## 5 Conclusions and Policy Implications
Therefore, it is necessary for the country and departments to introduce systematic GPPs for farmers with a policy system covering the entire industrial chain, including pre-production, mid-production, and post-production. Second, it is necessary to formulate and improve guidance policies and incentive policies, and to guarantee policy systems, as well as supporting measures, to strengthen the supervision of the market consumption and production of green agricultural products. Short-term policies and policy uncertainty increase the risks of farmers' production transformation, reduce the efficiency and effectiveness of policy implementation, and make it difficult to achieve the expected policy goals. Therefore, support for small farmers will inevitably require the use of mid-term policy tools [48]. To ensure sustainability in both policy formulation and implementation, the transformation of farmers from traditional production to green production will not be an overnight process and will require policy guidance and protection for farmers. Third, in the process of implementing agricultural policies, taking into account the opinions of farmers can effectively improve their satisfaction with policy implementation and, to some extent, can eliminate or alleviate obstacles to the transformation to agricultural green production. Fourth, in the implementation process of agricultural GPPs, efforts should be made to increase policy implementation and promotion. In addition to the traditional agricultural technology promotion system, new information dissemination channels such as television broadcasting, WeChat on mobile phones, and short videos should also be emphasized. Because of the relatively small scope of farmers' activities, the final implementation of agricultural policies is generally carried out by village cadres. In the rural environment of trust among acquaintances, farmers have a higher level of trust in village cadres to carry out policy propaganda both at home and in the field. This form of propaganda can be used as an important means of publicity, especially for elderly farmers and farmers with lower education levels. Finally, the subjective evaluation of policy implementation by farmers directly determines their satisfaction with the policy. Thus, the end of policy implementation does not necessarily mean that the expected goals of the policy can be achieved. It is more important to consider the subjective evaluation of policy implementation by farmers to serve as an important basis for the dynamic evaluation and adjustment optimization of policies. The main contribution of this study is the revelation of the mechanisms of the impacts of policy structure and policy implementation on farmers' satisfaction with GPPs. The results and policy implications of this study are significant for policy evaluation, adjustment,and optimization under sustainable agricultural development in China and other countries. However, this study was characterized by some limitations. Within the available limits, only the GPP satisfaction of farmers in Anhui Province, China, was analyzed. In future research, more data from different regions of China will be analyzed to identify spatial differences, and samples will be tracked and surveyed to evaluate the dynamic trend of farmers' satisfaction with agricultural GPPs. Moreover, this study focused only on the green production of farmers without considering the differences between different agricultural production processes. In addition, it must be determined how to utilize the conclusions of this study to further explore policy structure adjustment and implementation path optimization. These interesting topics will be explored in a future series of investigations. All authors contributed to the study conception and design.