Humic Matter in Soil and the Environment Principles and Controversies, Second Edition

Issue of Organic Matter
Concept of Organic Matter
Issue of Biomass
Terrestrial and Aquatic Organic Matter
Issue of Dissolved Organic Matter or DOM
Effect of Organic Matter on Ecology and Water Chemistry
Issue of Acronyms

Concept of Humus
Issue of Humus
Nonhumic Fraction of Humus
Humic Fraction of Humus
Issue of Glomalin

Concepts of Humic Matter
Overview: From Biopolymers to Nanotube Supramolecular Assemblages
Biopolymer Concept
Operational Concept
Issue of Real Compounds
Micellar Concept
Supramolecular Concept
Nanotube Membrane Concept

Nature and Distribution of Humic Matter
Historical Background: Era of Ulmic, Crenic, and Geic Acids
Distribution of Humic Matter
Classification of Humic Matter

Genesis of Humic Matter
Major Pathways of Humification
Precursors of Humic Matter
Theories of Humification
Statistical Modeling of Humification

Extraction and Fractionation of Humic Substances
Search for Extractants
Terrestrial Humic Matter
Fractionation of Humic Substances
Aquatic Humic Matter
Determination of DOC and DOM
Types of Humic Substances

Chemical Composition of Humic Matter
Elemental Composition
Group Composition
Theory of Minimum Formula Weights
Molecular Structures
Computer Modeling of Humic Acid Structures

Characterization of Humic Substances
Chemical Characterization
Molecular Weights
Ultraviolet and Visible Light Spectrophotometry
Infrared Spectroscopy
Nuclear Magnetic Resonance Spectroscopy
Electron Microscopy of Humic Matter

Electrochemical Properties of Humic Matter
Origin and Types of Electric Charges
Surface Charge Density
Electric Double Layer
Chemical Reactions and Interactions
Complex Reaction and Chelation
Bridging Mechanism

Agronomic Importance of Humic Matter
Importance in Soils
Effect on Soil Physical Properties
Effect on Soil Chemical Properties
Effect on the Soil Redox System
Effect on Soil Biological Properties
Importance in Plant Growth

Environmental and Industrial Importance of Humic Matter
Importance in the Environment
Importance in Industry
Importance as Pharmaceuticals
References and Additional Readings
Appendix A: Greek Alphabet
Appendix B: Atomic Weights of Major Elements in Soils

Biography

Kim Howard Tan, Ph.D., is professor emeritus at the Department of Crops and Soil Science, University of Georgia, Athens, USA, where he has taught basic soils, soil chemistry, advanced soil chemistry, and methodology of soil and plant analysis for more than 25 years. His humic acid research has made him one of the authorities on humic acid chemistry and organic–inorganic interaction reactions. He was named Fellow of the American Society of Agronomy and the Soil Science Society of America and is a member of the International Union of Soil Science. Dr. Tan is an author or coauthor of more than 200 articles, abstracts, proceedings, and book chapters, as well as the author, coauthor, or editor of 13 books.