Regional-scale controls on dissolved nitrous oxide in the Upper Mississippi River

Geophysical Research Letters
By: , and 

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Abstract

The U.S. Corn Belt is one of the most intensive agricultural regions of the world and is drained by the Upper Mississippi River (UMR), which forms one of the largest drainage basins in the U.S. While the effects of agricultural nitrate (NO3-) on water quality in the UMR have been well documented, its impact on the production of nitrous oxide (N2O) has not been reported. Using a novel equilibration technique, we present the largest data set of freshwater dissolved N2O concentrations (0.7 to 6 times saturation) and examine the controls on its variability over a 350 km reach of the UMR. Driven by a supersaturated water column, the UMR was an important atmospheric N2O source (+68 mg N2ONm-2 yr-1) that varies nonlinearly with the NO3-concentration. Our analyses indicated that a projected doubling of the NO3-concentration by 2050 would cause dissolved N2O concentrations and emissions to increase by about 40%.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Regional-scale controls on dissolved nitrous oxide in the Upper Mississippi River
Series title Geophysical Research Letters
DOI 10.1002/2016GL068710
Volume 43
Issue 9
Year Published 2016
Language English
Publisher AGU Publications
Contributing office(s) National Research Program - Central Branch
Description 8 p.
First page 4400
Last page 4407
Country United States
Other Geospatial Upper Mississippi River
Online Only (Y/N) N
Additional Online Files (Y/N) N