ARS | Publication request: Characterizing Phosphorus Release from a Northern Temperate Wetland

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 4, 2006
Publication Date: N/A

Technical Abstract: Water quality of lakes, reservoirs, rivers and streams can be degraded by runoff from a variety of land uses, including runoff or drainage from agricultural cropland, pastures, feedlots, golf courses and suburban/urban lawns. Excess nutrients become a concern when they are readily available for transport to waterways. Abundance of phosphorus (P) in surface water results in an ecological imbalance, increased growth of undesirable algae and aquatic weeds, hypoxia and accelerated eutrophication. In the upper Midwestern United States, fresh water lakes are experiencing degradation at an unprecedented rate. This research characterized P loads at the inlet and outlet of a ditch-drained wetland to determine if the wetland behaves as a sink for P, from surrounding drainage areas, or as a source of P, to a downstream lake. Total and ortho phosphorus at the outlet of the wetland exceeded that of the inlet for 2004, (TPinlet 219 kg < TPoutlet 441 kg and OPi 80 kg < OPo 211 kg) and 2005 (TPi 69 kg < TPo 1496 kg and OPi 36 kg < OPo 571 kg) for the months of July – September. Fluctuations in hydrology had an impact on P loading to the ditch system. Rice Lake Wetland acts as a source of P to the ditch system and has the potential to release large pulses of P. Characterizing sources, timing, and the amount of P contributed to the lake by the wetland and ditch systems will aid federal, state, and local agencies in determining effective remediation strategies.