Soil Organic Matter: Its Nature, Its Role in Soil Formation and in Soil Fertility focuses on the contributions of soil organic matter in soil formation and fertility, including weathering, decomposition, and synthesis of humus substances. The publication first elaborates on the main stages in the history of soil humus study and ideas on the composition of soil organic matter and nature of humus substances. Discussions focus on organic substances of individual nature, strictly humus substances in soil organic matter, and humus substances as a complex of high molecular- weight compounds. The text then examines the biochemistry of humus formation, including the role of physical, chemical, and biological factors, origin of humus substances, possible participation of lignin in the formation of humus substances, and the role of oxidizing enzymes in the synthesis of humus substances. The manuscript takes a look at the importance of organic matter in soil formation and soil fertility and the natural factors of humus formation. Topics include the role of organic matter in the weathering and decomposition of soil minerals; role of organic matter in the formation of soil structure; effect of organic matter on the growth and development of plants; and influence of chemical and physicochemical soil properties on humus formation. The publication is a dependable source material for readers interested in the influence of soil organic matter in soil formation and fertility.