Location: Water Quality and Ecology Research
2017 Annual Report
Accomplishments
1. Agricultural conservation practices improve lake water quality in agricultural watersheds. ARS researchers in Oxford, Mississippi, have studied lake nutrient concentrations for over 20 years in Beasley Lake watershed in the Mississippi Delta as part of the Conservation Evaluation Assessment Program (CEAP). Over this time, within-field, edge-of-field, and Conservation Reserve Program (CRP) practices have been implemented within the watershed. Decreasing total phosphorus, ammonium, and nitrate concentrations in Beasley Lake coincide with the amount and location of best management practices implemented in the watershed. These results provide evidence that agricultural best management practices may improve and sustain lake and floodplain water quality in agroecosystems.
2. Wetland vegetation can reduce loads of fertilizer and pesticides in agricultural runoff and maintain ecological and economic values of water bodies. Agricultural runoff containing pesticides and excessive nutrients can damage ecosystems and harm fish, invertebrates, and other aquatic organisms. ARS researchers in Oxford, Mississippi, conducted an experiment using a series of artificial wetlands planted with two aquatic plant species, common cattail and parrot feather. The wetlands were dosed with fertilizer and permethrin insecticide to measure how well the two plant species alone or in combination could remove the nitrogen and insecticide mixture when water was either flowing or stagnant. During the flow period, the combination of two parrot feather wetlands in tandem removed fertilizer more efficiently than the combination of cattail-parrot feather wetlands. When water was stagnant, the cattail only wetland most efficiently removed fertilizer. All wetlands were equally efficient at removing insecticide. The study showed that different wetland plants alone and in combinations have different removal efficiencies for fertilizer while having the same for insecticide in water.
Review Publications
Nifong, R.L. 2017. Experimental effects of grazers on autotrophic species assemblages across a nitrate gradient in Florida springs. Aquatic Botany. doi:10.1016/j.aquabot.2017.02.010.
Huang, Y., Yasarer, L.M., Li, Z., Sturm, B.S., Zhang, Z., Guo, J., Shen, Y. 2017. Air–water CO2 and CH4 fluxes along a river–reservoir continuum: Case study in the Pengxi River, a tributary of the Yangtze River in the Three Gorges Reservoir, China. Environmental Monitoring and Assessment. 189:223. doi:10.1007/s10661-017-5926-2.
