Nitrogen in the Environment, Volume 2: Soil-Plant-Nitrogen Relationships is the second of a two-volume treatise based on manuscripts presented at the international conference on ""Nitrogen in the Environment,"" held at the University of California Conference Center, Lake Arrowhead, in February, 1977. All original manuscripts were revised in accordance with discussions at the conference. The chapters published in these volumes are those revised manuscripts, with provisions in each chapter to preserve the major suggestions for their improvement. These two volumes—Nitrogen Behavior in Field Soil and Soil-Plant-Nitrogen Relationships—should be of value in bringing into perspective current knowledge on selected aspects of nitrogen in the environment. The book contains 22 chapters and opens with a study on the factors influencing nitrate acquisition by plants; assimilation and fate of reduced nitrogen. Separate chapters follow on topics such as absorption and utilization of ammonium nitrogen by plants; potential nitrate levels in edible plant parts; control of biological nitrogen fixation; and methods for analysis of denitrification in soils.

Nitrogen in the Environment, Volume 1: Nitrogen Behavior in Field Soil is the first of a two-volume treatise based on manuscripts presented at the international conference on ""Nitrogen in the Environment,"" held at the University of California Conference Center, Lake Arrowhead, in February, 1977. All original manuscripts were revised in accordance with discussions at the conference. The chapters published in these volumes are those revised manuscripts, with provisions in each chapter to preserve the major suggestions for their improvement. These two volumes—Nitrogen Behavior in Field Soil and Soil-Plant-Nitrogen Relationships—should be of value in bringing into perspective current knowledge on selected aspects of nitrogen in the environment. This book contains 26 chapters and begins with a paper on field trials with isotopically labeled nitrogen fertilizer. Separate chapters follow on topics such as computer simulation modeling for nitrogen in irrigated croplands; spatial variability of nitrogen in soils; application of gaseous-diffusion theory to measure denitrification; and measurement and prediction of anaerobiosis in soils.

Soil-plant relationships once had a limited meaning. To the student of agriculture it meant creating optimum conditions for plant growth. To the ecologist it meant explaining some plant community distribu tion patterns by correlation with soil type or conditions. This dual view has been greatly expanded at an academic level by the discovery of the ecosystem as a practical working unit. A flood of concepts and information subsequently emerged from the International Biological Programme. At a totally different level of resolution, it is appreciated that certain soil-based ecological problems have a molecular basis, and must be addressed by physiological or biochemical approaches. From ecosystem to molecule we have powerful new tools to increase the flow of ecological data and process it for interpretation. Society is now experiencing a series of adverse global phenomena which demand an appreciation of soil-plant relationships. These include desertification leading to famine, soil degradation accom panying forest destruction, acidification of watersheds and the spasmodic dispersal of radionuclides and other pollutants. It is public policy, not merely to identify problems, but to seek strategies for minimising their ill effects. This book is written as a guide to soil-plant relationships, cen trally oriented towards ecology, but of interest to students of geo graphy and agriculture. For ecology students it will bring together subfields such as microbiology, plant physiology, systematics and pro vide interfaces with animal biology, meteorology and soil science.

Nitrogen Economy in Tropical Soils presents an authoritative and comprehensive state-of-the-art review on soil/plant nitrogen inter-relationships, with special reference to tropical soils and crops in aerobic and anaerobic environments. Use of isotopically labelled nitrogen in experimentation, especially in tropical environments, and recently developed analytical techniques for soil and plant materials are presented. An important aspect is the emphasis placed on the impact of the tropical environment on nitrogen transformations in the soil environment. This book should be an excellent source of information for senior undergraduate and graduate students with interest in soil/plant nitrogen inter-relationships, and for all levels of research workers in these fields.