Download or read book The Isotopic Signature of Nitrous Oxide Emitted from Agricultural Soils Measured by FTIR Spectroscopy written by Stephen Parkes and published by . This book was released on 2008 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Nitrous Oxide Emissions from Agriculture in a Changing Global Environment written by Charlotte Decock and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Agricultural soils encompass one of the major sources of anthropogenic nitrous oxide (N2O), a potent greenhouse gas and stratospheric ozone depleting substance. Therefore, accurate prediction of N2O emissions from soils and development of effective mitigation strategies are pertinent. However, the scientific understanding of mechanisms underlying N2O emissions is limited, in part, by the lack of suitable methods to assess sources of N2O, especially under field conditions and in undisturbed soil cores. In this dissertation, two ecological applications of source-partitioning N2O were considered: (1) the feedback of N2O emissions to elevated atmospheric CO2 and tropospheric O3 and (2) mechanisms underlying N2O emissions during a simulated rainfall event in a tomato cropping system in California. Furthermore, four methods were evaluated for their utility in source-partitioning N2O with minimal disturbance of the system: (1) tracing of added 15N enriched NH4 and/or NO3− to N2O, (2) use of natural abundance 15N of N2O and its precursors, (3) measuring the intramolecular distribution of 15N in N2O, expressed as site preference (SP), and (4) determining relationships between natural abundance 18O and 15N. Method comparisons elucidated that the use of isotope models that include all natural abundance isotopes of N2O and its precursors and uncertainty deductions for isotope fractionation factors to estimate N transformation rates and sources of N2O during peak N2O emissions is the most promising approach to improve our understanding of mechanisms underlying N2O emissions with minimal sampling-associated disturbance of the system. Various approaches to study sources of N2O and N-cycling suggested that elevated CO2 and O3 will unlikely cause a feedback on global climate change through altered N2O emissions in soybean agroecosystems in the Midwestern USA. Furthermore, elevated CO2 decelerated, whereas elevated O3 accelerated N-cycling if integrated over longer time scales. In a California tomato cropping system, N2O reduction to N2 decreased progressively as soil dried out following wetting up. Overall, this dissertation illustrates the added benefit of studying mechanisms underlying N2O emissions in addition to field N2O fluxes per se and encourages further research to source-partition N2O emissions and its needed methodology to understand N2O responses of agroecosystems in a changing global environment.

Download or read book Update of Emission Factors for Nitrous Oxide from Agricultural Soils on the Basis of Measurements in the Netherlands written by P.J. Kuikman and published by . This book was released on 2006 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Update of Emission Factors for Nitrous Oxide from Agricultural Soils on the Basis of Measurements in the Netherlands written by and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emissions of nitrous oxide (N2O) in the Netherlands are reported to the UNFCCC on the basis of a country specific methodology. In this study we have identified and analysed the values for emission factors in measurement from in the Netherlands in the period 1993 – 2003. The overall averaged emission factor extracted from over 86 series of one year measurements on nitrous oxide emission from agricultural fields in the Netherlands is 1.1% and a weighed average for soil types is 1.01%. The average for mineral soils is 0.88%. The calculated emission factors are lower than the value suggested by the IPCC for EF1 for fertilizer and animal manure of 1.25%. We recommend to use a value of 1.0% for EF1 and to use corrections of EF1 in reporting the use of fertilizers without nitrate (0.5%), for subsurface application of manure (1.5%) and for fertilizer, manure and urine on organic soils (2.0%)

Download or read book Estimating Regional Nitrous Oxide Emissions Using Isotopic Ratio Observations and a Bayesian Inverse Framework written by Michael James McClellan and published by . This book was released on 2018 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric nitrous oxide (N2O) significantly impacts Earth's climate due to its dual role as an inert potent greenhouse gas in the troposphere and as a reactive source of ozone-destroying nitrogen oxides in the stratosphere. Global atmospheric concentrations of N2O, produced by natural and anthropogenic processes, continue to rise due to increases in emissions linked to human activity. The understanding of the impact of this gas is incomplete as there remain significant uncertainties in its global budget. The experiment described in this thesis, in which a global chemical transport model (MOZART-4), a fine-scale regional Lagrangian model (NAME), and new high-frequency atmospheric observations are combined, shows that uncertainty in N2O emissions estimates can be reduced in areas with continuous monitoring of N2O mole fraction and site-specific isotopic ratios. Due to unique heavy-atom (15N and 18O) isotopic substitutions made by different N2O sources, the measurement of N2O isotopic ratios in ambient air can help identify the distribution and magnitude of distinct sources. The new Stheno-TILDAS continuous wave laser spectroscopy instrument developed at MIT, recently installed at the Mace Head Atmospheric Research Station in western Ireland, can produce high-frequency timelines of atmospheric N2O isotopic ratios that can be compared to contemporaneous trends in correlative trace gas mole fractions and NAME-based statistical distributions of the origin of air sampled at the station. This combination leads to apportionment of the relative contribution from five major N2O sectors in the European region (agriculture, oceans, natural soils, industry, and biomass burning) plus well-mixed air transported from long distances to the atmospheric N2O measured at Mace Head. Bayesian inverse modeling methods that compare N2O mole fraction and isotopic ratio observations at Mace Head and at Diibendorf, Switzerland to simulated conditions produced using NAME and MOZART-4 lead to an optimized set of source-specific N2O emissions estimates in the NAME Europe domain. Notably, this inverse modeling experiment leads to a significant decrease in uncertainty in summertime emissions for the four largest sectors in Europe, and shows that industrial and agricultural N2O emissions in Europe are underestimated in inventories such as EDGAR v4.3.2. This experiment sets up future work that will be able to help constrain global estimates of N2O emissions once additional isotopic observations are made in other global locations and integrated into the NAME-MOZART inverse modeling framework described in this thesis.

Download or read book Stable Isotopes in Nitrous Oxide Emitted from Tropical Rain Forest Soils and Agricultural Fields written by Tibisay Josefina Pérez and published by . This book was released on 1999 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nitrous Oxide Emission from Agricultural Soils Experimental Approach and Simulation written by Daan Beheydt and published by . This book was released on 2006 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nitrous Oxide Emission from Agricultural Soils written by G.L. Velthof and published by . This book was released on 2018 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Properties of Organic Amendments Influence Nitrous Oxide Emissions from Agricultural Soils written by Anaïs Charles and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Prediction of organic amendment's (OA) potential to emit soil nitrous oxide (POA-N2O) is difficult because of the variable composition of OAs and of complex interactions with soil properties and environmental conditions. The objectives of this thesis were (1) to conduct a meta-analysis of in-field N2O emissions following OA application to agricultural soils to assess the global emission factor (EF) for all organic sources (EForg) and its modulation by environmental and management-related factors; (2) to determine how experimental conditions affect the POA-N2O and select optimal conditions for laboratory-based assessment; (3) to measure the immediate (P1), short- (P2) and medium-term (P3) POA-N2O with the selected laboratory-based incubation method and then, relate P1, P2, and P3 to the physico-chemical characteristics of more than 131 OAs. The meta-analysis conducted on 256 EFs from 43 sites in 12 countries yielded an EForg equal to 0.57 ± 0.30%, which is lower than the IPCC default EF of 1% for synthetic fertilizer (SF). Three groups of OAs with similar EFs were identified: the high-risk group including animal manures, waste waters and biosolids (1.09 ± 0.17%); the medium-risk group including composts with fertilizers and crop residues with fertilizers (0.46 ± 0.22%); and the low-risk group including composts, crop residues, paper mill sludge and pellets (0.25 ± 0.20%). The EF was modulated by the C/N ratio of the OA, soil properties and precipitation. The EFs were on average 2.8 times greater in fine-textured soils than coarse-textured soils. The comparative incubation study showed that O2-limited conditions in headspace of a sealed-jar system increased the magnitude of N2O fluxes by 1.1 to 2.3-fold compared to open-jar systems. Intermittent aerations of a sealed-jar system relying on repeated measurement periods was then selected to assess P1 (48h), P2 (2nd wk), and P3 (3rd wk). In O2-limited conditions created in a Kamouraska clay soil, maximum P1 was reached for crop residues (CR) with C/N ratio

Download or read book Method to Estimate Direct Nitrous Oxide Emissions from Agricultural Soils written by A. F. Bouwman and published by . This book was released on 1994 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Physical Properties and Nitrous Oxide Emission from Agricultural Soils written by Natalya P. Buchkina and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil Physical Properties and Nitrous Oxide Emission from Agricultural Soils.

Download or read book Nitrous Oxide Emissions from Arable Soils written by and published by . This book was released on 2014 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the main anthropic sources of nitrous oxide (N2O) emissions, being an important greenhouse gas (GHG), is arable soil. With respect to the increasing world population an enhanced agricultural production with large- scale impacts on the nitrogen (N) cycle is most likely. Anyway, not all N flows and transformations in soils are yet fully understood, in particular denitrification as one of the key processes. Denitrification transforms nitrate (NO3-) via nitrite and nitric oxide to N2O and finally into dinitrogen (N2) and both production and...

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2726 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 Measurements of N2O Isotopologues 15 N 14 NO 14 N 15 NO and N2 18 O written by Sunyoung Park and published by . This book was released on 2005 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Carbon Isotopic Tracers in Investigating Soil Carbon Sequestration and Stabilization in Agroecosystems written by International Atomic Energy Agency and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This publication provides an overview of conventional and isotopic methods available for measuring and modelling soil carbon dynamics. It includes information on the use of carbon isotopes in soil and plant research, including both theoretical and practical aspects of nuclear and radioisotope tracer techniques for in situ glasshouse and field labelling techniques to assess soil organic carbon turnover and sequestration, and provides up-to-date information on topics related to soil carbon sequestration and stabilization in agroecosystems. With its focus on practical application of radiotracer and stable isotope tracer techniques, it will be particularly useful for university and national research scientists working to improve soil organic matter management and conservation in agricultural systems."--Publisher's description.

Download or read book Emission and sorption of the greenhouse gas nitrous oxide by agricultural soils and natural wetlands Final report written by K A. Smith and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: