Farmland Ecosystem Environment Monitoring And Evaluation In Mingshan District

Agriculture is the foundation of our country. In recent years, our country pays much attention to perfect the rural infrastructure construction, but continuous deteriorations of rural area ecological environment haven’t gotten effective improve.Environment determines the outside condition of our survival and development. Environment monitoring and assesses is prior and fundamental work for environment protection, meanwhile, it is also a scientific proof of regional environmental management. Though environment assess, the main pollutants and pollution resources can be fond in the regional environment,primary environment problems can be figured out,ascertain the change rules of environment development,and providing scientific proofs for regions to formulate regulations which is related to the protection of environment.This thesis focuses on the research in Mingshan District,Ya’an City and mainly carry on the research of environment condition of farmland ecosystem in Ming shan.According to soil environment quality standard and irrigation water quality standard,we establish the evaluation index of main pollutants in research area, do detections and analysis towards samples of soil and water in Mingshan District,and confirm the type of pollutants and the pollution degree,we also confirm the manage objects and priorities, thus, this provides scientific proof for guaranteeing the production of food as well as the sustainable development of ecosystem. Here are the main conclusions of the study:The comprehensive pollution index of soil quality condition in Mingshan District is 0.818,which is almost up to the secondary standard of soil pollution index evaluation standard.However, in the soil, Pi, the pollution index of some heavy mental is greater than 1. There is one sample for cuprum exceeding and 15 samples for cadmium exceeding.From this statistics, we can see the cadmium exceed in the soil of Ming shan is relatively serious.There are three reasons of cadmium exceeding:first of all, in southeast edge of Sichuan Basin Area, cadmium accumulation in the lead-Zinc Zone, and in supergene environment, cadmium has a particular high content; Secondly, the improper use of pesticides and fertilizers, while the rock phosphate naturally associated with cadmium, so if the phosphatic fertilizer is improper used, it will cause a seriously cadmium pollution.Thirdly, it is caused by the house refuse and the exhaust gas, water waste, waste residue which are discharged from industrial parks. In Mingshan District, the soil showed varying degrees of acidification, which increases the activity of heavy metal pollution.In the investigation of soil fertility, it showed that in Mingshan District,the soil fertility is in good condition, however, total nitrogen and available phosphorus in the soil is unevenly distributed,and it varies in different regions.If nitrogen and available nitrogen is low in soil, we should add a certain amount of potash, nitrogen fertilizer to improve soil condition.The irrigation water environment comprehensive pollution index is 0.271,the water quality is up to the primary standards of our country’s standard for irrigation water quality(GB5084-92). Water quality test results show that the heavy metal proportion of plumbum, mercury, cadmium, arsenic is too low while hexavalent chromium has a little higher content, but also in line with the primary standard of irrigation water quality index.The ecosystem’s comprehensive pollution index in Ming shan is 0.627, the integrated assessment of environment is at first class, the ecosystem quality is so good that can guarantee the healthy growing of crops such as paddies, wheats and commercial crops such as rapes and tea trees.To ensure the sustainable development of Ming shan ecological environment, we should strengthen environment supervision and management of agricultural soils and enhance the regulation of key pollution sources that influence the ecological environment,take a strict control of sewage irrigation in major grain producing areas and vegetable base,strengthen the environment management of pesticides, fertilizers and exhaust packaging and the use of plastic sheeting.