Abstract
Elementary composition and absorption spectra of humic acids (HAs) and fulvic acids (FAs) obtained from 4 Canadian and 2 Japanese soils were determined, and the relationships between these 2 properties were discussed. In this study, FA refers to the PVP adsorbed, i.e. coloured substances in what has been designated, in previous reports, as FA. In 3 soil samples, FA was divided into the acid (pH 1.0)-precipitable FA1 and non-precipitable FA2 fractions.