Download or read book Quantification and Characterization of Measured Nitrous Oxide Emission from Perennial Grasses written by Cedric Wood Mason and published by . This book was released on 2016 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soils, especially those that are agriculturally managed, are a primary source of atmospheric nitrous oxide, but quantification of emission from soils over large spatial and temporal scales is quite uncertain to due to a high degree of heterogeneity in the processes within soils that regulate production of nitrous oxide and its transmission to the atmosphere. There is very little knowledge of the magnitude and trends in nitrous oxide emissions from perennial grass bioenergy crops in particular. Arrays of enclosed chambers can be used to measure emission rates at discrete points across a soil surface, but these must be spatially and temporally interpolated in order to determine emissions over broader areas and timespans, and this can induce errors. The eddy covariance method can be used to continuously monitor nitrous oxide emissions at the field scale, but this approach poses instrumental and computational challenges. We conducted studies during the growing season of years 2013 and 2014 using closed chambers to monitor nitrous oxide emissions from four different perennial grass ecosystems, and used those observations to estimate long-term emissions from each system. We used a bootstrapping technique to estimate the uncertainty in spatially upscaled estimates coupled with a monte carlo approach to estimate uncertainty over integrated time periods. We examined the results of the chamber studies to identify trends in the occurrence of nitrous oxide emission hotspots. We also compared eddy covariance measurement of nitrous oxide to the spatially and temporally upscaled emission estimates that were established using the closed chambers. We conclude that approximately 2.5% of applied nitrogen is lost as nitrous oxide in these fertilized perennial grass systems, and that hotspots constitute about 1/3rd of these emissions. The field scale nitrous oxide emission estimates from eddy covariance did not contradict the upscaled estimates from closed chambers, but closed chambers seem to offer more accurate quantification at low emission rates.
Download or read book Spring thaw Nitrous Oxide Emissions from Reed Canarygrass on Wet Marginal Soil in New York State written by Cedric Wood Mason and published by . This book was released on 2014 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: In temperate climates, a significant fraction of annual emissions of nitrous oxide (N2O) from agricultural land occurs during soil thaw. The objective of this study is to determine the impact of conversion of long-term fallow grassland to perennial grass bioenergy crops on N2O emissions during spring-thaw, and to identify field-scale features that influence emissions. We measured mid-afternoon fluxes daily from March 27th to April 7th 2013 from fallow and reed canarygrass over a short topological gradient using static chambers. Soil temperature, volumetric water content, and above-ground biomass were also observed, as were hourly air temperature and precipitation. Hot-moment analysis, non-parametric statistics and modeling results show that in the reed canarygrass, the topologically low subplots exhibited significantly elevated emissions compared to the fallow. Our results suggest that conversion of fallow grassland to perennial grass cropping systems for bioenergy or other uses could increase spring-thaw N2O emissions in wetness prone areas.
Download or read book Nitrous Oxide Emissions written by Miguel Andres Arango Argoti and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen is critical for plant growth and is a major cost of inputs in production agriculture. Too much nitrogen (N) is also an environmental concern. Agricultural soils account for 85% of anthropogenic N2O which is a major greenhouse gas. Management strategies for N fertilization and tillage are necessary for enhancing N use efficiency and reducing negative impacts of N to the environment. The different management practices induce changes in substrate availability for microbial activity that may result in increasing or reducing net N2O emitted from soils. The objectives of this research were to (1) integrate results from field studies to evaluate the effect of different management strategies on N2O emissions using a meta-analysis, (2) quantify N2O-N emissions under no-tillage (NT) and tilled (T) agricultural systems and the effect of different N source and placements, (3) perform sensitivity analysis, calibration and validation of the Denitrification Decomposition (DNDC) model for N2O emissions, and (4) analyze future scenarios of precipitation and temperature to evaluate the potential effects of climate change on N2O emissions from agro-ecosystems in Kansas. Based on the meta-analysis there was no significant effect of broadcast and banded N placement. Synthetic N fertilizer usually had higher N2O emission than organic N fertilizer. Crops with high N inputs as well as clay soils had higher N2O fluxes. No-till and conventional till did not have significant differences regarding N2O emissions. In the field study, N2O-N emissions were not significantly different between tillage systems and N source. The banded N application generally had higher emissions than broadcasted N. Slow release N fertilizer as well as split N applications reduced N2O flux without affecting yield. Simulations of N2O emissions were more sensitive to changes in soil parameters such as pH, soil organic carbon (SOC), field capacity (FIELD) and bulk density (BD), with pH and SOC as the most sensitive parameters. The N2O simulations performed using Denitrification Decomposition model on till (Urea) had higher model efficiency followed by no-till (compost), no-till (urea) and till (compost). At the regional level, changes in climate (precipitation and temperature) increased N2O emission from agricultural soils in Kansas. The conversion from T to NT reduced N2O emissions in crops under present conditions as well as under future climatic conditions.
Download or read book Biogenic Trace Gases written by P. A. Matson and published by John Wiley & Sons. This book was released on 2009-05-27 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trace gases are those that are present in the atmosphere at relatively low concentrations. Small changes in their concentrations can have profound implications for major atmospheric fluxes, and thereore, can be used as indicators in studies of global change, global biogeochemical cycling and global warming. This new how-to guide will detail the concepts and techniques involved in the detection and measurement of trace gases, and the impact they have on ecological studies. Introductory chapters look at the role of trace gases in global cycles, while later chapters go on to consider techniques for the measurement of gases in various environments and at a range of scales. A how-to guide for measuring atmospheric trace gases. Techniques described are of value in addressing current concerns over global climate change.
Download or read book Landscape and Regional scale Quantification of Nitrous Oxide Emission from a Subhumid Transitional Grassland forest Region written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was conducted to obtain landscape- and regional-scale estimates of N2O emissions for a representative part of the Black soil zone of Saskatchewan. A 4318-km2 study region was stratified based on soil texture and land use. At the regional scale, soil texture was the proxy variable used to represent the differences in soil moisture regimes and soil fertility, whereas land use was the surrogate variable used to reflect the differences in N and C cycling. Soil landscapes were selected to cover the range of soil texture and land use characteristics in the study region. At the landscape level, shoulder and footslope complexes were used as the spatial sampling units to cover the range of topographical and soil characteristics within the landscape. At the landform complex level, soil moisture (as assessed by volumetric moisture content and water-filled pore space) was the most important factor controlling N2O emission. At the landscape scale, soil moisture was, in turn, influenced by topography, and on the seasonal scale it was affected by climatic factor(s) (e.g., precipitation). The annual N2O emissions were calculated as the sum of the spring and the summer to fall fluxes. The spring emission was estimated by interpolating the N2O fluxes measured on discrete sampling days, whereas the summer to fall emission was estimated by establishing regression models that related N2O fluxes to water-filled pore space. Regional estimates of N2O emissions were obtained using the GIS database of soil texture and land use types. The average annual fluxes for fertilized cropped, fallow, pasture, and forest areas, weighted by their areal extent in the different textural areas of the study region, were 2.01, 0.12, 0.04, and 0.02 kg N2O-N ha-1 yr-1 respectively. The weighted-average annual fluxes for the medium- to fine-textured and sandy-textured areas were 1.31 and 0.04.
Download or read book The Role of Negative Emission Technologies in Addressing Our Climate Goals written by Jennifer Wilcox and published by Frontiers Media SA. This book was released on 2020-04-20 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement and Simulation of Nitrous Oxide Fluxes from Perennial Forage Grasses and Annual Crops Amended with Pig Manure and Inorganic Fertilizer written by Mayowa Francis Adelekun and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crop and nutrient management on agricultural soils are essential considerations for mitigating greenhouse gas emissions in our environment. This thesis aimed to simulate and compare nitrous oxide (N2O) fluxes from perennial forage grasses (FPP) and annual crops (ANN) amended with solid pig manure (SPM), liquid pig manure (LPM) and inorganic urea fertilizer (FER). Two field studies were carried out at different sites Carman and Carberry, Manitoba, Canada. At Carman, N2O fluxes were monitored from FPP following its termination and restoration. At the Carberry, N2O fluxes were measured from LPM applied to soil annually at a rate of 56,000 L ha-1, FER applied at the equivalent rate as total available N from the LPM and un-amended control (CON) plots. At Carberry, in 2011 and 2014 when applied manure N was low, emission factor and emission intensity from LPM was one-half of that from FER. At Carman, the result showed that the termination of perennial forage grasses in combination with applied manure leads to increased soil nitrogen content and N2O fluxes. However, when FPP were replanted in 2014, N2O emission from FPP was 30% less than that from ANN treatments. The data from the Carman site were used to evaluate the performance of the DeNitrification-DeComposition (DNDC) model to predict soil moisture and N2O fluxes. The DNDC model output compared well with the field observed values on the ANN (cumulative N2O flux and daily soil moisture Nash-Sutcliffe efficiency (NSE) > 0.7) but not on the FPP (cumulative N2O flux and daily soil moisture NSE
Download or read book Characterization of Nitrous Oxide Emission Sources written by Rebecca Lynn Peer and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 New Zealand Journal of Agricultural Research written by and published by . This book was released on 2007 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Nitrous Oxide Emission Sources written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Healthcare Simulation Research written by Debra Nestel and published by Springer Nature. This book was released on 2019-11-13 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with a detailed orientation to healthcare simulation research, aiming to provide descriptive and illustrative accounts of healthcare simulation research (HSR). Written by leaders in the field, chapter discussions draw on the experiences of the editors and their international network of research colleagues. This seven-section practical guide begins with an introduction to the field by relaying the key components of HSR. Sections two, three, four, and five then cover various topics relating to research literature, methods for data integration, and qualitative and quantitative approaches. Finally, the book closes with discussions of professional practices in HSR, as well as helpful tips and case studies.Healthcare Simulation Research: A Practical Guide is an indispensable reference for scholars, medical professionals and anyone interested in undertaking HSR.
Download or read book Computational and Experimental Approaches Related to Nitrous Oxide Emissions and Economic Analysis of Private and Social Returns from Maize Fertilization written by Ivy Yin Sean Tan and published by . This book was released on 2007 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the process complexities in the soil-plant-atmosphere system, modeling of N2O losses was challenging, especially for short-term periods. The incorporation of the biological aspects of the denitrification process is important to capture the dynamics involved in the production of N 2O fluxes.
Download or read book Handbook of Soil Sciences written by Pan Ming Huang and published by CRC Press. This book was released on 2011-11-17 with total page 1427 pages. Available in PDF, EPUB and Kindle. Book excerpt: An evolving, living organic/inorganic covering, soil is in dynamic equilibrium with the atmosphere above, the biosphere within, and the geology below. It acts as an anchor for roots, a purveyor of water and nutrients, a residence for a vast community of microorganisms and animals, a sanitizer of the environment, and a source of raw materials for co
Download or read book Greenhouse Gas Emissions written by Narasinha Shurpali and published by Springer. This book was released on 2018-10-31 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the exchange of greenhouse gases in various ecosystems, biomes and climatic zones, and discusses the measurement, modelling and processes involved in these exchange dynamics. It reflects the growing body of knowledge on the characterization, feedback processes and interaction of greenhouse gases with ecosystems and the impact of human activities. Offering a compilation of selected case studies prepared by international researchers working in the field, it represents a valuable resource for researchers and students alike.
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 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.
