Designed as a reference text in soil organic matter chemistry, recognition of the important role of organic substances in environmental processes is given, linking soil science, organic geochemistry, forestry and environmental science. The volume examines the reactions of naturally-occurring organic substances in soils, pools of organic matter in soils, transformations, methods of extraction and fractionation. Basic organic chemistry of humic substances and the importance of organic matter associations and interactions in soils are also discussed.