  As global climate change and environmental issues escalate, carbon reduction
has emerged as a paramount global concern. Agriculture accounts for
approximately 30% of global greenhouse gas emissions, making carbon reduction
in this sector crucial for attaining global emission targets. Carbon sink
trading serves as a supplementary mechanism to achieve carbon peaking and
neutrality, helping to lower the rate ofcarbon emissions. However, practical
projects and research in the field of carbon sink trading are not enough
currently. This work aims to thoroughly explore the cooperative models between
farmers and retailers within the context of agricultural carbon sink trading,
as well as the optimal decisions on the efforts to reduce carbon emission for
both parties under different cooperative models. To this end, we delve into
three distinct cooperative frameworks: the decentralized, the Stackelberg, and
the centralized models, each accompanied by a corresponding differentialgame
model. The Hamilton-Jacobi-Bellman equation is utilized to investigate the
equilibrium strategies of each participant under these three cooperative
models, respectively. Furthermore, we conducte numerical simulations to analyze
the carbon emission reduction efforts of farmers and retailers, the carbon
emission reduction level of the agricultural supply chain, and the overall
profits of the supply chain. We also compare scenarios with and without carbon
sink trading to provide a comprehensive assessment. The numerical results
indicate that the centralized modelexcels in all aspects, followed by the
Stackelberg model, with the decentralized model showing the weakest
performance. Additionally, carbon sink trading can significantly increase the
profits of the participants under each cooperative model.
