2023 Early Hearing Detection & Intervention Conference
March 5-7, 2023 • Cincinnati, OH
5/20/2019 | 2:45 PM - 3:00 PM | RECOGNIZING BOTH DENITRIFICATION AND CONSUMPTIVE PROCESSES IMPROVES WHOLE SYSTEM DIEL N2 FLUX MODELS IN DISCRETE REACHES OF AGROECOSYSTEMS | 250 AB
RECOGNIZING BOTH DENITRIFICATION AND CONSUMPTIVE PROCESSES IMPROVES WHOLE SYSTEM DIEL N2 FLUX MODELS IN DISCRETE REACHES OF AGROECOSYSTEMS
There is considerable interest in enhancing denitrification within intervening aquatic habitats between agricultural areas and downstream aquatic ecosystems to reduce N loading impacts. We conducted a series of experiments to examine how manipulating ditch environments can promote denitrification within agricultural drainage networks. Laboratory incubations demonstrate that ecological (wetland vegetation) and bioengineering (hardwood mulch addition) manipulations significantly enhance denitrification potential within ditch sediments. However, experiments comparing whole system diel N2 fluxes between control and vegetation or mulch manipulations uncovered complex patterns suggesting fluxes may be controlled by the balance of both N2 production via denitrification and consumption driven by physical or biological processes. We expand the current one-station model to a two-station model and investigate potential improvement added by a N2 consumption term to represent biological (N fixation) or physical (bubble formation and N2 scavenging) mechanisms associated with daytime photosynthesis . More work is needed to understand specific mechanisms associated with N2 consumption processes in small agricultural drainages; however this modified diel N2 flux model enhances model fit and increases model utility in systems where discontinuities create severe diel patterns in dissolved gas concentrations and prohibit accurate estimates of N2 flux.
- Modeling
- Nitrogen
- Non-point Source
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Presenters/Authors
Rachel Nifong
(), Agricultural Research Service, USDA, rachel.nifong@ars.usda.gov;
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Jason M. Taylor
(), USDA, Agricultural Research Service, National Sedimentation Lab, jason.taylor@ars.usda.gov;
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Matt Moore
(), USDA, Agricultural Research Service, National Sedimentation Lab, matt.moore@ars.usda.gov;
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Jerry Farris
(), Arkansas State University, jlfarris@astate.edu;
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