Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2004
Publication Date: 10/15/2004
Citation: Hunt, P.G., Poach, M.E., Szogi, A.A. 2004. Constructed wetland nitrogen balances [abstract]. Agronomy Abstracts. 2004 CDROM.
Technical Abstract: Constructed wetlands have been found to be effective in removing large amounts of N (more than 20 Kg N/ha/day) from animal wastewater. At lower loading rates, plant uptake and soil accumulation are significant components of N removal. However, once the loading rate exceeds 10 kg N/ha/day, plant and soil removal capacities are surpassed. Major losses of N can occur via ammonia volatilization if large areas of open water are exposed such as in marsh-pond-marsh wetland. However, it has been shown that ammonium volatilization in surface flow constructed wetlands is relatively small, even at high loading rates, when there is substantial vegetative cover. Denitrification is likely to be the mechanism for very high rates of N removal in constructed wetlands. Denitrification enzyme activity values for constructed wetlands have been reported that are consistent with high removal of N via denitrification. Scientific acceptance and commercial utilization of this very high denitrification will likely require better understanding of both oxygen transfer and alternative denitrification pathways.