Location: Water Quality and Ecology Research
Title: Seasonal and interspecific nutrient mitigation comparisons of three emergent aquatic macrophytes Authors
Submitted to: Bioremediation Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 13, 2013
Publication Date: N/A
Interpretive Summary: Excessive nutrients entering rivers and lakes cause significant damage to plants and animals in aquatic receiving systems. Conservation practices are needed to help reduce nutrient runoff into water bodies. Three aquatic plant species were evaluated for their ability to remove nutrients from runoff water during both summer and winter months. Results demonstrated one particular plant was able to remove more nitrate in summer than winter, while a different plant removed more phosphorus in winter than summer. This suggests a mixture of plants within the drainage ditches is most beneficial for year-round maximum nutrient processing. Farmers, landowners, conservationists, and regulators will benefit from this study.
Technical Abstract: The purpose of this experiment was to measure both summer and winter nutrient mitigation efficiencies of three aquatic plants found in agricultural drainage ditches in the lower Mississippi River Basin. Mesocosms (1.25 x 0.6 x 0.8 m) were filled with sediment and planted with monocultures of one of three obligate wetland plant species Typha latifolia, Thalia dealbata, and Sagittaria latifolia, or left non-vegetated to serve as controls. Mesocosms were amended with nitrate, ammonium, and phosphate over a 4 h hydraulic retention time, followed by an 8 h flushing with non-amended water to assess residual nutrient leaching in both summer and winter exposures. Significant interactions between vegetation type and season were noted for both nitrate and total inorganic phosphorus concentrations and loads. Future research will focus on altering hydraulic retention time for improved efficiency, as well as the specific contribution of microbial activity to nutrient mitigation.