|Fausey, Norman - Norm|
Submitted to: American Ecological Engineering Society Conference
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2005
Publication Date: 5/19/2005
Citation: Baker, B.J., Allred, B.J., Fausey, N.R., Clevenger, B., Prill, G., Labarge, G., Brown, L. 2005. Wrsis: an innovative approach to agricultural water treatment and recycling. American Ecological Engineering Society Conference. Poster. Interpretive Summary:
Technical Abstract: A Wetland Reservoir Subirrigation System, or WRSIS for short, is an innovative agricultural water management system. Three WRSIS demonstration sites are located in the northwest Ohio portion of the Maumee River Basin (Defiance, Fulton, and Van Wert Counties) and have been in operation since 1996/1997. WRSIS is comprised of three main components, which include a wetland and a water storage reservoir linked to a network of subsurface pipes used at different times to either drain or irrigate crops through the root zone. Runoff and subsurface drainage are routed from corn and soybean cropland into a constructed wetland. Natural processes in the wetland treat the water by removing some of the nutrients, pesticides, and sediment. The water is then piped to a storage reservoir and held until needed to subirrigate the crops during dry parts of the growing season. The storage reservoir also provides a further opportunity for sediment and adsorbed nutrients to settle out of the water. The integration of these components allows WRSIS to operate in a closed loop mode most of the time, thus restricting offsite water release. WRSIS can offer a number of advantages including, (1) enhanced crop yields, (2) additional wetland vegetation and wildlife habitat, and (3) water treatment of nutrients, pesticides, and sediment. Through the 2003 growing season, WRSIS subirrigated field crop yield increases for corn and soybeans, respectively, were 47.6 % and 39.7 % during drier growing seasons, 10.1 % and 8.8 % during near average to wetter growing seasons, and 18.9 % and 18.2 % overall. A passive approach using no deliberate seeding or planting was adopted with regard to WRSIS wetland vegetation establishment. Six years after construction, a total of 77 species of vegetation were identified in constructed wetlands at the three WRSIS locations. Wetland indicator species made up 45% of the total vegetation species present. Wetland wildlife inventories were conducted at two of the WRSIS sites (Defiance and Fulton Counties), first in 1999, and second in 2003. At the Fulton County WRSIS location, the number of wildlife species increased from 75 in 1999 to 85 in 2003. For the Defiance County site, the number of wetland wildlife species increased from 80 in 1999 to 100 to 2003. Perhaps most exciting, the Defiance County WRSIS wetland has a thriving population of Blanchard’s Cricket Frogs, a species that is on the decline elsewhere in Ohio. Preliminary results indicate that WRSIS wetlands are effective in the partial treatment of agricultural waters. In 2003, at the Defiance County location, there was a 95% reduction in the yearly average nitrate nitrogen concentration from water entering the wetland compared to water exiting the wetland. Reductions in the yearly average of 36% and 31% were also found for the sediment and total phosphorus, respectively. Consequently, WRSIS can provide a win-win scenario where there are both increased crop yields and substantial environmental benefits.