2010 Annual Report 1a.Objectives (from AD-416) We propose to evaluate fluidized gas desulfurization (FGD) gypsum influence on surface soil properties that determine soil resistance to erosion losses. The research will help establish proper rates of FGD gypsum to reduce runoff and erosion losses, and improve soil productivity under different tillage systems. We will also provide documentation of water quality improvement associated with FGD gypsum needed to help qualify practices for use as a BMP and water quality credits. 1b.Approach (from AD-416) The research will be conducted at The University of Tennessee, Research and Education Center, Milan, and in the Department of Biosystems Engineering and Soil Science, Knoxville. The effect of fluidized gas desulfurization (FGD) gypsum on soil properties and cotton yields will be evaluated using both conventional and no-till management systems. FGD gypsum will be applied at rates of 0, 1, 2, 3, and 5 tons per acre to replicated conventional and no-till cotton plots. Cotton yields will be measured at the end of the growing season. Soil samples collected each year will be characterized: for total carbon, nitrogen, and sulfur; pH; extractable aluminum, potassium, and phosphorus; particle size distribution and water dispersible clay. The most appropriate FGD gypsum amendment rate, in terms of yield increases and reduced soil erodibility, will be selected from these data. 3.Progress Report Forty experimental field plots were installed for the second growing season to evaluate the effects of flue gas desulfurization gypsum on the yields of cotton planted on highly erodible loess soils. Soil water probes have been installed for the purpose of monitoring water contents during the growing season. Soil cores collected to a depth of five feet are being characterized for a range of physical and chemical properties. Cotton yields are being estimated at the end of the growing season. A comprehensive progress report was prepared for the two power companies, and two semi-annual research update meetings were conducted by ARS scientists with stakeholders and cooperators. Also, a presentation was made as part of the University of Tennessee, Milan Field Day Tour on the potential use of flue gas desulfurization gypsum in agriculture.