通过农产品质量认证的合作社影响农业化肥用量的理论机制与实证分析

化肥减量施用是实现中国农产品质量安全与农业绿色高质量发展的重要举措之一，而小规模分散化的经营格局不利于化肥减量技术的推广使用。农民合作社是弥补小规模经营不足与实施农产品质量认证的重要制度安排，其能否以及如何促进农业化肥减量是当前亟待回答的重大现实问题。本文阐明了通过农产品质量认证的合作社对农业化肥用量的影响及作用机制，并基于2007—2018年中国30个省级（市、自治区）面板数据展开实证分析。研究结果表明：通过农产品质量认证的合作社存在显著的化肥减施效应，其主要通过质量溢价、组织规范、组织支持传导路径实现农业化肥减量。从区域差异看，在化肥用量处于高分位点的省份，通过农产品质量认证的合作社表现出更为显著的化肥减施效应；从农作物差异看，通过农产品质量认证的合作社对农业化肥减量施用的贡献主要来自水稻、小麦、玉米三大粮食作物，以及棉花、甘蔗、苹果、柑子四类经济作物的化肥减施效应。

Theoretical mechanism and empirical analysis on the influence of agricultural chemical fertilizer input by cooperatives with agricultural product quality certification

Promoting chemical fertilizer reduction is an effective measure to improve the quality of agricultural products and achieve the high-quality agriculture in China. Nevertheless, numerous smallholders with the characteristics of scattered plots and small-scale is not conducive to the popularization of technology to reduce the amount of chemical fertilizer. Agricultural cooperative has been proposed as an important institutional arrangement to make up for the shortage of smallholders and implement agricultural product quality certification. In the process of cooperative development, whether and how cooperatives can promote chemical fertilizer reduction is an important practical question to be answered urgently. This study focuses on cooperatives that have been obtained agricultural product quality certification, and explore the impact of cooperative development on the amount of chemical fertilizer and its mechanism. The panel data from 30 provincial-level regions in China from 2007 to 2018 were used to conduct an empirical analysis. The results show that: (1) Cooperatives that have obtained agricultural product quality certification have a significant effect on the reduction of fertilizer application, which can achieve the goal mainly through transmission paths including quality premiums, organizational norms and organizational support. (2) In terms of regional differences, our results show that in provinces with larger fertilizer applications, the effect of fertilizer reduction of agricultural product quality certification cooperatives is more significant. In terms of crop differences, the chemical fertilizer reduction effects of cooperatives with agricultural product quality certification are related with the three major grain crops (i.e., rice, wheat and corn), as well as the commercial crops such as cotton, sugarcane, apples and oranges.