基于农户经济和环境“双优”目标的粮食主产区化肥施用优化模拟分析——以邯郸地区小麦生产为例

Analysis of fertilizer-use optimization under the joint framework of economic rationality and environmental sustainability:Evidence from wheat farmers in Handan,Hebei rovince

我国目前面临着粮食供求紧平衡和化肥过量施用导致农业面源污染的严峻挑战。利用河北邯郸地区1026户小麦种植农户的调研数据,构建经济理性与环境可持续双目标下的农户化肥施用模型,并进行优化模拟分析,旨在探讨应该如何优化粮食主产区农户的化肥施用行为,以实现经济与环境的"双优"目标。结果表明:农户对化肥的认知和化肥价格是实现"双优"目标的关键因素。现阶段农户过高估计了化肥投入对粮食增产的效果,农户的预期化肥产出弹性显著高于化肥实际产出弹性,化肥使用效率偏低;当前粮食主产区化肥价格是模拟优化分析结果中最优化肥价格的一半左右,较低的化肥施用成本促使农户倾向高化肥投入以实现粮食增产。基于研究结果,提出了矫正农户施肥认知偏差、科学高效施肥和适当提高化肥价格水平、优化化肥使用结构等政策建议。

China has faced severe challenges from the tight balance of food security and the pollution caused by the excessive use of agricultural fertilizers.How to optimize the fertilizer uses to ensure national food security and agricultural environmental sustainability has become a great concern.The purpose of this paper is to explore ways to optimize the application of chemical fertilizer under the joint framework of economic rationality and environmental sustainability in major grain-producing areas.Using the survey data from 1026 wheat-growing farmers in Handan,Hebei province,we build a quantitative model of small holders’use of chemical fertilizers to analyze the obstacles in achieving economic rationality and environmental sustainability simultaneously.The results show that farmers’expectation of chemical fertilizer’s output elasticity in the sampling region is significantly higher than the actual elasticity,indicating that,generally speaking,the farmers overestimated the effect of fertilizer on improving grain production,thus using more fertilizers.Meanwhile,the current price of chemical fertilizer in the study area is about half of the optimal price estimated in the analysis,indicating that the cost of chemical fertilizers is relatively low compared with other agricultural inputs,e.g.,labor,thus farmers tend to be more dependent on chemical fertilizers in pursuing higher yield.Hence,taking into account the national food security and agricultural environment sustainability,our results suggest that:(1)It is necessary to correct farmers’cognitive bias towards the(in-)effectiveness of fertilizer use to promote scientific fertilization;(2)Fertilizer market structure and the relative price between synthetic and organic fertilizers should be more differentiated through the supply-side reform,so as to fundamentally mitigate fertilizer’overuse’in China.