title: Advancing the Food-Energy-Water Nexus: Closing Nutrient Loops in Arid River Corridors.
abstract: Closing nutrient loops in terrestrial and aquatic ecosystems is integral to achieve resource security in the food-energy-water (FEW) nexus. We performed multiyear (2005-2008), monthly sampling of instream dissolved inorganic nutrient concentrations (NH4-N, NO3-N, soluble reactive phosphorus-SRP) along a ∼ 300-km arid-land river (Rio Grande, NM) and generated nutrient budgets to investigate how the net source/sink behavior of wastewater and irrigated agriculture can be holistically managed to improve water quality and close nutrient loops. Treated wastewater on average contributed over 90% of the instream dissolved inorganic nutrients (101 kg/day NH4-N, 1097 kg/day NO3-N, 656 kg/day SRP). During growing seasons, the irrigation network downstream of wastewater outfalls retained on average 37% of NO3-N and 45% of SRP inputs, with maximum retention exceeding 60% and 80% of NO3-N and SRP inputs, respectively. Accurate quantification of NH4-N retention was hindered by low loading and high variability. Nutrient retention in the irrigation network and instream processes together limited downstream export during growing seasons, with total retention of 33-99% of NO3-N inputs and 45-99% of SRP inputs. From our synoptic analysis, we identify trade-offs associated with wastewater reuse for agriculture within the scope of the FEW nexus and propose strategies for closing nutrient loops in arid-land rivers.
authors.affiliation: Department of Civil Engineering, University of New Mexico , Albuquerque, New Mexico 87131 United States.
authors.forename: Jacob G
authors.initials: JG
authors.lastname: Mortensen
authors.affiliation: Department of Civil Engineering, University of New Mexico , Albuquerque, New Mexico 87131 United States.
authors.forename: Ricardo
authors.initials: R
authors.lastname: González-Pinzón
authors.affiliation: Department of Biology, University of New Mexico , Albuquerque, New Mexico 87131 United States.
authors.forename: Clifford N
authors.initials: CN
authors.lastname: Dahm
authors.affiliation: Department of Economics, University of New Mexico , Albuquerque, New Mexico 87131 United States.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Division of Biology, Kansas State University , Manhattan, Kansas 66506 United States.
authors.forename: Lydia H
authors.initials: LH
authors.lastname: Zeglin
authors.affiliation: Department of Biology, University of New Mexico , Albuquerque, New Mexico 87131 United States.
authors.forename: David J
authors.initials: DJ
authors.lastname: Van Horn
mesh_terms: D057914:Agricultural Irrigation; D000383:Agriculture; D004784:Environmental Monitoring; D005308:Fertilizers / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D045483:Rivers; D012621:Seasons; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005308:Fertilizers; D009584:Nitrogen; D010758:Phosphorus; D062065:Wastewater; D014874:Water Pollutants, Chemical