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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #137350
Title: REDUCING MANURE PHOSPHORUS SOLUBILITY WITH ALUM AND COAL COMBUSTION BYPRODUCTS

Author
item DOU, Z - UNIV. OF PENNSYLVANIA
item ZHANG, G - SOIL SCI. INST.
item Stout, William
item TOTH, J - UNIV. OF PENNSYLVANIA
item FERGUSON, J - UNIV. OF PENNSYLVANIA

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2002
Publication Date: 7/20/2003
Citation: DOU, Z., ZHANG, G.Y., STOUT, W.L., TOTH, J.D., FERGUSON, J.D. REDUCING MANURE PHOSPHORUS SOLUBILITY WITH ALUM AND COAL COMBUSTION BYPRODUCTS. JOURNAL OF ENVIRONMENTAL QUALITY. 2003. v. 32(4). p. 1490-1497.

Interpretive Summary: Animal manures contain large amounts of soluble phosphorus that can run off cropland during rainstorms and cause pollution of streams and rivers. A way to reduce the pollution would be to reduce the solubility of phosphorus in the manure. We tested the efficacy of alum and three coal combustion byproducts in reducing P solubility when added to dairy, swine, or broiler litter manures in a laboratory incubation study. Compared to un-amended controls, alum reduced the phosphorus solubility in all of the manures 80% to 99%. The reduction in manure phosphorus solubility from the addition of combustion byproducts ranged from 0% to 85% depending on the byproduct and type of manure. Where coal combustion byproducts are locally available, they may provide an economical alternative to alum as a means of reducing phosphorus solubility in manures. Some coal combustion byproducts, such as flue gas desulfurization gypsum, also have the additional benefits of supplying calcium, which can improve soil quality.

Technical Abstract: Animal manures contain large amounts of soluble phosphorus (P). This P is prone to runoff losses when manure is surface applied, contributing to water quality decline and eutrophication of streams and rivers. Here we report the efficacy of alum and three coal combustion byproducts in reducing P solubility when added to dairy, swine, or broiler litter manures in a laboratory incubation study. Compared to un-amended controls, alum effectively reduced readily soluble P, determined in water extracts of moist manure samples with 1-h shaking, for all three manures. The reduction ranged from 80% to 99% at treatment rates of 100 to 250 g alum kg-1 manure dry matter (DM). The fluidized bed combustion flyash (FBC) reduced readily soluble P by 50-60% at a rate of 400 g kg-1 for all three manures. Flue gas desulfurization byproduct (FGD) was ineffective for the dairy manure but highly effective for the swine manure and broiler litter with nearly an 80% decrease in readily soluble P when amended at 150 and 250 g kg-1. Another byproduct, anthracite refuse flyash (ANT) was ineffective for all three manures. In all cases, reduction in readily soluble P is primarily associated with inorganic P whereas changes in organic P were negligibly small. Sequential extraction results indicate that the coal combustion byproduct treatments shifted manure P from water extractable into a less vulnerable fraction, mostly extracted in 0.5 M NaHCO3, while the alum treatment shifted the P into even more stable forms, extracted in 0.1 M NaOH. Such shifts in P fractions would have little impact on P availability for crop uptake over the long term but would retard and reduce potential losses of P following manure applications.