Spatial-temporal evolution and driving factors of low-carbon use efficiency of cultivated land in China

Abstract: Low-carbon utilization efficiency of cultivated land can offer significant insights for the decision-making on the cultivated land utilization in ecological agriculture. In this study, an evaluation system was established for the low-carbon utilization efficiency of cultivated land, further exploring the spatial-temporal evolution and driving factors. A super-efficiency Slacks-Based Measure (SBM) model was adopted to evaluate the efficiency using the data of 30 provinces in China from 1998 to 2018. Furthermore, a systematic investigation was made to reveal the spatial-temporal evolution and regional differences in the low-carbon utilization efficiency of cultivated land with kernel density estimation, visualization mapping, and Global Differentiation Index (GDI). Finally, a geographical detector was used to explore the driving factors and mechanism for the low-carbon utilization efficiency evolution of cultivated land. The results showed that: 1) The low-carbon utilization efficiency of cultivated land was gradually improved from the perspective of temporal evolution. The average level of cultivated land low-carbon use efficiency in western and eastern China was higher than that in the whole country, whereas, the average level in central China was higher than the national average level. There was a spatial pattern of "high in the west and low in the east, while, high in the north and low in the south", indicating that the spatial distribution was changed from the scattered to the concentrated pattern. Specifically, the high-efficiency areas lay in the western and northeastern regions, whereas, the low-efficiency areas were in the lower Yangtze Region. 2) There was a relatively low and gradually narrow regional difference in cultivated land low-carbon utilization efficiency in China, where the GDI of cultivated land low-carbon utilization efficiency dropped from 0.185 4 to 0.141 8. The regional differences in the cultivated land low-carbon utilization efficiency were ranked in descending order to central, eastern, and western China. Specifically, the GDI of cultivated land low-carbon utilization efficiency in eastern China showed a "W" shaped fluctuation trend, and the GDI dropped from 0.159 8 to 0.154 1. There was a "U" shaped fluctuation trend of the GDI in the central China, where the GDI dropped from 0.261 1 to 0.198 3. A continuous decrease trend was found in western China, where the GDI dropped from 0.131 6 to 0.075 0. 3) The cultivated land's low-carbon utilization efficiency depended mainly on the natural environment condition, cultivated land endowment, economic development level, and agricultural production conditions. In addition, the driving force of multiple cropping index, per capita net income of farmers, and irrigation index dropped from 0.367 2 to 0.339 4, 0.374 5 to 0.129 1, and 0.469 8 to 0.397 7, respectively, whereas, the driving force of per capita cultivated land increased from 0.302 4 to 0.403 1. Moreover, the interaction of factors positively strengthened the single-factor driving force, indicating the outstanding divergence in the driving force of various factors. The interaction type of two driving factors was double or nonlinear enhancement. In conclusion, the findings can provide a promising guideline for the study on cultivated land utilization efficiency and the decision making on the sustainable cultivated land utilization and green agriculture development.