|Shields Jr, Fletcher|
Submitted to: Mississippi Water Resources Research Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 13, 2010
Publication Date: N/A
Interpretive Summary: Abstract Only - No Interpretative Summary Required
Technical Abstract: Research by the USDA Agricultural Research Service (ARS) National Sedimentation Laboratory includes long-term and comprehensive evaluations of conservation practices and assessment of their influence on the water quality and biological health of watersheds in the Mississippi Delta alluvial plain, with extensive plans for future projects beginning to be implemented. Existing ongoing research is part of the ARS national Conservation Effects Assessment Project (CEAP). Data from these studies include soil quality characterizations, cropping patterns, management practices, topography, climate, runoff, ecological assessments, and lake water quality. In addition to direct applications toward resource management, data have also been used in validating predictive computer models of agricultural practices such as AnnAGNPS. With contaminants from agricultural watersheds cited as major contributors to environmental problems such as hypoxia in coastal areas, loss of ecosystem services, and soil and water quality degradation, ARS research includes monitoring of water quality and fish resources and evaluation of runoff from areas where management practices such as CRP and buffer strips are implemented. Focus of the water quality evaluations include not only lacustrine (Beasley Lake project formed from a 915-ha oxbow lake watershed with a 15-year extensive data base) and riverine systems that are part of a network of ARS projects along the Mississippi River that contribute to the Mississippi River Basin Initiative, but also within-field and edge-of-field studies of vegetated agricultural ditches and water retention structures. Planned new research will include ecological assessment of three Mississippi Delta watersheds for the development of science-based TMDLs. This project will be focused on watersheds currently impaired by elevated suspended sediment and turbidity, low dissolved oxygen (DO) concentrations, nutrients and hydrologic perturbations. Watersheds will be monitored for up to three years to gather baseline information and document temporal variability of stream water quality and biological parameters. Following this, each watershed will be subjected to treatment intended to either reduce or increase biotic impairment. Candidate treatments include flow augmentation, flow diversion through wetlands, the establishment of within stream structures, agronomic conservation practices or simulated pollution events. Resulting changes in water quality, habitat and biological community will be observed. In addition to general ecological benefits, this research in the Mississippi Delta is expected to benefit a large number of stakeholders, including farmers, Delta FARM, Delta Wildlife, Delta Council, Mississippi Soil and Water Conservation Service, the Yazoo-Mississippi Delta Water Management District, Mississippi Department of Environmental Quality, USEPA, and USDA-NRCS.