Spatiotemporal Dynamics and Mediated–Moderated Effects of the Digital Economy on Agricultural Carbon Emissions in the Yangtze River Economic Belt

Agricultural carbon reduction is increasingly important for advancing low-carbon and sustainable agricultural development. Using provincial panel data for the Yangtze River Economic Belt (YEB) from 2007 to 2022, this study examines the spatiotemporal evolution of the digital economy (DE) and agricultural carbon emissions (ACE), and applies a two-way fixed-effects model with mediation and moderation analyses. The results show that digital economy (DE) increased steadily across the YEB, while agricultural carbon emissions (ACE) showed clear spatiotemporal variation. Digital economy (DE) is significantly negatively associated with agricultural carbon emissions (ACE), indicating that digital development can support agricultural carbon reduction. The Bootstrap results show that technological innovation and industrial agglomeration are statistically supported mediating pathways. Technological innovation is the primary mechanism, accounting for 44.02% of the total effect, while industrial agglomeration has a smaller but significant mediation share of 0.25%. Industrial structure optimization and fiscal investment are not confirmed as robust indirect pathways. The moderation results show that environmental regulation weakens the negative DE–ACE relationship, whereas agricultural fiscal expenditure strengthens it. These findings highlight the importance of green innovation, agglomeration effects, and supportive fiscal conditions in digital agricultural carbon reduction.