Population Shrinkage and Spatio-Temporal Changes in Cultivated Land Use Efficiency in China’s Agro-Pastoral Ecotone

Revealing the level of cultivated land use efficiency and its influencing factors in the northern agro-pastoral ecotone from the perspective of population contraction can provide a decision-making reference for ensuring national food security and promoting the implementation of rural revitalization strategies. In this paper, using the stochastic frontier production function and a Tobit regression model, we reveal the current situation of rural population shrinkage in the agro-pastoral ecotone in northern China and the spatial and temporal evolution characteristics of cultivated land use efficiency, and identify influencing factors based on the perspective of “human–land”. The results show the following: (1) The rural population in all provinces and counties in the agro-pastoral ecotone in northern China showed a continuous loss trend. The southwest was a hot spot area for rural population reduction, and the northeast was a cold spot area for rural population reduction. (2) During 2000–2020, the cultivated land use efficiency in the agro-pastoral ecotone in northern China showed a fluctuating upward trend, rising from 0.595 in 2000 to 0.754 in 2020. Spatially, the cultivated land use efficiency in the agro-pastoral ecotone in northern China showed the characteristic of being higher in the northeast and lower in the southwest, and the cultivated land use efficiency in some counties in the central and southwestern parts showed a downward trend. (3) The cultivated land use efficiency in the agro-pastoral ecotone in northern China is comprehensively affected by multiple factors. The following factors were determined, presented in descending order of the absolute value of influence degree: proportion of the population over 65 years old > multiple cropping index > proportion of cultivated land area > proportion of rural population > average years of education > population change rate. Based on these results, this paper puts forward measures to improve cultivated land use efficiency in the agro-pastoral ecotone in northern China from the perspective of population shrinkage, so as to provide references for ensuring national food security and promoting rural revitalization.