TRACE ELEMENTAL CHARACTERIZATION OF COMPOSTED POULTRY MANURE

Aerobically composted poultry manure was comprehensively characterized with respect to elemental content. Total, water-extractable and 1N ni tric-acid-extractable concentrations of 21 trace, minor and major elem ents: Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg Mn, Mo, Na, Ni, P, Pb, Rb, S, Sr, Ti, V and Zn, were determined in manure slurry composted with barl ey/oat straw or sphagnum peat moss bulking agents. Levels originated p redominantly from the manure and total concentrations in composts, exp ressed as mg/kg on a dry basis, ranged from 0.2 for Cd, 2-5 for Cr, Mo , Ni, Pb, Ti and V, to 37000 for Ca. Extractable concentrations varied with extractant and element from a low of 2% of total for Ba with wat er to 100% for most elements with acid. Nitric acid facilitated quanti tative leaching of virtually every element tested with the exception o f Mo. Cadmium, Na and Rb were fairly completely leached out with both water and acid. The effect of composting time for four elements with s ufficient data, Cu, Fe, Mn and Zn, suggested a hint of immobilization of Mn and Zn with respect to water extraction and of Cu and Fe with re spect to acid extraction and increased lability of Mn and Zn to acid e xtraction after composting. Copyright (C) 1996 Minister of Supply and Services Canada.