"Nitrous oxide, N2O, is the third most important (in global warming terms) of the greenhouse gases, after carbon dioxide and methane. As this book describes, although it only comprises 320 parts per billion of the earth's atmosphere, it has a so-called Global Warming Potential nearly 300 times greater than that of carbon dioxide. N2O emissions are difficult to estimate, because they are predominantly biogenic in origin. The N2O is formed in soils and oceans throughout the world, by the microbial processes of nitrification and denitrification, that utilise the reactive N compounds ammonium and nitrate, respectively. These forms of nitrogen are released during the natural biogeochemical nitrogen cycle, but are also released by human activity. In fact, the quantity of these compounds entering the biosphere has virtually doubled since the beginning of the industrial age, and this increase has been matched by a corresponding increase in N2O emissions. The largest source is now agriculture, driven mainly by the use of synthetic nitrogen fertilisers. The other major diffuse source derives from release of NOx into the atmosphere from fossil fuel combustion and biomass burning, as well as ammonia from livestock manure. Some N2O also comes directly from combustion, and from two processes in the chemical industry: the production of nitric acid, and the production of adipic acid, used in nylon manufacture. Action is being taken to curb the industrial point-source emissions of N2O, but measures to limit or reduce agricultural emissions are inherently more difficult to devise. As we enter an era in which measures are being explored to reduce fossil fuel use and/or capture or sequester the CO2 emissions from the fuel, it is likely that the relative importance of N2O in the 'Kyoto basket' of greenhouse gases will increase, because comparable mitigation measures for N2O are inherently more difficult, and because expansion of the land area devoted to crops, to feed the increasing global population and to accommodate the current development of biofuels, is likely to lead to an increase in N fertiliser use, and thus N2O emission, worldwide. The aim of this book is to provide a synthesis of scientific information on the primary sources and sinks of nitrous oxide and an assessment of likely trends in atmospheric concentrations over the next century and the potential for mitigation measures"--Publisher's description.

Rice (Oryza sativa L.) is a common crop grown in Arkansas under flooded-soil conditions. The saturated to nearly saturated soil makes rice production an ideal environment for the production of potent greenhouse gases, such as nitrous oxide (N2O). The objectives of this study were to i) evaluate the impact of water management practice (full-season-flood and intermittent-flood) and cultivar (pure-line and hybrid) on N2O fluxes, season-long N2O emissions, and global warming potential (GWP; 2016) and ii) evaluate the impact of tillage practice [conventional tillage and no-tillage (NT)] and type of urea fertilizer [ N-(n-butyl) thiosphosphoric triamide (NBPT)-coated and non-coated urea] on N2O fluxes, season-long N2O emissions and GWP (2017). For both objectives, rice was grown in a direct-seeded, delayedflood production system. Gas samples were collected from enclosed chambers at 20-min intervals for 1 hr approximately weekly between flood establishment and 4 to 7 days after endof- season flood release. In 2016, both N2O fluxes and season-long N2O emissions were unaffected (P > 0.1) by water management or cultivar. However, season-long N2O emissions ranged from 0.38 to 0.84 kg N2O-N ha-1 season-1 from the full-season-flood/hybrid and intermittent-flood/hybrid treatment combinations, respectively. The GWP differed (P 0.1) by water management or cultivar. However, season-long N2O emissions ranged from 0.38 to 0.84 kg N2O-N ha-1 season-1 from the full-season-flood/hybrid and intermittent-flood/hybrid treatment combinations, respectively. The GWP differed (P 0.1) by tillage practice or type of urea fertilizer. The NT/non-coated-urea combination (2204 CO2 eq. ha-1 season-1) had the numerically largest GWP, but GWP was unaffected (P > 0.05) by tillage or fertilizer type. There are limited N2O emissions studies that have been conducted in rice production in the US, therefore, it is important to quantify and evaluate N2O emissions from common rice production practices (full-season-flood and conventional tillage) and their alternatives (intermittent-flood and no-tillage) to estimate the environmental impacts of these practices when rice producers are considering a conversion to more sustainable practices. 0.05) by tillage or fertilizer type. There are limited N2O emissions studies that have been conducted in rice production in the US, therefore, it is important to quantify and evaluate N2O emissions from common rice production practices (full-season-flood and conventional tillage) and their alternatives (intermittent-flood and no-tillage) to estimate the environmental impacts of these practices when rice producers are considering a conversion to more sustainable practices.

Nitrous oxide gas is a long-lived relatively active greenhouse gas (GHG) with an atmospheric lifetime of approximately 120 years, and heat trapping effects about 310 times more powerful than carbon dioxide per molecule basis. It contributes about 6% of observed global warming. Nitrous oxide is not only a potent GHG, but it also plays a significant role in the depletion of stratospheric ozone. This book describes the anthropogenic sources of N2O with major emphasis on agricultural activities. It summarizes an overview of global cycling of N and the role of nitrous oxide on global warming and ozone depletion, and then focus on major source, soil borne nitrous oxide emissions. The spatial-temporal variation of soil nitrous oxide fluxes and underlying biogeochemical processes are described, as well as approaches to quantify fluxes of N2O from soils. Mitigation strategies to reduce the emissions, especially from agricultural soils, and fertilizer nitrogen sources are described in detail in the latter part of the book.

A derivative of the Encyclopedia of Inland Waters, River Ecosystem Ecology reviews the function of rivers and streams as ecosystems as well as the varied activities and interactions that occur among their abiotic and biotic components. Because the articles are drawn from an encyclopedia, the articles are easily accessible to interested members of the public, such as conservationists and environmental decision makers. - Includes an up-to-date summary of global aquatic ecosystems and issues - Covers current environmental problems and management solutions - Features full-color figures and tables to support the text and aid in understanding

Inland aquatic habitats occur world-wide at all scales from marshes, swamps and temporary puddles, to ponds, lakes and inland seas; from streams and creeks to rolling rivers. Vital for biological diversity, ecosystem function and as resources for human life, commerce and leisure, inland waters are a vital component of life on Earth. The Encyclopedia of Inland Waters describes and explains all the basic features of the subject, from water chemistry and physics, to the biology of aquatic creatures and the complex function and balance of aquatic ecosystems of varying size and complexity. Used and abused as an essential resource, it is vital that we understand and manage them as much as we appreciate and enjoy them. This extraordinary reference brings together the very best research to provide the basic and advanced information necessary for scientists to understand these ecosystems – and for water resource managers and consultants to manage and protect them for future generations. Encyclopedic reference to Limnology - a key core subject in ecology taught as a specialist course in universitiesOver 240 topic related articles cover the field Gene Likens is a renowned limnologist and conservationist, Emeritus Director of the Institute of Ecosystems Research, elected member of the American Philosophical Society and recipient of the 2001 National Medal of Science Subject Section Editors and authors include the very best research workers in the field