AbstractA sandy loam soil was amended insitu with three sewage sludges and after 3 yr extracted with N,N‐dimethylformamide (DMF) or sodium pyrophosphate (SP) to determine which organic fractions are associated with metals. A separate portion of the soil was pretreated by acid dialysis followed by DMF extraction. The DMF extracts and fulvic acid from the SP extract were fractionated on nonpolar, nonionic macroreticular and ion exchange resins into acidic, neutral, and basic hydrophobic organic solute fractions and acidic, neutral, and basic hydrophilic organic solute fractions. The amounts of metals associated with the hydrophilic and hydrophobic fractions depended on the metal examined, extractant used, the pretreatment, and the kind of sludge added to the soil. Cadmium was not detected in any of the organic fractions. Copper, Zn, and Ni were generally recovered least efficiently from the soil treated with a sludge highest in these metals. Most of the metals were generally associated with the hydrophobic portion following dialysis, but Cu was most often associated with the hydrophilic base fraction. This fractionation method has been demonstrated to be effective in separating metal/organic components in extracts from a soil to which three sludges were added. The data indicate that there were several mechanisms operative in combining metals with organic fractions—at least two for Cu and four each for Zn, Ni, and Pb.