Efficacy of alum and coal combustion by-products in stabilizing manure phosphorus.
Animal manures contain large amounts of soluble phosphorus (P), which is prone to runoff losses when manure is surface-applied. Here we report the efficacy of alum and three coal combustion by-products in reducing P solubility when added to dairy, swine, or broiler litter manures in a laboratory incubation study. Compared with unamended controls, alum effectively reduced readily soluble P, determined in water extracts of moist manure samples with 1 h of 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. The fluidized bed combustion fly ash (FBC) reduced readily soluble P by 50 to 60% at a rate of 400 g kg(-1) for all three manures. Flue gas desulfurization by-product (FGD) reduced readily soluble P by nearly 80% when added to swine manure and broiler litter at 150 and 250 g kg(-1). Another by-product, anthracite refuse fly ash (ANT), was ineffective for all three manures. In all cases, reduction in readily soluble P is primarily associated with inorganic phosphorus (P(i)) with little change in organic phosphorus (P(o)). Sequential extraction results indicate that the by-product treatments shifted manure P from H2O-P into a less vulnerable fraction, NaHCO3 - P, while the alum treatment shifted the P into even more stable forms, mostly NaOH-P. Such shifts in P fractions would have little influence on P availability for crops over the long-term but would retard and reduce potential losses of P following manure applications.
Dou
Z
Z
Center for Animal Health and Productivity, School of Veterinary Medicine, Univ. of Pennsylvania, 382 West Street Road, Kennett Square, PA 19348, USA. dou@cahp.vet.u-penn.edu
Zhang
G Y
GY
Stout
W L
WL
Toth
J D
JD
Ferguson
J D
JD
D000383:Agriculture; D000534:Alum Compounds / Q000737:chemistry*; D000818:Animals; D001682:Biological Availability; D002417:Cattle; D002645:Chickens; D003031:Coal; D017745:Incineration; D008372:Manure; D010758:Phosphorus / Q000737:chemistry*; D012995:Solubility; D013552:Swine; D014876:Water Pollution / Q000517:prevention & control*
D000534:Alum Compounds; D003031:Coal; D008372:Manure; D010758:Phosphorus; C041524:aluminum sulfate