Spatiotemporal Evolution and Influencing Factors of Multifunctional Cultivated Land in Southwestern Mountainous Areas under the Background of Sustainable Agricultural Development

With the rapid development of urbanization and industrialization in China, the expansion of construction land and irrational utilization of cultivated land have led to issues such as cultivated land marginalization, extensive use, non-grain conversion, and non-agriculturalization. These issues are a major threat to sustainable agricultural development, but existing research suffers from limitations including failure to assess the multifunctionality of cultivated land (MCL) from the perspective of sustainable agricultural development. This study constructed an agricultural production function (APF)-social security function (SSF)-ecological maintenance function (EMF)-landscape aesthetic function (LAF) classification system. Using this comprehensive evaluation model, the MCL values for typical provinces in southwestern mountainous areas of China (Guizhou, Sichuan, and Yunnan) were calculated in detail, and their spatiotemporal evolutionary characteristics were explored. Concurrently, the Spearman rank correlation coefficient, geographically weighted regression (GWR) and redundancy model were used to deeply explore the relationships among cultivated land functions and their influencing factors. The results showed three important points. (1) Over the past two decades, the comprehensive values and four sub-functional values of cultivated land in southwestern mountainous areas have shown increasing trends in the order of SSF > EMF > LAF > APF. The values and rates of change of each sub-functional value show obvious spatial variation. However, the spatial gap in cultivated land functions has adverse effects on sustainable agricultural development. (2) There are clear correlations between each pair of the four major functions of cultivated land during the study period, and the number of results reaching significance among the six correlations between the four main cultivated land functions increased significantly from 2000 to 2020. Simultaneously, there are noticeable spatiotemporal differences in the trade-offs and synergies among the MCLs. (3) The development of MCL is most significantly influenced by socioeconomic factors such as the per capita net income of rural residents. Therefore, formulating reasonable land protection policies is imperative for promoting the sustainable development of agriculture. The results of this study can provide guidance for the rational layout and coordinated development of MCL space, for promoting sustainable agricultural development and ensuring food security.