Study on the Characteristics and Influencing Factors of Spatiotemporal Mismatch Between Grain Production and Cultivated Land in the Lower Yangtze River Economic Belt

Grain and cultivated land resources constitute the most fundamental means of human subsistence, and their spatial mismatch can directly reveal issues related to the rationality of regional resource utilization and urban–rural development patterns. The downstream region of the Yangtze River Economic Belt, as a major grain-producing area in China, holds significant importance for optimizing regional arable land utilization patterns, achieving sustainable use of cultivated land resources, and ensuring national food security through the investigation of the spatiotemporal mismatch characteristics between grain production and arable land resources and their influencing factors. This study focuses on the downstream region of the Yangtze River Economic Belt, employing the Center of Gravity Transfer Model, Spatial Mismatch Model, and Geographical and Temporal Weighted Regression Model to analyze the spatiotemporal variation characteristics of grain production and cultivated land area, as well as their mismatch patterns. It further investigates the factors that influence such mismatches and their spatial heterogeneity. The research findings indicate that, in terms of temporal characteristics, grain production in the downstream region of the Yangtze River Economic Belt exhibited an upward, fluctuating trend from 2000 to 2023. The cultivated land area initially decreased, then gradually increased, while the overall quantity showed a net reduction. From the perspective of spatial changes, the migration rate of grain production was significantly higher than that of cultivated land. The center of gravity of grain production shifted 78.85 km northwestward, while the center of gravity of cultivated land moved 4.16 km in the same direction. The overall mismatch between grain production and cultivated land shows fluctuating changes, while its spatial characteristics show an increasing trend toward polarization. The average intensity order of influencing factors is as follows: effective irrigated area > fertilizer’s equivalent weight > the proportion of agricultural output value > total power of agricultural machinery > urbanization rate > the proportion of people employed in the primary industry. Meanwhile, these influencing factors exhibit significant spatial heterogeneity characteristics, with their impact directions and intensities varying across different development stages in distinct regions. From a spatiotemporal perspective, the research findings provide differentiated policy recommendations for the efficient utilization of cultivated land resources and grain production in the downstream region of the Yangtze River Economic Belt.