ORIGINS OF HUMUS VARIATION - EFFECTS OF LEACHING AND SEASONAL FLOODING ON AROMATICITY

Humic and fulvic acids from a range of depositional environments in the Myall Lakes area of New South Wales, Australia have been examined by high resolution solid state nuclear magnetic resonance spectroscopy. For the first time definitive evidence is presented which shows that the local oxidizing/reducing environment greatly alters the gross structural group content of the soil organic matter. In addition, swamp water located between two soils in the area has been studied. The swamp water is shown to contain tannins and be terrestrially derived. However there appears to be a contribution from microorganisms to the organic matter in the swamp sediments.