important rice-producing areas. The spatial distribution of wheat production remained relatively stable and was concentrated mainly in the Yellow River Basin and the northern part of the Yangtze Plain. Maize exhibited the greatest migration amplitude among the three major crops, driving the national grain production shift. Further analysis revealed that the amount of fertilizer application (AFA) and financial support intensity for agriculture have gradually become key restrictive factors in food security development. These findings directly link changing land use patterns to environmental and governance challenges. This study provides critical insights for optimizing the national food security strategies and achieving sustainable development in the grain industry.