Download or read book Diurnal and Seasonal Variability in Emission of Nitrous Oxide from Soil written by Susan Gatter Robbins and published by . This book was released on 1981 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Diurnal Variability of Nitrous Oxide Emissions from Agricultural Soils written by Yuk Faat Wu and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Emission of Nitrous Oxide and its Mitigation written by David Ussiri and published by Springer Science & Business Media. This book was released on 2012-11-13 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Carbon and Nitrogen in the Terrestrial Environment written by R. Nieder and published by Springer Science & Business Media. This book was released on 2008-05-30 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon and Nitrogen in the Terrestrial Environment is a comprehensive, interdisciplinary description of C and N fluxes between the atmosphere and the terrestrial biosphere; issues related to C and N management in different ecosystems and their implications for the environment and global climate change; and the approaches to mitigate emission of greenhouse gases. Drawing upon the most up-to-date books, journals, bulletins, reports, symposia proceedings and internet sources documenting interrelationships between different aspects of C and N cycling in the terrestrial environment, Carbon and Nitrogen in the Terrestrial Environment fills the gap left by most of the currently available books on C and N cycling. They either deal with a single element of an ecosystem, or are related to one or a few selected aspects like soil organic matter (SOM) and agricultural or forest management, emission of greenhouse gases, global climate change or modeling of SOM dynamics.

Download or read book The Emissions of Nitrous Oxide from Agricultural Fields in New York State written by Marina Molodovskaya and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The atmospheric nitrous oxide (N2O) is of special interest, due to its persistent effect as a potent greenhouse gas and stratospheric ozone destructor. Animal manure fertilization is one of the key factors contributing to N2O formation. In the Northeastern US, dairy industry is the largest agricultural activity, and the manure cropland fertilization is a common practice. Continuous monitoring of N2O emissions from croplands in New York State was conducted by eddy covariance method from 2006 to 2009. The research was aimed at quantification of N2O emissions from manure-fertilized corn (Zea mays) and alfalfa (Medicago sativa) fields, estimating strength and spatial variability of soil N2O sources by conducting simultaneous static chamber campaign, and analysis of temporal distribution of N2O fluxes as affected by seasonality of climate variations and manure practices. The analysis of cumulative N2O emissions and source contributions into the integrated flux showed that manure nitrogen (N) was the most important factor controlling the extent of N2O formation: areas which received more manure N were stronger N2O emitters. Whereas N availability determined a magnitude of N2O emissions, the environmental changes altering soil moisture and temperature status were major N2O event triggers. The temporal flux distribution demonstrated episodic event-induced nature of N2O peak fluxes, which were primarily driven by strong rainfall and warm temperatures in growing season and soil thaw in winter and early spring. The greatest N2O emissions were observed when flux-triggering weather events coincided with or followed manure application. The most intense single N2O peak event was produced from combination of summer manure spreading and strong rainfall; however spring thaw-induced N2O fluxes showed more consistent seasonal year-to-year trend. The daily average fluxes measured by the EC and chamber techniques were in good agreement. The spatial variability of chamber measurements was mainly caused by high heterogeneity of soil N2O formation, which resulted both in net N2O production and consumption. The EC integrated flux was strongly dependent on wind direction and contributing footprint. The combination of the two different scale methods may help in reducing temporal and spatial variability of N2O estimates and improving N2O emission data quality. .

Download or read book Atmospheric Boundary Layer Flows written by J. C. Kaimal and published by Oxford University Press, USA. This book was released on 1994 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text gives a simple view of the structure of the boundary layer, the instruments available for measuring its mean and turbulent properties, how best to make the measurements, and ways to process and analyze the data.

Download or read book Masters Theses in the Pure and Applied Sciences written by Wade Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 26 (thesis year 1981) a total of 11 ,048 theses titles from 24 Canadian and 21 8 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 26 reports theses submitted in 1981, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.

Download or read book Methods for Measuring Greenhouse Gas Balances and Evaluating Mitigation Options in Smallholder Agriculture written by Todd S. Rosenstock and published by Springer. This book was released on 2016-08-23 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​​This book provides standards and guidelines for quantifying greenhouse gas emissions and removals in smallholder agricultural systems and comparing options for climate change mitigation based on emission reductions and livelihood trade-offs. Globally, agriculture is directly responsible for about 11% of annual greenhouse gas (GHG) emissions and induces an additional 17% through land use change, mostly in developing countries. Farms in the developing countries of sub-Saharan Africa and Asia are predominately managed by smallholders, with 80% of land holdings smaller than ten hectares. However, little to no information exists on greenhouse gas emissions and mitigation potentials in smallholder agriculture. Greenhouse gas measurements in agriculture are expensive, time consuming, and error prone, challenges only exacerbated by the heterogeneity of smallholder systems and landscapes. Concerns over methodological rigor, measurement costs, and the diversity of approaches, coupled with the demand for robust information suggest it is germane for the scientific community to establish standards of measurements for quantifying GHG emissions from smallholder agriculture. Standard guidelines for use by scientists, development organizations will help generate reliable data on emissions baselines and allow rigorous comparisons of mitigation options. The guidelines described in this book, developed by the CGIAR Research Program on Climate Change, Agriculture, and Food Security (CCAFS) and partners, are intended to inform anyone conducting field measurements of agricultural greenhouse gas sources and sinks, especially to develop IPCC Tier 2 emission factors or to compare mitigation options in smallholder systems.

Download or read book Nitrous Oxide Emission from Riparian Buffers in Agricultural Landscapes of Indiana written by Katelin Rose Fisher and published by . This book was released on 2013 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Riparian buffers have well documented capacity to remove nitrate (NO3-) from runoff and subsurface flow paths, but information on field-scale N2O emission from these buffers is lacking. This study monitored N2O fluxes at two agricultural riparian buffers in the White River watershed (Indiana) from December 2009 to May 2011 to assess the impact of landscape and hydrogeomorphologic factors on emission. Soil chemical and biochemical properties were measured and environmental variables (soil temperature and moisture) were monitored in an attempt to identify key drivers of N2O emission. The study sites included a mature riparian forest (WR) and a riparian grass buffer (LWD); adjacent corn fields were also monitored for land-use comparison. With the exception of net N mineralization, most soil properties (particle size, bulk density, pH, denitrification potential, organic carbon, C:N) showed little correlation with N2O emission. Analysis of variance (ANOVA) identified season, land-use (riparian buffer vs. crop field), and site geomorphology as major drivers of N2O emission. At both study sites, N2O emission showed strong seasonal variability; the largest emission peaks in the riparian buffers (up to 1,300 % increase) and crop fields (up to 3,500 % increase) occurred in late spring/early summer as a result of flooding, elevated soil moisture and N-fertilization. Nitrous oxide emission was found to be significantly higher in crop fields than in riparian buffers at both LWD (mean: 1.72 and 0.18 mg N2O-N m-2 d-1) and WR (mean: 0.72 and 1.26 mg N2O-N m-2 d-1, respectively). Significant difference (p=0.02) in N2O emission between the riparian buffers was detected, and this effect was attributed to site geomorphology and the greater potential for flooding at the WR site (no flooding occurred at LWD). More than previously expected, the study results demonstrate that N2O emission in riparian buffers is largely driven by landscape geomorphology and land-stream connection (flood potential).

Download or read book Nitrogen Fertilization in the Environment written by Peter Bacon and published by CRC Press. This book was released on 1995-01-23 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Soil Management written by Jerry L. Hatfield and published by John Wiley & Sons. This book was released on 2020-01-22 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Degradation of soils continues at a pace that will eventually create a local, regional, or even global crisis when diminished soil resources collide with increasing climate variation. It's not too late to restore our soils to a more productive state by rediscovering the value of soil management, building on our well-established and ever-expanding scientific understanding of soils. Soil management concepts have been in place since the cultivation of crops, but we need to rediscover the principles that are linked together in effective soil management. This book is unique because of its treatment of soil management based on principles—the physical, chemical, and biological processes and how together they form the foundation for soil management processes that range from tillage to nutrient management. Whether new to soil science or needing a concise reference, readers will benefit from this book's ability to integrate the science of soils with management issues and long-term conservation efforts.

Download or read book Effect of Sampling Strategies and Nitrogen Fertilization Best Management Practices on Cumulative Nitrous Oxide Emissions written by Pedro Vitor Ferrari Machado and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis consists of firstly, an assessment of diurnal variation (DV) and effect of sampling frequency on N2O cumulative emissions, and secondly, an evaluation of N2O emissions in response to N fertilization best management practices (BMPs) in a corn field. The first study was performed by sub-sampling a high frequency dataset for growing and non-growing seasons. For growing seasons, taking mid-morning samples twice per week after N fertilization, with an extra sample taken after >10 mm rainfall resulted in lowest uncertainties among the studied strategies. For non-growing seasons mid-morning and mid-afternoon measurements introduced positive errors into the analysis, but taking bi-weekly mid-morning samples still underestimated fluxes due to missing N2O emission events. For the second study, the interaction of soil water content and soil nitrate influenced N2O emissions and the tested BMPs were effective to mitigate N2O emissions when nitrate accumulation was delayed to periods when soil was drier.

Download or read book Effects of Management on Selected Soil Properties and Nitrous Oxide Fluxes in Dairy Cropping Systems written by Emily Paige Ball and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates selected soil properties and management decisions and their effect on nitrous oxide (N2O) emissions from agricultural soils. Nitrate, an inorganic form of N, is extremely mobile in soils, making it susceptible to loss through processes like denitrification. Denitrification is an anaerobic microbial process that reduces nitrate to N2 or incompletely to N2O, a potent greenhouse gas. The experimental site for this research was the Sustainable Dairy Cropping System (SDCS) located at Penn States Agronomy Farm. Chapter one is a review of the literature on nitrogen (N) cycling in agriculture, N loss pathways and the management and environmental factors affecting denitrification. This process is driven by soil properties, nitrate availability, and other factors. A prior study in this experiment in 2015 and 2016 found that the driving factors for N2O emissions in some of the same treatments were explained by days after manure application, growing degree days (GDD), and manure rate.Research on the effects of prior crop and management on N2O emissions in a typical PA dairy cropping system is described in chapter two. Labile carbon, total carbon, inorganic N species, and other environmental data were measured to determine their impact on measured N2O fluxes in 2017 and 2018. However, the measured soil and environmental properties in this experiment were not able to explain the observed patterns in N2O emissions through a regression analysis. The highest N2O fluxes were measured in 2018 in Corn after two years of Alfalfa (Medicago sativa) + Orchardgrass (Dactylis glomerata). Cumulative emissions were more than six times higher than those measured in treatments without a winter cover in the same year.Based on findings in 2017, chapter three investigates the impact of termination timing of Alfalfa+Orchardgrass on spring N2O fluxes and soil properties in 2018. This management decision is becoming more popular in the Northeast as spring conditions become wetter, making the proper timing of spring management events difficult. The findings from this experiment are promising for farmers interested in adopting this management practice as yields did not significantly differ from the subsequent corn crop and although they did not significantly differ, spring cumulative emissions from the spring terminated treatment were more than three times those from the fall terminated treatment. Because N2O emissions were not measured in the fall, however, the comparison of the two treatments in this study was not comprehensive.Chapter four described an investigative study on redox potentials in unsaturated agricultural soils. Equipment constraints and spatial variability made understanding and interpreting these results difficult. There were diurnal trends exhibited in some treatments, reflecting diurnal changes in soil moisture but not others. There also seemed to be stratification in depth, although this trend also differed across treatments. Overall, there is evidence that different crops can facilitate different redox environments and in turn, different microbial processes. However, more research and equipment advances need to take place before redox potential could be considered a useful indicator of microbial processes in unsaturated soils.Finally, the conclusions summarized the major findings of each of these experiments and discussed the impact of sustainable management practices on improving soil resiliency. Implementing sustainable practices like cover cropping and no-till can improve soil, although trade-offs of higher N2O emissions may result. Further research on these practices and their impact on soil properties is necessary as the effects of climate change are becoming more apparent.

Download or read book Temporal variations in nitrous oxide fluxes from urine affected grassland written by D L. Williams and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluxes of nitrous oxide (N2O) from a permanent pasture were measured during a 1-y period using flux; chambers, Intact soil cores from the same pasture were also treated with cow urine (19 g N m(-2)) in a laboratory incubation experiment. Diurnal variations in flux rates were determined using a mobile laboratory for continuous field measurements of N2O fluxes at the field site. Nitrous oxide fluxes peaked after fertilizer (urea and NH4NO3) application, and winter fluxes were comparable to those measured during other parts of the year, with the annual N2O flux estimated at 3.2 kg N ha(-1) y(-1) or 1.3% of the fertilizer-N applied, Nitrous oxide fluxes followed the same diurnal variation as soil temperature, with N2O production peaking in late afternoon, Multiple linear regression analyses demonstrated weak relationships between N2O flux, rainfall and soil temperature (R-2 = 0.28). There was an immediate increase in N2O emission after urine application with rates reaching a peak of 89 mg N m(-2) d(-1) within 6 h, with an estimated 7% of the applied urine-N being lost as N2O over 42 d. Results indicate that the large spatial and temporal variability in N2O fluxes have to be assessed if accurate estimates of N2O losses are to be derived for gazed grasslands.

Download or read book Nitrous Oxide Emissions in a Landscape Transitioning to the Energy Crops Miscanthus and Switchgrass written by Debasish Saha and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrous oxide (N2O) emissions from soils are an important component of the greenhouse gas (GHG) balance of agricultural systems. These emissions are particularly relevant when considering the transition of land under the Conservation Reserve Program (CRP) grassland to energy crop, like switchgrass and Miscanthus. The N2O fluxes are in general spatially and temporally variable, which makes field monitoring of this flux challenging. Using the infrequent chamber-based method requires knowledge of spatial and temporal inequality of N2O flux distribution. This dissertation focuses on estimating N2O flux from energy crops aforementioned in a landscape typical of Ridge and Valley region with soil and hydrologic heterogeneity.In chapter 2, I used simulation models and statistical methods to assess the uncertainties of cumulative N2O flux estimates obtained by different temporal sampling frequencies. As a corollary of this work, a robust rule-based sampling framework was designed that provides better estimates of this flux with a lower number of sampling events than the typical fixed-interval sampling methods. The daily soil N2O flux was simulated for Ames, IA; College Station, TX; Fort Collins, CO, and Pullman, WA. A regular sampling of 4- and 8-day interval is required at College Station and Ames, respectively, to yield ±20% accuracy in the flux estimate, while a 12-day interval renders the same accuracy at Fort Collins and Pullman. The uncertainty of the annual N2O flux estimation increased with increasing interval in the fixed interval method, higher in sites with greater flux variability. The rule-based method provided the same accuracy as that of fixed interval with 60% reduction in sampling numbers. The efficiency is higher in sites with greater flux variability.In chapter 3, I examined the effect of land conversion from CRP to energy crops on N2O emissions and how biogeochemical and hydrological factors control the spatial and temporal inequality of N2O flux distribution. The experiment was located in typical Ridge and Valley landscape near the town of Leck Kill, PA. Soil N2O flux, soil mineral nitrogen availability, and profile soil moisture were monitored in shoulder, backslope, and footslope positions under each plot during the growing season of 2013, the second year after land transition. The cumulative N2O flux was significantly (P = 0.009) influenced by vegetation-by-landscape position interaction. Landscape position, nitrate nitrogen, and subsoil soil aeration ([theta]A) were the most important variables to influence soil N2O emissions. The regression tree identified highest N2O emissions occur when [theta]A at 20-40 cm depth is 0.03 m3 m-3, and when there is nitrate in the soil layer. The footslope positions under energy crops were the hot spots of N2O emissions due to prolonged soil saturation and mineral nitrogen availability. The peak emission was triggered by a 100-mm rain event in early June, and contributed 26% of the cumulative flux. Nitrogen fertilization in switchgrass and chisel plowing during Miscanthus establishment caused 48 and 78% higher cumulative flux than the CRP, respectively. The results suggest that land transition only caused significant increase in N2O emissions from the footslope, while the major part of the watershed is at lesser risk of large emissions.The knowledge of hot spots and hot moments of N2O emissions in the landscape is important for its accurate spatial and temporal monitoring, quantification of the emissions, and to minimize the adverse environmental effects of landscape management. A novel application of the concept of inequality (Lorenz curve and Gini coefficients, G) was used to quantify the heterogeneous distribution of N2O in space and time. The G was better correlated (R2 = 0.71, P 0.001, n = 16) with daily N2O emissions than the coefficient of variation and skewness. The hot moment by 100 mm rain event caused highly heterogeneous distribution (G = 0.70) of N2O fluxes in the landscape; however, had little influence on inequality of soil CO2 (G = 0.39) flux distribution among the vegetation types and landscape positions. Overall inequality of N2O flux distribution followed the trend: footslope (G = 0.75) backslope (G = 0.67) shoulder (G = 0.43). Event-based evolution of N2O flux inequality was in accordance with the hydrologic inequality, given the biogeochemical equality prevails in the landscape. The Lorenz curve and G in association with spatial maps are useful tools to guide landscape-scale management strategies to reduce N2O emissions, as well as spatial and temporal monitoring of N2O emissions.Based on the critical threshold of [theta]A

Download or read book Advances in Agronomy written by and published by Academic Press. This book was released on 2004-07-10 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Agronomy continues to be recognized as a leading reference and a first-rate source of the latest research in agronomy. Major reviews deal with the current topics of interest to agronomists, as well as crop and soil scientists. As always, the subjects covered are varied and exemplary of the myriad subject matter dealt with by this long-running serial. Editor Donald Sparks, former president of the Soil Science Society of America and current president of the International Union of Soil Science, is the S. Hallock du Pont Chair of Plant and Soil Sciences at The University of Delaware. Volume 84 contains six excellent reviews that discuss topics critical to agricultural and environmental sustainability. * Maintains the highest impact factor among serial publications in Agriculture * Presents timely reviews on important agronomy issues * Enjoys a long-standing reputation for excellence in the field

Download or read book Methods in Methane Metabolism Part B written by Amy Rosenzweig and published by Academic Press. This book was released on 2011-03-17 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Produced by microbes on a large scale, methane is an important alternative fuel as well as a potent greenhouse gas. This volume focuses on microbial methane metabolism, which is central to the global carbon cycle. Both methanotrophy and methanogenesis are covered in detail. Topics include isolation and classification of microorganisms, metagenomics approaches, biochemistry of key metabolic enzymes, gene regulation and genetic systems, and field measurements. The state of the art techniques described here will both guide researchers in specific pursuits and educate the wider scientific community about this exciting and rapidly developing field. Topics include isolation and classification of microorganisms, metagenomics approaches, biochemistry of key metabolic enzymes, gene regulation and genetic systems and field measurements The state-of-the-art techniques described here will both guide researchers in specific pursuits and educate the wider scientific community about this exciting and rapidly developing field