Phosphorus-31 nuclear magnetic resonance spectroscopy transect study of poultry operations on the Delmarva Peninsula

J Environ Qual. 2009 Jan 13;38(1):130-8. doi: 10.2134/jeq2007.0587. Print 2009 Jan-Feb.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Agriculture
  • Animals
  • Chickens
  • Fertilizers*
  • Magnetic Resonance Spectroscopy
  • Manure / analysis*
  • Mid-Atlantic Region
  • Phosphorus / analysis*
  • Phosphorus Isotopes
  • Phytic Acid / analysis*
  • Soil / analysis*
  • Virginia

Substances

  • Fertilizers
  • Manure
  • Phosphorus Isotopes
  • Soil
  • Phosphorus
  • Phytic Acid