Study On Regulation Strategy Of Agricultural Non-point Source Pollution In Dongting Lake Region Based On Evolutionary Game

The coordinated development of ecological environment and agricultural economy is an important requirement to promote the green and sustainable development of agricultural economic production in China.In recent years,agricultural non-point source pollution incidents emerge one after another and have become the most important pollution type in rural areas,agricultural non-point source pollution has become the main source of pollution,according to the results of the second national survey of pollution sources,Chinese government departments have always attached great importance to agricultural non-point source pollution and have issued the no.1 central document for four consecutive years.The urgency of 2018 points out:strengthen the control of agricultural non-point source pollution,actively promote the use of organic fertilizer in agricultural production;In 2019,the following supplementary proposals were put forward:carry out the action of saving the use of fertilizers and pesticides in agricultural production,and realize the negative growth of the application of fertilizers and pesticides;2020 comprehensive proposed:in-depth development of pesticide and fertilizer reduction action guidance;In 2021,we will promote the green and sustainable development of agriculture and the resource utilization of livestock and poultry waste on the premise of reducing the amount of chemical fertilizers and pesticides and increasing the efficiency.It can be seen that the key measures to solve agricultural non-point source pollution are to effectively control the excessive application of chemical fertilizer and resource recovery of livestock and poultry waste.This paper focuses on the role of livestock and poultry waste recycling in promoting environmental regulation of agricultural non-point source pollution,and studies how farmers and breeding enterprises actively participate in the reduction of chemical fertilizer and the livestock and poultry waste recycling.Firstly,the stakeholder theory was used to analyze the stakeholders of fertilizer application and livestock manure discharge,including farmers and breeding enterprises.Secondly,with the help of evolutionary game theory,the complex interaction mechanism between farmers and breeding enterprises is analyzed on the premise of clarifying the stakeholders.Secondly,game matrix and payment function are constructed according to externality theory and principal agent theory.Finally,the influence of each main body behavior strategy choice variables,by copying dynamic equation and the jacobian matrix,get the evolutionary stable equilibrium(ESS),which defines the ideal situation,clarify the key variables influence on equilibrium results,at the same time,using system dynamics method to simulation of the key variables,to verify the validity of evolution game result.The results show that:(1)Farmers and breeding enterprises can promote agricultural non-point source pollution control only by taking the initiative to fertilize organic manure and recycle livestock and poultry waste.The results of the evolutionary game between farmers and breeding enterprises show that when the optimal behavior strategy of farmers and breeding enterprises is(organic fertilizer,resource utilization),the evolutionary game tends to be the optimal solution,and the resource utilization of livestock and poultry waste and the application of organic fertilizer become the consensus of both sides to promote the control of agricultural non-point source pollution.(2)The government’s reward to breeding enterprises is the optimal scenario to realize effective control of agricultural non-point source pollution.The system dynamics simulation results of the evolutionary game show that when the government incentive standard μ=0.55,the probability of farmers choosing organic fertilizer strategy and breeding enterprises choosing resource strategy tends to 1 the fastest after 3 cycles and 1 cycle respectively.(3)The case of Anhua county verifies the effectiveness of evolutionary game and simulation analysis.According to the field survey,the incentive and subsidy standards for local fecal and sewage recycling from 2018 to 2020 are 25%,35%and 45%respectively,and the number of breeding enterprises participating in the reclamation and reconstruction from 2018 to 2020 is 37,118,274,with an increase of 218.9%and 132.2%respectively.Therefore,the government’s incentive to aquaculture enterprises is an important measure to realize the regulation of agricultural non-point source pollution,and administrative efficiency is also a key variable affecting the active resource conversion and reconstruction of aquaculture enterprises.