| Modern agricultural specialization,industrialization and intensif ication improved agric ultural productivity,land productivity and resource utilization. However,it has broken the cycle of matter and energy between the traditional farming and aquaculture as well. The great achievements of agricultural development in China are largely dependent on a lot of production data input, and have come at great environmental cost. Numerous studies show that the agricultural nonpoint source pollution mainly result from excessive use of chemical fertilizers and pesticides,disorderly discharge of livestock and poultry,casual disposal of rural sewage and solid waste,irrational industrial structure and spatial distribution of agr iculture,rural residents’ backwardness of rural environmental awareness,the absence of main body of rural environmental management and the imperfect agricultural environmental management policies, which lead to the basin water eutrophication that has been a serious threat to drinking water safety and people’s health and restrict the sustainable development of the agricultural economy. The contradiction of the agricultural economic development,the effective utilization of agricultural resources and the protection of rural ecological environment should be resolved objectively. However,the policies and measures of the agricultural ecological environment management have lost ground to the growing agricultural non-point source pollution in our country. The transformation of agricultural economic development mode,the effective supply of the agricultural environment management system and policy ar e the effective ways to change the dual structure of the agricultural and rural ecological environment. Existing research of the internal relations of agricultural development between and ecological environment,the constraints and incentive mechanism of agricultural non-point source pollution source controll,management system of agro ecological public policy is insufficient. Therefore,this study has important theoretical and practical significance in effectively solving environmental pollution and other prominent issues faced by China’s agricultural development,enhancing farmers’ environmental awareness and sense of participation to control agricultural non-point source pollution,objectively evaluating the quality of regional agr icultural economic growth,improving and constructing the agricultural environmental policy system with Chinese characteristics,maintaining the balance of agro-ecosystems and restoring ecological civilization.Taking the Three Gorges Reservoir in Chongqing section as the study area,on the basis of the literature study and review,guided by the theories in agricultural economics,land resources, environmental economics and econometrics and so on,this paper,from the meso-level,suggests that the adjustment and optimization of agricultural planting structure should not only start from the adjustment of the proportions of the crops,but also from the application and promotion of cleaner production technologies to promote the development of green,organic production and achieve optimum economy and total emissions control. From the macro-level,the paper starts with the mechanism of agricultural nonpoint source pollution and water security in watershed and discusses the environmental efficiency of agricultural economic development in Three Gorges Reservoir,shadow prices of pollutants and its influencing factors,clearing the connotation of agriculture and rural economy policies,qualitatively analyzing the impact of the entire rural and agricultural economy system evolution on the agricultural nonpoint s ource pollution and then constructing an index system to quantitatively analyze of the relationship between agricultural non-point source pollution and agricultural economy policies. From the micro-level,the paper explores the farmers’ environmental awareness and behavior in agricultural nonpoint source pollution control and studies the micro subject behavior which is displayed in decision-making of chemical fertilizer,adoption of clean agricultural production technology behavior,and their cognition and consciousness of agricultural nonpoint source pollution. The specific study can be concluded as follows :(1)Pollution emission coefficient was used to estimate the average emissions of COD,NH3-N,TN and TP of the three major kinds of pollution sources including agricultural fertilizer,livestock and poultry breeding,rural domestic pollution in the 21 counties(districts) in Chongqing Section of the Three Gorges Reservoir Region from 1998 to 2011. Geographic Information System(GIS) was applied to analyze spatial differentiation of average emissions quantity. Consequently,coupling error back propagation and projection pursuit(BPPP) mode was employed to predict emissions quantity in the low-emission and high-emission situations. To explore the evolutionary process and inner mechanism between agricultural nonpoint pollution source and river basin water resource security in Chongqing Section,based on DPSIR frame,using structural equation model,this paper makes an assessment of river basin water resource security level over the period 2000-2011.(2)Based on the TPB and the survey data collected from 688 farming households in the ecological barrier zone of Three Gorges Reservoir Area,using structural equation model,this paper analyzes farmers,behavioral attitude,subjective norm and perceived behavior control. According to the surveys of the farmers in Chongqing section of the Three Gorges Reservoir Area,this paper uses PCE semi-parametric model to make an empirical analysis of the reservoir area farmers’ willingness to pay for the non-point source pollution reduction and influencing factors.(3)According investigation data, the paper analyzes the farmers’ harm cognition,avoidance willingness and the influencing factors of the excess fertilization by using the stochastic frontier production function and the double variable Probit model in the typical regions.(4)This paper analyzes farmers’ adoption behavior of clean production technology and the influencing factors by using the multivar iate probit regression model,evaluates the farmers’ cognition of agricultural environmental pollution and influencing factors by using the multivariate probit regression model.( 5) The influence of agricultural development and environmental policies on agricultural non-point source pollution by using the econometric analysis method and the panel data of the Three Gorges Reservoir area of Chongqing. By using the 2000-2012 panel data of Chongqing section of Three Gorges reservoir region and the parameters of the directional distance function,the agricultural non-point source pollution emission efficiency and shadow price have been calculated. Based on the random effects panel data Tobit model, the paper analyzes the factors which influence the agricultural nonpoint source pollution emission efficiency and shadow prices.(6)Based on the dual goals of the optimal agricultural economic benefits and non-point source pollution emission reduction, using the linear programming model, the paper designs the optimization of planting structure and clean agricultura l production in the ecological barriers(Chongqing section) of the Three Gorges Reservoir Region.The main conclusions of the research are as follows:1. Agricultural non-point source pollution emissions impacted water resources security in Chongqing section of the Three Gorges Reservoir area. The results indicate that the average emissions of COD,NH3-N,TN and TP is 449551.65,91646.4,134076.92,61651.66t/a respectively in Chongqing section from 1998 to 2011.Agricultural fertilizer covering 50.38% among the three kinds of NPS has become the chief object of pollution control. The emissions and intensities also bear regional characteristics. The emissions quantity in the tail of the Reservoir near the downtown of the city are lower,but conversely,they are higher in the hinterland and peripheral mountain areas where agricultural fertilizer,livestock and poultry breeding are major sources of pollution. The prediction results of BPPP model demonstrate that simulation of high emission has little influence on the mitigation of pollution emissions while simulation of low emissions will cause all kinds of pollution emissions down by 20%.The river basin water resources security level can be divided into two stages. During 2000—2005 the water resources safety level was degraded from the general security to very insecurity. However,during 2005—2011 the security level was upgraded from very insecurity to security.2. Analysis of the farmer’s willingness and behavior to participate in control agricultural non-point source pollution. Farmers,willingness to participate in controlling agr icultural non-point source pollution are affected by their perceived behavior control and they are in the important transition period. The fertilizer use efficiency of the farmers’ in the main mustard tuber planting areas was 0.571; 42.9% fertilizer cannot be utilized and absorbed by the crops; the average excessive fertilizer comes to 11.61 kg per mu. The farmers’ cognition of the harmfulness of overuse of fertilizer can be influenced by their education level,years of being engaged in agriculture,fertilizer use technical training and household diversity. The farmers’ evasion willingness can be mainly influenced by their education level,years of being engaged in agriculture,agr icultural technical training,the household diversity,the family labor force,the use of organic fertilizer and the quality,type and land fragmentation of the mustard tuber plots.3. Analysis on the adoption behavior and the persistence adoption intention of the household cleaner production technology. Farmers have certain cognition on clean production technologies,but the farmers’ level of adopting clean production technologies is relatively low. The important influencing factors which affect the farmers’ behavior include their age,their education,whether being village leaders or not,their risk preference for technologies,the main source of family income,the number of agricultural labor,total agricultural family income and planting scale. there are relatively close relationship among the evaluation of farmers adopting cleaner production technologies,perceived usefulness and lasting adoption adopt intentions. Farmers’ perceived usefulness of cleaner production technologies and satisfaction of aadoption have a signif icant positive impact on the adoption intention lasting cleaner production technologies. In the short term,the government should encourage farmers to adopt cleaner production technologies by incentives way. In the long term,it should develop alternative cleaner production technologies to meet the needs of farmers as soon as possible.4. Agricultural development policy and environmental policy affect agricultural non-point source. Policies of agricultural industrialization,national finance direct subsidy on chemical fertilizer and grain have a positive effect on the agricultural non-point source pollution,which will increase the non-point source pollution. Agricultural technology promotion subsidies,agricultural eco-engineering construction,the adjustment of planting structure and formula fertilization by soil testing policy are the negative inf luence. They will slow the agriculture non-point source pollution. There are no significant correlation between the investments in agricultural science and technology, farmland water conservancy construction and agricultural environmental protec tion and agricultural non-point source pollution. During 2000—2012,agricultural non-point source pollution emission efficiency is 0.6499, the average shadow prices of four kinds of pollutants TN,TP,COD and NH3-N are respectively 0.3729,0.0326,0.1371,0.0533 ten thousands yuan/ton; There are some differences in the agricultural non-point source pollution emission efficiency and shadow price in different areas. The agricultural non-point source pollution emission efficiency in the paralleled ridge valley region of the Three Gorges Reservoir,the hinterland area,the hinter land along the peripheral mountain area is low while the shadow price of the pollutant is high. The factors which influence the agricultural non-point source pollution emission efficiency and shadow price include the proportion of main economic crops and the grain crops,the agricultural production facilities and education level of rural residents.5. Planting structure optimization of agricultural non-point source pollution control.The optimization results showed that the optimal paths to maximize the crop net income were as follows: The land area for grain production should cover 119.16×104 hm2,the land area for vegetables planting should be 33.25×104 hm2 and the total land area for tobacco, fruits and tea planting should be 17.05×104 hm2. In the premise of stable grain production, the conventionally grown grain, corn and soybean planting area can be gradually reduced. Otherwise, the planting areas of tobacco, vegetables, fruits and tea can be appropriately increased. In the process of crops production, according to the present ecological agriculture construction, the clean production can be vigorously promoted. The soil testing and formulated fertilization areas for food production in rice, wheat, oil crops, corn and soybean must be expanded. The organic vegetable planting can be increased positively.According to the above research conclusion,the prevention and control source of agricultural non-point source need implement policies for agricultural development and rural environmental protection policy, transform the mode of economic growth of agriculture,plan layout industrial structure of agriculture, strengthen agricultural science and technology innovation, promot e agricultural cleaner production technologies and establish incentive and restraining mechanism of micro subject behavior. Some feasible policies are proposed such as clearing responsibility of government and related systems security, diversifying agricultural technology popular ization system,promoting the level of farmers’ technical education and training,expanding agricultural technology diffiision channel,improving farmers’ participation in environmental management. |
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