|Deaver, Emily - CHOWAN COLLEGE|
Submitted to: Society of Environmental Toxicology and Chemistry Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 30, 2004
Publication Date: November 16, 2003
Citation: Deaver, E., Moore, M.T., Cooper, C.M., Knight, S.S. 2003. Efficiency of three aquatic macrophytes in mitigating nutrient runoff: a mesocosm study. Abstract Book of the 24th Annual Meeting of the Society Of Environmental Toxicology And Chemistry. p. 252. Technical Abstract: Ditches lining agricultural fields are used to convey runoff water and are typically mowed to reduce vegetative growth. If agricultural ditches are viewed as a type of wetland, vegetation within the ditch might be utilized to remove excess nutrients in runoff water. It was hypothesized that particular species of ditch vegetation would be more effective than others at removing nutrients in runoff water. Replicate 379L Rubbermaid tubs were planted with individual species of soft rush (Juncus effusus), yellow primrose (Ludwigia peploides), and cutgrass (Leersia oryzoides), common wetland macrophytes found in Mississippi agricultural ditches. Nutrient enriched water (5 mg/L) was pumped in at a 4 hour hydraulic retention time at one end of the tub and discharged at the far end. Water samples were collected from the discharge hose at one hour intervals for 9 hours and analyzed for nutrient concentration. Nutrient removal rates were compared for all plant treatments and an unplanted sediment-water control. Results indicated that no single species was most effective at removing both nitrogen and phosphorus although all three plant treatments lowered nutrient concentrations in the water relative to the unplanted controls. Ammonia concentrations in water were reduced the most in L. peploides tubs and total orthophosphate was reduced most by J. effusus. These same two plant species reduced nitrate at a similar rate. L. oryzoides was the least effective at removing nitrate and ammonia.