title: Phosphorus-31 nuclear magnetic resonance spectroscopy transect study of poultry operations on the Delmarva Peninsula.
abstract: Nonpoint source phosphorus (P) pollution into the Chesapeake Bay watershed from poultry operations contributes to the algal blooms, hypoxia, anoxia, and fish kill events that occur there most years. A major source of soluble, bioavailable P species is poultry litter, which is used as a crop fertilizer on fields adjacent to the tributaries of the Bay. A potentially significant source of orthophosphate in the litter is the heavily phosphorylated compound myo-inositol hexakisphosphate (phytate), which is indigestible by poultry and thus becomes a major component of their excreta. Phytate evaluation in environmental samples is expensive; hence, its impact is not captured in standard farmer-friendly eutrophication potential guides, like Delaware's Phosphorus Site Index. In this transect study of two poultry operations on the Delmarva Peninsula, we measured the incidence of all P compounds using solution 31P nuclear magnetic resonance (NMR) spectroscopy and extracts, relating them to relevant geochemical properties. The contribution of phytate to the overall pool of P declined from around 50% in manures to between 2 and 13% in down-gradient soils and sediments, corresponding to a rise in the relative proportion of orthophosphate (increasing from 39% to 65-88%). The results show that the large pool of phytate P spread onto croplands during standard operating practice at poultry farms on the Delmarva Peninsula does not appear to accumulate; rather, phytate decreases in down-gradient locations, most likely due to transport off-site and/or through in situ biological activity.
authors.affiliation: Chemical Engineering, Environmental Engineering Program, Yale University, Mason Lab., Room 318, 9 Hillhouse Ave., New Haven, CT 06520-8286, USA. jane.hill@uvm.edu
authors.forename: Jane E
authors.initials: JE
authors.lastname: Hill
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Cade-Menun
mesh_terms: D000383:Agriculture; D000818:Animals; D002645:Chickens; D005308:Fertilizers; D009682:Magnetic Resonance Spectroscopy; D008372:Manure / Q000032:analysis*; D008873:Mid-Atlantic Region; D010758:Phosphorus / Q000032:analysis*; D010759:Phosphorus Isotopes; D010833:Phytic Acid / Q000032:analysis*; D012987:Soil / Q000032:analysis*; D014768:Virginia
chemical_list: D005308:Fertilizers; D008372:Manure; D010759:Phosphorus Isotopes; D012987:Soil; D010758:Phosphorus; D010833:Phytic Acid