title: Assessment of nitrogen excess in an agricultural area using a nitrogen balance approach.
abstract: A pilot study has been initiated to develop an approach for quantification of nitrogen excesses from agricultural activities that involve greenhouse farming in Kumluca Plain, Turkey. Detailed calculations utilizing the nitrogen balance method (NBM) were carried out at nine different locations within the plain over a time period of one year. The major contributing factors and governing operative mechanisms taken into consideration were nitrogen application rates both as organic and chemical fertilizers, irrigation water application practices, and nitrogen uptake by plants. The adopted approach yielded valuable information such as plant nitrogen uptake efficiencies, excess nitrogen, leaching rates and leachate nitrogen concentrations. Further, a site specific multiple linear regression model has been developed to estimate the ratio (N(leachate)/N(groundwater)) as a function of independent variables: farming age, excess nitrogen application and SEEPAGE Index Number. The negative sign of the model parameters implies that the ratio (N(leachate)/N(groundwater)) decreases as values of the independent variables increase. The adopted approach and the obtained results can beneficially be applied to similar sites to establish basic parameters of irrigation and fertilizer application operations.
authors.affiliation: Akdeniz University, Environmental Engineering Department, 07059 Antalya, Turkey. muhammetoglu@usa.net
authors.forename: H
authors.initials: H
authors.lastname: Muhammetoglu
authors.forename: A
authors.initials: A
authors.lastname: Muhammetoglu
authors.forename: S
authors.initials: S
authors.lastname: Soyupak
mesh_terms: D003247:Conservation of Natural Resources; D018556:Crops, Agricultural / Q000378:metabolism; D004784:Environmental Monitoring; D005308:Fertilizers; D016014:Linear Models; D008372:Manure; D008962:Models, Theoretical; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism; D014421:Turkey; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism; D014881:Water Supply / Q000032:analysis*
chemical_list: D005308:Fertilizers; D008372:Manure; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D009584:Nitrogen