| The changes in soil,water and air caused by agricultural non-point source pollution(the Agri-NPSP for short)worldwide have become one of the important factors threatening the social and economic development of human beings and the safety of the ecological environment.The administration of the Agri-NPSP has become the consensus of the international community.China’s agricultural non-point source pollution is intertwined with economic development and people’s livelihood issues.The relationship is complex and the interests are diverse.It has become a problem in rural social governance after the safety of agricultural products,land expropriation,protection of farmers’ rights and interests,and supply of rural social public services.New problems to be solved urgently.As a major agricultural province with an added value of my country’s primary industry of more than 500 billion yuan,Sichuan Province also faces the problems of small per capita arable land,large total non-point source pollution,various types,and high governance difficulties.Taking excessive fertilization as an example,it is not only easy to cause soil compaction,but also often affects the surrounding water quality,and even causes air ammonia nitrogen pollution.The wide range of AgriNPSP increases the difficulty of prevention and control and hinders the sustainable development of agriculture.This paper firstly defines the core concepts of this paper based on basic theories such as agricultural sustainable development theory and environmental regulation theory,and builds an analytical framework.Secondly,this paper takes21 cities and prefectures in Sichuan Province as the research object,and uses the inventory analysis method to estimate the Agri-NPSP emissions from 2014 to 2019 in 21 cities and prefectures.Besides,Arc GIS was used to analyze the temporal and spatial distribution characteristics of Agri-NPSP in Sichuan Province.Then,using the above accounting results,it is studied whether the relationship between agricultural economic development and non-point source pollution in Sichuan Province conforms to the environmental Kuznets curve hypothesis,and the shape of the EKC curve is fitted.stage and its future development trend.On this basis,a fixed-effect model for the research on the influencing factors of non-point source pollution is constructed to empirically explore the influence of factors such as population,economy,nature,and agricultural structure on non-point source pollution.Lastly,according to the regression results,combined with the situation of Sichuan Province,put forward policy recommendations for the method of controlling Agri-NPSP.This study has the following main conclusions:(1)Agri-NPSP emissions and sources in Sichuan Province.From 1998 to 2019,the average annual discharge of chemical oxygen demand(COD)in the province was 986,600 tons,the average annual discharge of total nitrogen(TN)was 524,800 tons,and the average annual discharge of total phosphorus(TP)was 64,000 tons.COD is the primary pollutant.COD pollution sources in descending order of contribution rate: livestock and poultry breeding,rural life,farmland solid waste;TN pollution sources in descending order of contribution rate: livestock and poultry breeding,agricultural fertilizer,rural life,farmland solid waste;TP The sources of pollution are ranked in descending order of contribution rate: livestock and poultry farming,farmland solid waste,agricultural fertilizers,and rural life.Livestock and poultry farming is the most dominant source of Agri-NPSP in Sichuan Province.(2)The spatiotemporal characteristics of non-point source pollution in Sichuan Province.From 1998 to 2016,the Agri-NPSP in Sichuan Province increased year by year,and stopped the increase after reaching a peak in 2006.From 2006 to 2019,the growth rates of COD,TN,and TP were-1.53%,-1.39%,and-1.14%,respectively.From the perspective of spatial characteristics,Liangshan Prefecture,Aba Prefecture,Chengdu,Nanchong and other places all rank in the forefront,and Ya’an and Zigong have the lowest total emissions;when the government strengthens the management of Agri-NPSP affected areas,it should focus on Consider areas with higher total emissions.(3)Demonstration of the relationship between the Agri-NPSP and agricultural economic growth.There is a positive N-type EKC curve relationship between the total agricultural production value of Sichuan Province and the three types of a AgriNPSP emissions.Only Ganzi Prefecture,Abazhou City and Panzhihua City have not broken through the first inflection point of COD and TP.The remaining 17 cities and prefectures have all broken through the first inflection point,and Chengdu City has broken through the second inflection point,indicating that most cities and prefectures in Sichuan have moved towards the inflection point.The new stage of transformation of the production mode of modern agriculture,constantly reducing the excessive dependence on pesticides and fertilizers,is taking steps towards the development of green agriculture.(4)Empirical analysis of the influencing factors of Agri-NPSP.The factors that have a positive correlation with the total COD,TN,and TP emissions in Sichuan Province are: the rural population size,agricultural structure and planting structure;the negative correlation factors are: the level of financial support to agriculture and the level of non-agricultural employment.It shows that further increasing the government’s subsidies to agriculture,rationally guiding the direction of the use of subsidies,optimizing the employment structure of rural residents,and reducing the proportion of cash crops in the planting industry can reduce the discharge of agricultural pollutants to a certain extent.Based on the research conclusions,this paper proposes optimization measures to reduce the Agri-NPSP emissions in Sichuan Province from the aspects of improving the level of financial support for agriculture,scientifically planning the structure and layout of planting industry,and strengthening the concept and behavior guidance of agricultural producers,so as to promote agricultural production as well as the green stable development,and consolidate the important strategic position of food security in Sichuan Province. |
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