This study examines the interactions between nitrogen and the ecosystem and discusses nitrogen fertilization practices around the world. Simulation models that play an important role in determining the dynamics of source-sink relationships are presented, helping to pinpoint inefficiencies and develop strategies to synchronize nitrogen supply and demand.
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.
Nitrate and nitrite are two ions largely diffused in the environment because they take part in the nitrogen cycle. Moreover, a great part of atmospheric nitrogen may be oxidized to nitrite and nitrate by microorganisms in plants, soil or water. The more stable form of oxidized nitrogen is nitrate ion, but, through microbial activity, it can be reduced to nitrite ion which is more chemically reactive. Nitrate and its salts are widely used, especially as inorganic fertilizers, and for many other purposes such as oxidizing agents, explosives, in the chemical industry and as food preservatives. This book discusses the agricultural uses, management practices and environmental effects of nitrogen fertilizers.
Food production remains the highest agricultural priority, subject to the constraint that it be done in harmony with nature, or at least with minimum environmental pollution. The amount of fertilizer applied can be controlled using modern application techniques, including soil and crop management, guaranteeing higher economic profit and lower environmental cost. It is in such a context that the present book addresses the efficient and rational use of mineral and organic fertilizers while preserving environmental quality. The book discusses the impact on surface and groundwaters, soils and crops, and experience of nitrate leaching, denitrification, ammonia volatilization, heavy metal pollution, agricultural and urban waste management, and international and national legislation. Audience: Agronomists, environmentalists, soil and food chemists, ecologists, policy makers, and managers in the fertilizer industry concerned with the trend of public opinion.
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.
Nitrogen (N) is a major limiting nutrient to sustain crop yields and quality. As a result, N fertilizer is usually applied in large quantity to increase crop production throughout the world. Application of N fertilizers has increased crop yields and resulted in achievement of self-sufficiency in food production in many developing countries. Excessive application of N fertilizers beyond crops,Äô demand, however, has resulted in undesirable consequences of degradation in soil, water, and air quality. These include soil acidification, N leaching in groundwater, and emissions of nitrous oxide (N2O), a potent greenhouse gas that contributes to global warming. Long-term application of ammonia-based N fertilizers, such as urea, has increased soil acidity which rendered to soil infertility where crops fail to respond with further application of N fertilizers. Another problem is the groundwater contamination of nitrate-N (NO3-N) which can be a health hazard to human and livestock if its concentration goes above 10¬†mg¬†L,àí1 in drinking water. The third problem is emissions of N2O gas which is 300 times more powerful than carbon dioxide in terms of global warming potential. This chapter examines the effect of N fertilization on soil and environmental quality and crop yields.
Plant nutrients are the vital elements essential for plant growth and survival, with key roles in adapting to challenging environments. Each nutrient, whether required in relatively large (macronutrients) or minute concentrations (micronutrients) plays a unique role in plant life cycle. Both the insufficient and surplus concentrations of these nutrients may render negative impacts on plant growth and development and therefore their homeostasis is considered critical for optimal plant growth and yield. Plant Nutrition and Food Security in the Era of Climate Change comprehensively reviews all critical plant nutrients. Chapters include topics such as: biological roles, uptake and transport of vital nutrients in plants; an in-depth review of the roles of potassium, calcium, magnesium and trace element; molecular breeding approaches for enhanced plant nutrients; and exploring the rhizosphere microbiome for enhance nutrient availability. Written by leading experts in the field of plant biology, this is an essential read for researchers and scientists interested in plant science, agronomy, food security and environmental science. A comprehensive review of all the important plant nutrients Discusses plant homeostasis under natural and changing environments Introduces novel approaches and state-of-the-art tool for enhancing the levels of targeted nutrients within plant tissues
Long-awaited second edition of classic textbook, brought completely up to date, for courses on tropical soils, and reference for scientists and professionals.
Nitrogen is the most important nutrient in agricultural practice because the availability of nitrogen from the soil is generally not enough to support crop yields. To maintain soil fertility, the application of organic matters and crop rotation have been practiced. Farmers can use convenient chemical nitrogen fertilizers to obtain high crop yields. However, the inappropriate use of nitrogen fertilizers causes environmental problems such as nitrate leaching, contamination in groundwater, and the emission of N2O gas. This book is divided into the following four sections: “Ecology and Environmental Aspects of Nitrogen in Agriculture”, “Nitrogen Fertilizers and Nitrogen Management in Agriculture”, “N Utilization and Metabolism in Crops”, “Plant-Microbe Interactions”.
Nitrogen is indispensable to all life on Earth. However, humans now dominate the nitrogen cycle, and nitrogen emissions from human activity have real costs: water and air pollution, climate change, and detrimental effects on human health, biodiversity, and natural habitats. Too little nitrogen limits ecosystem processes, while too much nitrogen transforms ecosystems profoundly. The California Nitrogen Assessment is the first comprehensive account of nitrogen flows, practices, and policies for California, encompassing all nitrogen flows—not just those associated with agriculture—and their impacts on ecosystem services and human wellbeing. How California handles nitrogen issues will be of interest nationally and internationally, and the goal of the assessment is to link science with action and to produce information that affects both future policy and solutions for addressing nitrogen pollution. This book also provides a model for application of integrated ecosystem assessment methods at regional and state (subnational) levels.
