Littérature scientifique sur le sujet « Soil gases »
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Articles de revues sur le sujet "Soil gases"
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Maček, Irena, Damijana Kastelec et Dominik Vodnik. « Root colonization with arbuscular mycorrhizal fungi and glomalin-related soil protein (GRSP) concentration in hypoxic soils in natural CO2 springs ». Agricultural and Food Science 21, no 1 (12 mars 2012) : 62–71. http://dx.doi.org/10.23986/afsci.5006.
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Changed ratios of soil gases that lead to hypoxia are most often present in waterlogged soils, but can also appear in soils not saturated with water. In natural CO2 springs (mofettes), gases in soil air differ from those in typical soils. In this study, plant roots from the mofette area Stavešinci (Slovenia) were sampled in a spatial scale and investigated for AM fungal colonization. AM fungi were found in roots from areas with high geological CO2 concentration, however mycorrhizal intensity was relatively low and no correlation between AM fungal colonization and soil pattern of CO2/O2 concentrations (up to 37% CO2) was found. The relatively high abundance of arbuscules in root cortex indicated existence of functional symbiosis at much higher CO2 concentrations than normally found in soils. In addition, concentration of two different glomalin-related soil protein fractions – EE-GRSP and TG-GRSP – was measured. No significant correlation between any of the fractions and soil gases was found, however the concentration of both fractions was significantly higher in the upper 0–5 cm, compared to the 5–10 cm layer of the soil.
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Gerke, Jörg. « The Central Role of Soil Organic Matter in Soil Fertility and Carbon Storage ». Soil Systems 6, no 2 (31 mars 2022) : 33. http://dx.doi.org/10.3390/soilsystems6020033.
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The aim of the paper is to give an overview on the chemistry of soil organic carbon (SOC) affecting nutrient availability, the emission of greenhouse gases and detoxifying harmful substances in soil. Humic substances represent the stable part of SOC, accounting for between 50 and more than 80% of organically bound carbon in soil. Humic substances strongly affect the soil solution concentration of several plant nutrients and may increase P-, Fe-, and Cu- solubility, thereby increasing their plant availability. Soil organic carbon, mainly humic substances, can detoxify monomeric Al in acid soils, can strongly bind toxic heavy metals, making them unavailable to the plant roots, and may strongly bind a vast variety of harmful organic pollutants. Increasing SOC is an important goal in agriculture. The inclusion of mixtures of semi-perennial plant species and cultivars may strongly increase SOC and humic substance content in soils. To increase SOC, farmyard manure and its rotted or composted forms are superior compared to the separate application of straw and slurry to soil. The storage of carbon, mainly in organic form, in soils is very important in the context of the emission of greenhouse gases. Worldwide, soils release about 10 times more greenhouse gases compared to fossil fuel combustion. Small increments in SOC worldwide will strongly affect the concentration of atmospheric CO2. The public discussion on soil fertility and greenhouse gas emissionshas been politically controlled in a way that leaves the important and positive contribution of soil organic carbon and mainly humic substances partly misinterpreted and partly underestimated.
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Clough, T. J., R. R. Sherlock, K. C. Cameron, R. J. Stevens, R. J. Laughlin et C. Müller. « Resolution of the 15N balance enigma ? » Soil Research 39, no 6 (2001) : 1419. http://dx.doi.org/10.1071/sr00092.
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The enigma of soil nitrogen balance sheets has been discussed for over 40 years. Many reasons have been considered for the incomplete recovery of 15N applied to soils, including sampling uncertainty, gaseous N losses from plants, and entrapment of soil gases. The entrapment of soil gases has been well documented for rice paddy and marshy soils but little or no work appears to have been done to determine entrapment in drained pasture soils. In this study 15N-labelled nitrate was applied to a soil core in a gas-tight glovebox. Water was applied, inducing drainage, which was immediately collected. Dinitrogen and N2O were determined in the flux through the soil surface, and in the gases released into the glovebox as a result of irrigation or physical destruction of the core. Other components of the N balance were also measured, including soil inorganic-N and organic-N. Quantitative recovery of the applied 15N was achieved when the experiment was terminated 484 h after the 15N-labelled material was applied. Nearly 23% of the 15N was recovered in the glovebox atmosphere as N2 and N2O due to diffusion from the base of the soil core, convective flow after irrigation, and destructive soil sampling. This 15N would normally be unaccounted for using the sampling methodology typically employed in 15N recovery experiments.
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Werner, S. F., C. T. Driscoll, P. M. Groffman et J. B. Yavitt. « Landscape patterns of soil oxygen and atmospheric greenhouse gases in a northern hardwood forest landscape ». Biogeosciences Discussions 8, no 6 (8 novembre 2011) : 10859–93. http://dx.doi.org/10.5194/bgd-8-10859-2011.
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Abstract. The production and consumption of the greenhouse gases, carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4), are controlled by redox reactions in soils. Together with oxygen (O2), seasonal and spatial dynamics of these atmospheric gases can serve as robust indicators of soil redox status, respiration rates, and nitrogen cycling. We examined landscape patterns of soil oxygen and greenhouse gas dynamics in Watershed 3 at the Hubbard Brook Experimental Forest, NH, USA. We analyzed depth profiles of soil O2, CO2, N2O, and CH4 approximately bimonthly for one year. Soil gas depth profiles were obtained from several different soil types encompassing a range of topographic positions, drainage classes, and organic matter content. Soil O2 was a good predictor of greenhouse gas concentrations. Unsaturated soils always had O2 concentrations >18 %, while saturated soils had O2 ranging from 0 to 18 %. For unsaturated soils, changes in CO2 were nearly stoichiometric with O2. High concentrations of CH4 (>10 μL L−1) were typically associated with saturated soils; CH4 was typically below atmospheric concentrations (<1.8 μL L−1) in unsaturated soils. High concentrations of N2O (>5000 nL L−1) were found only in well-aerated soils after summer rainfall events and in marginally-anoxic soils; N2O was consumed (<200 nL L−1) under anoxic conditions. The production and consumption of greenhouse gases were linked to functionally distinct biogeochemical zones of variable redox conditions (hotspots), which exhibit dynamic temporal patterns of redox fluctuations (hot moments). These soil redox hot phenomena were temporally driven by climate and spatially organized by soil type (reflective of topographic position) further constrained by subsurface hydrology.
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Zhu, Xiao-cong, Dong-rui Di, Ming-guo Ma et Wei-yu Shi. « Stable Isotopes in Greenhouse Gases from Soil : A Review of Theory and Application ». Atmosphere 10, no 7 (6 juillet 2019) : 377. http://dx.doi.org/10.3390/atmos10070377.
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Greenhouse gases emitted from soil play a crucial role in the atmospheric environment and global climate change. The theory and technique of detecting stable isotopes in the atmosphere has been widely used to an investigate greenhouse gases from soil. In this paper, we review the current literature on greenhouse gases emitted from soil, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). We attempt to synthesize recent advances in the theory and application of stable isotopes in greenhouse gases from soil and discuss future research needs and directions.
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Sysalová, Jiřina, Jan Kučera, Barbora Drtinová, Rostislav Červenka, Ondřej Zvěřina, Josef Komárek et Jan Kameník. « Mercury species in formerly contaminated soils and released soil gases ». Science of The Total Environment 584-585 (avril 2017) : 1032–39. http://dx.doi.org/10.1016/j.scitotenv.2017.01.157.
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Hale, Martin. « Mineral deposits and chalcogen gases ». Mineralogical Magazine 57, no 389 (décembre 1993) : 599–606. http://dx.doi.org/10.1180/minmag.1993.057.389.04.
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AbstractSulphide minerals and their analogues yield gases as a result of oxidation reactions. Even where sulphide minerals are in contact with mildly reducing groundwaters, S2- ions pass into solution and their dispersion patterns can be detected in soil as acid-released H2S. In more oxidising conditions, the metastable gases COS and CS2 are generated. Anomalous dispersion patterns of COS have been reported in soils above more than ten sulphide ore deposits, many of them concealed beneath transported exotic overburden. High concentrations of CS2 occur in the soils over several of the same deposits and uniquely reflect others. Anomalies of SO2 over sulphide deposits are confined to arid terrains. Certain anomalous dispersion patterns of arsenic and tellurium in soils are attributed to the generation and migration of unspecified gases from the oxidation of arsenide and telluride minerals.
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Signor, Diana, et Carlos Eduardo Pellegrino Cerri. « Nitrous oxide emissions in agricultural soils : a review ». Pesquisa Agropecuária Tropical 43, no 3 (septembre 2013) : 322–38. http://dx.doi.org/10.1590/s1983-40632013000300014.
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The greenhouse gases concentration in the atmosphere have significantly increased since the beginning of the Industrial Revolution. The most important greenhouse gases are CO2, CH4 and N2O, with CH4 and N2O presenting global warming potentials 25 and 298 times higher than CO2, respectively. Most of the N2O emissions take place in soils and are related with agricultural activities. So, this review article aimed at presenting the mechanisms of N2O formation and emission in agricultural soils, as well as gathering and discussing information on how soil management practices may be used to reduce such emissions. The N2O formation in the soil occurs mainly through nitrification and denitrification processes, which are influenced by soil moisture, temperature, oxygen concentration, amount of available organic carbon and nitrogen and soil C/N ratio. Among these factors, those related to soil could be easily altered by management practices. Therefore, understanding the processes of N2O formation in soils and the factors influencing these emissions is fundamental to develop efficient strategies to reduce N2O emissions in agricultural soils.
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Kim, D. G., R. Vargas, B. Bond-Lamberty et M. R. Turetsky. « Effects of soil rewetting and thawing on soil gas fluxes : a review of current literature and suggestions for future research ». Biogeosciences 9, no 7 (9 juillet 2012) : 2459–83. http://dx.doi.org/10.5194/bg-9-2459-2012.
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Abstract. The rewetting of dry soils and the thawing of frozen soils are short-term, transitional phenomena in terms of hydrology and the thermodynamics of soil systems. The impact of these short-term phenomena on larger scale ecosystem fluxes is increasingly recognized, and a growing number of studies show that these events affect fluxes of soil gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ammonia (NH3) and nitric oxide (NO). Global climate models predict that future climatic change is likely to alter the frequency and intensity of drying-rewetting events and thawing of frozen soils. These future scenarios highlight the importance of understanding how rewetting and thawing will influence dynamics of these soil gases. This study summarizes findings using a new database containing 338 studies conducted from 1956 to 2011, and highlights open research questions. The database revealed conflicting results following rewetting and thawing in various terrestrial ecosystems and among soil gases, ranging from large increases in fluxes to non-significant changes. Studies reporting lower gas fluxes before rewetting tended to find higher post-rewetting fluxes for CO2, N2O and NO; in addition, increases in N2O flux following thawing were greater in warmer climate regions. We discuss possible mechanisms and controls that regulate flux responses, and recommend that a high temporal resolution of flux measurements is critical to capture rapid changes in gas fluxes after these soil perturbations. Finally, we propose that future studies should investigate the interactions between biological (i.e., microbial community and gas production) and physical (i.e., porosity, diffusivity, dissolution) changes in soil gas fluxes, apply techniques to capture rapid changes (i.e., automated measurements), and explore synergistic experimental and modelling approaches.
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Bálint, Ágnes, Sándor Hoffmann, Attila Anton, Tibor Szili-Kovács et György Heltai. « Contribution of Agricultural Field Production to Emission of Greenhouse Gases (Ghg) ». Ecological Chemistry and Engineering S 20, no 2 (1 juin 2013) : 233–45. http://dx.doi.org/10.2478/eces-2013-0016.
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Abstract According to global inventories the agricultural field production contributes in a significant measure to increase of concentration of greenhouse gases (CO2, N2O, CH4) in the atmosphere, however their estimated data of emissions of soil origin differ significantly. Particularly estimates on nitrogen-oxides emissions show a great temporal and spatial variability while their formations in microbial processes are strongly influenced by biogeochemical and physical properties of the soil (eg microbial species, soil texture, soil water, pH, redox-potential and nutrient status) and land use management through the impact of the application of natural and synthetic fertilisers, tillage, irrigation, compaction, planting and harvesting. The different monitoring systems and inventory models were developed mostly from atmospheric chemistry point of view and little comprehensive data exist on the processes related to GHG emissions and their productions in agricultural soils under ecological conditions of Central Europe. This paper presents the new results of a project aimed elaboration of an experimental system suitable for studying relationships between the production and emission of greenhouse gases and plant nutrition supply in agricultural soils under Hungarian ecological conditions. The system was based on a long-term fertilisation field experiment. Mesocosm size pot experiments were conducted with soils originating from differently treated plots. The production of CO2 and N2O was followed during the vegetation period in gas traps built in 20 cm depth. Undisturbed soil columns were prepared from the untreated side parcels of the field experiment and the production of CO2 and N2O was studied at 20, 40 and 60 cm depth. A series of laboratory microcosm experiments were performed to clarify the microbial and environmental effects influencing the gas production in soils. The CO2 and N2O were determined by gas chromatography. The NOx was detected by chemiluminescence method in headspace of microcosms. In the mesocosm and soil columns experiments influence of plant nutrition methods and environmental factors was successfully clarified on seasonal dynamics and depth profile on CO2 and N2O productions. The database developed is suitable for estimating CO2 and N2O emissions from agricultural soils.
Thèses sur le sujet "Soil gases"
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McGinley, Susan. « Measuring Soil Gases ». College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/622349.
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Bottoms, Emily L. « Soil greenhouse gas emissions and soil C dynamics in bioenergy crops ». Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=194783.
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The second generation bioenergy crops Miscanthus x giganteus and short rotation coppice (SRC) willow are the two main bioenergy crops in the UK and have become an integral part of legislation to provide an alternative to fossil fuels and to reduce national greenhouse gas (GHG) emissions. To reach emission targets, it is estimated that approximately 350,000 ha of land could be made available for bioenergy crops by 2020. Despite the promise of these crops, there have been very few field-studies regarding soil GHG (CO2, CH4 and N2O) emissions and many of the published studies are life cycle analyses or modelled fluxes from soils using default values from the IPCC. The first aim of this research was to quantify the in situ soil GHG budget and to establish the drivers of these GHG fluxes for Miscanthus and SRC willow. The second aim of this research was to provide a more in-depth understanding of C cycling under Miscanthus i.e. litter and roots through two field experiments. Overall, the results from this work confirm minimal emissions of CH4 and N2O from soil under Miscanthus and SRC willow. CO2 flux was found to be the major efflux from soils and it was found in Miscanthus, that the majority of this flux was derived from below ground respiration. Litter played an important part in providing nutrients to the soil, which is vital in systems that are not fertilised. Litter also contributed to SOM accumulation on the soil surface and may promote long-term C sequestration. The results from this work combined with other literature would suggest that these second generation crops offer advantages to first generation crops, but more field-based studies are required to say if they can offer the large-scale GHG savings needed to be a viable alternative to fossil fuels.
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Nkongolo, Nsalambi Vakanda. « Quantification of greenhouse gas fluxes from soil in agricultural fields ». Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1474.
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Field studies were conducted at Lincoln University of Missouri (USA) and Hokkaido University (Japan) to: (i) study the relationships between greenhouse gases emissions and soil properties, (ii) assess the influence of agricultural practices on greenhouse gas fluxes and soil properties and (iii) improve the quantification of greenhouse gases from soil in agricultural fields using geospatial technologies. Results showed that besides soil temperature (T), soil thermal properties such as thermal conductivity (K), resistivity (R) and diffusivity (D) and soil pore spaces indices such as the pore tortuosity factor and the relative gas diffusion coefficient (Ds/Do) are controlling factors for greenhouse gases emissions. Soil thermal properties correlated with greenhouse gases emissions when soil temperature could not. The study has found that predicted Ds/Do and correlate with greenhouse gas fluxes even when the air-filled porosity and the total porosity from which they are predicted did not. We have also showed that Ds/Do and can be predicted quickly from routine measurements of soil water and air and existing diffusivity models found in the literature. Agricultural practices do seriously impact greenhouse gases emissions as showed by the effect of mechanized tillage operations on soil physical properties and greenhouse gas fluxes in a corn and soybean fields. In fact, our results showed that tractor compaction increased soil resistance to penetration, water, bulk density and pore tortuosity while reducing air-filled porosity, total pore space and the soil gas diffusion coefficient. Changes in soil properties resulted in increased CO2, NO and N2O emissions. Finally, our results also confirmed that greenhouse gas fluxes vary tremendously in space and time. As estimates of greenhouse gas emissions are influenced by the data processing approach, differences between the different calculation approaches leads to uncertainty. Thus, techniques for developing better estimates are needed. We have showed that Geographic Information Systems (GIS), Global Positioning System (GPS), computer mapping and geo-statistics are technologies that can be used to better understand systems containing large amounts of spatial and temporal variability. Our GIS-based approach for quantifying CO2, CH4 and N2O fluxes from soil in agricultural fields showed that estimating (extrapolating) total greenhouse gas fluxes using the “standard” approach – multiplying the average flux value by the total field area – results in biased predictions of field total greenhouse gases emissions. In contrast, the GIS-based approach we developed produces an interpolated map portraying the spatial distribution of gas fluxes across the field from point measurements and later process the interpolated map produced to determine flux zones. Furthermore, processing, classification and modeling enables the computation of field total fluxes as the sum of fluxes in different zones, therefore taking into account the spatial variability of greenhouse gas fluxes.
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Goeschel, Tyler. « Quantifying Soil Greenhouse Gas Emissions And Soil Carbon Storage To Determine Best Management Practices In Agroecosystems ». ScholarWorks @ UVM, 2016. http://scholarworks.uvm.edu/graddis/644.
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Intensive agriculture, coupled with an increase in nitrogen fertilizer use, has contributed significantly to the elevation of atmospheric greenhouse gases (GHGs), including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Rising GHG emissions usually mean a decrease in soil carbon. Currently, soil C is twice that of all standing crop biomass, making it an extremely important player in the C cycle. Fortunately, agricultural management practices have the potential to reduce agricultural GHG emissions whilst increasing soil C. Management practices that impact GHG emissions and soil C include various tillage practices, different N fertilization amounts and treatments (synthetic N, cattle manure, or a combination of both), the use of cover crops, aeration, and water levels. Employing agricultural best management practices (BMPs) can assist in the mitigation and sequestration of CO2, N2O and soil C. Measuring soil carbon storage and GHG emissions and using them as metrics to evaluate BMPs are vital in understanding agriculture's role in climate change. The objective of this research was to quantify soil carbon and CO2 and N2O emissions in agroecosystems (dairy, crop, and meat producing farms) under differing management practices.
Three farms were selected for intensive GHG emissions sampling: Shelburne Farm in Shelburne, VT, a dairy in North Williston, VT, and Borderview Farm in Alburgh, VT. At each site, I collected data on GHG (CO2 and N2O) emissions and soil carbon and nitrogen storage to a depth of 1 meter. Soil emissions of CO2 and N2O were taken once every two weeks (on average) from June 2015 through November, 2015 using static flux chambers and a model 1412 Infrared Photoacoustic Spectroscopy (PAS) gas analyzer (Innova Air Tech Instruments, Ballerup, Denmark). Fluxes were measured on 17 dates at Shelburne Farms, 13 dates at the Williston site, and 13 dates in the MINT trial. Gas samples were taken at fixed intervals over a 10-14 minute time frame, with samples normally taken every one or two minutes. I also measured soil carbon to a depth of 1m in six BMPs at Borderview Farm.
Overall, I found that manure injection increased N2O and CO2 emissions, but decreased soil C storage at depth. Tillage had little to no impact on N2O emissions, except at Shelburne Farms, where aeration tillage decreased N2O emissions (marginally significant, P < 0.1). No-till did, however, decrease CO2 emissions relative to other conservation tillage practices (strip and vertical tillage) but we were unable to detect a significant change in soil C due to tillage practices. At Borderview farm, N2O emissions increased with soil NO3 and soil moisture, while CO2 emissions increased with soil temperature and nitrate. At Williston, CO2 emissions only increased with temperature; at Shelburne CO2 emissions increased with nitrate. N2O fluxes at Shelburne and Williston were not associated with any of the measured covariates.
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Miller, Gemma A. « The impacts of agricultural land management on soil carbon stabilisation ». Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/25437.
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Soil is the largest terrestrial carbon (C) store, containing an estimated ~1500 Gt C in the upper 1 m of soil. The long term storage of soil organic C (SOC) requires that it is somehow protected from microbial decomposition – or ‘stabilised’ – in the soil matrix. Three mechanisms are commonly identified as factors controlling the stability of SOM: chemical recalcitrance, physical protection in aggregates and adsorption to soil mineral surfaces. The stability of SOC in the soil matrix can be influenced by management practices and changes in soil structure can lead to loss of SOC and increases in greenhouse gas (GHG) emissions. It is, therefore, important to understand the impact that management practices have on SOC stability and to manage soils in such a way as to optimise the volume of SOC which is locked away for climatically significant periods of time. Two methods are generally used to estimate SOC stability: indirectly by measuring CO2 fluxes as a proxy for SOC microbial decomposition, or directly through physical fractionation of soil in to pools with different levels of physical and chemical protection. Both methods were employed in this thesis. Arable and grassland soils which represent the range of soil textures and climatic conditions of the main agricultural areas in the UK were incubated at two different moisture contents and with or without inorganic fertiliser application and GHG fluxes from them were monitored. Soil texture, mineral N concentration and soil C concentration were found to be the most important measured variables controlling GHG fluxes of the UK agricultural soils in this study. The results were generally in support of those found in the literature for a wide range of soils, conditions and locations; however, N2O emissions from the two Scottish soils appeared to be more sensitive to inorganic N fertilisation at the higher moisture content than the other soils, with the N2O emissions being exceptionally high in comparison. Although incubations of whole soils are useful in measuring the impacts of soil management practices on GHG emissions under controlled conditions they do not identify the mechanisms controlling the stability of SOC. Dividing SOM into functional pools may identify different C stabilising mechanisms and improves soil C models. A large number of operationally defined separation methods have been used to fractionate SOM into biologically meaningful pools of different stability. Direct comparisons of different fractionation methods using radiocarbon (14C) dating and spectroscopic analyses has not previously been undertaken. Average 14C ages and chemical composition of SOM fractions isolated from a grassland soil using three published and frequently applied fractionation methods were compared. (1) a density separation technique isolating three fractions (2) a combined physical and chemical separation isolating five fractions (3) a hot-water extraction method isolating two fractions. The fractions from Method 1 had the most distinct average 14C ages, the fractions from Method 2 fell into two age groups, and both Method 3 fractions were dominated by modern C. The average 14C ages of the labile fractions from Method 1 and 2 were higher than the mineral bound fractions, although they made up a relatively small proportion of the total SOC. This was a surprising result, and spectroscopic analysis confirmed that these fractions had greater relative contents of aliphatic and aromatic characteristics than the mineral bound fractions. The presence of black C in a whole soil sample and one of the labile fractions from Method 2 was confirmed by hydrogen pyrolysis. The availability of archived soils from an abandoned long term tillage treatment experiment and the ability to relocate the plots provided a unique opportunity to assess the resilience of SOC stocks to land management practices several years after the conversion from arable to grassland. SOC stability was assessed by soil fractionation of archived (1975) and freshly collected (2014) soil samples. The mass corrected SOC stocks from the four different treatments (deep plough, shallow plough, chisel plough and direct drill) were higher in 2014 than 1975 across the whole profile (0 – 36 cm). Reductions were observed at some depths for some treatments but the overall effect was an evening out of SOC stocks across all plots. The fractionations (using Method 2), revealed that there was a relative increase in the mass of the sand and aggregate fraction but a decrease in the relative proportion of SOC stored in this fraction (physically protected). There was also a significant increase in the C:N ratio of the silt and clay fraction (chemical adsorption). This suggests that reduced disturbance of agricultural soils leads to preferential physical stabilisation of fresh SOM but also increased adsorption of older material to mineral surfaces. The labile fractions were sensitive to land-use change in all tillage treatment plots, but were more sensitive in the low impact tillage plots (chisel plough and direct drill) than the inversion tillage plots (deep plough and shallow plough). It is well established that tillage disrupts aggregation. However, a direct measurement of the level of SOM physical protection in the soil matrix due to aggregation has not previously been undertaken. The soil was fractionated using Method 1 (fractions with distinctly different 14C ages) and isolated soil fractions were incubated separately, recombined and mixed in to whole soil at three different temperatures. The C respiration rate of the isolated intra-aggregate fraction was generally consistently as high as the whole soil. This supports the theory that there is a labile component of soil which is protected from decomposition by physical protection within aggregates. Therefore, the lack of any priming effect with the addition of labile fractions to the whole soil, and indeed the suppression of emissions relative to the whole soil, was unusual. Fractions and whole soils incubated at 25 and 35 °C had a wider range of Q10 (temperature sensitivity) values than those incubated at 15 and 25 °C, however, median values were surprisingly similar (range from 0.7 to 1.9). Overall, the results from this thesis highlight the importance of the soil structure in stabilising C. Disrupting aggregates leaves a proportion of otherwise stable C susceptible to loss through microbial decomposition, particularly when the entire soil matrix is disrupted. It also provided some unexpected results which warrant future investigation; in particular, further direct measurement of physical stabilisation of SOM in soils of different type, from different climates and different land uses would be useful.
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Parmar, Kim. « Impacts of land use change to short rotation forestry for bioenergy on soil greenhouse gas emissions and soil carbon ». Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/16159.
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Short Rotation Forestry (SRF) for bioenergy could be used to meet biomass requirements and contribute to achieving renewable energy targets. As an important source of biomass it is important to gain an understanding of the implications of large-scale application of SRF on the soil-atmosphere greenhouse gas (GHG) exchange. This study examined the effects of land use change (LUC) from grassland to SRF on soil fluxes of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2), and the important drivers in action. Examining soils from a range of sites across the UK, CO2 emission potentials were reduced under SRF with differences between coniferous and broadleaved transitions; these changes were found to be related to changes in soil pH and microbial biomass. However, there were limited effects of SRF tree species type on CH4 and N2O fluxes. A detailed study at an experimental SRF site over 16 months demonstrated a reduction in CH4 and net CO2 emissions from soils under SRF and revealed intriguing temporal dynamics of N2O under Sitka spruce and common alder. A significant proportion of the variation in soil N2O fluxes was attributed to differences between tree species, water table depth, spatial effects, and their interactions. The effects of microtopography (ridges, troughs, flats), and its interactions with water table depth on soil GHG fluxes under different tree species was tested using mesocosm cores collected in the field. Microtopography did not significantly affect soil GHG fluxes but trends suggested that considering this spatial factor in sampling regimes could be important. N2O fluxes from Sitka spruce soils did not respond to water table depth manipulation in the laboratory suggesting that they may also be determined by tree-driven nitrogen (N) availability, with other research showing N deposition to be higher in coniferous plantations. An N addition experiment lead to increased N2O emissions with greatest relative response in the Sitka spruce soils. Overall, LUC from rough grassland to SRF resulted in a reduction in soil CH4 emissions, increased N2O emissions and a reduction or no change in net CO2 emissions. These changes in emissions were influenced both directly and indirectly by tree species type with Sitka spruce having the greatest effect on N2O in particular, thus highlighting the importance of considering soil N2O emissions in any life cycle analysis or GHG budgets of LUC to SRF for bioenergy. This research can help inform decisions around SRF tree species selection in future large-scale bioenergy planting.
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Bicalho, Elton da Silva. « Soil greenhouse gas emissions and their relations to soil attributes in a sugarcane area / ». Jaboticabal, 2016. http://hdl.handle.net/11449/135903.
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Orientador: Newton La Scala JúniorAbstract: The production of the main soil greenhouse gases (GHG: CO2, CH4 and N2O) is influenced by agricultural practices that causes changes in soil phys¬ical, chemical and biological attributes, directly affecting their emission to the atmos¬phere. The aim of this study was to investigate the infield soil CO2 emissions (FCO2) and the soil CO2, CH4 and N2O production potentials (PCO2, PCH4 and PN2O, respec¬tively) in laboratory conditions, and their relationship to soil attributes in a mechanically harvested sugarcane area. The experimental area consisted of a 50 × 50-m radially symmetrical grid containing 133 points spaced at minimum distances of 0.5 m in the center of the sample grid. It was carried out eight evaluations of FCO2, soil temperature and soil moisture over a period of 19 days. Soil physical and chemical attributes were determined by sampling at a depth of 0-10 cm. The quantification of PCO2, PCH4 and PN2O consisted of laboratory incubation and determination of gas concentration by gas chromatography. FCO2 presented an infield average emission value of 1.19 µmol CO2 m−2 s−1, while GHG production in laboratory was 2.34 µg C-CO2 g−1 d−1 and 0.20 ng N-N2O g−1 d−1 for PCO2 and PN2O, respectively. No significant production or oxidation was observed for CH4. The factor analysis showed the formation of two independent processes that explained almost 72% of the total variance observed in the data. The first process was related to the transport of FCO2 and its relation to soil p... (Complete abstract click electronic access below)
Resumo: A produção dos principais gases de efeito estufa (GEE: CO2, CH4 e N2O) é influenciada por práticas agrícolas que causam alterações nos atributos físi¬cos, químicos e biológicos do solo, afetando diretamente sua emissão para a atmos¬fera. O objetivo deste estudo foi investigar a emissão de CO2 do solo (FCO2) em con¬dições de campo e a produção potencial de CO2, CH4 e N2O do solo (PCO2, PCH4 e PN2O, respectivamente) em condições de laboratório, além de suas relações com os atributos do solo em uma área de cana-de-açúcar colhida mecanicamente. A área experimental constituiu-se de um gradeado simétrico radialmente de 50 × 50 m con-tendo 133 pontos espaçados em distâncias mínimas de 0,5 m no centro da malha amostral. Foram conduzidas oito avaliações para FCO2, temperatura e umidade do solo durante um período de 19 dias. Os atributos físicos e químicos do solo foram determinados por meio de amostragem na profundidade de 0-10 cm. A quantificação de PCO2, PCH4 e PN2O consistiu de incubação em laboratório e determinação da con¬centração dos gases por meio de cromatografia gasosa. FCO2 apresentou um valor de emissão média de 1,19 µmol CO2 m−2 s−1, enquanto a produção de GEE em laborató¬rio foi de 2,34 µg C-CO2 g−1 d−1 e 0,20 ng N-N2O g−1 d−1 respectivamente para PCO2 e PN2O. Não foi observada produção ou oxidação significativa de CH4. A análise de fatores mostrou a formação de dois processos independentes que explicaram quase 72% da variância total observada nos dados. O primeiro proce... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor
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Mata, Ricardo Manuel Reis. « Assessment of the environmental impact of yeast waste application to soil : an integrated approach ». Master's thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/12979.
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Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia - ULThe yeast production industry (e.g. distillery, brewing, baking industries) has been growing globally over the last years generating a large amount of sub-products. Laboratory experiments, under controlled conditions, were performed to investigate the impact of yeast waste application to a sandy texture soil. Experimental treatments were: surface application of yeast and decanted-yeast (CMSs and CMSds), surface application of yeast and decantedyeast followed by incorporation in the 0-5 cm soil layer (CMSm and CMSdm), surface application of ammonium nitrate (AN) (not applied in short-term experiment) and a control (soil only) (CTR). The amount of yeast applied was 2 g in the short-term experiment and equivalent to 170 kgN.ha-1 in the long-term experiment. A short-term (38-day period) leaching experiment was performed with 5 weekly irrigation events (5 treatments × 3 replications) to assess N, P, K losses. Results showed that yeast application increased NH4+, PT and KT leaching relative to control while decreased NO3- leaching relative to a high initial content of control, during first irrigation events. Incorporation treatments increased NH4+, NO3- and PT losses earlier. KT losses were higher in surface treatments. A long-term leaching experiment (73-day period) with 6 irrigation events every two weeks was then performed (6 treatments × 4 replicates) to assess N, P losses. A two parallel incubation experiment (6 treatments × 3 replicates) were simultaneously performed to measure GHG emissions (CO2, N2O, CH4) and to assess the N mineralization in each treatment. Results showed that yeast application increased initial NH4+ concentration in leachates and soil relative to control and NO3- increased afterwards. N2O and CO2 increased significantly relative to control on the first days after yeast application. AN treatment emissions were very similar to control but had a small increase of N2O. CH4 emissions were insignificant. The global warming potential (GWP) of yeast and AN were 6× and 2× times higher than control, respectively
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Bradford, Mark Alexander. « The response of methane oxidation to environmental change ». Thesis, University of Exeter, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286477.
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Begum, Khadiza. « Modelling soil organic carbon sequestration and greenhouse gas mitigation potentials in Bangladesh agriculture ». Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=237655.
Texte intégralRésumé :
Soil organic carbon (SOC) is important not only for improving soil quality but also for contributing to climate change mitigation in agriculture. However, net greenhouse gas (GHG) balances, including methane (CH4) and nitrous oxide (N2O), need to be considered, as practices that increase SOC might increase GHG emissions. Sustainable use of soil resources needs to be assessed over long time periods and across spatial scales; biogeochemical models are useful tools to estimate GHG emissions and corresponding mitigation potentials. A process-based, ecosystem model DayCent that simulates soil carbon and nitrogen dynamics from diverse agroecosystems, has been applied to observe SOC sequestration, GHG emissions and yield in a contrasting climatic region UK and Bangladesh agriculture. The study mainly focus on determination of GHG mitigation potentials under improved management practices in rice based cropland Bangladesh. We hypothesized that alternative management would increase SOC and reduce net GHG emissions. As crop yield is the most important variable for Bangladesh, it was includes in the simulations. Since site test simulations under different management using the DayCent model were satisfactory, the model was used to simulate GHG covering 64 districts of Bangladesh, considering climate, soil and SOC content for the period 1996-2015. An integrated management scenario consisting of irrigation, tillage with residue management, reduced mineral nitrogen fertilizer and manure application increased annual SOC stocks, and offset net GHG emissions while maintaining yield. The model outcome suggests that the “4 per mille” target is feasible for Bangladesh. It is also possible to contribute to the GHG reduction target by 2030 set by policy makers.
Livres sur le sujet "Soil gases"
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Lindeen, Carol K. Soil basics. Mankato, Minn : Pebble Books, 2007.
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A, Matson P., et Harriss R. C. 1941-, dir. Biogenic trace gases : Measuring emissions from soil and water. Oxford [England] : Blackwell Science, 1995.
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Gascoyne, Mel. Helium in soil gases in the Whiteshell Research area. Pinawa, Man : AECL, Whiteshell Laboratories, 1995.
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B, Roen John, et Geological Survey (U.S.), dir. Near-surface anomalies associated with faults and gas accumulations in western Pennsylvania. [Reston, Va.?] : U. S. Dept. of the Interior, Geological Survey, 1985.
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B, Roen John, et Geological Survey (U.S.), dir. Near-surface anomalies associated with faults and gas accumulations in western Pennsylvania. [Reston, Va.?] : U. S. Dept. of the Interior, Geological Survey, 1985.
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B, Roen John, et Geological Survey (U.S.), dir. Near-surface anomalies associated with faults and gas accumulations in western Pennsylvania. [Reston, Va.?] : U. S. Dept. of the Interior, Geological Survey, 1985.
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B, Roen John, et Geological Survey (U.S.), dir. Near-surface anomalies associated with faults and gas accumulations in western Pennsylvania. [Reston, Va.?] : U. S. Dept. of the Interior, Geological Survey, 1985.
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European Congress on Biotechnology (9th 1999 Brussels, Belgium). Biotechnology for the environment : Soil remediation. Dordrecht : Kluwer Academic, 2002.
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R, Lal, dir. Soil management and greenhouse effect. Boca Raton : Lewis Publishers, 1995.
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Environment, Alberta Alberta, dir. Specified gas emitters regulation : Soil carbon custom coefficient/protocols guidance document. [Edmonton] : Alberta Environment, 2007.
Trouver le texte intégralChapitres de livres sur le sujet "Soil gases"
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Rettenberger, G., et F. H. Trier. « Retentive Capacity of Incapsulations Regarding Gases ». Dans Contaminated Soil ’90, 1207–8. Dordrecht : Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-011-3270-1_276.
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Hewitt, A. K. J., et S. G. McRae. « The Effects of Gases Emitted From Landfills on Soils and Crops ». Dans Contaminated Soil, 251–53. Dordrecht : Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-5181-5_31.
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Engel, H., et G. Rettenberger. « Experiences with Thermal Disposal of Gases from Contaminated Soil ». Dans Contaminated Soil ’88, 845–48. Dordrecht : Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-2807-7_134.
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Bohn, H. L. « Soil Treatment of Organic Waste Gases ». Dans Soils for Management of Organic Wastes and Waste Waters, 605–18. Madison, WI, USA : American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, 2015. http://dx.doi.org/10.2134/1977.soilsformanagementoforganic.c24.
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Swati, Indu Shekhar Thakur et Arti Mishra. « Rising Greenhouse Gases in the Atmosphere : The Microbes Can Be a Solution—A Review ». Dans Soil Biology, 623–36. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-76863-8_32.
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Conrad, Ralf. « Metabolism of Nitric Oxide in Soil and Soil Microorganisms and Regulation of Flux into the Atmosphere ». Dans Microbiology of Atmospheric Trace Gases, 167–203. Berlin, Heidelberg : Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-61096-7_11.
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Wagner-Riddle, Claudia, et Alfons Weersink. « Net Agricultural Greenhouse Gases ». Dans Sustaining Soil Productivity in Response to Global Climate Change, 169–82. Oxford, UK : Wiley-Blackwell, 2011. http://dx.doi.org/10.1002/9780470960257.ch12.
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Zaman, M., K. Kleineidam, L. Bakken, J. Berendt, C. Bracken, K. Butterbach-Bahl, Z. Cai et al. « Greenhouse Gases from Agriculture ». Dans Measuring Emission of Agricultural Greenhouse Gases and Developing Mitigation Options using Nuclear and Related Techniques, 1–10. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-55396-8_1.
Texte intégralRésumé :
AbstractThe rapidly changing global climate due to increased emission of anthropogenic greenhouse gases (GHGs) is leading to an increased occurrence of extreme weather events such as droughts, floods, and heatwaves. The three major GHGs are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The major natural sources of CO2 include ocean–atmosphere exchange, respiration of animals, soils (microbial respiration) and plants, and volcanic eruption; while the anthropogenic sources include burning of fossil fuel (coal, natural gas, and oil), deforestation, and the cultivation of land that increases the decomposition of soil organic matter and crop and animal residues. Natural sources of CH4 emission include wetlands, termite activities, and oceans. Paddy fields used for rice production, livestock production systems (enteric emission from ruminants), landfills, and the production and use of fossil fuels are the main anthropogenic sources of CH4. Nitrous oxide, in addition to being a major GHG, is also an ozone-depleting gas. N2O is emitted by natural processes from oceans and terrestrial ecosystems. Anthropogenic N2O emissions occur mostly through agricultural and other land-use activities and are associated with the intensification of agricultural and other human activities such as increased use of synthetic fertiliser (119.4 million tonnes of N worldwide in 2019), inefficient use of irrigation water, deposition of animal excreta (urine and dung) from grazing animals, excessive and inefficient application of farm effluents and animal manure to croplands and pastures, and management practices that enhance soil organic N mineralisation and C decomposition. Agriculture could act as a source and a sink of GHGs. Besides direct sources, GHGs also come from various indirect sources, including upstream and downstream emissions in agricultural systems and ammonia (NH3) deposition from fertiliser and animal manure.
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Grantham, Gary, et Melanie K. D. Eddis. « Contamination of Soils by Hazardous Gases : Investigation, Monitoring, Diagnosis and Treatment ». Dans Contaminated Soil ’90, 681–89. Dordrecht : Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-011-3270-1_141.
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Zaman, M., K. Kleineidam, L. Bakken, J. Berendt, C. Bracken, K. Butterbach-Bahl, Z. Cai et al. « Direct and Indirect Effects of Soil Fauna, Fungi and Plants on Greenhouse Gas Fluxes ». Dans Measuring Emission of Agricultural Greenhouse Gases and Developing Mitigation Options using Nuclear and Related Techniques, 151–76. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-55396-8_5.
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AbstractSoils harbour diverse soil faunaand a wide range of soil microorganisms. These fauna and microorganisms directly contribute to soil greenhouse gas (GHG) fluxes via their respiratory and metabolic activities and indirectly by changing the physical, chemical and biological properties of soils through bioturbation, fragmentation and redistribution of plant residues, defecation, soil aggregate formation, herbivory, and grazing on microorganisms and fungi. Based on recent results, the methods and results found in relation to fauna as well as from fungi and plants are presented. The approaches are outlined, and the significance of these hitherto ignored fluxes is discussed.
Actes de conférences sur le sujet "Soil gases"
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Matichenkov, V. « REDUCTION OF GREENHOUSE GASES EMISSION UNDER SILICON FERTILIZER APPLICATION ». Dans Land Degradation and Desertification : Problems of Sustainable Land Management and Adaptation. LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1701.978-5-317-06490-7/165-169.
Texte intégralRésumé :
The application of Si fertilizer is example of “green” low emission technology. The using of biochemical active forms of Si allow to reduce the greenhouse gases emission from cultivated soils, increase the carbon content in soil matrix, increase cultivated plants resistance to abiotic stresses and increase the quality and quantity of crop. Our investigations have sowed the presence of monosilicic acid in soil provide the reduction of N2O emission in 1.6-2 times because the denitrification process in such soil are complete with final formation of N2. The application of Si fertilizer increased the rice crop on 5-55% with carbon sequestration up to 15 t/ha of CO2 during one season.
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Jadhav, R. S., R. S. Amano, J. Jatkar et R. J. Lind. « Simulation Study of Heated Soil Vapor ». Dans ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47054.
Texte intégralRésumé :
Soil remediation using Heated Soil Vapor Extraction System has gained a significant attention in recent years. The process, developed by Advanced Remedial Technology**, comprises of a heat well (heat source) and an extraction well (sink). These wells are pipes, which are implanted in the soil. Heating is accomplished by circulating hot oil through the heat exchange units in heat well. The extraction well has a blower, which sucks the air, and other volatile gases that are evaporated due to heating. An analysis aimed at improving the predictability of the process using numerical tools has been carried out. The key parameters in the process can be identified as the distance between the wells, the temperature that has to be maintained in the heat well and the time required vaporizing the gases and taking them off the soil. These parameters are strongly dependent on the properties of the soil and properties of the chemical pollutants present in the soil. An attempt has been made to model the real process of heating the soil and vaporizing of chemicals in the soil. Such comprehensive analysis will be very much helpful in predicting the different parameters as discussed above and result in increase in effectiveness and efficiency of the process.
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Roy, T., R. S. Amano et J. Jatkar. « A Transient Simulation of Heated Soil Vapor Extraction System ». Dans ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56425.
Texte intégralRésumé :
Soil remediation process by heated soil vapor extraction system has drawn considerably attention for the last few years. The areas around chemical companies or waste disposal sites have been seriously contaminated from the chemicals and other polluting materials that are disposed off. Our present study is concentrated on modeling one transient Heated Soil Vapor Extraction System and predicting the time required for effective remediation. The process developed by Advanced Remedial Technology, consists of a heating source pipe and the extraction well embedded in the soil. The number of heat source pipes and the extraction wells depends on the type of soil, the type of pollutants, moisture content of the soil and the size of the area to be cleaned. The heat source heats the soil, which is transported in the interior part of the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then driven out of the soil by the extraction well. The extraction well consists of the blower which would suck the vaporized gases out of the system. A three-dimensional meshed geometry was developed using gambit. Different boundary conditions were used for heating and suction well and for other boundaries. Concentrations of different chemicals were collected from the actual site and this data was used as an initial condition. The analysis uses the species transport and discrete phase modeling to predict the time required to clean the soil under specific conditions. This analysis could be used for predicting the changes of chemical concentrations in the soil during the remediation process. This will give us more insight to the physical phenomena and serve as a numerical predictive tool for more efficient process.
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MIELCAREK, Paulina, Wojciech RZEŹNIK et Zbyszek ZBYTEK. « THE EFFECT OF SOLID MANURE INCORPORATION INTO THE SOIL ON THE EMISSION OF GASES AND ODOURS ». Dans RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.098.
Texte intégralRésumé :
The aim of the study was to determine the level of emission reduction of selected harmful gases and odours following immediate manure incorporation into soil, using the prototype manure applicator. The research was carried out at the Experimental Station of the National Research Institute of Animal Production, in September 2016. Two experimental fields size 6 x 100 m were located on corn stubble in the distance of 40 m. In field A, the solid manure was incorporated into the soil using the prototype manure applicator. In field B, manure application was made by manure spreader. The prototype manure applicator was designed and made by Industrial Institute of Agricultural Engineering. The concentration of harmful gases (NH3, CO2, CH4, N2O) and odours was measured during the study. Measurements were made in the following periods: immediately after application and 2, 4, 6, 10 and 14 hours after application. The concentration of studied gases was measured immediately after sampling by the photoacoustic spectrometer (Multi Gas Monitor Innova 1312). The odours concentration was determined within 30 hours after air sampling by dynamic olfactometry using the TO 8 olfactometer. The solid manure incorporation reduced NH3 emissions by an average of 66%. For the other studied gases the differences in concentration were too small or this concentration was similar to concentration of these gases in surrounding air. The incorporation of solid manure limited also odour emissions. The level reduction decreased with time and amounted to an average of 25%.
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Siltumens, Kristaps, Sindija Liepa, Inga Grinfelde, Diana Ruska et Dzidra Kreismane. « IMPACTS OF GRASSLAND PLANT COMPOSITION ON GHG EMISSIONS IN CLAY SOIL ». Dans 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/4.1/s19.42.
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One of the largest producers of GHG emissions in agriculture is the dairy and meat livestock sector. Grassland is the main feed base for dairy and meat cattle. Managed grasslands can become a major contributor to and leverage of GHG gas exchange. High quality information with studies on the flow of the three main GHG gases and concentration linked to different management strategies is important for the development of good management practices, as well as for the development of climateresilient landscapes and the reduction of climate impacts on agricultural lands. The aim of this study is to identify the impacts of the composition of grassland plants on GHG emissions on clay soils, as well as to clarify the impact of fertiliser on these gases. The pilot research used a field of 45 m wide and 34 m long, which was divided into 64 squares. The squares of field were divided into 2 parts � fertilised and non-fertilised, creating four repetitions. Each of the groups consisted of eight fields, each of which was filled with herbaceous grasslands in accordance with Latvian climate conditions. Measurements of GHG emissions were carried out weekly from 5 June to 16 September. N2O, CH4, CO2, gases were measured with CRDS gas measurement device PICARO G2508. Each field was measured for four minutes, a minute pause was withheld between the measurements, for measurement accuracy. Grass composition has an impact on GHG emissions, as the results have revealed a significant difference between the selected grass mixtures. The lowest N2O emissions, as well as one of the largest CH4 sequestration, but CO2 emissions are among the average. Additional an analysis of the data, it was found that the fertiliser had not affected GHG emissions, this is due to the correct selection of the fertiliser.
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Roy, T., R. S. Amano et J. Jatkar. « A Study of Soil Remediation by Vapor Extraction System and Air Sparging ». Dans ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60289.
Texte intégralRésumé :
Soil remediation by heated soil vapor extraction system and air sparging is a new technology developed by Advanced Remedial Technology, Inc. The areas around chemical companies or waste disposal sites have been seriously contaminated from the chemicals and other polluting materials that are disposed off. The process developed by Advanced Remedial Technology, consists of a heater/boiler that pump and circulates hot oil through a one-inch pipeline that is enclosed in a six-inch pipe. This six-inch pipe is vertically installed within the contaminated soil up to a certain depth and is welded at the bottom and capped at the top. Pea gravel or fine sand fills the six-inch pipe and thus acts as a heat transfer medium. The number of heat source pipes and the extraction wells depends on the type of soil, the type of pollutants, moisture content of the soil and the size of the area to be cleaned. The heat source heats the soil, which is transported in the interior part of the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then driven out of the soil by the extraction well. The extraction well consists of the blower which would suck the vaporized gases out of the system. Soil vapor extraction cannot remove contaminants in the saturated zone of the soil that lies below the water table. In that case air sparging may be used. In air sparging system air is pumped into the saturated zone to help flush the contaminants up into the unsaturated zone where the contaminants is removed by SVE well. In our present study we concentrated on modeling one Heated Soil Vapor Extraction System with air sparging and predicting the behavior of different chemicals in the saturated and unsaturated zone of the soil. This analysis uses the species transport and discrete phase modeling to predict the behavior of different chemicals when it is heated and driven out by the sucking well.
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Amano, Ryo S., Jose Martinez Lucci, Krishna S. Guntur, M. Mahmun Hossain, M. Monzur Morshed, Matthew E. Dudley et Franklin Laib. « Experimental Study of Treating Volatile Organic Compounds ». Dans ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34579.
Texte intégralRésumé :
Heated Soil Vapor Extraction (HSVE) is a technology that has been used successfully to clean up subsurface soils at sites containing chlorinated solvents and petroleum hydrocarbons. The costs have been extremely high due to the large amount of energy required to volatilize high molecular weight polycyclic aromatic hydrocarbon (PAH) compounds present in the soil matrix. One remediation contractor states that hydrocarbons are oxidized in situ by achieving temperatures in the >1000 F range near the heaters [1]. A critical question is whether the volatile portion of manufactured gas plant (MGP) hydrocarbons (VOCs) can be stripped out at lower temperatures such that the remaining contaminants will be unavailable for transport or subsequent dissolution into the groundwater. Soil remediation by heated soil vapor extraction system is a relatively new technology developed by Jay Jatkar Inc. (JJI) along with the University of Wisconsin-Milwaukee [2]. The areas around chemical companies or waste disposal sites have been seriously contaminated from the chemicals and other polluting materials that are disposed off. The process developed by JJI, consists of a heater/boiler that pump and circulates hot oil through a pipeline that is enclosed in a larger-diameter pipe. This extraction pipe is vertically installed within the contaminated soil up to a certain depth and is welded at the bottom and capped at the top. The number of heat source pipes and the extraction wells depends on the type of soil, the type of pollutants, moisture content of the soil and the size of the area to be cleaned. The heat source heats the soil, which is transported in the interior part of the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then driven out of the soil by the extraction well. The extraction well consists of the blower which would suck the vaporized gases out of the system. Our previous studies had removed higher boiling compounds, such as naphthalene, etc., to a non-detectable level. Thus, the current technology is very promising for removing most of the chemical compounds; and can also remove these boiling compounds from the saturated zone. Gas chromatography (GC) is utilized in monitoring the relative concentration changes over the extraction period. Gas chromatography-mass spectrometry (GC-MS) assists in the identification and separation of extracted components. The experimental research is currently being conducted at the University of Wisconsin-Milwaukee. The objectives of this study are to identify contaminants and time required to remove them through HSVE treatment and provide data for computation fluid dynamics CFD analysis.
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Amano, Ryo S., Jose Martinez Lucci et Krishna S. Guntur. « Experimental and Computational Study of Vaporization of Volatile Organic Compounds ». Dans ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41086.
Texte intégralRésumé :
Heated Soil Vapor Extraction (HSVE) is a technology that has been used successfully to clean up subsurface soils at sites containing chlorinated solvents and petroleum hydrocarbons. The costs have been extremely high due to the large amount of energy required to volatilize high molecular weight polycyclic aromatic hydrocarbon (PAH) compounds present in the soil matrix. One remediation contractor states that hydrocarbons are oxidized in situ by achieving temperatures in the >1000 F range near the heaters [1]. A critical question is whether the volatile portion of manufactured gas plant (MGP) hydrocarbons (VOCs) can be stripped out at lower temperatures such that the remaining contaminants will be unavailable for transport or subsequent dissolution into the groundwater. Soil remediation by heated soil vapor extraction system is a relatively new technology developed at the University of Wisconsin-Milwaukee [2]. The areas around chemical companies or waste disposal sites have been seriously contaminated from the chemicals and other polluting materials that are disposed off. The process developed at UWM, consists of a heater/boiler that pump and circulates hot oil through a pipeline that is enclosed in a larger-diameter pipe. This extraction pipe is vertically installed within the contaminated soil up to a certain depth and is welded at the bottom and capped at the top. The number of heat source pipes and the extraction wells depends on the type of soil, the type of pollutants, moisture content of the soil and the size of the area to be cleaned. The heat source heats the soil, which is transported in the interior part of the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then driven out of the soil by the extraction well. The extraction well consists of the blower which would suck the vaporized gases out of the system. Our previous studies had removed higher boiling compounds such as naphthalene, etc., to non-detectable level. Thus, the current technology is very promising for removing most of the chemicals compounds; and can also remove these high boiling compounds from the saturated zone. Gas chromatography (GC) is utilized in monitoring the relative concentration changes over the extraction period. Gas chromatography-mass spectrometry (GCMS) assists in the identification and separation of extracted components. The experimental research is currently being conducted at the University of Wisconsin-Milwaukee. The objectives of this study are to identify contaminants and time required to remove them through HSVE treatment and provide data for computation fluid dynamics CFD analysis.
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Volpi, Iride, Giorgio Ragaglini, Enrico Bonari et Simona Bosco. « Monitoring of greenhouse gases from soil during two cropping seasons of maize in a Mediterranean environment. » Dans 2019 IEEE International Workshop on Metrology for Agriculture and Forestry (MetroAgriFor). IEEE, 2019. http://dx.doi.org/10.1109/metroagrifor.2019.8909268.
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Liepa, Sindija, Kristaps Siltumens, Jovita Pilecka-Ulcugaceva, Inga Grinfelde et Dace Butenaite. « EFFECT OF SOIL PHYSICAL PROPERTIES ON N2O ISOTOPE FORMATION ». Dans 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/4.1/s19.41.
Texte intégralRésumé :
In order for life to arise and exist on earth, a number of important processes take place in it, based on various elements. One of these elements is nitrogen (N). Nitrogen is the most common element in the atmosphere approximately 78% of the atmosphere consists of nitrogen gas (N2), but in this way, the majority of the living organisms cannot absorb nitrogen. Nitrogen fixation occurs during the nitrogen cycle and results in a number of complex organic compounds required for living organisms. During the nitrogen life cycle, the formation of the organic compounds required for plants results in byproducts, which may have a negative impact on the environment. One of these byproducts is N2O gas.N2O is one of the greenhouse gases. The purpose of this article is to clarify the impact of soil physical properties on the formation of N2O isotopes. The samples were collected in 28 test fields. Samples were weighed in 3 l buckets, each in 1.8 kg of soil. Two samples were from each field to allow different humidity conditions. Wetting is designed for wet aerobic and humid anaerobic soil conditions. Information on soil weight changes following soil wetting was also collected. Measurements for N2O isotopes were performed in laboratory conditions using Picarro G5131-i. The data obtained were collected and analyzed. It was concluded that not all of the resulting differences in isotope data and interlineations of N2O could be directly linked to the physical properties of the soil. Differences between the enzymatic differences of microorganisms and the effect of the population of microorganisms cannot be excluded.
Rapports d'organisations sur le sujet "Soil gases"
1
Wyatt, D. E., R. J. Pirkle et D. J. Masdea. Barometric pumping of burial trench soil gases into the atmosphere at the 740-G Sanitary Landfill. Office of Scientific and Technical Information (OSTI), décembre 1992. http://dx.doi.org/10.2172/6730554.
Texte intégral
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Quale, Thomas. A Study of the Adsorption of Some Atmospheric Gases on Soils of the Willamette Valley River Basin. Portland State University Library, janvier 2000. http://dx.doi.org/10.15760/etd.1997.
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Guidati, Gianfranco, et Domenico Giardini. Verbundsynthese «Geothermie» des NFP «Energie». Swiss National Science Foundation (SNSF), janvier 2020. http://dx.doi.org/10.46446/publikation_nfp70_nfp71.2020.4.de.
Texte intégralRésumé :
Die oberflächennahe Geothermie mit Wärmepumpen ist Stand der Technik und in der Schweiz bereits stark verbreitet. Im künftigen Energiesystem soll zusätzlich die mitteltiefe bis tiefe Geothermie (1–6 km) eine wichtige Rolle spielen. Im Vordergrund steht die Lieferung von Wärme für Gebäude und industrielle Prozesse. Diese Form der Erdwärmenutzung setzt einen gut durchlässigen Untergrund voraus, damit ein Fluid – in der Regel Wasser – die natürlich vorhandene Gesteinswärme übernehmen und an die Oberfläche transportieren kann. Bei Sedimentgesteinen ist dies meist von Natur aus gegeben, wogegen bei Graniten und Gneisen die Durchlässigkeit mittels Einpressen von Wasser künstlich herbeigeführt werden muss. Die so gewonnene Wärme nimmt mit zunehmender Bohrtiefe zu: In 1 km Tiefe liegt die Untergrundtemperatur bei ca. 40 °C und in 3 km Tiefe bei ca. 100 °C. Um eine Dampfturbine für die Stromproduktion anzutreiben, sind Temperaturen von über 100 °C notwendig. Da dafür grössere Tiefen von 3 bis 6 km erforderlich sind, steigt auch das Risiko der durch die Bohrungen induzierten Seismizität. Der Untergrund eignet sich ausserdem auch zur Speicherung von Wärme und Gasen, zum Beispiel Wasserstoff oder Methan, sowie zur definitiven Einlagerung von CO2. Dazu muss er ähnliche Voraussetzungen erfüllen wie bei der Wärmegewinnung, zusätzlich ist jedoch eine über dem Reservoir liegende dichte Deckschicht erforderlich, damit das Gas nicht entweichen kann. Im Verbundprojekt «Wasserkraft und Geothermie» des NFP «Energie» wurde vor allem der Frage nachgegangen, wo sich in der Schweiz geeignete Bodenschichten finden, die die Anforderungen der verschiedenen Nutzungen optimal erfüllen. Ein zweiter Forschungsschwerpunkt betraf Massnahmen zur Reduktion der durch Tiefenbohrungen induzierten Seismizität und der daraus folgenden Schäden an Bauten. Im Weiteren wurden Modelle und Simulationen entwickelt, die zu einem besseren Verständnis der Vorgänge im Untergrund bei der Erschliessung und Nutzung der geothermischen Ressourcen beitragen. Zusammengefasst zeigen die Forschungsergebnisse, dass in der Schweiz gute Voraussetzungen vorhanden sind für die Nutzung der mitteltiefen Erdwärme (1–3 km), sowohl für den Gebäudepark als auch für industrielle Prozesse. Auch in Bezug auf die saisonale Speicherung von Wärme und Gasen ist Optimismus angebracht. Die Potenziale für die definitive Einlagerung von CO2 in relevanten Mengen sind demgegenüber als eher limitiert zu bezeichnen. Hinsichtlich der Stromproduktion aus Erdwärme mittels der tiefen Geothermie (> 3 km) besteht noch keine abschliessende Gewissheit, wie gross das wirtschaftlich nutzbare Potenzial im Untergrund wirklich ist. Diesbezüglich sind dringend industriell betriebene Demonstrationsanlagen notwendig, um die Akzeptanz bei der Bevölkerung und bei Investoren zu stärken.