|FRANKLIN, DORY - University Of Georgia|
Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2017
Publication Date: 3/8/2018
Citation: Schomberg, H.H., Endale, D.M., Jenkins, M., Chaney, R.L., Franklin, D.H. 2018. Metals in soil and runoff from a piedmont hayfield amended with broiler litter and flue gas desulfurization gypsum. Journal of Environmental Quality. 47:326-335. https://doi.org/10.2134/jeq2017.09.0353.
Interpretive Summary: Flue gas desulfurization gypsum (FGDG) is a by-product from electric generation plants created when removing sulfur from burning coal. Large quantities are available in many areas of the US. Heavy metals were once found in coal combustion by-products but new technology has reduced their potential to contaminate FGDG. Broiler litter from chicken growing facilities contains plant available nitrogen, phosphorus, and potassium that can be used as fertilizer. Additions to poultry diets of compounds to improve bird health have resulted in broiler litter having unwanted elements like arsenic (As), copper (Cu), and zinc (Zn). FGDG provides calcium which can reduce runoff losses of phosphorus and could reduce runoff losses of other elements. Scientists from USDA, ARS evaluated the potential for FGDG to reduce loss of As, Cu, and Zn from a Coastal bermudagrass (Cynodon dactylon L.) hayfield using simulated rainfall. Runoff concentrations of arsenic were 6 times greater where plots received broiler litter. Additions of FGDG did not reduce arsenic losses. After three years of applications of FGDG and broiler litter, soil concentrations of arsenic, mercury and chromium were well below levels of environmental concern. Although FGDG did not reduce runoff losses of As from broiler litter, it also did not cause any identifiable environmental risks indicating FGDG can safely be used in agricultural systems. This information will be useful to scientists designing strategies to use by-products from power generation plants and from poultry operations.
Technical Abstract: Flue gas desulfurization gypsum (FGDG) from coal-fired power plants is available for agricultural use in many US regions. Broiler litter (BL) provides plant available N, P, and K but may be a source of unwanted arsenic (As), copper (Cu), and zinc (Zn). FGDG provides Ca and S and can reduce runoff losses of P and may reduce losses of other elements from areas receiving BL. Accumulation and transport of As, Cu, Cd, Cr, Hg, Pb, and Zn from a Coastal bermudagrass (Cynodon dactylon L.) hayfield fertilized for three years with BL (13.5 Mg ha-1) was evaluated at four FGDG rates (0, 2.2, 4.5, 9 Mg ha-1) using simulated rainfall. Controls included 0-0 and 9-0 Mg ha-1 (FGDG-BL). Replicated 2.0 m2 plots were established on a piedmont Cecil soil. Runoff concentrations of As were 6-fold greater with BL than without (less than 0.01) and were similar to BL alone with 2.2, 4.5 and 9 Mg ha-1 FGDG (less than 0.10). FGDG without BL did not increase runoff concentrations of measured elements. After three applications of FGDG and BL, soil concentrations of As, Cr, Pb, Hg, and Cu were well below levels of environmental concern. Our findings indicate FGDG does not reduce runoff losses of As arising from BL application, but supports other research indicating no identifiable environmental risks from FGDG beneficial use in agricultural systems.