The researchers studied agricultural pollution sources in Heilongjiang Province using statistical data. They found that livestock and poultry contribute to COD pollution, while fertilizers are the main source of TN pollution. Pollutant emissions are influenced by rural population size, and in 2007 and 2008, TN and TP concentrations exceeded safety levels. Phosphorus and nitrogen were the main pollutants causing water pollution. These findings help in planning to control agricultural pollution in the province.