Agricultural Cropping Patterns And Nonpoint Source Pollution Control Within The Songhua Reservoir Basin

A survey of 3 land using types which include bottomland, wheat/vegetables rotation field, growing flowers field under greenhouse within the Songhua reservoir basin (Kunming, China) was undertaken to determine soil pollutants and other changes in physical and chemical properties,investigating pollutants content in soil percolating water and fertilizer rate,in order to reveal the generation, migration and transformation mechanisms of agricultural non-point source pollution in Songhua reservoir basin.The results showed:?Soil pollutants in different land using types mainly accumulated in the plow layer, and it has no significant difference in the following tillage layer.It may be an important way to make the pollutants loss by underground water washing.Water immersion plow layer, may cause serious pollution of groundwater.Comparing with traditional cultivation, the soil pollutants in growing flowers field under greenhouse were significantly higher,? and a high proportion of nitrogen and organic matter was made, nitrogen lost very easy.Cropping pattern with high pollutants loss can not plant at higher land where underground water will not enter the plow layer.Cropping rotation can improve the soil nutrients and reduce the loss of pollutants.