Pour voir les autres types de publications sur ce sujet consultez le lien suivant : Soil gases.
Articles de revues sur le sujet « Soil gases »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 50 meilleurs articles de revues pour votre recherche sur le sujet « Soil gases ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les articles de revues sur diverses disciplines et organisez correctement votre bibliographie.
1
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.
Texte intégralRésumé :
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.
2
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.
Texte intégralRésumé :
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.
3
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.
Texte intégralRésumé :
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.
4
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.
Texte intégralRésumé :
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.
5
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.
Texte intégralRésumé :
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.
6
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.
Texte intégral
7
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.
Texte intégralRésumé :
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.
8
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.
Texte intégralRésumé :
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.
9
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.
Texte intégralRésumé :
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.
10
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.
Texte intégralRésumé :
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.
11
Abeysinghe, A. M. S. N., M. M. T. Lakshani, U. D. H. N. Amarasinghe, Yuan Li, T. K. K. Chamindu Deepagoda, Wei Fu, Jun Fan et al. « Soil-Gas Diffusivity-Based Characterization of Variably Saturated Agricultural Topsoils ». Water 14, no 18 (16 septembre 2022) : 2900. http://dx.doi.org/10.3390/w14182900.
Texte intégralRésumé :
Soil-gas diffusivity and its variation with soil moisture plays a fundamental role in diffusion-controlled migration of climate-impact gases from different terrestrial agroecosystems including cultivated soils and managed pasture systems. The wide contrast in soil texture and structure (e.g., density, soil aggregation) in agriculture topsoils (0–10 cm) makes it challenging for soil-gas diffusivity predictive models to make accurate predictions across different moisture conditions. This study characterized gas diffusivity and gas-phase tortuosity in soils sampled from managed pasture and cultivated sites in Sri Lanka at 0–10 cm depth, together with selected soil-gas diffusivity data from the literature. Soil-gas diffusivity was measured using a one-chamber diffusion apparatus using N2 and O2 as experimental gases. The measured diffusivity, together with literature data representing both intact and repacked soils, were tested against five existing widely known gas diffusivity predictive models. The tested models tended to mischaracterize the two-region behavior in some of the aggregated soils, suggesting the need of soil-specific diffusivity models to better describe gas diffusivity in agricultural soils. We suggested a new parametric two-region model, developed in line with literature-based models, to represent both unimodal and bimodal/two-region behavior of selected soils. The new model statistically outperformed the existing predictive models for both intact and repacked soils and, hence, demonstrated its applicability to better characterize site-specific greenhouse gas emissions under different soil water regimes.
12
Loc, Nguyen Xuan. « EFFECTS OF WATER MANAGEMENT AND SOIL TYPE ON GREENHOUSE GASES EMISSION FROM RICE PRODUCTION IN AN GIANG PROVINCE ». Vietnam Journal of Science and Technology 58, no 3A (25 mai 2020) : 178. http://dx.doi.org/10.15625/2525-2518/58/3a/14359.
Texte intégralRésumé :
Mekong delta has been well known for rice production of Vietnam and had great contribution of rice export of Vietnam and for acid sulfate and alluvial soils. Greenhouse gases emission from rice has been raised for its contribution to global warming. The technique of alternate wetting and drying (AWD) has been recommended used for reduction of greenhouse gases. An experiment was set up with 3 factors of water management (AWD and CF-continuous flooding), soil type (acid sulfate and alluvial soil) and seasonal effect (Spring Summer, Summer Autumn and Winter Spring) for collecting emission of CH4, N2O and rice yield. The CH4emission was less in the AWD 2.76 mgCH4.m-2.h-1than in the CF 4.66 mgCH4.m-2.h-1(p<0.05). Also, the rice yield was 5.87 ton.ha-1.season-1for AWD and higher than 4.80 ton.ha-1.season-1for CF (p<0.05). The soil type did not affect the greenhouse gases emission and the rice yield. The N2O emission was very low and variation. The AWD should be applied broadly to all the area of rice production in the Mekong delta due to its less greenhouse gases emission.
13
Meredith, Laura K., Kristin Boye, Kathleen Savage et Rodrigo Vargas. « Formation and Fluxes of Soil Trace Gases ». Soil Systems 4, no 2 (16 avril 2020) : 22. http://dx.doi.org/10.3390/soilsystems4020022.
Texte intégral
14
Seely, Gregory E., Ronald W. Falta et James R. Hunt. « Buoyant Advection of Gases in Unsaturated Soil ». Journal of Environmental Engineering 120, no 5 (septembre 1994) : 1230–47. http://dx.doi.org/10.1061/(asce)0733-9372(1994)120:5(1230).
Texte intégral
15
Rose, Arthur W., Adam R. Hutter et John W. Washington. « Sampling variability of radon in soil gases ». Journal of Geochemical Exploration 38, no 1-2 (août 1990) : 173–91. http://dx.doi.org/10.1016/0375-6742(90)90100-o.
Texte intégral
16
Szajdak, Lech Wojciech, Wioletta Gaca, Jürgen Augustin et Teresa Meysner. « Impact of Shelterbelts on Oxidation-Reduction Properties and Greenhouse Gases Emission from Soils ». Ecological Chemistry and Engineering S 25, no 4 (1 décembre 2018) : 643–58. http://dx.doi.org/10.1515/eces-2018-0043.
Texte intégralRésumé :
Abstract The Typic Hapludalfs soils under two old shelterbelts (200 years old) Robinia pseudacacia and Crataegus monogyna, multi species of trees (young shelterbelt - 20 years old) and neighbouring cultivated fields were investigated. The function of shelterbelts of different age and plant composition in agricultural landscape and estimation of biochemical and chemical soil conditions for the decrease of greenhouse gases release from soil to the atmosphere was the aim of the research. In soils under shelterbelts were estimated activities of several enzymes participating in the oxidation-reduction processes, ferric and ferrous ions and the evolutions of gases like N2, N2O, CO2, and CH4. The soils under old shelterbelts characterized higher peroxidase activity than in young shelterbelt and adjoining cultivated fields. However, no significant differences were observed for nitrate reductase activity between old and young shelterbelts. There were proved differences between emission of N2O in soils under shelterbelts and in adjoining cultivated fields. Furthermore, it was observed significant effect of the young shelterbelt on the decrease of carbon dioxide release than in the adjoining cultivated field. The manipulation of the landscape through the introduction of shelterbelts of different age and the composition of plants leads to the modification of biogeochemical soil conditions for N2O and N2 formation and finally decrease of the greenhouse gases evolution from soils to the atmosphere. Thus the creation of new shelterbelts is favourable factor for agricultural landscape.
17
Du, Zhe, Diego A. Riveros-Iregui, Ryan T. Jones, Timothy R. McDermott, John E. Dore, Brian L. McGlynn, Ryan E. Emanuel et Xu Li. « Landscape Position Influences Microbial Composition and Function via Redistribution of Soil Water across a Watershed ». Applied and Environmental Microbiology 81, no 24 (2 octobre 2015) : 8457–68. http://dx.doi.org/10.1128/aem.02643-15.
Texte intégralRésumé :
ABSTRACTSubalpine forest ecosystems influence global carbon cycling. However, little is known about the compositions of their soil microbial communities and how these may vary with soil environmental conditions. The goal of this study was to characterize the soil microbial communities in a subalpine forest watershed in central Montana (Stringer Creek Watershed within the Tenderfoot Creek Experimental Forest) and to investigate their relationships with environmental conditions and soil carbonaceous gases. As assessed by tagged Illumina sequencing of the 16S rRNA gene, community composition and structure differed significantly among three landscape positions: high upland zones (HUZ), low upland zones (LUZ), and riparian zones (RZ). Soil depth effects on phylogenetic diversity and β-diversity varied across landscape positions, being more evident in RZ than in HUZ. Mantel tests revealed significant correlations between microbial community assembly patterns and the soil environmental factors tested (water content, temperature, oxygen, and pH) and soil carbonaceous gases (carbon dioxide concentration and efflux and methane concentration). With one exception, methanogens were detected only in RZ soils. In contrast, methanotrophs were detected in all three landscape positions. Type I methanotrophs dominated RZ soils, while type II methanotrophs dominated LUZ and HUZ soils. The relative abundances of methanotroph populations correlated positively with soil water content (R= 0.72,P< 0.001) and negatively with soil oxygen (R= −0.53,P= 0.008). Our results suggest the coherence of soil microbial communities within and differences in communities between landscape positions in a subalpine forested watershed that reflect historical and contemporary environmental conditions.
18
Minh, Dang Duy, Ben Macdonald, Sören Warneke et Ian White. « Fluxes of greenhouse gases from incubated soils using different lid-closure times ». Soil Research 56, no 1 (2018) : 39. http://dx.doi.org/10.1071/sr17050.
Texte intégralRésumé :
Different sampling times for greenhouse gas measurements have been proposed in many incubation studies. Little is known about effects of closure time on denitrification and nitrification rates from incubation experiments. The objectives of this study were to analyse greenhouse gas (carbon dioxide, methane and nitrous oxide) production from different soils with different times of lid closure and to assess effects of different activation times (defined as additional pre-incubation periods before incubation experiments) on gas emissions from soils. Forty grams of air-dried soil samples (depth 0–10 cm) were incubated in 125-mL jars at 25°C with the addition of glucose and nitrate. The first experiment measured greenhouse gas fluxes at different lid-closure times (40, 80, 120 and 1440 min). The second experiment assessed the effects of different durations of soil activation (0.7, 1.3, 2 and 24 h) on gas emissions. Both were conducted with a completely randomised design, with three replicates per treatment. Our findings showed closure time <1 h or >2 h may cause an underestimate of greenhouse gas emissions. Lengthening activation times resulted in different emission rates consistent with soil characteristics. To measure gas fluxes based on linear regression would require four or five sampling points and sampling at a 20-min interval over a maximum period of 80 min for estimating gas fluxes from soil. Because pre-incubation time is critical and a driving factor in the measurement of soil-induced gas emissions, a standardised procedure to quantify gas fluxes is needed for application to other soils.
19
Gagliano, A. L., S. Calabrese, K. Daskalopoulou, J. Cabassi, F. Capecchiacci, F. Tassi, S. Bellomo et al. « Degassing and Cycling of Mercury at Nisyros Volcano (Greece) ». Geofluids 2019 (14 août 2019) : 1–18. http://dx.doi.org/10.1155/2019/4783514.
Texte intégralRésumé :
Nisyros Island (Greece) is an active volcano hosting a high-enthalpy geothermal system. During June 2013, an extensive survey on Hg concentrations in different matrices (fumarolic fluids, atmosphere, soils, and plants) was carried out at the Lakki Plain, an intracaldera area affected by widespread soil and fumarolic degassing. Concentrations of gaseous elemental mercury (GEM), together with H2S and CO2, were simultaneously measured in both the fumarolic emissions and the atmosphere around them. At the same time, 130 samples of top soils and 31 samples of plants (Cistus creticus and salvifolius and Erica arborea and manipuliflora) were collected for Hg analysis. Mercury concentrations in fumarolic gases ranged from 10,500 to 46,300 ng/m3, while Hg concentrations in the air ranged from high background values in the Lakki Plain caldera (10-36 ng/m3) up to 7100 ng/m3 in the fumarolic areas. Outside the caldera, the concentrations were relatively low (2-5 ng/m3). The positive correlation with both CO2 and H2S in air highlighted the importance of hydrothermal gases as carrier for GEM. On the other hand, soil Hg concentrations (0.023-13.7 μg/g) showed no significant correlations with CO2 and H2S in the soil gases, whereas it showed a positive correlation with total S content and an inverse one with the soil pH, evidencing the complexity of the processes involving Hg carried by hydrothermal gases while passing through the soil. Total Hg concentrations in plant leaves (0.010-0.112 μg/g) had no direct correlation with soil Hg, with Cistus leaves containing higher values of Hg with respect to Erica. Even though GEM concentrations in the air within the caldera are sometimes orders of magnitude above the global background, they should not be considered dangerous to human health. Values exceeding the WHO guideline value of 1000 ng/m3 are very rare (<0.1%) and only found very close to the main fumarolic vents, where the access to tourists is prohibited.
20
Besen, Marcos, Ricardo Ribeiro, Alessandra Rigo, Guilherme Iwasaki et Jonatas Piva. « Soil conservation practices and greenhouse gases emissions in Brazil ». Scientia Agropecuaria 9, no 3 (28 septembre 2018) : 429–39. http://dx.doi.org/10.17268/sci.agropecu.2018.03.15.
Texte intégral
21
Gagliano, A. L., S. Calabrese, K. Daskalopoulou, J. Cabassi, F. Capecchiacci, F. Tassi, M. Bonsignore et al. « MOBILITY OF MERCURY IN THE VOLCANIC/GEOTHERMAL AREA OF NISYROS (GREECE) ». Bulletin of the Geological Society of Greece 50, no 4 (28 juillet 2017) : 2118. http://dx.doi.org/10.12681/bgsg.14264.
Texte intégralRésumé :
In the summer 2013, mercury concentrations in soils and air from Nisyros (Greece), an active volcanic island located in the Aegean Sea, were determined. Up to 102 samples of soil were collected in the Lakki plain caldera and analyzed for mercury by using a cold vapour atomic absorption analyzer, following 7473 US EPA method. Concentrations of mercury in air were also investigated in the same sites with a portable spectrophotometer (Lumex RA-915M). Soil mercury concentrations were in the range from 0.023 to 13.7 µg/g. The mercury concentrations in air showed high background values in the Lakki plain caldera, ranging from 21 to 36 ng/m3 and maximum values up to 493 ng/m3 in the proximity of the fumarolic areas, in contrast with the relatively low values (from 2 to 5 ng/m3 ) measured in the distal sites outside of the caldera. The positive correlation between mercury and CO2 and H2S in the atmosphere highlights the important role of fumarolic gases as carrier for gaseous mercury (Hg0 ). On the contrary, mercury does not show significant correlations with CO2 and H2S in the soil gases. This finding evidences the complexity of the processes affecting mercury in hydrothermal gases passing through the soil.
22
Criscuoli, Irene, Maurizio Ventura, Andrea Sperotto, Pietro Panzacchi et Giustino Tonon. « Effect of Woodchips Biochar on Sensitivity to Temperature of Soil Greenhouse Gases Emissions ». Forests 10, no 7 (17 juillet 2019) : 594. http://dx.doi.org/10.3390/f10070594.
Texte intégralRésumé :
Research Highlights: Biochar is the carbonaceous product of pyrolysis or the gasification of biomass that is used as soil amendment to improve soil fertility and increase soil carbon stock. Biochar has been shown to increase, decrease, or have no effect on the emissions of greenhouse gases (GHG) from soil, depending on the specific soil and biochar characteristics. However, the temperature sensitivity of these gas emissions in biochar-amended soils is still poorly investigated. Background and Objectives: A pot experiment was set up to investigate the impact of woodchips biochar on the temperature sensitivity of the main GHG (CO2, CH4, and N2O) emissions from soil. Materials and Methods: Nine pots (14 L volume) were filled with soil mixed with biochar at two application rates (0.021 kg of biochar/kg of soil and 0.042 kg of biochar/kg of soil) or with soil alone as the control (three pots per treatment). Pots were incubated in a growth chamber and the emissions of CO2, CH4, and N2O were monitored for two weeks with a cavity ring-down gas analyzer connected to three closed dynamic chambers. The temperature in the chamber increased from 10 °C to 30 °C during the first week and decreased back to 10 °C during the second week, with a daily change of 5 °C. Soil water content was kept at 20% (w/w). Results: Biochar application did not significantly affect the temperature sensitivity of CO2 and N2O emissions. However, the sensitivity of CH4 uptake from soil significantly decreased by the application of biochar, reducing the CH4 soil consumption compared to the un-amended soil, especially at high soil temperatures. Basal CO2 respiration at 10 °C was significantly higher in the highest biochar application rate compared to the control soil. Conclusions: These results confirmed that the magnitude and direction of the influence of biochar on temperature sensitivity of GHG emissions depend on the specific GHG considered. The biochar tested in this study did not affect soil N2O emission and only marginally affected CO2 emission in a wide range of soil temperatures. However, it showed a negative impact on soil CH4 uptake, particularly at a high temperature, having important implications in a future warmer climate scenario and at higher application rates.
23
Rétháti, Gabriella, Adrienn Vejzer, Barbara Simon, Ramadan Benjared et György Füleky. « Examination of zinc adsorption capacity of soils treated with different pyrolysis products ». Acta Universitatis Sapientiae, Agriculture and Environment 6, no 1 (1 novembre 2014) : 33–38. http://dx.doi.org/10.2478/ausae-2014-0010.
Texte intégralRésumé :
Abstract Organic matter input into soils is essential regarding agricultural, environmental and soil science aspects as well. However, the application of the pyrolysed forms of biochars and materials with different organic matter content gained more attention in order to decrease the emission of the green house gases (CO2, N2O) from the soil. During pyrolysis, the materials containing high organic matter (biomass-originated organic matter) are heated in oxygen-free (or limited amount of oxygen) environment. As a result, the solid phase, which remains after eliminating the gases and liquid phase, is more stable compared to the original product, it cannot be mineralized easily in the soil and its utilization is more beneficial in terms of climatic aspects. Furthermore, it can improve soil structure and it can retain soil moisture and cations in the topsoil for long periods of time, which is very important for plants. In our experiment, the effects of biochar and bone char were examined on soils by zinc adsorption experiments. Based on our experiments, we concluded that the pyrolysis products can have significant Zn adsorption capacity compared to the soil. Bone ash can adsorb more Zn than the charcoal product. The Zn adsorption capacity of soils treated by pyrolysis products can be described by Langmuir adsorption isotherms. However, based on the amount of pyrolysis products, one or two term Langmuir isotherm fits well on the experiment data, which depends on the time the pyrolysis product has spent in the soil.
24
Vargas, Rodrigo, et Van Huong Le. « The paradox of assessing greenhouse gases from soils for nature-based solutions ». Biogeosciences 20, no 1 (3 janvier 2023) : 15–26. http://dx.doi.org/10.5194/bg-20-15-2023.
Texte intégralRésumé :
Abstract. Quantifying the role of soils in nature-based solutions requires accurate estimates of soil greenhouse gas (GHG) fluxes. Technological advances allow us to measure multiple GHGs simultaneously, and now it is possible to provide complete GHG budgets from soils (i.e., CO2, CH4, and N2O fluxes). We propose that there is a conflict between the convenience of simultaneously measuring multiple soil GHG fluxes at fixed time intervals (e.g., once or twice per month) and the intrinsic temporal variability in and patterns of different GHG fluxes. Information derived from fixed time intervals – commonly done during manual field campaigns – had limitations to reproducing statistical properties, temporal dependence, annual budgets, and associated uncertainty when compared with information derived from continuous measurements (i.e., automated hourly measurements) for all soil GHG fluxes. We present a novel approach (i.e., temporal univariate Latin hypercube sampling) that can be applied to provide insights and optimize monitoring efforts of GHG fluxes across time. We suggest that multiple GHG fluxes should not be simultaneously measured at a few fixed time intervals (mainly when measurements are limited to once per month), but an optimized sampling approach can be used to reduce bias and uncertainty. These results have implications for assessing GHG fluxes from soils and consequently reduce uncertainty in the role of soils in nature-based solutions.
25
Kumar, Nirmal, JI Meghabarot, Priyakanchini Gupta et Kanti Patel. « An Evaluation of Short Term Greenhouse Gas Emissions from Soil and Atmosphere Exchange in Response to Controlling Edaphic Factgors of Eucalyptus Plantation, Gujarat, India ». International Journal of Environment 3, no 3 (12 septembre 2014) : 59–77. http://dx.doi.org/10.3126/ije.v3i3.11064.
Texte intégralRésumé :
A considerable amount of atmospheric GHG is produced and consumed through soil processes. Soils provide the largest terrestrial store for carbon (C) as well as the largest atmospheric CO2 sources through autotrophic and heterotrophic organisms. Soils are also the greatest source (∼60%) of CH4 and N2O through microbially mediated processes of methanogensis, nitrification and denitrification. Short term CO2, CH4 and N2O gas fluxes from soil under a Eucalyptus plantation in central Gujarat, Western India were measured for three month duration (February to April, 2013) at fifteen days interval using closed static chamber technique and gas chromatography method. Simultaneously soils were analyzed at 0.0-10, 10-20, and 20-30 cm depth for pH, conductivity, organic carbon, nitrogen, phosphate, sulphate to correlate with gas emissions. The results showed that the soil in our study was a sink of atmospheric CO2, CH4 and N2O which the flux varied from -65.27 to 14.6, -0.005 to 0.07 and -0.03 to 0.33 mg m-2 h-1respectively. CO2 emissions were found maximum as compared to other two gases. Variations in soil N2O emissions could be primarily explained by litter C:N ratio and soil total N stock. Differences in soil CH4 uptake could be mostly attributed to the soil CO2 flux and water filled pore space (WFPS). Soil C:N ratio could largely account for variations in soil CO2 emissions. A strong positive relationship existed between CH4 flux and soil temperature. The N2O flux correlated with WFPS and the global warming potential of N2O is highest compared to other two principal gases. DOI: http://dx.doi.org/10.3126/ije.v3i3.11064 International Journal of Environment Vol.3(3) 2014: 59-77
26
Baldock, J. A., I. Wheeler, N. McKenzie et A. McBrateny. « Soils and climate change : potential impacts on carbon stocks and greenhouse gas emissions, and future research for Australian agriculture ». Crop and Pasture Science 63, no 3 (2012) : 269. http://dx.doi.org/10.1071/cp11170.
Texte intégralRésumé :
Organic carbon and nitrogen found in soils are subject to a range of biological processes capable of generating or consuming greenhouse gases (CO2, N2O and CH4). In response to the strong impact that agricultural management can have on the amount of organic carbon and nitrogen stored in soil and their rates of biological cycling, soils have the potential to reduce or enhance concentrations of greenhouse gases in the atmosphere. Concern also exists over the potential positive feedback that a changing climate may have on rates of greenhouse gas emission from soil. Climate projections for most of the agricultural regions of Australia suggest a warmer and drier future with greater extremes relative to current climate. Since emissions of greenhouse gases from soil derive from biological processes that are sensitive to soil temperature and water content, climate change may impact significantly on future emissions. In this paper, the potential effects of climate change and options for adaptation and mitigations will be considered, followed by an assessment of future research requirements. The paper concludes by suggesting that the diversity of climate, soil types, and agricultural practices in place across Australia will make it difficult to define generic scenarios for greenhouse gas emissions. Development of a robust modelling capability will be required to construct regional and national emission assessments and to define the potential outcomes of on-farm management decisions and policy decisions. This model development will require comprehensive field datasets to calibrate the models and validate model outputs. Additionally, improved spatial layers of model input variables collected on a regular basis will be required to optimise accounting at regional to national scales.
27
Swerts, M., G. Uytterhoeven, R. Merckx et K. Vlassak. « Semicontinuous Measurement of Soil Atmosphere Gases with Gas-Flow Soil Core Method ». Soil Science Society of America Journal 59, no 5 (septembre 1995) : 1336–42. http://dx.doi.org/10.2136/sssaj1995.03615995005900050020x.
Texte intégral
28
da Silva Bicalho, Elton, Mara Regina Moitinho, Daniel De Bortoli Teixeira, Alan Rodrigo Panosso, Kurt Arnold Spokas et Newton La Scala. « Soil Greenhouse Gases : Relations to Soil Attributes in a Sugarcane Production Area ». Soil Science Society of America Journal 81, no 5 (20 juillet 2017) : 1168–78. http://dx.doi.org/10.2136/sssaj2017.02.0043.
Texte intégral
29
Scheutz, Charlotte, et Peter Kjeldsen. « Biodegradation of Trace Gases in Simulated Landfill Soil ». Journal of the Air & ; Waste Management Association 55, no 7 (juillet 2005) : 878–85. http://dx.doi.org/10.1080/10473289.2005.10464693.
Texte intégral
30
Gat-Tilman, G. « Soil gases and the germination of Aizoon hispanicum ». Journal of Arid Environments 28, no 1 (septembre 1994) : 39–44. http://dx.doi.org/10.1016/s0140-1963(05)80019-9.
Texte intégral
31
Nikolett Szőllősi, Csaba Juhász, Györgyi Kovács et József Zsembeli. « The effect of crop coverage on the daily dynamism of the soil’s CO2 emission ». Acta Agraria Debreceniensis, no 42 (22 décembre 2010) : 97–102. http://dx.doi.org/10.34101/actaagrar/42/2667.
Texte intégralRésumé :
Nowadays one of main goals of international ecosystem research the measurement of greenhouse gases (CO2, N2O and CH4) in different places. The fluctuation of these greenhouse gases – quantity and trend in the case of CO2 and CH4 – could be diverse with atmosphere because it depends on several effects of factors like climate, soil type, vegetation. In grassland out of the three greenhouse gases which fill a part in gas emission, in the case of CO2 soil and vegetation are the most important factors (Soussana et al., 2007).In the aspect of global carbon balance grasslands are very important by their large area extension, total carbon content, organic content store (10% of the global carbon storage) (Lemmens et al., 2006). In this summer measurements were carried out to determine CO2 emission of the soil from different soil surfaces like grass covered and bare soil surface during a whole day.
32
Spuny, Marina, Mariya Tikhonova, Elena Iliushkova, Aleksey Buzylev et Yaroslava Zhigaleva. « Dynamics greenhouse gases in the soil ecological station on RGAU-MTAU named after Timiryazev ». АгроЭкоИнфо 4, no 52 (31 août 2022) : 29. http://dx.doi.org/10.51419/202124429.
Texte intégralRésumé :
In recent years, the main problem of greening urban areas is the development of large areas, which creates an increased load on the soil and leads to a change in the water regime of the territories, thereby potentially increasing the dynamics of greenhouse gases from the soil. To regulate this process, it is necessary to conduct environmental monitoring of greenhouse gas from soils in order to analyze the patterns of their dynamics in urban areas where waterlogging of the soil is often observed. In addition, it is necessary to plant species in such areas that can withstand prolonged moisture without losing their decorative appearance and ecological functions. For scientific research experiments, it is important to create ecological station that will allow testing for environmental research. The materials of the conducted studies can be used to refine the estimates of soil greenhouse gas in conditions characteristic of urban areas with changes in the hydrological regime of the soil. Keywords: GREENHOUSE GAS FLOWS, EMISSION, CARBON DIOXIDE, NITROGEN OXIDE, SOIL MOISTURE, CLIMATE CHANGE
33
Sabrin, Samain, Rouzbeh Nazari, Md Golam Rabbani Fahad, Maryam Karimi, Jess W. Everett et Robert W. Peters. « Investigating Effects of Landfill Soil Gases on Landfill Elevated Subsurface Temperature ». Applied Sciences 10, no 18 (14 septembre 2020) : 6401. http://dx.doi.org/10.3390/app10186401.
Texte intégralRésumé :
Subsurface temperature is a critical indicator for the identification of the risk associated with subsurface fire hazards in landfills. Most operational landfills in the United States (US) have experienced exothermic reactions in their subsurface. The subsurface landfill area is composed of various gases generated from chemical reactions inside the landfills. Federal laws in the US mandate the monitoring of gases in landfills to prevent hazardous events such as landfill fire breakouts. There are insufficient investigations conducted to identify the causes of landfill fire hazards. The objective of this research is to develop a methodological approach to this issue. In this study, the relationship was investigated between the subsurface elevated temperature (SET) and soil gases (i.e., methane, carbon dioxide, carbon monoxide, nitrogen, and oxygen) with the greatest influence in landfills. The significance level of the effect of soil gases on the SET was assessed using a decision tree approach. A naïve Bayes technique for conditional probability was implemented to investigate how different gas combinations can affect different temperature ranges with respect to the safe and unsafe states of these gases. The results indicate that methane and carbon dioxide gases are strongly associated with SETs. Among sixteen possible gas combinations, three were identified as the most probable predictors of SETs. A three-step risk assessment framework is proposed to identify the risk of landfill fire incidents. The key findings of this research could be beneficial to landfill authorities and better ensure the safety of the community health and environment.
34
Bhattarai, Hem Raj, Maija E. Marushchak, Jussi Ronkainen, Richard E. Lamprecht, Henri M. P. Siljanen, Pertti J. Martikainen, Christina Biasi et Marja Maljanen. « Emissions of atmospherically reactive gases nitrous acid and nitric oxide from Arctic permafrost peatlands ». Environmental Research Letters 17, no 2 (1 février 2022) : 024034. http://dx.doi.org/10.1088/1748-9326/ac4f8e.
Texte intégralRésumé :
Abstract Soils are important sources of nitric oxide (NO) and nitrous acid (HONO) in the atmosphere. These nitrogen (N)-containing gases play a crucial role in atmospheric chemistry and climate at different scales because of reactions modulated by NO and hydroxyl radicals (OH), which are formed via HONO photolysis. Northern permafrost soils have so far remained unexplored for HONO and NO emissions despite their high N stocks, capacity to emit nitrous oxide (N2O), and enhancing mineral N turnover due to warming and permafrost thawing. Here, we report the first HONO and NO emissions from high-latitude soils based on measurements of permafrost-affected subarctic peatlands. We show large HONO (0.1–2.4 µg N m−2h−1) and NO (0.4–59.3 µg N m−2h−1) emissions from unvegetated peat surfaces, rich with mineral N, compared to low emissions (⩽0.2 µg N m−2h−1 for both gases) from adjacent vegetated surfaces (experiments with intact peat cores). We observed HONO production under highly variable soil moisture conditions from dry to wet. However, based on complementary slurry experiments, HONO production was strongly favored by high soil moisture and anoxic conditions. We suggest urgent examination of other Arctic landscapes for HONO and NO emissions to better constrain the role of these reactive N gases in Arctic atmospheric chemistry.
35
Donovan, S. M., A. M. Skartsila, M. K. Head et N. Voulvoulis. « An Initial Investigation into the Use of a Flux Chamber Technique to Measure Soil-Atmosphere Gas Exchanges from Application of Biosolids to UK Soils ». Applied and Environmental Soil Science 2011 (2011) : 1–10. http://dx.doi.org/10.1155/2011/957181.
Texte intégralRésumé :
While a significant amount of work has been conducted to assess the concentration of pollutants in soils and waterways near land that has been amended with biosolids, a relatively small body of research investigating emissions to atmosphere is available in the literature. Some studies have indicated that while the CO2emissions from soils decrease with fertiliser application, the CH4and N2O emissions might be increased, offsetting the benefit. The objective of the research presented in this paper was to address this gap, by the use of a flux chamber technique to measure soil-atmosphere gas exchanges from the application of biosolids to land. This was done by applying three different types of biosolids to soils and measuring gases at the soil-atmosphere interface. The measurements were taken on areas with three different types of vegetation. The gases were collected using a flux chamber technique and analysed by gas chromatography. The results presented here are preliminary findings of an ongoing experiment. Insignificant variation appeared to occur between different areas of vegetation; however, small variations in gas concentrations were observed indicating a need for continued monitoring of soil-atmosphere gas exchanges to determine the long-term impacts on the atmosphere and the environment.
36
Li, Xiaoyu, Lirong Zhang, Lifeng Zhou, Jian Liu, Meng Zhou, Zhengyu Lin, Min Luo, Baohua Zhang et Leilei Xiao. « Production Potential of Greenhouse Gases Affected by Microplastics at Freshwater and Saltwater Ecosystems ». Atmosphere 13, no 11 (30 octobre 2022) : 1796. http://dx.doi.org/10.3390/atmos13111796.
Texte intégralRésumé :
Currently, microplastic pollution poses a great threat to diverse ecosystems. Microplastics can potentially change soil characteristics and impact soil microorganisms, and then affect the production of CO2, CH4 and other greenhouse gases. However, experimental study on different ecological soils is lacking. Herein, we experimentally analyzed the CO2 and CH4 production potential affected by four types of microplastics in freshwater (Poyang Lake in Jiangxi province, paddy soil in Hunan province) and saltwater (Salt marsh in Shandong province, mangrove soil in Fujian province) ecosystems. Microplastics promoted CO2 production, of which polyethylene terephthalate (PET) had the greatest impact. In our study, the microplastics that had the greatest impact on CH4 concentration emissions were high-density polyethylene (1276 umol·g−1·L−1), followed by polyvinyl chloride (384 umol·g−1·L−1), polyethylene terephthalate (198 umol·g−1·L−1), and polyamide (134 umol·g−1·L−1). In addition, the largest impact on CO2 concentration emissions was displayed by polyethylene terephthalate (2253 umol·g−1·L−1), followed by polyvinyl chloride (2194 umol·g−1·L−1), polyamide (2006 umol·g−1·L−1), and high-density polyethylene (1522 umol·g−1·L−1). However, the analysis results based on one-way ANOVA showed that CO2 emission was most significantly affected by soil properties rather than microplastics types. In comparison, the influencing factor on CH4 production changed from soil types to the interaction between soil types and microplastics, and finally to the microplastics with the increase in incubation time. Further, by comparing CO2 and CH4 production and Global Warming Equivalent (GWE) affected by microplastics, freshwater ecosystems were more sensitive than saltwater. For all the soil types used in this study, high-density polyethylene had the greatest impact on CH4 production potential. In conclusion, our study provided basic data for further understanding the effects of microplastics on soil greenhouse gas emissions from different sources.
37
Pillar, VD, CG Tornquist et C. Bayer. « The southern Brazilian grassland biome : soil carbon stocks, fluxes of greenhouse gases and some options for mitigation ». Brazilian Journal of Biology 72, no 3 suppl (août 2012) : 673–81. http://dx.doi.org/10.1590/s1519-69842012000400006.
Texte intégralRésumé :
The southern Brazilian grassland biome contains highly diverse natural ecosystems that have been used for centuries for grazing livestock and that also provide other important environmental services. Here we outline the main factors controlling ecosystem processes, review and discuss the available data on soil carbon stocks and greenhouse gases emissions from soils, and suggest opportunities for mitigation of climatic change. The research on carbon and greenhouse gases emissions in these ecosystems is recent and the results are still fragmented. The available data indicate that the southern Brazilian natural grassland ecosystems under adequate management contain important stocks of organic carbon in the soil, and therefore their conservation is relevant for the mitigation of climate change. Furthermore, these ecosystems show a great and rapid loss of soil organic carbon when converted to crops based on conventional tillage practices. However, in the already converted areas there is potential to mitigate greenhouse gas emissions by using cropping systems based on no soil tillage and cover-crops, and the effect is mainly related to the potential of these crop systems to accumulate soil organic carbon in the soil at rates that surpass the increased soil nitrous oxide emissions. Further modelling with these results associated with geographic information systems could generate regional estimates of carbon balance.
38
Muñoz, Cristina, Milagros Ginebra et Erick Zagal. « Variation of Greenhouse Gases Fluxes and Soil Properties with Addition of Biochar from Farm-Wastes in Volcanic and Non-Volcanic Soils ». Sustainability 11, no 7 (27 mars 2019) : 1831. http://dx.doi.org/10.3390/su11071831.
Texte intégralRésumé :
The decomposition of organic wastes contributes to greenhouse gas (GHG) emissions and global warming. This study evaluated the effect of biochar (BC) produced from different farm wastes (chicken, pig and cow manures) on greenhouse gas emissions and soil chemical and biological properties in different grassland soils (volcanic and non-volcanic soils). A 288-day laboratory experiment was carried out, monitoring CO2, N2O and CH4 emissions and evaluating total C, soil pH, microbial biomass and enzymatic activity in three grassland soils. The results varied depending on the soil type and feedstock of BC produced. BC-cow decreased emissions of CO2 and CH4 fluxes for volcanic and non-volcanic soils, probably due to decreases in β-glucosidase activity. Biochars from cow and pig manures increased soil C content, favouring the persistence of C into the soil at 288-days of incubation. Soil pH increased with the application of BC in the soils.
39
Niraula, Suresh, Shafiqur Rahman et Amitava Chatterjee. « Release of Ammonia and Greenhouse Gases along Moisture Gradient from Manure and Urea Applied Fargo Silty Clay Soil ». Applied Engineering in Agriculture 34, no 6 (2018) : 939–52. http://dx.doi.org/10.13031/aea.12985.
Texte intégralRésumé :
Abstract. Greenhouse gas (GHG) [nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4)] emission and ammonia (NH3) volatilization from organic and commercial fertilizers are likely related to soil moisture levels. Effect of soil moisture [(30%, 60%, and 90% water-holding capacity (WHC)] on emissions from urea and manure treated (215 kg ha-1) Fargo-Ryan silty clay soil was studied under laboratory conditions. Soils (250 g) amended with solid beef manure (SM), straw-bedded solid beef manure (BM), urea (UR), and control (CT) were incubated for 28 days at 22±1°C, to determine GHGs (N2O, CO2, and CH4) emission and NH3 volatilization loss. The cumulative emission of N2O-N, CO2-C, and CH4-C ranged from 27 to 4402 µg N2O-N kg-1, 272 to 2030 mg CO2-C kg-1, and 10.1 to 1389 µg CH4-C kg-1 soil, respectively. The daily fluxes and cumulative emissions of N2O and CO2 generally followed the decreasing order of 30% < 90% < 60% of WHC. At 60% WHC, 1.01% of the total applied N was lost as N2O from urea treated soil. Carbon dioxide emission from manure treated soil (SM and BM) was up to two times the emission from UR treated soils. The Fargo clay soils showed higher CH4 emission at 90% WHC level. The cumulative NH3 volatilization loss from soil ranged from 29.4 to 1250.5 µg NH3-N kg-1, with the highest loss from UR amended soils at 30% WHC. These results suggest that gaseous emissions from manure and urea application under laboratory study are influenced by moisture levels of Fargo-Ryan silty clay soil. Keywords: Beef manure, Greenhouse gas, Soil water, Urea, Water holding capacity.
40
Atilano-Camino, Marina M., Ana P. Canizales Laborin, Angelita M. Ortega Juarez, Ana K. Valenzuela Cantú et Aurora M. Pat-Espadas. « Impact of Soil Amendment with Biochar on Greenhouse Gases Emissions, Metals Availability and Microbial Activity : A Meta-Analysis ». Sustainability 14, no 23 (24 novembre 2022) : 15648. http://dx.doi.org/10.3390/su142315648.
Texte intégralRésumé :
The effect of soil amendment with biochar has been widely evaluated for its effects in mitigating greenhouse gas emissions (GHG) and remediating polluted soils with metals; however, a synergic understanding of the system, including biochar, soil, and microbial activity, is lacking. In this study, a meta-analysis of 854 paired data from 73 studies demonstrate that biochar application in soil affects GHG emissions and soil metal availability. First, several properties of biochar, soil, and microbial activity were considered as parameters in the meta-analysis. Then, the size effect was evaluated using the percentage of change (Pc) as obtained by the meta-analyzed data. Several parameters were related as influencer factors in GHG emissions and soil metal availability. Notably, biochar addition in soil resulted in a significant CO2 increase in emissions, whereas N2O emissions decreased; these results were directly correlated with microbial activity. Although this trend, demonstrated by the data analysis, differs from results of other studies found in the literature, it also emphasized the need for a deep understanding of the effect of biochar addition to soil (properties, nutrients, gas exchange, etc.) and to microorganisms (activity, diversity, etc.). Furthermore, it was also proved, that soil metal concentration decreases significantly when biochar was added (Cd > Zn > Pb > Cu > Fe). According to the results, biochar addition in soils contaminated with Cd and Cu was related to an increase in the microbial activity; while, soils amended with biochar but polluted with Pb, Zn, and Fe presented a higher inhibition effect on microorganisms. To improve the interpretation of soil amendment with biochar, it would be necessary to standardize the form for reporting results, particularly of the microbial activity and GHG emissions, in order to be used for future comparative studies.
41
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 Discussions 8, no 5 (4 octobre 2011) : 9847–99. http://dx.doi.org/10.5194/bgd-8-9847-2011.
Texte intégralRésumé :
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 has only recently been fully appreciated, and a growing number of studies show that these events affect various biogeochemical processes including 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, highlighting the importance of understanding how rewetting and thawing will influence soil gas fluxes. Here we summarize findings in a new database based on 338 studies conducted from 1956 to 2010, and highlight open research questions. The database revealed conflicting results following rewetting and thawing in various terrestrial ecosystems, ranging from large increases in gas fluxes to non-significant changes. An analysis of published field studies (n = 142) showed that after rewetting or thawing, CO2, CH4, N2O, NO and NH3 fluxes increase from pre-event fluxes following a power function, with no significant differenced among gases. We discuss possible mechanisms and controls that regulate flux responses, and note 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. flux, diffusion, dissolution) changes in soil gas fluxes, and explore synergistic experimental and modelling approaches.
42
Björn, Lars Olof, Beth A. Middleton, Mateja Germ et Alenka Gaberščik. « Ventilation Systems in Wetland Plant Species ». Diversity 14, no 7 (27 juin 2022) : 517. http://dx.doi.org/10.3390/d14070517.
Texte intégralRésumé :
Molecular oxygen and carbon dioxide may be limited for aquatic plants, but they have various mechanisms for acquiring these gases from the atmosphere, soil, or metabolic processes. The most common adaptations of aquatic plants involve various aerenchymatic structures, which occur in various organs, and enable the throughflow of gases. These gases can be transferred in emergent plants by molecular diffusion, pressurized gas flow, and Venturi-induced convection. In submerged species, the direct exchange of gases between submerged above-ground tissues and water occurs, as well as the transfer of gases via aerenchyma. Photosynthetic O2 streams to the rhizosphere, while soil CO2 streams towards leaves where it may be used for photosynthesis. In floating-leaved plants anchored in the anoxic sediment, two strategies have developed. In water lilies, air enters through the stomata of young leaves, and streams through channels towards rhizomes and roots, and back through older leaves, while in lotus, two-way flow in separate air canals in the petioles occurs. In Nypa Steck palm, aeration takes place via leaf bases with lenticels. Mangroves solve the problem of oxygen shortage with root structures such as pneumatophores, knee roots, and stilt roots. Some grasses have layers of air on hydrophobic leaf surfaces, which can improve the exchange of gases during submergence. Air spaces in wetland species also facilitate the release of greenhouse gases, with CH4 and N2O released from anoxic soil, which has important implications for global warming.
43
Ma, Qiaoying, Jiwei Li, Muhammad Aamer et Guoqin Huang. « Effect of Chinese Milk Vetch (Astragalus sinicus L.) and Rice Straw Incorporated in Paddy Soil on Greenhouse Gas Emission and Soil Properties ». Agronomy 10, no 5 (17 mai 2020) : 717. http://dx.doi.org/10.3390/agronomy10050717.
Texte intégralRésumé :
Paddy soil is an important emission source of agricultural greenhouse gases. The excessive application of chemical fertilizer to paddy soil is one of the important reasons for high greenhouse gas emissions. Emissions can be reduced through optimized agricultural management measures. The incorporation of Chinese milk vetch (CMV) and rice straw in the field to replace some of the chemical fertilizer can reduce the emissions of greenhouse gases, but the relationship between these emissions and soil properties after the incorporation of CMV and rice straw is unclear. Through the continuous determination of greenhouse gases and the physical and chemical properties of soil, it was found that the addition of CMV and straw could increase the emissions of methane (CH4) and carbon dioxide (CO2), but nitrous oxide (N2O) emissions were lower. The effect of the combined incorporating of CMV and rice straw on soil properties was more significant than CMV alone. It was also found that CH4 and CO2 emissions were positively correlated with microbial biomass carbon and nitrogen, pH, and soil catalase and β-xylosidase activities. In practice, we can reduce greenhouse gas emissions by water and fertilizer management.
44
Samson, Marianne I., Roland J. Buresh et Surajit K. De Datta. « Evolution and soil entrapment of nitrogen gases formed by denitrification in flooded soil ». Soil Science and Plant Nutrition 36, no 2 (juin 1990) : 299–307. http://dx.doi.org/10.1080/00380768.1990.10414996.
Texte intégral
45
Hadi, Abdul, Dedi Nursyamsi Affandi, Rosenani Abu Bakar et Kazuyuki Inubushi. « Greenhouse Gas Emissions from Peat Soils Cultivated to Rice Field, Oil Palm and Vegetable ». JOURNAL OF TROPICAL SOILS 17, no 2 (13 novembre 2012) : 105. http://dx.doi.org/10.5400/jts.2012.v17i2.105-114.
Texte intégralRésumé :
Presently, about 20% of oil palm (Elaeis guineensis Jacq) fields in Indonesia are on peat soil, in addition to that otherarea of peat soil has been conventionally used for rice field and vegetables. To elucidate the global warmingpotentials of peat soils cultivated to oil palm, vegetable or rice field, field experiment has been carried out in SouthKalimantan. Air samples were taken from rice field, oil palm and vegetable fields in weekly basis for six month periodand analyzed for concentrations of N2O, CH4 and CO2. The global warming potentials (GWP) of the three gases werecalculated by multiplying the emission of each gas with their respective mole warming potential. This step wasfollowed by the addition of the three gases’ GWP to have the total GWP. The results showed that the emissions ofgreenhouse gases from peat soils changed seasonally and varied with the crops cultivated. Oil palm has resultedthe highest GWP, mostly contributed by N2O. There was no statistical different in total GWP of paddy andvegetable fields. The annual N2O emission from oil palm field was 4,582 g N ha-1 yr-1. Water, nutrients and organicmatter managements are among the potential techniques to minimize gas emissions from oil palm field which needfield trials.
46
Kumputa, Supitrada, Patma Vityakon, Patcharee Saenjan et Phrueksa Lawongsa. « Carbonaceous Greenhouse Gases and Microbial Abundance in Paddy Soil under Combined Biochar and Rice Straw Amendment ». Agronomy 9, no 5 (6 mai 2019) : 228. http://dx.doi.org/10.3390/agronomy9050228.
Texte intégralRésumé :
Little is known about the carbonaceous greenhouse gases and soil microbial community linked to the combination of biochar (BC) and rice straw (RS) in paddy soils. The objectives of this research were to evaluate the effects of combining BC and RS on (1) CH4 and CO2 production from paddy soil, (2) archaeal and bacterial abundance, and (3) rice grain yield. The experiments consisted of a pot trial and an incubation trial, which had a completely randomized design. The experiments included five treatments with three replications: (a) the control (without BC, RS, and chemical fertilizer (CF)); (b) CF; (c) BC 12.50 t ha−1; (d) RS 12.50 t ha−1; and (e) combined BC 6.25 t ha−1 + RS 6.25 t ha−1 + CF. In the sole RS treatment, CH4 production (0.0347 mg m−2 season−1) and the archaeal and bacterial abundance (5.81 × 108 and 4.94 × 1010 copies g−1 soil dry weight (DW)) were higher than outcomes in the sole BC treatment (i.e., 0.0233 mg m−2 season−1 for CH4 production, and 8.51 × 107 and 1.76 × 1010 copies g−1 soil DW for archaeal and bacterial abundance, respectively). CH4 production (0.0235 mg m−2 season−1) decreased significantly in the combined BC + RS + CF treated soil compared to the soil treated with RS alone, indicating that BC lessened CH4 production via CH4 adsorption, methanogenic activity inhibition, and microbial CH4 oxidation through bacterial methanotrophs. However, the archaeal abundance (3.79–5.81 × 108 copies g−1 soil DW) and bacterial abundance (4.94–5.82 × 1010 copies g−1 soil DW) in the combined BC+ RS + CF treated soil and the RS treated soil were found to increase relative to the treatments without RS. The increase was due to the easily decomposable RS and the volatile matter (VM) constituent of the BC. Nevertheless, the resultant CO2 production was relatively similar amongst the BC, RS, and BC + RS treated soils, which was indicative of several processes, e.g., the CO2 production and reduction that occurred simultaneously but in different directions. Moreover, the highest yield of rice grains was obtained from a combined BC + RS + CF treated soil and it was 53.47 g pot−1 (8.48 t ha−1). Over time, the addition of BC to RS soil enhanced the archaeal and bacterial abundance, thereby improving yields and reducing CH4 emissions.
47
Peng, Yuanying, Sean C. Thomas et Dalung Tian. « Forest management and soil respiration : Implications for carbon sequestration ». Environmental Reviews 16, NA (décembre 2008) : 93–111. http://dx.doi.org/10.1139/a08-003.
Texte intégralRésumé :
It is recognized that human activities, such as fossil fuel burning, land-use change, and forest harvesting at a large scale, have resulted in the increase of greenhouse gases in the atmosphere since the onset of the industrial revolution. The increasing amounts of greenhouse gases, particularly CO2 in the atmosphere, is believed to have induced climate change and global warming. With the ability to remove CO2 from the atmosphere through photosynthesis, forests play a critical role in the carbon cycle and carbon sequestration at both global and local scales. It is necessary to understand the relationship between forest soil carbon dynamics and carbon sequestration capacity, and the impact of forest management practices on soil CO2 efflux for sustainable carbon management in forest ecosystems. This paper reviews a number of current issues related to (1) carbon allocation, (2) soil respiration, and (3) carbon sequestration in the forest ecosystems through forest management strategies. The contribution made by forests and forest management in sequestrating carbon to reduce the CO2 concentration level in the atmosphere is now well recognized. The overall carbon cycle, carbon allocation of the above- and belowground compartments of the forests, soil carbon storage and soil respiration in forest ecosystems and impacts of forest management practices on soil respiration are described. The potential influences of forest soils on the buildup of atmospheric carbon are reviewed.
48
Bay, Sean, Belinda Ferrari et Chris Greening. « Life without water : how do bacteria generate biomass in desert ecosystems ? » Microbiology Australia 39, no 1 (2018) : 28. http://dx.doi.org/10.1071/ma18008.
Texte intégralRésumé :
Many of the world's most arid deserts harbour surprisingly diverse communities of heterotrophic bacteria. These organisms persist in surface soils under extreme climatic conditions, despite lacking obvious energy inputs from phototrophic primary producers. A longstanding conundrum has been how these communities sustain enough energy to maintain their diversity and biomass. We recently helped to resolve this conundrum by demonstrating that some desert communities are structured by a minimalistic mode of chemosynthetic primary production, where atmospheric trace gases, not sunlight, serve as the main energy sources. These findings are supported by pure culture studies that suggest atmospheric trace gases are dependable energy sources for the long-term survival of dormant soil bacteria. We predict that atmospheric trace gases may be a major energy source for desert ecosystems worldwide.
49
Barančíková, G., J. Halás, M. Gutteková, J. Makovníková, M. Nováková, R. Skalský et Z. Tarasovičová. « Application of RothC model to predict soil organic carbon stock on agricultural soils of Slovakia ». Soil and Water Research 5, No. 1 (26 février 2010) : 1–9. http://dx.doi.org/10.17221/23/2009-swr.
Texte intégralRésumé :
Soil organic matter (SOM) takes part in many environmental functions and, depending on the conditions, it can be a source or a sink of the greenhouse gases. Presently, the changes in soil organic carbon (SOC) stock can arise because of the climatic changes or changes in the land use and land management. A promising method in the estimation of SOC changes is modelling, one of the most used models for the prediction of changes in soil organic carbon stock on agricultural land being the RothC model. Because of its simplicity and availability of the input data, RothC was used for testing the efficiency to predict the development of SOC stock during 35-year period on agricultural land of Slovakia. The received data show an increase of SOC stock during the first (20 years) phase and no significant changes in the course of the second part of modelling. The increase of SOC stock in the first phase can be explained by a high carbon input of plant residues and manure and a lower temperature in comparison with the second modelling part.
50
Ning, Jiao, Xiong Z. He, Fujiang Hou, Shanning Lou, Xianjiang Chen, Shenghua Chang, Cheng Zhang et Wanhe Zhu. « Optimizing alfalfa productivity and persistence versus greenhouse gases fluxes in a continental arid region ». PeerJ 8 (10 mars 2020) : e8738. http://dx.doi.org/10.7717/peerj.8738.
Texte intégralRésumé :
Alfalfa in China is mostly planted in the semi-arid or arid Northwest inland regions due to its ability to take up water from deep in the soil and to fix atmospheric N2 which reduces N fertilizer application. However, perennial alfalfa may deplete soil water due to uptake and thus aggravate soil desiccation. The objectives of this study were (1) to determine the alfalfa forage yield, soil property (soil temperature (ST), soil water content (SWC), soil organic carbon (SOC) and soil total nitrogen (STN)) and greenhouse gas (GHG: methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2)) emissions affected by alfalfa stand age and growing season, (2) to investigate the effects of soil property on GHG emissions, and (3) to optimize the alfalfa stand age by integrating the two standard criteria, the forage yield and water use efficiency, and the total GHG efflux (CO2-eq). This study was performed in alfalfa fields of different ages (2, 3, 5 and 7 year old) during the growing season (from April to October) in a typical salinized meadow with temperate continental arid climate in the Northwest inland regions, China. Despite its higher total GHG efflux (CO2-eq), the greater forage yield and water use efficiency with lower GEIhay and high CH4 uptake in the 5-year alfalfa stand suggested an optimal alfalfa stand age of 5 years. Results show that ST, SOC and RBM alone had positive effects (except RBM had no significant effect on CH4 effluxes), but SWC and STN alone had negative effects on GHG fluxes. Furthermore, results demonstrate that in arid regions SWC superseded ST, SOC, STN and RBM as a key factor regulating GHG fluxes, and soil water stress may have led to a net uptake of CH4 by soils and a reduction of N2O and CO2 effluxes from alfalfa fields. Our study has provided insights into the determination of alfalfa stand age and the understanding of mechanisms regulating GHG fluxes in alfalfa fields in the continental arid regions. This knowledge is essential to decide the alfalfa retention time by considering the hay yield, water use efficiency as well as GHG emission.