title: Anthropogenic nitrogen sources and exports in a village-scale catchment in Southeast China.
abstract: An experimental village-scale catchment was selected for investigation of nitrogen (N) sources and exports. The mean N application rate over the catchment was 350.2 kg N ha(-1), but this rate varied spatially and temporally. The N leaching loss rate varied from 8.1 to 52.7 kg N ha(-1) under different land use regimes. The average N leaching loss rate was 13.4 kg N ha(-1) over the whole catchment, representing about 3.8% of the total N inputs. The N export rate through stormflows was 28.8 kg N ha(-1), about 8.2% of the total N inputs. Seasonal patterns showed that 95% of N exports through stormflows occurred during July to September in 2002. Overall, the maximum riverine N exports were 12.1% of total N inputs and 15.5% of the inorganic fertilizer N applied. Understanding N sources and exports in a village-scale catchment can provide a knowledge base for amelioration of diffuse agricultural pollution.
authors.affiliation: State Key Laboratory of Marine Environmental Science, Ministry of Education, Environmental Science Research Centre, Xiamen University, 361005 Xiamen, China. wzcao@xmu.edu.cn
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Cao
authors.forename: Huasheng
authors.initials: H
authors.lastname: Hong
authors.forename: Yuzhen
authors.initials: Y
authors.lastname: Zhang
authors.forename: Nengwang
authors.initials: N
authors.lastname: Chen
authors.forename: Yue
authors.initials: Y
authors.lastname: Zeng
authors.forename: Weiping
authors.initials: W
authors.lastname: Wang
mesh_terms: D000383:Agriculture; D000818:Animals; D002681:China; D004784:Environmental Monitoring; D005308:Fertilizers; D005618:Fresh Water / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D008372:Manure; D009584:Nitrogen / Q000032:analysis*; D010945:Plants, Edible / Q000737:chemistry / Q000254:growth & development; D011891:Rain; D012307:Risk Factors; D012621:Seasons; D012722:Sewage / Q000032:analysis* / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005308:Fertilizers; D008372:Manure; D012722:Sewage; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D009584:Nitrogen