SREL Reprint #2659

Trace Element Speciation in Poultry Litter

B. P. Jackson1, P. M. Bertsch1,2, M. L. Cabrera2, J. J. Camberato3, J. C. Seaman1, and C. W. Wood4

1Advanced Analytical Center for Environmental Sciences, Savannah River Ecology Laboratory,
University of Georgia, P.O. Drawer E, Aiken, SC 29802
2Department of Crop and Soil Sciences, University of Georgia, Athens, GA 30602
3Department of Crop and Soil Environmental Science, Clemson University, Clemson, SC 29634
4Department of Agronomy and Soils, Auburn University, Auburn, AL 36849

Abstract: Trace elements are added to poultry feed for disease prevention and enhanced feed efficiency. High concentrations are found in poultry litter (PL), which raises concerns regarding trace element loading of soils. Trace metal cation solubility from PL may be enhanced by complexation with dissolved organic carbon (DOC). Mineralization of organo-As compounds may result in more toxic species such as AS(III) and As(V). Speciation of these elements in PL leachates should assist in predicting their fate in soil. Elemental concentrations of 40 PL samples from the southeastern USA were determined. Watersoluble extractions (WSE) were fractionated into hydrophobic, anionic, and cationic species with solid-phase extraction columns. Arsenic speciation of seven As species, including the main As poultry feed additives, roxarsone (ROX; 3-nitro4-hydroxyphenylarsonic add) and p-arsanilic acid (p-ASA; 4-aminophenylarsonic acid), was performed by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). Total As concentrations in the litter varied from 1 to 39 mg kg-1, averaging 16 mg kg-1. Mean total Cu, Ni, and Zn concentrations were 479, 11, and 373 mg kg-1, respectively. Copper and Ni were relatively soluble (49 and 41% respectively) while only 6% of Zn was soluble. Arsenic was highly soluble with an average of 71% WSE. Roxarsone was the major As species in 50% of PL samples. However, the presence of As(V) as the major species in 50% of the PL samples indicates that mineralization of ROX had occurred. The high solubility of As from litter and its apparent ready mineralization to inorganic forms coupled with the large quantity of litter that is annually land-applied in the USA suggests a potential detrimental effect on soil and water quality in the long term.

SREL Reprint #2659

Jackson, B. P., P. M. Bertsch, M. L. Cabrera, J. J. Camberato, J. C. Seaman, and C. W. Wood. 2003. Trace element speciation in poultry litter. Journal of Environmental Quality 32:535-540.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).