Evaluating Plant Species-Specific Contributions to Nutrient Mitigation in Drainage Ditch Mesocosms

• Published in: Water, air, and soil pollution air, and soil pollution, 2011-05, Vol.217 (1-4), p.445-454
• Main Authors: Moore, M. T, Kröger, Robert
• Format: Article
• Language: English
• Subjects: Agricultural land; ammonium nitrogen; Applied sciences; Aquatic plants; Aquatic reptiles; Aquatic resources; Atmospheric Protection/Air Quality Control/Air Pollution; Best management practices; Climate Change/Climate Change Impacts; Closed ecological systems; Ditches; Drainage; drainage channels; Drainage ditches; Earth and Environmental Science; Echinodorus; Environment; Environmental monitoring; Eutrophication; Exact sciences and technology; Experiments; Flowers & plants; Hydrogeology; Indigenous species; Laboratories; Lacertilia; Leaching; Mesocosms; Monoculture; Myriophyllum spicatum; nitrate nitrogen; Nitrates; Nitrogen; Nutrient retention; nutrient uptake; Nutrients; Panicum hemitomon; Phosphorus; Plant species; Pollution; pollution control; Retention; Retention time; River basins; Rivers; Runoff; Saururus; Saururus cernuus; Sedimentation & deposition; Soil Science & Conservation; Statistical analysis; Studies; Surface water; Thalia dealbata; Typha latifolia; Vegetation mapping; Water pollution; Water quality; Water Quality/Water Pollution; Wetlands
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-010-0599-2

Eutrophication of surface water bodies is a worldwide concern. In the USA alone, excessive nutrients are blamed for nearly 5,700 impairments of surface water bodies. Innovative measures, such as maximizing drainage ditch nutrient retention, are being examined to decrease the amount of nitrogen (N) and phosphorus (P) running off agricultural lands and into aquatic receiving systems. The goal of this experiment was to measure the nutrient mitigation ability of six aquatic plants typically found in agricultural drainage ditches in the lower Mississippi River Basin. Experimental mesocosms (1.25 × 0.6 × 0.8 m) were filled with sediment and planted with monocultures of one of six obligate wetland plant species (Typha latifolia (broadleaf cattail), Panicum hemitomon (maidencane), Thalia dealbata (powdery alligator-flag), Echinodorus cordifolia (creeping burhead), Myriophyllum spicatum (Eurasian watermilfoil), and Saururus cernuus (lizard's tail)), while three replicates were left non-vegetated to serve as controls. Mesocosms were amended with 5 mg L⁻¹ (each) of nitrate, ammonia, dissolved inorganic phosphorus, and total inorganic phosphorus, while nitrite amendments (1 mg L⁻¹) were also made over a 4-h hydraulic retention time. Following the 4-h exposure, “clean” (non-amended) water was flushed through mesocosms for an additional 8 h to assess residual leaching of nutrients. Outflow water concentrations and loads decreased for all examined forms of N and P. In certain cases, there were significant differences between plant species; however, for the majority, there was no statistical difference in percent decrease between plant species. While native aquatic vegetation shows promise for mitigation of nutrient runoff, further studies altering the hydraulic retention time for improved efficiency should be conducted.