# Urbanization and Grain Production Pattern of China: Dynamic Effect and Mediating Mechanism
###### Abstract
In an open market environment, farmers in different regions face a reduction in cropland and changes in farming labor, which will force farmers to adjust their cropland utilization according to the rise in production costs and changes in expected returns, either by increasing the intensity of factor inputs and adjusting the planting structure to improve unit output and returns or by directly abandoning the land and resorting to land circulation. At the macro level, the urbanization process has accelerated the spatial flow of production factors and the agricultural technology progress [8]. As a result, the intensity and allocation of factor inputs on the stock of cropland have been altered, triggering changes in the cropland utilization in different regions. The upgrades to the industrial structure and rising production costs have eliminated the comparative advantages of grain production in regions with high urbanization levels, and the proportion of grain production has gradually decreased. In short, this is the result of self-balancing between different grain planting behaviors and cropland utilization by micro-farmers in different regions facing urbanization and socioeconomic and institutional constraints, which at the macro level manifests itself in the spatial imbalance of grain production pattern (GPP) triggered by the regional endowment characteristics of grain production and the spatial flow of factors [9]. Thus, the effect of urbanization on GPP and the paths of those effects are of interest in academic circles. Answering these questions could, on the one hand, help us to further understand the relationship between urbanization and GPP and, on the other hand, provide important theoretical reference for stabilizing China's grain production, grasping the development of the grain production pattern, and formulating scientific grain production policies during the high-quality transformation of urbanization. In the meantime, China's experience in rapid urbanization and steadily increasing grain production could also provide lessons for the United Nations to achieve the sustainable development goals of poverty and hunger eradication. Since 1995, scholars have shifted their focus to the changes in characteristics of the GPP and concluded that the center of grain production in China has gradually transferred northward through either qualitative or quantitative methods [10, 11, 12]. More attention was paid to the causes behind the northward transfer of the grain production center. Most of the existing studies investigating the effects of natural and socioeconomic factors such as cropland endowment [13], technological progress [14], economic growth [15], natural conditions [16], and agricultural policies [17] on the GPP have been based on the analysis of the spatial characteristics of the changes in the grain production pattern. [PERSON] et al. [18] found that the shift from southern grain to the north to northern grain to the south in China occurred in the mid-1980s due to the difference in the comparative advantages of grain production in the regional economic development of the south and the north during the market-oriented reform, where farmers reallocated, their resources mainly based on the relative prices and comparative returns of factors. In contrast, most of the existing studies on the relationship between urbanization and grain production explored dimensions such as food security [19; 20], technical efficiency of grain production [21; 22], and rural labor outflow [23; 24]. Thus, studies exploring changes in the GPP from the urbanization perspective are still lacking. A study by [PERSON] et al. [14] based on the county perspective found distinct spatial regional pattern characteristics in China's grain production. Farmers in regions with rapid urbanization have been mostly engaged in industries with higher income than agriculture, resulting in grain production declining, especially in the southern coastal regions. There is a rich body of literature on the causes of changes in the GPP.