Nitrogen (N) is potentially one of the most complex elements on the Earth. It is necessary for all biological activity, but creates negative impacts on water and air quality. There is a balancing act between deficiency and surplus and the forms of N available further complicate our understanding of the dynamics. Biological fixation provides some plants with N supply while others are totally dependent upon N being available in the soil profile for the roots to extract. Nevertheless, the demand for N will increase because the human population with its increasing growth requires more protein and thus more N. Understanding the global N cycle is imperative to meeting current and future nitrogen demands while decreasing environmental impacts. This book discusses availability, production, and recycling of N in air, water, plants, and soils. It features information on N impacts to soil and water quality, management of N in agroecosystems, and techniques to maximize the use efficiency while minimizing the risks of leakage of reactive N into the environment. This volume in the Advances in Soil Science series is specifically devoted to availability, production, and recycling of N with impact on climate change and water quality, and management of N in agroecosystems in the context of maximizing the use efficiency and minimizing the risks of leakage of reactive N (NO-3, N¬2O) into the environment.

This book highlights the latest discoveries about the nitrogen cycle in the soil. It introduces the concept of nitrogen fixation and covers important aspects of nitrogen in soil and ecology such as its distribution and occurrence, soil microflora and fauna and their role in N-fixation. The importance of plant growth-promoting microbes for a sustainable agriculture, e.g. arbuscular mycorrhizae in N-fixation, is discussed as well as perspectives of metagenomics, microbe-plant signal transduction in N-ecology and related aspects. This book enables the reader to bridge the main gaps in knowledge and carefully presents perspectives on the ecology of biotransformations of nitrogen in soil.

Long-awaited second edition of classic textbook, brought completely up to date, for courses on tropical soils, and reference for scientists and professionals.

Review of the principles and management implications related to nitrogen in the soil-plant-water system.

North American Agroforestry Explore the many benefits of alternative land-use systems with this incisive resource Humanity has become a victim of its own success. While we’ve managed to meet the needs—to one extent or another—of a large portion of the human population, we’ve often done so by ignoring the health of the natural environment we rely on to sustain our planet. And by deteriorating the quality of our air, water, and land, we’ve put into motion consequences we’ll be dealing with for generations. In the newly revised Third Edition of North American Agroforestry, an expert team of researchers delivers an authoritative and insightful exploration of an alternative land-use system that exploits the positive interactions between trees and crops when they are grown together and bridges the gap between production agriculture and natural resource management. This latest edition includes new material on urban food forests, as well as the air and soil quality benefits of agroforestry, agroforestry’s relevance in the Mexican context, and agroforestry training and education. The book also offers: A thorough introduction to the development of agroforestry as an integrated land use management strategy Comprehensive explorations of agroforestry nomenclature, concepts, and practices, as well as an agroecological foundation for temperate agroforestry Practical discussions of tree-crop interactions in temperate agroforestry, including in systems such as windbreak practices, silvopasture practices, and alley cropping practices In-depth examinations of vegetative environmental buffers for air and water quality benefits, agroforestry for wildlife habitat, agroforestry at the landscape level, and the impact of agroforestry on soil health Perfect for environmental scientists, natural resource professionals and ecologists, North American Agroforestry will also earn a place in the libraries of students and scholars of agricultural sciences interested in the potential benefits of agroforestry.

Nitrogen is an essential element for plant growth and development and a key agricultural input-but in excess it can lead to a host of problems for human and ecological health. Across the globe, distribution of fertilizer nitrogen is very uneven, with some areas subject to nitrogen pollution and others suffering from reduced soil fertility, diminished crop production, and other consequences of inadequate supply. Agriculture and the Nitrogen Cycle provides a global assessment of the role of nitrogen fertilizer in the nitrogen cycle. The focus of the book is regional, emphasizing the need to maintain food and fiber production while minimizing environmental impacts where fertilizer is abundant, and the need to enhance fertilizer utilization in systems where nitrogen is limited. The book is derived from a workshop held by the Scientific Committee on Problems of the Environment (SCOPE) in Kampala, Uganda, that brought together the world's leading scientists to examine and discuss the nitrogen cycle and related problems. It contains an overview chapter that summarizes the group's findings, four chapters on cross-cutting issues, and thirteen background chapters. The book offers a unique synthesis and provides an up-to-date, broad perspective on the issues of nitrogen fertilizer in food production and the interaction of nitrogen and the environment.

Several textbooks and edited volumes are currently available on general soil fertility but‚ to date‚ none have been dedicated to the study of “Sustainable Carbon and Nitrogen Cycling in Soil.” Yet this aspect is extremely important, considering the fact that the soil, as the ‘epidermis of the Earth’ (geodermis)‚ is a major component of the terrestrial biosphere. This book addresses virtually every aspect of C and N cycling, including: general concepts on the diversity of microorganisms and management practices for soil, the function of soil’s structure-function-ecosystem, the evolving role of C and N, cutting-edge methods used in soil microbial ecological studies, rhizosphere microflora, the role of organic matter (OM) in agricultural productivity, C and N transformation in soil, biological nitrogen fixation (BNF) and its genetics, plant-growth-promoting rhizobacteria (PGPRs), PGPRs and their role in sustainable agriculture, organic agriculture, etc. The book’s main objectives are: (1) to explain in detail the role of C and N cycling in sustaining agricultural productivity and its importance to sustainable soil management; (2) to show readers how to restore soil health with C and N; and (3) to help them understand the matching of C and N cycling rules from a climatic perspective. Given its scope, the book offers a valuable resource for educators, researchers, and policymakers, as well as undergraduate and graduate students of soil science, soil microbiology, agronomy, ecology, and the environmental sciences. Gathering cutting-edge contributions from internationally respected researchers, it offers authoritative content on a broad range of topics, which is supplemented by a wealth of data, tables, figures, and photographs. Moreover, it provides a roadmap for sustainable approaches to food and nutritional security, and to soil sustainability in agricultural systems, based on C and N cycling in soil systems.