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Alternative futures of dissolved inorganic nitrogen export from the Mississippi River Basin896.74 kB
CC BY V4.0, Open Access
Journal article
Alternative futures of dissolved inorganic nitrogen export from the Mississippi River Basin: influence of crop management, atmospheric deposition, and population growth
Biogeochemistry, Vol.133(3), pp.263-277
05/01/2017
Handle:
https://hdl.handle.net/2376/124253
PMCID: PMC6260936
PMID: 30505046
Abstract
Nitrogen (N) export from the Mississippi River Basin contributes to seasonal hypoxia in the Gulf of Mexico (GOM). We explored monthly dissolved inorganic N (DIN) export to the GOM for a historical year (2002) and two future scenarios (year 2022) by linking macroeonomic energy, agriculture market, air quality, and agriculture land management models to a DIN export model. Future scenarios considered policies aimed at encouraging bioenergy crop production and reducing atmospheric N-emissions, as well as the effect of population growth and the states’ infrastructure plans on sewage fluxes. Model-derived DIN export decreased by about 9% (from 279 to 254 kg N km
−2
year
−1
) between 2002 and 2022 due to a 28% increase in area planted with corn, 24% improvement in crop N-recovery efficiency (NRE, to 0.52), 22% reduction in atmospheric N deposition, and 23% increase in sewage inputs. Changes in atmospheric and sewage inputs had a relatively small effect on DIN export and the effect of bioenergy crop production depended on nutrient management practices. Without improved NRE, increased production of corn would have increased DIN export by about 14% (to 289 kg N km
−2
year
−1
) between 2002 and 2022. Model results suggest that meeting future crop demand while reducing the areal extent of hypoxia could require aggressive actions, such improving basin-level crop NRE to 0.62 or upgrading N-removal capabilities in waste water treatment plants beyond current plans. Tile-drained cropland could contribute up to half of DIN export; thus, practices that reduce N losses from tile drains could also have substantial benefit.
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Details
- Title
- Alternative futures of dissolved inorganic nitrogen export from the Mississippi River Basin: influence of crop management, atmospheric deposition, and population growth
- Creators
- Michelle L McCrackin - Washington State UniversityJohn A Harrison - Washington State UniversityEllen J Cooter - Environmental Protection AgencyRobin L Dennis - Environmental Protection AgencyJana E Compton - Environmental Protection Agency
- Publication Details
- Biogeochemistry, Vol.133(3), pp.263-277
- Academic Unit
- Environment, School of the (CAS); Harrison Research Group: Global Change and Watershed Biochemistry
- Identifiers
- 99900667889801842
- Language
- English
- Resource Type
- Journal article