|HILL, N - UNIVERSITY OF GEORGIA
Submitted to: Georgia Water Resources Conference
Publication Type: Proceedings
Publication Acceptance Date: 3/25/2005
Publication Date: 5/25/2005
Citation: Endale, D.M., Franzluebbers, A.J., Stuedemann, J.A., Hill, N.S., Franklin, D.H. 2005. Hydrologic and water quality implications of management of tall fescue pastures in a southern piedmont environment. In: Proceedings on the Georgia Water Resources Conference. 25-27 April 2005, Athens, Georgia. p. 482-485.
Interpretive Summary: Half of the Nation’s waters surveyed by states and tribes are considered unsuitable to support aquatic life due to excess nutrients, primarily nitrogen and phosphorous coming predominantly from agricultural sources. Nutrient enrichment of water sources also is as much a health as environmental concern, especially in regions like the Southern Piedmont where surface water provides the majority of drinking water. In two and half years of study, scientists at the USDA Agricultural Research Service, J. Phil Campbell Sr. Natural Resource Conservation Center in Watkinsville, GA, and the Crop and Soil Sciences Department at the University of Georgia, Athens, GA, compared hydrologic and water quality impacts of pastures under three important management systems that are used by producers in the Georgia Piedmont. These included 1) three fescue types, 2) poultry litter or inorganic fertilization, and 3) grazing cattle or haying. Treatments did not influence amount of runoff. Average concentration of ammonium-nitrogen (NH4-N) and nitrate nitrogen (NO3-N) in runoff were low - less than 1 parts per million (ppm). However concentrations of dissolved phosphorus were elevated in the grazing treatments, and were higher with poultry litter (average: 1.2 to 3.3 ppm) compared to hayed treatments (average 0.5). These types of data are very crucial in 2 primary areas. The first is for producers, commodity groups, extension agents, and federal agencies involved in insuring responsible stewardship of water resources to give them actual field scale ideas of the potential for water degradation under pasture management so that they can modify field practices as needed. The second is as an aid to the same groups working towards refining nationally-based water quality regulatory requirements, so that these have more relevance to particular regions. The United States Environmental Protection Agency has recently been encouraging the latter approach.
Technical Abstract: Runoff and nutrient losses were monitored over two and half years from different fescue management systems that are used by producers in the Georgia Piedmont. A randomized complete block arrangement of 14 paddocks under combinations of a grazing (grazed or hayed), fertilization (poultry litters or inorganic fertilizer) and tall fescue type (high endophyte high alkaloid, high endophyte low alkaloid, and endophyte free) treatments was used. The study was located at the USDA-ARS J. Phil Campbell Sr. Natural Resource Conservation Center, near Watkinsville, GA. Treatments did not influence amount of runoff. Mean concentrations of ammonium-nitrogen (NH4-N) and nitrate-nitrogen (NO3-N) in runoff were low (< 1 ppm). However, concentrations of dissolved reactive phosphorus (DRP) were elevated in the grazing treatments, and were higher with poultry litter (mean: 1.2 to 3.3 ppm) compared to hayed treatments (mean 0.5 pm). The study suggests that management practices that reduce DRP losses from grazing lands fertilized with poultry litter or inorganic fertilizer are needed to protect water resources.