ARS | Publication request: Extreme storm events causes distinctive nitrogen loads transported through a southeastern USA Coastal Plain in-stream wetland

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2008
Publication Date: October 5, 2008
Citation: Novak, J.M., Szogi, A.A., Chu, X., Stone, K.C. 2008. Extreme storm events causes distinctive nitrogen loads transported through a southeastern USA Coastal Plain in-stream wetland [abstract]. American Society of Agronomy-Crop Science Society of America-Soil Science Society of America Annual Meeting, November 5-9, Houston, Texas. 2008 CDROM

Technical Abstract: Nitrogen (N) is a major non-point source contributor to the eutrophication of coastal water bodies by causing nutrient enrichment and a rise in plant production. Fortunately, wetlands can remove N loads from water by biological uptake and/or through storage processes in sediments. The N stored in wetlands can, however, be transitory, because precipitation from storm events can create internal hydrological disturbances resulting in accelerated N export. The objective of this research was to determine the effects of storm events on N loads delivered during base flow and storm flow events from an in-stream wetland. The wetland is located in the southeastern USA Coastal Plain region; it occurs in a watershed with high livestock production. From 1991 to 1999, daily precipitation, wetland outflow measurements and composite water sampled were collected. A digital hydrological model was used to separate wetland out flow into base and storm flow events. In addition, sediment pore water N concentrations from 1997 to 1999 along with sediment N concentrations were also measured to corroborate shifts in N storage pools. Cumulative N loss (as NH4-N and NO3-N) varied substantially over the study period with highest N loss occurring in 1999 (after three successive hurricanes). Assessment of annual N loads transported during storm and base flow events along with shifts in sediment pore water N concentrations will be addressed.