Input of Fertilizers and Pesticides in Citrus Orchards in Headwater Area of Dongjiang River and Its Potential Environmental Impact

Through household interviews,input of fertilizers and pesticides in citrus orchards and its potential environmental impact in the headwater area of the Dongjiang River(HDR) was investigated and analyzed.Results show that the input is lower in cultivation of Wengan citrus than in that of navel orange.Inputs of fertilizers differ sharply between cultivation patterns,i.e."pig-biogas-fruit","fruit-tree only" and "organic".Moreover,the farmers generally apply fertilizers and spray pesticides only by experience.Over 50% of the farmers apply fertilizers excessively and most of them spray pesticides 12-13 times a year on average,which brings about a great pollution risk to the environment,especially water environment.Analysis shows that to intensify training and technical guidance of farmers in applying fertilizers and pesticides scientifically,to readjust the species composition of the orchards,and to promote organic cultivation through adoption of ecological compensation mechanisms are effective measures to reduce the environmental pollution caused by citrus orchards in HDR bring about to the environment.