Despite the large number of papers and books published on soil organic matter (humus), our knowledge of the subject is still very limited, as is our knowledge of humic acid. The author of this book began to study humus at the end of the 1940s and continued until 1984 when he retired from Nagoya University. With the intention of establishing a systematic understanding of soil organic matter, he has compiled facts and a discussion of humus based on his extensive experimental results during the past 40 years.In this book, humic acids are classified into A, B, Rp and P types, based on their optical properties. The elementary composition and other chemical properties of humic acid types are shown to be regularly different from each other. A new method for humus composition analysis applied to various kinds of soils in Japan and several other countries indicates that the diversity of humus compositions of soils is systematically understandable. These findings lead the author to novel theories on the chemical configuration and formation of humic acids and humic substances. Diagenesis of humus under terrestrial conditions is illustrated as to the buried humic horizons of Black soil (Andosol).The book will be useful not only to soil scientists and agronomists but also to geochemists, oceanographers, limnologists, water scientists, biologists and chemists who are dealing with organic matter in terrestrial, aquatic, and sedimentary environments.

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.

A thorough presentation of analytical methods for characterizing soil chemical properties and processes, Methods, Part 3 includes chapters on Fourier transform infrared, Raman, electron spin resonance, x-ray photoelectron, and x-ray absorption fine structure spectroscopies, and more.

Soil Organic Matter

The use of organic residues as a means of maintaining and increasing soil fertility is of long-standing. This tradition has been somewhat neglected since the introduc tion of mineral fertilizers at low cost. More and more farmers and scientists are now showing renewed interest in the proper and effective use of org~tnic residues, composts and other recycled organic additives. The role and function of organic amendments in modern agricultural systems have become topics of major interest in the scientific and agricultural communities. Research work on residue disposal has provided new concepts on the interaction between organic components and soils as well as new handling technologies (e. g. pelletizing of organic residues). The trend to conserve energy has led scientists to study the minimal tillage system, to find ways of replacing conventional inorganic fertilizers with natural organic prod ucts or microbial preparations, and to develop new composting methods. The drive to achieve higher yields in commercial greenhouse farming has led to a search for optimum substrates as growth media and for improved management techniques. This has led to the introduction of organic substitutes for peat, nota bly those originating from agricultural wastes. Another important aspect is the current interest in organic farming, where use of synthetic chemicals is avoided or prohibited. An increasing percentage of the population in highly developed countries is willing to pay premium prices for food produced on soils where inorganic fertilizers and other agricultural chemicals have not been used.

The Handbook of Soil Science provides a resource rich in data that gives professional soil scientists, agronomists, engineers, ecologists, biologists, naturalists, and their students a handy reference about the discipline of soil science. This handbook serves professionals seeking specific, factual reference information. Each subsection includes a description of concepts and theories; definitions; approaches; methodologies and procedures; tabular data; figures; and extensive references.