Chemicals Humus And The Soil

The case for fertilizers; The case against fertilizers.

This volume presents the proceedings of the 10th internationalsymposium Humus et Planta held in Prague in August 19-23,1991. The main topics of this book are devoted to the recentadvances in fundamental, as well as applied research of humicsubstances, the most abundant of the naturally occuringmacromolecules of nature, the understanding of their natureand how they react and interact in their natural environments.Texts are included on the structure, physical and chemicalproperties of humic substances; the relationships among humus,soil properties and fertility; the biotransformations oforganic substances in the soil; the relationships betweenhumic substances and plants and the interactions of humus andxenobiotic substances. This book presents recent knowledge ofthe complicated and challenging humic substances. It will beof interest not only to scientist, but also to Universityteachers and students of agricultural and environmentalsciences.

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.