Factors affecting denitrification in agricultural headwater streams in Northeast Ohio,USA |
| |
Authors: | Kyle S. Herrman Virginie Bouchard Richard H. Moore |
| |
Affiliation: | (1) School of Environment and Natural Resources, The Ohio State University, 210 Kottman Hall, 2021 Coffey Road, Columbus, OH 43210-1085, USA;(2) Department of Human and Community Resource Development, The Ohio State University, 208 Agricultural Administration Building, 2120 Fyffe Road, Columbus, OH 43210, USA |
| |
Abstract: | As a result of increased anthropogenic nitrogen (N) loading in surface waters of agricultural watersheds, there is enhanced interest to understand and quantify N removal mechanisms. Denitrification, an important N removal mechanism in aquatic systems, may contribute to reducing N pollution in agricultural headwater streams. However, the key factors controlling this process in lotic systems remain unclear. The objective of our study was to examine the factors regulating rates of denitrification in the sediments of agricultural headwater streams in the mid-western USA. Denitrification rates were variable among streams and treatments (<0.1–28.0 μg N g AFDM−1 h−1) and on average, were higher than those reported for similar headwater streams. Carbon quantity and quality, and pH had no effect on denitrification, while temperature and nitrate ( ) concentrations had a positive effect on rates of denitrification. Specifically, controlled denitrification following Michaelis-Menten kinetics. We calculated a value of km (1.0 mg -N L-1) that was comparable to other studies in aquatic sediments but was well below the median in-stream concentrations (5.2–17.4 mg -N L−1) observed at the study sites. Despite high rates of denitrification, this removal mechanism is most likely saturated in the agricultural headwater streams we examined, suggesting that these systems are not effective at removing in-stream N. Handling editor: D. Ryder |
| |
Keywords: | Denitrification Headwater stream Michaelis-Menten |
本文献已被 SpringerLink 等数据库收录! |
|