How does agricultural specialization affect carbon emissions in China?

Agricultural carbon emissions have long attracted scholars' interest. In recent decades, China has gradually explored the path of agricultural specialization without large-scale operation based on agricultural machinery service outsourcing driven by structural transformation. To date, our understanding of the impact of China's unique agricultural specialization on agricultural carbon emissions remains scant. Nevertheless, this issue is important for promoting China's carbon emission reduction and exploring a path of agricultural transformation that is both competitive and sustainable. Based on China's provincial panel data from 2000 to 2019, this paper constructed a mediating model to test empirically the impacts of agricultural specialization on agricultural carbon emissions. The results showed that agricultural specialization exerted a significant positive effect on agricultural carbon emissions by increasing agricultural external inputs. Specifically, in addition to promoting increased mechanization, agricultural specialization caused an even greater, excessive application of chemical fertilizers, which largely follows metabolic rift theory and substitution and remittance effects. The farmland operation scale had no significant effect on agricultural carbon emissions due to the offset of its significant negative effect on chemicalization and significant positive effect on mechanization. This finding demonstrates that, in the context of smallholder farming, the moderate expansion of farm size can reduce agricultural environmental pollution, but it cannot be proved to reduce agricultural carbon emissions. These findings challenge China's current unique path of agricultural specialization from the perspective of carbon emission reduction and demonstrate the applicability of the theory of metabolic rift to the current path of agricultural development in China. Accordingly, corresponding short-term and long-term implications related to agrarian transition and agricultural carbon emissions are provided.