Spatial-Temporal Evolution Patterns and Regulatory Strategies for Land Resource Carrying Capacity of China's Major Grain-Producing Areas

Research on land resource carrying capacity (LRCC) focuses on the population that regional land resources can support as well as the grain output they can deliver. China's major grain-producing areas consist of 13 provinces, and the grain produced in these areas makes up 75% of the country's gross grain output. To boost the land carrying capacity of major grain-producing areas and to ensure national food security, it is crucial to examine the spatial-temporal evolution patterns of LRCC and to devise optimal regulatory strategies. From the perspective of human-grain relationships, this paper looks into the evolutionary features of the spatial-temporal patterns of the LRCC of China's major grain-producing areas based on a land resource carrying capacity model, a land resource carrying capacity index model, and a land resource limitation model. We obtain three main results: (1) On the temporal scale, the land resource carrying capacity index (LRCCI) of China's major grain-producing areas as a whole tapered off over a period from 1980 to 2020, whereas the overall LRCC increased in this period, indicating that the human-grain relationship in China's major grain-producing areas is improving. (2) On a spatial scale, China's major grain-producing areas ranked by LRCC from the greatest to the lowest, in 2020, were North China, the middle and lower reaches of the Yangtze River, Northeast China, and other regions. In terms of the carrying state of land resources, provinces with grain surpluses significantly rose during 1980-2020, the growth of LRCC of the aforementioned four major regions markedly slowed down in 2015-2020, and a large gap exists in LRCCI between the 13 provinces, revealing an unbalanced, insufficient development of LRCC in each province. (3) From 2000 to 2020, the limit of land resources on population aggregation in most major grain-producing areas was negative, and its absolute value continued to increase; this suggests that the land resources of major grain-producing provinces set small limits on population aggregation, with great potential for increasing LRCC. Taking into account the research results, this paper gives strategies for regulating the LRCC of China's major grain-producing areas in a bid to further augment the human-grain carrying capacity of land resources in China's major grain-producing areas and to guarantee national food security.