Study On Environmental And Economic Performance For Farmland Ecological Ditch To Prevent And Control Non-point Source Pollution

This paper summarizes the research trends of agricultural non-point source pollution control and compensation in China and abroad, on this basis, providing a profound understanding and illustration about the agricultural non-point source pollution prevention and control theory. By analyzing the effect and practical measures of agricultural non-point source pollution prevention and control, and taking the local farming fertilizer N inputs field investigation, we could draw the conclusion that nitrogen content has exceed 225kgN?hm-2. By combining the ecological drains reconstruction project to control and reduce the farmland nutrients in water. We carry out the feasibility study of rebuilding the ecological ditch around Zhushan bay area to prevent and control the agricultural nonpoint source pollution and further propose the relevant policy advice.In this paper, the main conclusions are as follows:(1)In Zhushan bay area, the total rice planting N inputs is 292 kgN?hm-2, the total N inputs for the wheat planting is 247 kgN?hm-2, the fertilizer of the two mentioned crops have exceeded the farmland environment security technology’s N input safety limit. All the year around, fertilizer N input of the vegetables production is up to around 1300 kgN?hm-2. Every year the orchard fruit applicator the inorganic fertilizer, such action will make it easier for fertilizer with the surface runoff into the downstream water bodies brought the huge risk of agricultural non-point source pollution. And based on the moderate scale management policy and land circulation, we integrate the traditional fragmentary land and small-scale peasant operational mode into continuous land and make it possible to rebuild ecological intercepting ditch. Through farmland ecological ditches to reduce the nutrients in the farmland retire water, which will not only reserve both the agricultural ecological environment and landscape, but also plays a role in the control of agricultural non-point source pollution.(2)Though the reconstruction of farmland ecological canal in the Zhushan bay area, the ecological ditches can achieve the environmental benefits which can reduce of the total N and total P in farmland retire water, the number of which is 66 kg/ha and 7.8 kg/ha respectively; such way can realize the economic benefit by saving the original potential cost of discharging N and P elements which flow to the downstream water bodies, namely 3025.7 yuan/ha(201.7 yuan/mu).(3)Ecological canal reconstruction project of the net present value(NPV) is 72.794 yuan, the return internal rate(IRR) is 7.03%. The project is practical and economical. The empirical analysis shows that zhushan bay area ecological intercepting ditch project will not only bring the corresponding envir onmental improvement, also can bring real economic benefits.(4)The policy recommendations were further proposed to promote farmland ecological drainage reconstruction fully as the environment-friendly agricultural technology practice under the moderate scale management mode, mainly including three aspects: Firstly, to strengthen the long-term stable and effective agricultural environment support policy, especially the legislation on the implementation of the environmental-friendly agricultural technology practices, the incentive compensation mechanism forimplementers of these practices and compensation effect of evaluation mechanism. Secondly, to enhance the diversified financial support for the application of environmental-friendly agricultural technology practices, especially the infrastructure construction funding of farmland ecological drainage reconstruction and the operation funding for the popularization and training of these practice by local agricultural technology extension to farmers; Thirdly, to strengthen the standardization of the methods for evaluating the application effect of those practices so as to account fairly and accurately the environmental, economic and social benefits created by the farmland ecological drainage reconstruction as a pure public welfare environmental practice.