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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #281767
Title: Impact of FGD gypsum application on water quality in a coastal plain soil

Author
item Torbert, Henry - Allen
item Watts, Dexter

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2013
Publication Date: 1/8/2014
Citation: Torbert III, H.A., Watts, D.B. 2014. Impact of FGD gypsum application on water quality in a coastal plain soil. Journal of Environmental Quality. 43:273-280.

Interpretive Summary: There are growing concerns regarding the fate of nutrients, especially P, from land application of animal waste. One approach to reduce runoff losses of P is to treat manure or the soil receiving manure with chemical amendments such as gypsum. A study useing rainfall simulations to examine the impact of flue gas desulfurization (FGD) gypsum application on runoff nutrient losses on a Coastal Plains soil. Four rates of FGD gypsum (0, 2.2, 4.4, and 8.9 Mg ha-1) were applied to plots of Coastal bermudagrass, which had received application of 13.4 Mg ha-1 poultry litter. Plots with FGD gypsum but no poultry litter and plots with no litter or FGD gypsum were also utilized. Rainfall simulation was used to generate water runoff for 60 min and samples were analyzed for dissolved reactive P (SRP) and other total and soluble elements. Heavy metals were also analyzed. Results indicated a 51% reduction in total SRP load with the application of 8.9 Mg ha-1 FGD gypsum. Measurement of heavy metals in runoff where all found to be below detection limits. The results indicate that use of FGD gypsum on pastures receiving poultry litter in the Coastal Plains would be an effective method of reducing SRP losses to the environment.

Technical Abstract: There are growing concerns regarding the fate of nutrients, especially P, from land application of animal waste. One approach to reduce runoff losses of P is to treat manure or the soil receiving manure with chemical amendments such as gypsum. This study used rainfall simulations to examine the impact of flue gas desulfurization (FGD) gypsum application on runoff nutrient losses on a Coastal Plains soil (Luverne sandy loam; fine, mixed, semiactive, thermic Typic Hapludults). Four rates of FGD gypsum (0, 2.2, 4.4, and 8.9 Mg ha-1) were applied to plots of Coastal bermudagrass (Cynodon dactylon L.) which had received application of 13.4 Mg ha-1 poultry litter. Plots with 8.9 Mg ha-1 but no poultry litter and plots with no litter or FGD gypsum were also utilized. Rainfall simulation was used to generate water runoff for 60 min and samples were analyzed for dissolved reactive P (SRP) and soluble Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, and Zn. Total concentration of Ca, Mg, K, Na, Fe, Mn, and Zn and concentration of heavy metals Ar, Hg, AL, Sb, Ba, Be, Cd, Cr, Co, Cu, Pb, Ni, Si, V, Se, Tl, and Hexavalent Chromium were also analyzed. Results indicated that up to 61% reduction in SRP concentration in runoff with the application of 8.9 Mg ha-1 FGD gypsum. This translated to a 51% reduction in total SRP load during the 60 min runoff event. Measurement of heavy metals in runoff where all found to be below detection limits. The results indicate that use of FGD gypsum on pastures receiving poultry litter in the Coastal Plains would be an effective method of reducing SRP losses to the environment.