Location: Water Quality and Ecology Research2010 Annual Report
1a. Objectives (from AD-416)
We propose to evaluate FGD gypsum influences on soil properties that determine soil erodibility. The research will help establish proper rates of FGD gypsum to reduce runoff and erosion losses, and improve soil productivity. 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 improvement credits.
1b. Approach (from AD-416)
Two studies will be conducted at the Northeast Mississippi Experiment Station at Verona. In one study, we will evaluate the effects of FGD gypsum on an existing set of no-till cotton plots. The FGD gypsum application rates of 0, 1, 1.5, 2, and 3 tons/acre will be applied on a replicated plot experiment. The other study will evaluate the effects of tillage-gypsum interactions on soybean yields. The three tillage treatments are no-till, fall chisel-harrow, and conventional. Plot sizes, gypsum application rates, and replications are identical to those for no-till cotton. Crop yields will be measured by the experiment station personnel responsible for all agronomic practices. Following harvest each growing season, soil cores will be collected to a depth of 36 inches from each plot and characterized for water dispersible clay as a measure of erodibility, particle size distribution, organic carbon content, pH, exchangeable A1, exchangeable bases, total calcium, sulfur, nitrogen, and phosphorus.
3. Progress Report
The experimental field plot phase of the flue gas desulfurization gypsum research project was initiated for the third year. As in the two previous years, a total of 80 plots were installed for purposes of evaluating the effects of gypsum on crop yields and soil properties using soybean and cotton under different tillage systems. Soil water contents were measured weekly, and yields were estimated at the end of the growing season. A comprehensive progress report was prepared which summarized the research findings to date, and two meetings were conducted by ARS scientists with stakeholders and cooperators to review research results. Additionally, a presentation was made at the Southern Conservation Agricultural Systems Conference at Jackson, TN, on the potential use of flue gas desulfurization gypsum in agriculture.