Current and authoritative with many advanced concepts for petroleum geologists, geochemists, geophysicists, or engineers engaged in the search for or production of crude oil and natural gas, or interested in their habitats and the factors that control them, this book is an excellent reference. It is recommended without reservation. AAPG Bulletin.

The publication of this book Petroleum Formation and Occurrence by Bernard Tissot and Dietrich Welte will indeed be welcomed by pertroleum geologists, petroleum geochemists, teachers and students in these fields, and all others who are interested in the origin and accumulation of hydrocarbons in nature. It is indeed a privilege for us to have the opportunity of sharing with these two eminent scientists the wealth of information they have acquired and developed during long careers devoted to concentrated scholarly study and practical investigation of the nature, origin, and occurrence of petroleum. Professor Bernard Tissot graduated from the Ecole Nationale Superieure des Mines in 1954 and from the Ecole Nationale Superieure du Petrole in 1955. In 1955 he received a D. E. S. in geology from the University of Grenoble and then began research work on petroleum geology at the Institut Fran~ais du Petrole. He was made head of the Department of Geochemistry in 1965, and since 1970 has also been teaching organic geochemistry at the Ecole Nationale Superieure du Petrole where he became Profes sor in 1973. Professor Tissot has had a broad and varied background of practical experience. He has been a member of exploration teams in France, New Caledonia, and Sahara. In 196G-1963 he headed a mission of the IFP to the Department of National Development of Australia.

Current and authoritative with many advanced concepts for petroleum geologists, geochemists, geophysicists, or engineers engaged in the search for or production of crude oil and natural gas, or interested in their habitats and the factors that control them, this book is an excellent reference. It is recommended without reservation. AAPG Bulletin.

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.

Nitrogen in the Environment: Sources, Problems, and Management is the first volume to provide a holistic perspective and comprehensive treatment of nitrogen from field, to ecosystem, to treatment of urban and rural drinking water supplies, while also including a historical overview, human health impacts and policy considerations. It provides a worldwide perspective on nitrogen and agriculture. Nitrogen is one of the most critical elements required in agricultural systems for the production of crops for feed, food and fiber. The ever-increasing world population requires increasing use of nitrogen in agriculture to supply human needs for dietary protein. Worldwide demand for nitrogen will increase as a direct response to increasing population. Strategies and perspectives are considered to improve nitrogen-use efficiency. Issues of nitrogen in crop and human nutrition, and transport and transformations along the continuum from farm field to ground water, watersheds, streams, rivers, and coastal marine environments are discussed. Described are aerial transport of nitrogen from livestock and agricultural systems and the potential for deposition and impacts. The current status of nitrogen in the environment in selected terrestrial and coastal environments and crop and forest ecosystems and development of emerging technologies to minimize nitrogen impacts on the environment are addressed. The nitrogen cycle provides a framework for assessing broad scale or even global strategies to improve nitrogen use efficiency. Growing human populations are the driving force that requires increased nitrogen inputs. These increasing inputs into the food-production system directly result in increased livestock and human-excretory nitrogen contribution into the environment. The scope of this book is diverse, covering a range of topics and issues from furthering our understanding of nitrogen in the environment to policy considerations at both farm and national scales.

For many years, the subject matter encompassed by the title of this book was largely limited to those who were interested in the two most economically important organic materials found buried in the Earth, namely, coal and petroleum. The point of view of any discussions which might occur, either in scientific meetings or in books that have been written, was, therefore, dominated largely by these interests. A great change has occurred in the last decade. This change had as its prime mover our growing knowledge of the molecular architecture of biological systems which, in turn, gave rise to a more legitimate asking of the question: "How did life come to be on the surface of the Earth?" A second motivation arose when the possibilities for the exploration of planets other than the Earth-the moon, Mars, and other parts of the solar system-became a reality. Thus the question of the possible existence of life elsewhere than on Earth conceivably could be answered.

Soils comprise the largest pool of terrestrial carbon and therefore are an important component of carbon storage in the biosphere-atmosphere system. Structure and Organic Matter Storage in Agricultural Soils explores the mechanisms and processes involved in the storage and sequestration of carbon in soils. Focusing on agricultural soils - from tropical to semi-arid types - this new book provides an in-depth look at structure, aggregation, and organic matter retention in world soils. The first two sections of the book introduce readers to the basic issues and scientific concepts, including soil structure, underlying mechanisms and processes, and the importance of agroecosystems as carbon regulators. The third section provides detailed discussions of soil aggregation and organic matter storage under various climates, soil types, and soil management practices. The fourth section addresses current strategies for enhancing organic matter storage in soil, modelling techniques, and measurement methods. Throughout the book, the importance of the soil structure-organic matter storage relationship is emphasized. Anyone involved in soil science, agriculture, agronomy, plant science, or greenhouse gas and global change studies should understand this relationship. Structure and Organic Matter Storage in Agricultural Soils provides an ideal source of information not only on the soil structure-storage relationship itself, but also on key research efforts and direct applications related to the storage of organic matter in agricultural soils.