摘要：Understanding the impact of changes in cultivated land in terms of structure, distribution, and quantity on grain production potential (GPP) is essential for a sustainable land utilization strategy and food security. Cultivated land balance (CLB), as a critical policy aiming at protecting farmland in China, has greatly restricted the loss of cultivated land. However, changes in cultivated land were largely generated due to the land-use activities led by the CLB policy. To clarify how the spatiotemporal dynamics of cultivated land led by the CLB policy affects the GPP, this work discusses the impact mechanism of cultivated land changes on GPP and provides an empirical analysis in Hunan Province, China. This study shows that the activities that merely aim at restricting the loss of cultivated land under CLB cannot stop the decline in GPP in China, since it requires the government to reclaim a certain amount of cultivated land that is equal to that occupied for non-cultivated land use. Furthermore, the distribution of cultivated land changed after the implementation of CLB and, as a result, contributed to the decrease in the quality of cultivated land and GPP. Quantity, productivity, and other elements that may potentially facilitate cultivated land protection are greatly advocated to be considered to enrich the connotation of the CLB policy in China. It also found that less developed regions located in central and western Hunan Province, among other areas, observed a higher sensitivity of GPP to cultivated land change. More attention should be paid to protecting cultivated land in these regions and addressing issues such as the abandonment of high-quality cultivated land.
