SOIL ORGANIC MATTER AND NUTRIENT CYCLING TO SUSTAIN AGRICULTURE IN THE SOUTHEASTERN USA
Location: Athens, Georgia
Title: Environmental and production responses from tall fescue-endophyte associations in Georgia
Submitted to: SERA-IEG 8
Publication Type: Abstract Only
Publication Acceptance Date: November 14, 2011
Publication Date: November 14, 2011
Citation: Franzluebbers, A.J., Buyer, J.S., Endale, D.M., Franklin, D.H., Haney, R.L., Hill, N., Kaplan, R., Stuedemann, J., Zuberer, D. 2011. Environmental and production responses from tall fescue-endophyte associations in Georgia [abstract]. SERA-IEG 8.
This presentation reports on the 2011 activities from a long-term research experiment conducted at the USDA Agricultural Research Service in Watkinsville GA. Our general objective was to determine the dynamics of nutrient cycling, soil quality, and soil microbial biomass, activity, and community structure in response to pasture management strategies, varying in botanical composition, fertilization source, forage utilization, and stocking density. We report here the changes in soil compaction and soil carbon and nitrogen sequestration during 8 years of investigation. Soil organic carbon and nitrogen accumulated with time under all pasture management systems, but more so under grazed than under hayed management. This result was likely due to how the forage was harvested. Cattle consumed forage on the pasture, but returned a large portion of the carbon and nitrogen back to the pasture via feces. Carbon contained in the forage cut for hay was removed from the field to be fed to animals elsewhere. No differences were detected in soil organic matter among tall fescue-endophyte associations (wild, novel, and free), nor between nutrient sources applied to fertilize pastures (inorganic and broiler litter). The results of this research have important implications for assessing soil quality of grazing lands in the eastern USA, but also for assessing the impacts of agricultural management on the potential to mitigate greenhouse gases, such as carbon dioxide.