R.K. Hubbard, J.G. Davis, R.R. Lowrance, G.L. Newton, G. Vellidis, R. Dove 1
Riparian buffer systems have been shown to effectively filter nutrients entering from upslope agricultural fields. Nutrients are filtered in these systems by plant uptake and microbial processes such as denitrification. Guidelines developed for riparian buffer systems recommend three zones; a grass buffer zone for spreading water and sediment, an upland riparian forest zone for maximum plant growth and uptake of nutrients, and a streamside forested area that is maintained to protect stream banks and provide stream shading. Recent research at the Coastal Plain Experiment Station (CPES), Tifton, GA, is studying the concept of using the upper two zones of riparian buffer systems for utilizing agricultural effluents. Swine lagoon waste is being applied to replicated plots of three different vegetative treatments at two different waste application rates (high or low). The vegetative treatments are: (1) 10 m grass buffer and 20 m riparian forest, (2) 20 m grass buffer and 10 m riparian forest, (3) 10 m grass buffer and 20 m of the recommended wetland species maidencane. Research objectives are to determine the feasibility of using riparian buffer systems for utilizing nutrients from agricultural effluents, to determine which specific system and plant species combinations work best, and to determine effluent loading rates that do not result in environmental contamination. This paper presents results on the ability of these systems to utilize N and P contained in the waste.
