Performance of cropland low-carbon use in China: Measurement, spatiotemporal characteristics, and driving factors

Low-carbon cropland use is of significant importance in addressing global warming. Most research has paid attention to measuring cropland use efficiency under carbon emission constraints to reconcile carbon mitigation and food security. However, there are limitations with carbon accounting, approach selection, and subsequent regression. To extend existing research, this study aimed to evaluate the performance of cropland low-carbon use (PCLU) and determine the driving factors. In this study, carbon emissions and sequestration of cropland use in Chinese provinces from 2000 to 2019 were calculated. Based on the carbon accounting, an extended slack-based efficiency measurement was applied to evaluate the provincial PCLU. Besides, spatiotemporal characteristics of the PCLU were portrayed. Owing to spatial correlation, the spatial Durbin model was employed to elucidate the driving factors. The results indicate that: (1) cropland use systems acted as net carbon sinks in China with sequestration and emissions of 5.624 t/hm² and 1.980 t/hm², respectively. (2) In China, the average PCLU was 0.727, whereas the provinces had values ranging from 0.2-1.2, with significant gaps. (3) PCLU evolved stably in northeastern China and fluctuated in the other three regions. Meanwhile, provinces with high PCLU shifted from the south to the north of the country during the study period. The global Moran's index demonstrated that a positive spatial correlation existed. (4) Agricultural structure adjustment and urbanization can promote PCLU, whereas investment and disaster can undermine it. PCLU of a province would be affected by the agricultural structure and disaster in its nearby provinces owing to spillover effects. Consequently, it is suggested that emissions in provinces should be mitigated according to the local carbon structure. Harnessing the key factors and spatial interactions can potentially help achieve regional low-carbon cropland use.