Abstract: Ecological risk assessment integrates the ecological research, decision-making, and environment management efficiently, being applied to treat with the problems in ecological environment all over the world. The research of ecological risk assessment experienced a twenty-year development course of 1) risk source being developed from single to multiple, 2) risk receptor being developed from single to multiple, and 3) risk assessment scale being developed from population and ecosystem level to regional landscape level. In the previous researches, risk receptor was mostly at individual or population level, which should be extended. The qualitative and semi-quantitative methods adopted previously could not fit the demands of current research scale and integrated assessment, and thus, large-scale integrated quantitative assessment method and model based on the viewpoint of sustainable development would be the main research focus in the future.

Key words: Intensive cropping systems, Nitrogen budget, Nitrate accumulation in soil, Groundwater, Nitrate contamination