Evolutionary characteristics and influencing factors of non-grain of cultivated land in main grain-producing areas—A case study of Lianyungang City, China

It is significant to explore the evolution pattern and driving mechanism of non-grain of cultivated land in the main grain-producing areas to promote the sustainable development of agriculture and guarantee national food security. Taking Lianyungang City in Jiangsu Province as an example, the study uses remote sensing image interpretation, spatial autocorrelation analysis, and geographically weighted regression model to analyze the spatial and temporal evolution characteristics of non-grain of cultivated land, reveal the driving mechanism and formulate zonal regulation strategies. The results show that: (1) the level of non-grain of cultivated land in Lianyungang City increased gradually from 6.01% to 11.10% from 2002 to 2022, and grain cultivation was mainly shifted to greenhouse vegetables, construction and development and abandonment. (2) the level of non-grain of cultivated land showed a spatial pattern of high along the north-west-south-east and decreasing to the two sides, and the pattern showed a trend of gradual weakening, with Moran's I decreased from 0.90 to 0.42. (3) The dominant factors of the spatial differentiation of non-grain of cultivated land in different periods are different, among which GDP, population density, NDVI, and precipitation are always the main influencing factors. The evolution of non-grain of cultivated land is a complex result of the joint action of resource endowment of farm households, location conditions, and economic policies. (4) The evolution of non-grain of cultivated land can be classified into single-factor-dominated, two-factor-dominated, and multifactorial effects. Three primary zones and differentiated zoning regulation strategies are proposed from three perspectives: subject synergy, government regulation, and system element enhancement. The study can provide a reference basis for promoting the protection and use of cultivated land and formulating differentiated agricultural management strategies in grain-producing areas similar to Lianyungang City.