WINTER DENITRIFICATION POTENTIAL IN RESPONSE TO NITROGEN ADDITIONS TO THE KANSAS RIVER
Nitrogen (N) cycling processes, specifically denitrification, are most commonly studied in small streams during summer. Therefore, we know relatively little about winter denitrification rates in large rivers. From November 2017 to April 2018, high nitrate water was released into the Kansas River from a decommissioned fertilizer plant. When nitrate enters the waterway, it undergoes the stepwise process of denitrification, where nitrate reduces to N2 and is released to the atmosphere as a gas. Denitrification enzyme assays (DEAs) were used to measure the denitrification potential of the river water and sediment, spanning sampling sites from one mile upstream of the release point to 40 km downstream. We asked: How does denitrification in large rivers respond to wintertime N additions? Preliminary data from December 2017 indicated that denitrification rates increased downstream from the discharge point with the rates ranging from undetectable levels to 0.142 µg N2O-N/h downstream. The DEA data collected over the course of the winter will help us better understand how a large river processes large amounts of nitrate additions.
Cay Thompson (Primary Presenter/Author), Haskell Indian Nations University, firstname.lastname@example.org;
Emma Overstreet (Co-Presenter/Co-Author), Kansas Biological Survey, University of Kansas, Lawrence, KS, email@example.com;
Michelle Catherine Kelly (Co-Presenter/Co-Author), University of Kansas, firstname.lastname@example.org;
Amy Burgin (Co-Presenter/Co-Author), University of Kansas, email@example.com;
Terrance Loecke (Co-Presenter/Co-Author), University of Kansas, firstname.lastname@example.org;