Managing Global Resources for a Secure Future

2017 Annual Meeting | Oct. 22-25 | Tampa, FL

37-13 A Model to Simulate Microbial Denitrification with Epic: Description, Evaluation, and Applications.

See more from this Division: SSSA Division: Soils and Environmental Quality
See more from this Session: Soils and Environmental Quality General Oral I

Monday, October 23, 2017: 11:20 AM
Marriott Tampa Waterside, Grand Ballroom I

Roberto C. Izaurralde1, William B. McGill2, Jimmy R. Williams3, Curtis D Jones4, Robert P Link5, David H. Manowitz5, D. Elisabeth Schwab6, Xuesong Zhang5, G. Philip Robertson7 and Neville Millar8, (1)Department of Geographical Sciences, University of Maryland, College Park, MD
(2)University of Northern British Columbia, Prince George, BC, Canada
(3)Blackland Research and Extension Center, Texas A&M University, Temple, TX
(4)University of Maryland, University of Maryland, College Park, MD
(5)Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD
(6)University of Natural Resources and Applied Life Sciences, Vienna, Austria
(7)W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI
(8)Kellogg Biological Station, Michigan State University, Hickory Corners, MI
Abstract:
We will describe a mechanistic model to simulate microbial denitrification implemented in the terrestrial ecosystem model EPIC. Based on principles of chemistry, physics, and biology the model predicts nitrous oxide (N2O) and dinitrogen (N2) production under anaerobic conditions. Carbon oxidation releases electrons that drive a demand for electron acceptors such as O2 and oxides of N (NO3-, NO2-, and N2O). When denitrification occurs, there is an adjustment of C decomposition based on the ratio of actual vs. potential electrons accepted by O2 and oxides of N. Movement of O2, CO2, N2O, and N2 through the soil profile is modeled using the gas transport equation solved at hourly time steps. Bubbling equations also move N2O and N2 through the liquid phase to the soil surface under highly anaerobic conditions. We will present model evaluation results using data describing non-linear responses of N2O production to N application and other examples of N2O emissions under diverse experimental conditions.

See more from this Division: SSSA Division: Soils and Environmental Quality
See more from this Session: Soils and Environmental Quality General Oral I