ISOLATION OF CLAY-SIZE ORGANO-MINERAL COMPLEXES FROM SOILS OF THE LOWER FRASER VALLEY

Abstract

Three dispersion methods for the isolation of < 2 μ organo-mineral complexes were compared on 26 horizon samples, from soils representing seven subgroups of the Podzolic, Gleysolic and Brunisolic orders. Dispersion by shaking with chelating resin gave consistently higher yields of complexes than ultrasonic dispersion or simple manual stirring. This was attributed to both higher pH levels (9.5–10.2) in the resin treatment and to the chelating ability of the resin. Complexes obtained varied widely in carbon content (0.31–13.20%) which generally decreased with depth in the profile. Percent of total soil carbon recovered in the complexes was consistently higher with resin dispersion than with other methods, and ranged from 7.8 to 49.6 for the resin method.