RESEARCH PROGRESS OF SOURCE AND MECHANISM OF AGRICULTURAL NON-POINT SOURCE POLLUTION IN CHINA

Agricultural non-point source pollution of aquifer, lake, riverbank and other ecosystems is caused by chemical fertilizer, pesticide, animal manure and other organic or inorganic pollutants through surface runoff and farmland leaching in agricultural production. The non-point source pollution has the characteristics of wide distribution, concealment, randomness, hysteresis and complex formation mechanism, and thus it is difficult to study and control this type of pollution. Understanding the mechanism of agricultural non-point source pollution and comprehensively being aware of the pollution sources are of great theoretical and practical significance for future research. In this paper, the mechanism of agricultural non-point source pollution was analysed in terms of rainfall and runoff process, soil erosion process, pollutant migration and transformation, and so on. In addition, the sources and sinks of nitrogen, livestock and poultry pollutants, pesticides, plastic film and other pollution sources were discussed, and the results could be informative for the formulation of agricultural sustainable development policies.