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1
Kranabetter, John Marty. "Pulp fibre waste as a soil amendment : rates of net carbon mineralization." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29193.
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The potential for using RMP (refiner mechanical process) pulp mill fibre waste as a soil amendment was investigated by determining levels of net carbon mineralization. Under optimum conditions (laboratory incubation study), the pulp fibre waste, being a relatively homogeneous substrate, was found to mineralize at one rate of -0.0078 d⁻¹. In field applications the rate of net mineralization was slower, with rates of -0.0034 d⁻¹ and -0.0037 d⁻¹, as determined by soil respiration and litter bag trials, respectively. A loading effect was noted for this amendment, where increasing the levels of application was found to cause decreases in the mineralization rate.
Using pulp fibre waste in forest landing rehabilitation appears to increase the levels of microbial activity in the surface horizon. The higher levels of productivity should lead to improvements in soil structure, and would be a better alternative to only tilling and fertilizing the soil.<br>Land and Food Systems, Faculty of<br>Graduate
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Mfombep, Priscilla M. "Soil carbon sequestration: factors influencing mechanisms, allocation and vulnerability." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/16981.
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Doctor of Philosophy<br>Department of Agronomy<br>Charles W. Rice<br>Increasing atmospheric CO2 concentrations and other greenhouse gases have been linked to global climate change. Soil organic C (SOC) sequestration in both agricultural and native ecosystems is a plausible option to mitigate increasing atmospheric CO2 in the short term. Laboratory and field studies were conducted to (1) understand the influence of soil water content on the temperature response of SOC mineralization (2) investigate burn and nutrient amendment effects on biogeochemical properties of tallgrass prairie and (3) assess perennial and annual plant management practices on biophysical controls on SOC dynamics. The laboratory study was conducted using soils collected from an agricultural field, currently planted to corn (C4 crop), but previously planted to small grain (C3) crops. The changes in cultivated crops resulted in a δ¹³C isotopic signature that was useful in distinguishing older from younger soil derived CO2-C during SOC mineralization. Soils were incubated at 15, 25 and 35 oC, under soil water potentials of -1, -0.03 and -0.01 MPa. Soil water content influenced the effect of temperature on SOC mineralization. The impact of soil water on temperature effect on SOC mineralization was greater under wetter soil conditions. Both young and older SOC were temperature sensitive, but SOC loss depended on the magnitude of temperature change, soil water content and experiment duration. Microbial biomass was reduced with increasing soil water content. The first field experiment investigated burn and nutrient amendment effects on soil OC in a tallgrass prairie ecosystem. The main plots were burned (B) and unburned (UB) tallgrass prairie and split plots were nutrient amendments (N, P or N+P including controls). Vegetation was significantly altered by burning and nutrient amendment. Treatment effects on either TN or SOC were depth-specific with no impact at the cumulative 0-30 cm depth. The P amendment increased microbial biomass at 0-5 cm which was higher in unburned than burned. However, at 5-15 cm depth N amendment increased microbial biomass which was higher in burned than unburned. In conclusion, soil OC in both burned and unburned tallgrass prairie may have a similar trajectory however; the belowground dynamics of the burned and unburned tallgrass prairie are apparently different. Another field experiment assessed SOC dynamics under perennial and annual plant management practices. The main plots were grain sorghum (Sorghum bicolor) planted in no-tillage (NT) or continuous tillage (CT), and replanted native prairie grass, (Andropogon gerardii) (RP). The spit plots were phosphorus (+P) and control without P (-P). The P amendment was used to repress arbuscular mycorrhizal fungi (AMF), known to influence soil aggregation. The macroaggregate >250 µm, SOC and TN were higher in RP and NT than CT. The relative abundances of AMF and saprophytic fungi were greater with less soil disturbance in RP and NT than in CT. Therefore, less soil disturbance in RP and NT increased AMF and fungal biomasses. The higher relative abundances of AMF and fungi with less soil disturbance increased macroaggregate formation in RP and NT, which resulted in higher SOC sequestration in RP and NT than CT.
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Sajedi, Toktam. "The effects of excessive moisture on soil carbon and nitrogen mineralization and forest productivity." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/27030.
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Conifers of regenerating cedar-hemlock (CH) forests exhibit slow growth and nutrient deficiencies (N and P), which are not observed on adjacent cutovers of hemlock-amabilis fir (HA) forests. I test the theory that excessive moisture and resulting low oxygen availability in CH sites create the low N supply and poor growth in these ecosystems. A field experiment determined: 1) whether CH and HA forests differ in soil moisture and aeration, 2) whether decomposition rate and soil C stores differ in CH and HA forests, 3) whether composition of plant communities are related to soil moisture and aeration, and 4) the impact of harvesting CH and HA forests on moisture and aeration conditions. A laboratory experiment investigated the effects of moisture levels, from field capacity to saturation level, on C and N mineralization rates. Lastly, a field trial was carried out to assess drainage as a potential forest management solution in wetland forests by comparing C dynamics in drained and un-drained sites.
As hypothesized, CH forests were wetter, less aerated, had shallower aerated depth and higher frequency of anaerobic conditions compared with HA forests. Composition of plant species was related to soil moisture and aeration, however plant diversity was not. Soil aeration was the most important factor, explaining 25% of the variability of species within plant communities. Compared with HA forests with well-aerated soils, soils in HA clearcuts were anaerobic, had slower decomposition rate and shallower rooting depth. Microbial biomass, C mineralization and the soluble inorganic N: soluble organic N (SIN:SON) ratio all declined under water-saturated conditions. Concentrations of SIN increased with increasing moisture in HA soils; whereas in CH humus and soil, the SIN pool was small and decreased with increasing moisture. The results indicate that the low N availability on CH sites results from synergistic effects of litter quality and greater frequency of waterlogging. Drainage could be a useful silvicultural practice for improving the productivity of cedar-swamp ecosystems without stimulating loss of soil C, provided that redox levels are maintained at less than +300 mV, at which level oxygen is sufficient for plant growth but not for aerobic microbial decomposition.
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Calias, Pangiotis. "Forest soil organic matter of a European transect : carbon mineralization in response to temperature." Thesis, University of Exeter, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363387.
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Ma, Qian. "Effects of Crop Residue Quality and Nitrogen Fertilization on Priming of Soil Organic Carbon Mineralization." Kyoto University, 2021. http://hdl.handle.net/2433/261632.
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Stark, S. (Sari). "Reindeer grazing and soil nutrient cycling in boreal and tundra ecosystems." Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:9514266927.
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Abstract
In northernmost Fennoscandia, grazing by reindeer
(Rangifer tarandus L.) has a substantial impact on
the vegetation of boreal forests and arctic-alpine tundra heaths, which
are reflected in below-ground processes, such as nutrient mineralization
and soil organic matter decomposition. In the present thesis, the effects
of reindeer grazing on soil nutrient cycling were studied by comparing
grazed situation with an ungrazed control area in ten boreal forests and
six arctic-alpine tundra heaths.
In boreal forests, reindeer grazing reduced microbial respiration in
both the oligotrophic and mesotrophic study areas, indicating a deficiency
of labile substrates for the soil microbes due to reindeer grazing.
Simultaneously, there was heterogeneity in the impact on nitrogen
mineralization rates as at some sites, mineralization was enhanced by
grazing. The fertilization effect of urine and faeces can therefore be
strong enough a factor to outweigh a reduction in quality of soil organic
matter. In the oligotrophic forests, low soil moisture content in the
grazed areas could sometimes limit the mineralization rates even when the
potential for mineralization was enhanced by grazing.
In the tundra ecosystems, there was spatial variation in the impact
of grazing on microbial respiration and nitrogen mineralization. Low
grazing intensity occurring outside the growing season had a retarding
impact on nutrient cycling in both unfertilized, nutrient-poor and
fertilized, nutrient-rich conditions. In contrast, a relatively high
grazing intensity enhanced the mineralization rates in two nutrient-poor
and two nutrient-rich tundra heaths. When three different grazing
intensities were compared in one oceanic, nutrient-rich and one
continental, nutrient-poor tundra heath, the strongest positive effect of
grazing on soil nutrient cycling occurred in the heavily grazed areas. The
data do not support the assumption that soil nutrient availability
regulates whether herbivores enhance or retard nutrient cycling in the
soil. Instead, the net effect of grazing is determined by the balance
between the underlying mechanisms that may work at opposite directions.
The most important of these mechanisms are the grazer-mediated impact on
the decomposability of the dominant vegetation and fertilization by urine
and faeces.
The duration, intensity and seasonal timing of the grazing seem to
be important factors that regulate whether reindeer grazing enhances or
retards soil nutrient cycling in each specific area. Due to the high
spatial and temporal variation in the effects of grazing observed in this
study, it is not possible to generalize the overall impact of grazing.
Further study is required in order to determine the exact conditions under
which grazing enhances or it retards soil nutrient cycling.
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Neal, Andrew Wilson. "Soil Carbon and Nitrogen Dynamics Across the Hillslope-Riparian Interface in Adjacent Watersheds with Contrasting Cellulosic Biofuel Systems." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/48125.
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Climate change resulting from emissions of fossil fuel combustion has sparked considerable interest in renewable energy and fuel production research, particularly energy derived from cellulosic ethanol, which is derived from biomass such as wood and grass. Cellulosic ethanol demonstrates a more promising future as a global energy source than corn-derived ethanol because it does not displace food crops, irrigation is not required, and chemical application rates are much lower than for annual crops, such as corn. Growing cellulosic biomass for energy can help reduce greenhouse gas emissions via carbon (C) sequestration and by reducing demand for fossil fuel production. The objective of this study was to investigate how land use change affects soil properties and selected soil C and nitrogen (N) dynamics among alternative cellulosic biofuel treatments at the Weyerhaeuser Alabama Cellulosic Biofuel Research site in west-central Alabama. Composite soils for characterization, along with forest floor, were collected at year 1 and year 2 after treatment establishment at 0-15cm and 15-30cm depths at six locations along three hillslope-riparian transects in five experimental watershed treatments. Decomposition of loblolly pine needles was assessed in each watershed using an in situ litter bag method. Seasonal in situ net nitrogen mineralization was measured using a sequential core method, and an anaerobic incubation for N mineralization potential of composite soils was performed in the laboratory. Results revealed high variability of soil properties and processes within these watersheds, along with no consistent treatment effects. This study provides baseline data for these watershed treatments for future studies.<br>Master of Science
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Dang, Chansotheary. "Response of Soil Microbial Communities to Saltwater Intrusion in Tidal Freshwater Wetlands." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4466.
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Saltwater intrusion due to global change is expected to have a detrimental effect on the biogeochemistry of tidal freshwater wetlands. Of particular concern is that fact that salinization can alter the role of these ecosystems in the global carbon cycling by causing shifts in microbial metabolism that alter greenhouse gas emissions and increase carbon mineralization rates. However, our understanding of how wetland microbial community dynamics will respond to saltwater intrusion is limited. To address this knowledge gap and increase our understanding of how microbial communities in tidal freshwater wetlands change over time (1, 3, 12, and 49 weeks) under elevated salinity conditions, an in situ soil transplant was conducted. Throughout the 49 weeks of saltwater exposure, salinity had no effect on soil quality (organic matter content and C:N ratio). In contrast, the concentration of porewater ion species (SO4-2, NO3-, and NH4+) considerably increased. The activity of hydrolytic enzymes, (ß-1,4-glucosidase and 1,4-ß-cellobiohydrolase) gradually decreased with prolonged exposure to saline conditions; by the final sampling event (49 weeks), activity was reduced by ~70% in comparison to the freshwater controls. Short term exposure to salinity (3 and 12 weeks) had a greater effect on phenol oxidase, decreasing activity by 10-20%. Saltwater exposure had an immediate (1 week) effect on potential rates of carbon mineralization; overall, carbon dioxide production doubled and methane production decreased by ~20-fold. These changes in gas production were correlated to increased salinity and to changes in the abundance of methanogens and sulfate reducing bacteria, suggesting a shift in the terminal step in organic matter degradation from methanogenesis to sulfate reduction. Principal component analysis revealed distinct changes in soil environmental conditions and carbon metabolism within weeks, but the response of the microbial community was slower (months to a year). Taken together, results from this study indicate that the response of tidal freshwater wetlands to salinization is driven by complex interactions of microbial related processes and environmental changes that are dependent on the duration of exposure. Assessing the impact of environmental perturbation on ecosystem function may be better achieved by complementary analysis of both microbial community structure and function.
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Bierer, Andrew M. "Nitrogen dynamics and biological response to dairy manure application." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/90372.
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Animal manures are land applied in agronomic systems to supply essential crop nutrients and decrease dependency on chemical fertilizers. Liquid manures are traditionally surface broadcast to fields and sometimes incorporated to reduce odor and nutrient losses; however, incorporation is incompatible with no-till agriculture. Subsurface manure injection is a no-till compatible alternative application method which addresses these concerns, but likely changes the dynamics of nutrient cycling. Comparison of the two application methods has yielded mixed results and warrants further research. Therefore, the objectives of this research were to contrast the surface broadcast and subsurface injection of dairy slurry on nitrogen and carbon cycling, crop yield, and biologic responses to proxy soil health. In a forced air-flow laboratory incubation, manure injection reduced ammonia volatilization by 87% and 98% in a sandy loam and clay loam soil, respectively. The increased ammoniacal nitrogen recovery resulted in increases of soil nitrate of 13% for the sandy loam and 26% for the clay loam after 40 days of incubation. Microbial measurements were inconclusive in the laboratory. In 7 site-years of field study, soil nitrate was greater in 7 of 25 measurements under manure injection and 30% higher under injection on average during the corn pre side-dress nitrate test (PSNT) time. Soil nitrate sampling methods were assessed for fields injected with manure; a standard random sampling method had a coefficient of variation (C.V.) of 28% and was as equally repeatable as utilizing an equi-spaced distribution of cores taken across an injection band, C.V. of 30%. Both biological responses, carbon mineralization
(C-min) and substrate induced respiration (SIR), were not different between application methods; both were highly variable and C-min was especially intensive logistically. Corn yield showed no consistent response to application method, but probably was not nitrogen limited. In 2 years of field study conducted on a university research farm injection resulted in greater 0-15cm soil nitrate levels than surface broadcast 1 week after application and persisted for 9 additional weeks. In injected plots, nitrate was concentrated in the injection band; nitrate movement was significant only 10cm lateral to the injection band but overall distribution fit well to a second degree polynomial, especially 2 and 4 weeks after application, R2>0.80. Evidence of leaching was observed in one year after receiving considerable rainfall in weeks 1 and 2 after application. When corn grain yield was averaged year over year, injection was 26% greater than the no- manure control, and 15% greater than surface application. Both biological metrics, C-min and microbial biomass, were stratified by depth; C-min was concentrated within the manure band leading to greater mineralization under injected applications. Microbial biomass was significantly higher under injection at the 15-30cm depth. Overall biological response to manure application method was inconclusive, however manure injection is superior to surface application in terms of nitrogen recovery.<br>Doctor of Philosophy<br>Animal manures supply nutrients essential to crop growth (notably nitrogen and phosphorous); liquid manures (pigs and dairy cattle) are commonly applied by spraying them on soils before tillage. Where no-tillage is used as a conservation measure subsurface injection can be used as an alternative to leaving manure on the soil surface. The purpose of this research was to assess nutrient cycling, crop yield, and soil health impacts of surface applied and injected dairy manure applications. Manure injection greatly reduces a nitrogen loss pathway, and as a result supplies more plant available nitrogen to the crop. Methods of soil sampling fields using injection were compared and a recommended sampling method was defined. Transport of a form of nitrogen vulnerable to movement in the ground was found to only travel 10cm away from where manure was injected. Transport of this form of nitrogen below the injection area was observed after abundant rainfall. Crop yields were sometimes higher under injection however, yields are also determined by factors other than nitrogen. Soil health was not repeatably improved under one application method, but microbial activity was greater at shallower soil depths.
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Lynch, Madalyn Josephine. "A Measurement of Conservation Agriculture’s Effect on Nitrogen and Carbon Mineralization Rates for Agricultural Recommendations in Haiti’s Central Plateau." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51620.
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Much of Haitian agriculture is characterized by subsistence farming systems on eroded and nutrient-poor soils. Implementation of Conservation Agriculture systems has proven effective at improving soil quality and crop yield in many areas of the world, including areas similar to those in Haiti. While most Haitian smallholder farmers are highly resource-limited and adoption of new technologies is limited, these farmers are known to adopt new crops and practices if benefits that outweigh risks are demonstrated. Cover crops that help provide soil cover and increase nutrient mineralization are one of the most potentially beneficial changes that could be made on most smallholder farms. However, before specific cover crop recommendations can be made, their potential benefits need to be quantified. One field experiment in the summer of 2013 assessed decomposition rates and nutrient mineralization from common cash crops and two potential cover crops either on the soil surface or buried at 15 cm. The relative difficulty and expense of conducting these types of field trials led to the development and assessment of a laboratory-based system that could be used to simulate plant residue decomposition and nutrient release under controlled conditions. Additional benefits of a laboratory-based study include the ability to test significantly more treatment combinations than would likely be possible under field conditions and to control nearly all other experimental variables, other than the desired treatment comparisons.<br>Master of Science
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Keraval, Benoît. "Les métabolismes oxydatifs extracellulaires : une nouvelle vision des processus de minéralisation du carbone organique du sol." Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22740/document.
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Eliasson, Peter. "Impacts of climate change on carbon and nitrogen cycles in boreal forest ecosystems /." Uppsala : Swedish University of Agricultural Sciences, 2007. http://diss-epsilon.slu.se/archive/00001525/.
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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2007.<br>Thesis documentation sheet inserted. Includes appendix of four papers and manuscripts, three co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.
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Schütt, Marianne [Verfasser], and Egbert [Akademischer Betreuer] Matzner. "Carbon and nitrogen mineralization in temperate forest soils at low temperatures / Marianne Schütt. Betreuer: Egbert Matzner." Bayreuth : Universität Bayreuth, 2015. http://d-nb.info/1066729484/34.
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Nordström, Högberg Mona. "Carbon and nitrogen relations among soils, microbes and plants in boreal forests /." Uppsala : Dept. of Forest Mycology and Pathology, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/s314.pdf.
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Castro, Hector F. "Microbial ecology of anaerobic terminal carbon mineralization in everglades soils, with emphasis on sulfate-reducing prokaryotic assemblages." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001035.
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Thoman, Heather Marie. "A Critical Temperature Threshold for Early Leaf Litter Decomposition and Microbial Enzyme Activity." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1399571419.
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Langenbruch, Christina. "Effects of nutrient cycling through litter of different broadleaved deciduous tree species on soil biochemical properties and the dynamics of carbon and nitrogen in soil." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-F1C2-F.
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Henriques, Hermano José Ribeiro. "Sistemas de manejo do solo para retomada do plantio direto." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153651.
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Previous issue date: 2018-02-20<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>A utilização das regiões de cerrado para a produção agrícola se estabeleceu inicialmente pelo uso intensivo do solo proporcionando alterações nos atributos físicos, químicos e biológicos de acordo com o tipo de manejo adotado. O experimento foi realizado na Fazenda de Ensino, Pesquisa e Ensino (FEPE-Cerrado), pertencente à Faculdade de Engenharia de Ilha Solteira, no município de Selvíria- MS, em um LATOSSOLO VERMELHO Distroférrico, de textura argilosa (EMBRAPA, 2013), nos anos de 2016 a 2017 teve como objetivo de comparar os sistemas de manejo do solo a ser adotada em safras seguidas para estabilização do plantio direto (SPD) nas culturas de soja (verão) e do sorgo (outono-inverno). O delineamento experimental foi de blocos ao acaso, com quatro repetições e sete tratamentos: sistema de semeadura direta contínuo (de 23 e 24 anos de implantação), sendo que cultivo mínimo, preparo convencional do solo com grade pesada e arado de aiveca seguida de três gradagens leves e plantio direto sobre cada destes manejos do solo realizados continuamente com o mesmo número de safras seguidas até a 7° e 8° safra. Para comparação de medias foram avaliados os dados biométricos das culturas da soja e do sorgo, atributos físicos do solo e quantidade de carbono orgânico total. Os resultados obtidos indicaram que os sistemas de semeadura direta contínuo apresentaram maior quantidade de estoque de carbono orgânico total. A elevação da produtividade de grãos de soja está diretamente relacionada à maior presença de plantas no estande final quando o solo foi preparado com grade pesada seguida do tempo de implantação como sistema plantio direto, diferentemente dos manejos de preparo do solo com grade pesada e arado de aiveca contínuo terem menor sobrevivência de plantas, refletiu diretamente na queda de produtividades de grãos de soja em razão do maior campo de visão ter facilitado o ataque de pássaros. Os mesmos tratamentos de manejos do solo adotados na cultura do sorgo apresentaram efeito nulo sobre características biométricas, demostrando que independentemente do tempo de implantação do SPD e manejo do solo adotado anteriormente continua sendo a opção mais viável economicamente para a região de Cerrado.<br>The use of cerrado regions for agricultural production was established initially with intensive use of the soil, providing changes in the physical, chemical and biological attributes according to the type of management adopted. The experiment was carried out at the Fazenda de Ensino, Pesquisa e Ensino (FEPE-Cerrado), belonging to the Faculty of Engineering of Ilha Solteira, in the of Selvíria-MS, in an Oxisol (EMBRAPA, 2013), year period from 2016 to 2017, had the objective of comparing the soil tillage systems to be adopted in crop seasons for stabilization of no-tillage (SPD) in soybean (summer) and sorghum (autumn-winter). The experimental design was a randomized block design, using factorial arrangement with four replications and seven treatments: continuous no-tillage (23 and 24 years of implantation), with minimum tillage, conventional soil tillage with heavy grating, and shisel moldboard pow by three disk plowing followed and no-tillage on each of these soils managed continuously with the same number of harvests followed up to the 7th and 8th harvests. Biometric data from soybean and sorghum cultures, soil physical attributes and amount of total organic carbon were evaluated for comparison of means. The results showed that continuous direct seeding systems presented higher amounts of total organic carbon stock. The increase of soybean grain yield is directly related to the greater presence of plants in the final stand when the soil was prepared with heavy grating followed by the time of implantation as no-tillage system, unlike the soil preparation operations with heavy grating and shisel moldboard pow continued to have lower plant survival, directly reflected in the fall in yields of soybeans because the greater field of view facilitated the attack of birds. The same soil management treatments adopted in the sorghum crop showed zero effect on biometric characteristics, showing that regardless of the time of SPD implementation and previously adopted soil management, it remains the most economically viable option in the Cerrado.
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Lorenz, Klaus. "The role of microorganisms and organic matter quality for nutrient mineralization of carbon composition of organic layers in forests as influenced by site properties and soil management /." Stuttgart : Inst. für Bodenkunde und Standortslehre, 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009736028&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Thothong, Warinya. "Source, storage and mineralization of organic matter in a tropical water reservoir (Thailand) : relationship with soil erosion on the watershed." Paris 6, 2009. http://www.theses.fr/2009PA066231.
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L’étude des flux de C dans une retenue d’eau du nord de la Thaïlande (Mae Thang, 220 ha, 35 x 106 m3) révèle que des facteurs climatiques (intensité des pluies) et anthropiques (mise en culture du bassin versant) caractérisés par des effets seuils, contrôlent les apports et le stockage de C dans les sédiments. Pendant les périodes de faibles debits d’entrée, les caractéristiques de la colonne d’eau sont contrôlées par les processus de production - minéralisation. La source principale de C est représentée par la biomasse aquatique. Pendant les périodes de forts débits, les apports de C sont essentiellement terrestres (plus de ca. 90 %). Bien que des concentrations élevées en CH4 dissous (jusqu’à 1650 µmol. L-1) ont pu être mesurées dans l’hypolimnion pendant la saison des pluies, les processus d’oxydation, renforcés au niveau de la thermocline et en relation avec la circulation d’eau profonde, réduisent considérablement l’exportation de CH4 dans l’épilimnion et son émission vers l’atmosphère. L’ensemble de ces données montre que le barrage peut être considéré comme un “puits” de C pour l’atmosphère avec une forte capacité de stockage (23,8 tC. Ha-1. Yr-1) et de faibles emissions de CH4.
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Nguyen, Trung Hai [Verfasser], Anthony [Akademischer Betreuer] Whitbread, Klaus [Gutachter] Dittert, and Marife [Gutachter] Corre. "Measuring and modelling the dynamics of carbon and nitrogen mineralization from diverse plant residues in soil – plant systems / Trung Hai Nguyen. Betreuer: Anthony Whitbread. Gutachter: Klaus Dittert ; Marife Corre." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2016. http://d-nb.info/1105036243/34.
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Passos, Tassia Raquel GarcÃs. "Nitrogen and carbon mineralization and dynamics of Fe depending on the type of vegetation and shrimp aquaculture effluent in mangrove soils." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17143.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior<br>A mineralizaÃÃo do carbono e nitrogÃnio pode ser afetada por diversos fatores. Com esse estudo objetivou - se avaliar a influÃncia das vegetaÃÃes (Rhizophora e Avicennia) no potencial de mineralizaÃÃo do carbono e nitrogÃnio do solo; comparar a mineralizaÃÃo do nitrogÃnio e carbono do solo entre as Ãreas impactadas e nÃo impactada com efluente de carcinicultura e verificar o efeito da variaÃÃo da marà na mineralizaÃÃo do carbono e nitrogÃnio do solo. As amostras de solo foram coletadas em duas Ãreas (Ãrea impactada e nÃo impactada com efluente de carcinicultura) e com predomÃnio de duas vegetaÃÃes (Rhizophora e Avicennia). Em seguida, essas amostras foram incubadas em laboratÃrio por 30 dias para avaliar o potencial de mineralizaÃÃo do carbono e do nitrogÃnio em resposta ao hidroperÃodo (inundado 18h e 6h seco), ao tipo de vegetaÃÃo e ao impacto do solo por efluente de carcinicultura. Verificou - se que no solo da Ãrea impactada menor formaÃÃo da pirita no solo. NÃo houve diferenÃa significativa para os teores de COT, N-total, N-NH4+e N-NO3-para as Ãreas e para as vegetaÃÃes, entretanto foi observada a relaÃÃo positiva entre os teores de COT e de N-total do solo. Foi verificado correlaÃÃo positiva entre os teores de COT e o carbono mineralizado indicando que os procedimentos de inundaÃÃo e sem inundaÃÃo (18 e 6 horas, respectivamente) foram eficientes para promover a mineralizaÃÃo do carbono do solo.<br>A mineralizaÃÃo do carbono e nitrogÃnio pode ser afetada por diversos fatores. Com esse estudo objetivou-se avaliar a influÃncia das vegetaÃÃes (Rhizophora e Avicennia) no potencial de mineralizaÃÃo do carbono e nitrogÃnio do solo; comparar a mineralizaÃÃo do nitrogÃnio e carbono do solo entre as Ãreas impactadas e nÃo impactada com efluente de carcinicultura e verificar o efeito da variaÃÃo da marà na mineralizaÃÃo do carbono e nitrogÃnio do solo. As amostras de solo foram coletadas em duas Ãreas (Ãrea impactada e nÃo impactada com efluente de carcinicultura) e com predomÃnio de duas vegetaÃÃes (Rhizophora e Avicennia). Em seguida, essas amostras foram incubadas em laboratÃrio por 30 dias para avaliar o potencial de mineralizaÃÃo do carbono e do nitrogÃnio em resposta ao hidroperÃodo (inundado 18h e 6h seco), ao tipo de vegetaÃÃo e ao impacto do solo por efluente de carcinicultura. Verificou-se que no solo da Ãrea impactada menor formaÃÃo da pirita no solo. NÃo houve diferenÃa significativa para os teores de COT, N-total, N-NH4+ e N-NO3- para as Ãreas e para as vegetaÃÃes, entretanto foi observada a relaÃÃo positiva entre os teores de COT e de N-total do solo. Foi verificado correlaÃÃo positiva entre os teores de COT e o carbono mineralizado indicando que os procedimentos de inundaÃÃo e sem inundaÃÃo (18 e 6 horas, respectivamente) foram eficientes para promover a mineralizaÃÃo do carbono do solo
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Rigby, Deborah Monique. "Microbial Responses to Coarse Woody Debris in Juniperus and Pinus Woodlands." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3515.
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The ecological significance of coarse woody debris (CWD) is usually highlighted in forests where CWD constitutes much of an ecosystem's carbon (C) source and stores. However, a unique addition of CWD is occurring in semi-deserts for which there is no ecological analog. To stem catastrophic wildfires and create firebreaks, whole Juniperus osteosperma (Torr.) and Pinus edulis (Engelm.) trees are being mechanically shredded into CWD fragments and deposited on soils previously exposed to decades of tree-induced changes that encourage "tree islands of fertility." To investigate consequences of CWD on C and nitrogen (N) cycling, we evaluated microbial metabolic activity and N transformation rates in Juniperus and Pinus surface and subsurface soils that were either shredded or left untreated. We sampled three categories of tree cover on over 40 tree cover encroachment sites. Tree cover categories (LOW = 0-15%, MID ≥ 15-45%, HIGH ≥ 45%) were used to indicate tree island development at time of treatment. In conjunction with our microbial measurements, we evaluated the frequency of three exotic grasses, and thirty-five native perennial grasses to identify links between belowground and aboveground processes. The addition of CWD increased microbial biomass by almost two-fold and increased microbial efficiency, measured as the microbial quotient, at LOW Juniperus cover. C mineralization was enhanced by CWD only in Pinus soils at the edge of tree canopies. The addition of CWD had little impact on microbial activity in subsurface soils. CWD enhanced the availability of dissolved organic C (DOC) and phosphorus (P) but tended to decrease the overall quality of labile DOC, measured as the ratio of soil microbial biomass to DOC. This suggested that the increase in DOC alone or other environmental factors novel to CWD additions lead to the increase in biomass and efficiency. P concentrations were consistently higher following CWD additions for all encroachment levels. The CWD additions decreased N mineralization and nitrification in Juniperus and Pinus soils at LOW and MID tree cover but only in surface soils, suggesting that less inorganic N was available to establishing or residual plants. The frequency of native perennial grasses, especially Elymus elymoides (Raf.), was at least 65% higher under CWD additions for all categories of tree cover, while the frequencies of exotic annual and perennial grasses were not impacted by CWD. The frequency of all perennial grasses ranged from 10-27%. Our results suggest that CWD enhanced microbial activity even when the quality of C substrates declined requiring microbes to immobilize more N. The reduction in inorganic N may promote the establishment and growth of native perennial grasses. Ultimately, the addition of CWD improved soil conditions for microbes in tree islands of fertility.
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Iqbal, Akhtar. "Effets de la nature et décomposition des mulchs de résidus végétaux sur les services assurés par les sols en agriculture de conservation : Étude expérimentale et modélisation." Thesis, Reims, 2013. http://www.theses.fr/2013REIMS001.
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En agriculture de conservation (AC), les résidus de cultures sous forme de paillis à la surface du sol associés à la suppression du travail du sol sont une composante intrinsèque des systèmes de culture. L'objectif principal de ce travail était de comprendre les effets de la nature et de la décomposition de mulch de résidus s sur les services d'approvisionnement et de régulation fournis par les sols dans les agrosystèmes en AC de régions tempérées (France) et tropicales (Madagascar et le Brésil). Des études expérimentales ont été réalisées pour obtenir des paramètres de décomposition pour une large gamme représentative de la qualité des résidus végétaux des agrosystèmes étudiés et pour tester et améliorer un modèle de décomposition des mulchs. Ensuite nous avons utilisé le modèle PASTIS_MULCH qui simule les biotransformations C et N et le transport de solutés dans les sols lors de la décomposition des mulchs.Pour la gamme de résidus de tiges testées, la rétention d'eau maximale a varié considérablement et ceci a été expliqué par les caractéristiques physiques du résidu. Avec les données obtenues par une série d'incubations de décomposition de résidus, nous avons proposé un ensemble de paramètres biologiques unique pour le module de décomposition CANTIS, simulant une large gamme de qualité des résidus de culture. L'étude expérimentale dans les colonnes de sol a montré que le mulch de maïs + dolique se décompose plus rapidement que mulch de blé + luzerne. Un régime de pluies fines et fréquentes augmente la décomposition du mulch par rapport à des pluies plus rares et plus fortes et cela est dû au maintien de l'humidité du mulch.Les simulations de scénarios avec PASTIS_MULCH ont montré que la pluie et les conditions d'évaporation classent les résidus de culture vis-à-vis de la décomposition lorsque ceux-ci sont placés en mulch à la surface des sols, tandis que les caractéristiques chimiques des résidus classent ceux-ci vis-à-vis de la décomposition lorsqu'ils sont incorporés. Aucune des situations étudiées pourrait être définie au vu des résultats de simulation comme étant adaptée à toutes les conditions pédo-climatiques et agricoles<br>In conservation agriculture (CA), crop residues mulches are associated to reduction or suppression of soil tillage and are an intrinsic component of CA. The objective of this work was to understand the effects of nature and decomposition of crop residue mulches on the provisioning and regulating services of agrosystems provided by soils under temperate (France) and tropical (Madagascar and Brazil) conditions. Experimental studies were realized to get decomposition parameters for a large range of residue quality representative of the agrosystems studied and to test and improve a MULCH model. Then we used PASTIS_MULCH model which simulates the C and N biotransformations and solutes transport in soils during mulch decomposition.For a range of plant-stem residues tested, the maximal water retention varied greatly and was only explained by the physical features of the residue. With a series of decomposition incubations, we proposed a single set of biological parameters for CANTIS decomposition module, simulating a large range of crop residue quality. Experimental study in soil columns showed that maize+dolichos mulch decomposed faster than wheat+alfalfa mulch. Frequent and light rain enhanced mulch decomposition compared to infrequent and heavy rain and this was due to the mulch remaining wetter with frequent rain.The simulations of scenarios with PASTIS showed that rain and evaporation conditions ranked crop residues decomposition when placed as mulches while the residue chemical characteristics ranked crop residues decomposition when incorporated. None of the situations studied would be defined as suitable in all pedo-climatic and agricultural conditions
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Leão, Ricardo Elso. "Estabilização do carbono de resíduos culturais no solo com o uso de xisto retortado." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/5590.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>The impact of retorted oil shale (ROS) addition on the dynamics of carbon (C) of crop residues (CR) in the soil is little known. Under laboratory conditions, the present study aimed to evaluate the residual and immediate effects of ROS on C mineralization of CR, water stability aggregates and storage C in the particulate (>53 μm) and associated minerals fractions (<53μm) of organic matter (OM) of a Hapludalf. In experiment 1, treatments consisted of soil samples from plots that received four additions of ROS, totaling 0, 6,000 and 12,000 kg ha-1. In experiment 2, treatments consisted of soil with no history of application of ROS (0 kg ha-1), that in the laboratory received three doses of ROS (0, 1,500 and 3,000 kg ha-1). In both experiments, the treatments were evaluated in the presence (3,000 kg ha-1) and absence of leaves and stalks of soybeans. The release of C-CO2 was evaluated for 80 days and at the end of the experiment determined the aggregate stability and C storage in different OM fractions. The addition of CR in soil with a history of ROS addition did not alter the release of C-CO2 and also did not reduce the apparent mineralization of C of RC compared to addition of these residues in soil with no history. In experiment 2, there was a reduction in the release of C-CO2 compared to the control only the treatment with stalks + 3000 kg ROS ha-1. In experiment 2, the treatment stalks + 3000 kg ROS ha-1 provided an increase in aggregate stability compared with treatment with only stalks. In experiment 1, the ROS addition tended to higher retention of C stalks and leaves in the soil. In experiment 2, the application of CR + ROS promoted greater retention of soil C only in the treatment with leaves. Under laboratory conditions, the soil with a history of ROS addition did not affect mineralization and retention of crop residue C added to soil. Besides, the ROS showed an immediate effect, reducing C mineralization from stalks and increasing retention of C from leaves added to the soil.<br>O impacto da adição de xisto retortado (XR) sobre a dinâmica do carbono (C) de resíduos culturais (RC) no solo é pouco conhecido. Em condições de laboratório, o presente estudo objetivou avaliar o efeito residual e imediato do XR sobre a mineralização do C de RC, estabilidade de agregados em água e armazenamento de C nas frações particulada (>53 μm) e associada aos minerais (<53 μm) da matéria orgânica (MO) de um Argissolo Vermelho Distrófico arênico. No experimento 1, os tratamentos foram compostos por amostras de solo de parcelas que receberam quatro aplicações de XR, totalizando 0, 6.000 e 12.000 kg ha-1. Já no experimento 2, os tratamentos foram constituídos com solo somente da parcela sem histórico de aplicação de XR (0 kg ha-1), que no laboratório recebeu três doses de XR equivalentes a 0, 1.500 e 3.000 kg ha-1. Em ambos os experimentos os tratamentos foram avaliados na presença (3.000 kg ha-1) e ausência de folhas e talos de soja. A liberação de C-CO2 foi avaliada durante 80 dias e ao final do experimento determinados a estabilidade de agregados e o armazenamento de C nas diferentes frações da MO. A adição de RC no solo com histórico de adição de XR não alterou a liberação de C-CO2 e também não reduziu a mineralização aparente do C dos RC comparado a adição desses resíduos em solo sem histórico. No experimento 2, houve redução na liberação de C-CO2 em relação ao controle somente no tratamento com talos + 3.000 kg de XR ha-1. No experimento 2, o tratamento talos + 3.000 kg de XR ha-1 proporcionou incremento na estabilidade de agregados em comparação com o tratamento somente com talos. No experimento 1, a adição de XR apresentou tendência de maior retenção de C dos talos e folhas no solo. No experimento 2, a aplicação conjunta de resíduos e XR promoveu maior retenção de C no solo apenas no tratamento com folhas. Em condições de laboratório, o solo com histórico de aplicação de XR não afetou a mineralização e a retenção do C de resíduos culturais adicionados ao solo. Além disso, o XR apresentou efeito imediato, reduzindo a mineralização do C de talos e aumentando a retenção do C de folhas adicionadas ao solo.
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Raut, Yogendra Y. "Sustainable Bioenergy Feedstock Production Using Long-Term (1999-2014) Conservation Reserve Program Land." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu148344789416295.
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Heuck, Christine [Verfasser], and Marie [Akademischer Betreuer] Spohn. "Microbial nitrogen and phosphorus mineralization and microbial biomass stoichiometry as dependent on ratios of carbon, nitrogen and phosphorus in soils of temperate forests / Christine Heuck ; Betreuer: Marie Spohn." Bayreuth : Universität Bayreuth, 2018. http://d-nb.info/1177142074/34.
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Yemadje, Pierrot Lionel. "Influence des cycles humectation-dessiccation sur la minéralisation du carbone : cas de la zone cotonnière du Nord Cameroun." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS209/document.
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Le sol est un compartiment majeur de stockage du carbone (C) organique de l’écosystème terrestre. Il joue un rôle important dans la régulation du climat. Toute variation des flux de carbone entre l’atmosphère et l’écosystème terrestre pourrait avoir un impact important sur l’augmentation de CO2 dans l’atmosphère, mais aussi sur la diminution des teneurs en matière organique du sol et donc sur la fertilité des sols. Au Nord Cameroun, les sols sont exposés à de longues périodes sèches (5 à 6 mois par an) qui alternent avec une saison humide. La période de transition entre ces deux saisons, peut durer de mi-avril à fin juin et est caractérisée par des pluies très irrégulières. Ces cycles d’humectation-dessiccation pourraient selon la littérature accentuer la minéralisation du carbone organique du sol et le cycle des éléments nutritifs. L’objectif de cette étude est de quantifier l’impact des cycles humectation-dessiccation sur la minéralisation du carbone dans un contexte soudano-sahélien. Pour faire des mesures représentatives sur le terrain, il est nécessaire d’étudier la variation sur 24 heures de la respiration du sol après humectation suite à une période sèche. Cette mise au point méthodologique a montré que la respiration du sol présente une courbe quadratique au cours de la journée, devenant presque linéaire au cours de la nuit. La température et l’humidité du sol ont permis d’expliquer au moins 73% des variations sur 24 heures. Ces observations ont été utilisées pour proposer une méthode pour estimer la respiration moyenne diurne et nocturne après humectation des sols. La méthode proposée dans cette étude a l’avantage d’être basée sur un nombre réduit de mesures et est par conséquent plus facile à mettre en œuvre pour suivre la respiration du sol sur 24 heures après les premières pluies. Une première étude expérimentale de terrain a permis de montrer que la ré-humectation des sols et le mode de gestion des pailles ont augmenté la minéralisation du carbone de ces sols. En revanche, la fréquence des cycles humectation-dessiccation des sols sur une période de 50 jours n’a pas augmenté la minéralisation cumulée du carbone des sols. Au Nord Cameroun, la minéralisation rapide des pailles rend difficile l’augmentation des stocks de carbone du sol par conservation des pailles des cultures précédentes à la surface du sol. Dans une seconde expérimentation de laboratoire, en conditions contrôlées, les cycles humectation-dessiccation n’ont pas augmenté la minéralisation du carbone organique du sol et de l’azote (N) par rapport aux sols maintenus humides. Cependant, les émissions de CO2 ont augmenté avec l’addition de paille enrichie en carbone-13. Cette addition de la paille marquée a augmenté la minéralisation de la matière organique du sol (priming effect). La minéralisation de la paille a diminué avec les cycles humectation-dessiccation et la quantité de paille restante était de 102 µg Cg-1 sol sur les sols ré-humectés contre 48 µg Cg-1 sol sur les sols maintenus humides. L’absence de cette réponse de la minéralisation du carbone et d’azote du sol aux cycles humectation-dessiccation pourrait être liée à une baisse de l’activité microbienne durant les périodes de dessèchement et l’absence d’une augmentation soutenue des taux de minéralisation du carbone avec les cycles ultérieurs d’humectation-dessiccation<br>Soil as a major storage component for terrestrial ecosystem’s organic carbon plays an important role in regulating climate and agricultural production. Any variation of carbon fluxes between the atmosphere and the terrestrial ecosystem can have a significant impact on the increase of carbon dioxide in the atmosphere but also the decrease in soil organic matter and thus accelarate soil fertility degradation. In northern Cameroon, the transition period between long dry periods with a wet season is characterized by very irregular rainfall that can last several weeks. These wetting-drying cycles can accentuate the mineralization of soil organic carbon and nutrient cycling. The objective of this study is to assess the impact of wet-dry cycles on carbon mineralization in a sudano-sahelian context. From methodological stand field measurements require to study the soil respiration variation over 24 hours after a wet period. This methodological test has shown that soil respiration has a quadratic curve during the day, becoming almost linear during the night. The temperature and soil moisture have explained together the variation over 24 hours (at least 73% ; p< 0.001). These observations have been used to propose a method for estimating the mean daytime and nighttime soil respiration after wetting the soil. Indeed the method proposed in this study has the advantage of being based on a small number of measurements and is, therefore, easier to implement to monitor 24-h soil respiration after the first rains following a long dry period. A first experiment has shown that the wetting of the soil and mulching increased soil carbon mineralization. However, wetting-drying cycles on soil did not increase the cumulative mineralization of soil carbon more than keeping the soil continuously moist. Indeed, in northern Cameroon, the rapid mineralization of crop residues makes it difficult to increase soil carbon stocks by mulching. In a second laboratory experiment, the wetting-drying cycles did not increase organic carbon and nitrogen mineralization from soils added with straw. However, carbon dioxide emissions increased on straw amended soils compared to soils without straw. This addition of the labeled straw increased mineralization of soil organic matter (priming effect). The mineralization of the straw also decreased with the wetting-drying cycles, thus the amount of straw remaining on soils was 102 µg C g-1 soil on re-wetted soils compared to 48 µg C g-1 soil for those with constant moisture. The lack of response for C and N mineralization during wetting-drying cycles may be linked to a decrease of microbial activity during dry periods and the lack of a steady increase in the carbon mineralization rate with subsequent wetting-drying cycles
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Perveen, Nazia. "Intégration de l'écologie microbienne dans les modèles biogéochimiques : conséquences pour les prévisions du stockage du Carbone et la fertilité des sols." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066340.
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La prise en compte du priming effect * (PE) dans les modèles biogéochimiques est essentielle afin de mieux prévoir les conséquences du changement global sur le cycle du C (C) dans les écosystèmes et les interactions avec le climat. Au cours de la dernière décennie, de nombreux travaux ont été réalisés afin de modéliser le PE. Cependant, quelques connaissances de base nécessaires à cette modélisation du PE manquent tels que la relation entre le taux de décomposition des matières organique du sol (MOS) et la biomasse des décomposeurs (MB). En outre, le PE n'a jamais été inséré dans un modèle sol-plante afin de déterminer son rôle dans les interactions plante-sol. Dans ce contexte, les principaux objectifs de la thèse sont 1) d’intégrer l'activité, de la biomasse et de la diversité des microorganismes du sol dans les modèles de dynamique du C et de l’azote (N) des écosystèmes afin de simuler le PE, et 2) de déterminer les conséquences de cette intégration pour le fonctionnement des écosystèmes et la réponse au changement global. Ces objectifs ont été atteints grâce à la combinaison de la diverses approches telle que la modélisation, l’expérimentation et les analyses statistiques. Dans une expérience de laboratoire, je montre que le taux de décomposition des MOS augmente 1) linéairement avec la MB et 2) avec un effet de saturation avec la teneur en MOS. La réponse linéaire de décomposition des MOS à la MB s'explique par la colonisation très limitée du sol et des réserves des MOS par les microorganismes. Cependant, la limitation de la décomposition par la teneur en MOS montre que la disponibilité locale des MOS peut être un facteur limitatif pour la minéralisation microbienne. La co-limitation observée de la décomposition des MOS est correctement modélisée avec l'équation de Michaelis-Menten. L'intégration de cette équation dans un modèle simple de dynamique des MOS permet d’expliquer comment les MOS s'accumulent souvent continuellement dans les sols non perturbés alors qu'elles stagnent dans les sols cultivés. Cette présente également le premier modèle d’écosystème paramétré incorporant le PE (SYMPHONY). Ce modèle génère des prévisions réalistes sur la production de fourrage, stockage de C dans le sol et lessivage de l'azote pour des prairies permanentes. SYMPHONY montre également que la persistance des plantes dans les écosystèmes dépend d'un réglage fin de la minéralisation microbienne de MOS au besoin en nutriments des plantes. Ce réglage est modélisé par SYMPHONY en considérant la destruction de MOS par le PE et les interactions entre deux groupes fonctionnels microbiens: les décomposeurs des MOS et les stockeurs de MOS. Enfin, conformément aux récentes observations, SYMPHONY explique comment l’augmentation du CO2 atmosphérique induit une modification des communautés microbiennes du sol conduisant à une intensification de la minéralisation microbienne et à une diminution du stock des MOS dans le sol<br>Integration of the priming effect* (PE) in ecosystem models is crucial to better predict the consequences of global change on ecosystem carbon (C) dynamics and its feedbacks on climate. Over the last decade, many attempts have been made to model PE in soil. However, some basic knowledge to model the PE is lacking such as the relationship between decomposition rate of soil organic matter (SOM) and microbial biomass (MB). Moreover, the PE has never been inserted in a plant-soil model to analyze its role on plant-soil interactions. The main objectives of this thesis were to 1) integrate the activity, biomass and diversity of soil microorganisms in models of ecosystem C and nitrogen (N) dynamics in order to simulate the PE, and 2) determine the consequence of this integration for ecosystem functioning and response to global change. These objectives were achieved thanks to the combination of diverse approaches such as modeling, experimentation and statistical. In a lab experiment, I show that the rate of SOM decomposition increases 1) linearly with MB, and 2) with a saturating effect with SOM content. The linear response of SOM decomposition to MB is explained by the very limited microbial colonization of SOM reserves. However, the positive effect of SOM content on decomposition rate indicates that the local availability of SOM may be limiting for microbial mineralization. The observed co-limitation of SOM decomposition was accurately modeled with the Michaelis-Menten equation. Finally, incorporating this equation in a simple model of soil C dynamics explained how carbon often continuously accumulates in undisturbed soils whereas it reaches steady state in cultivated soils. Moreover, I present the first parameterized PE embedding plant-soil model (SYMPHONY) which provides realistic predictions on forage production, soil C storage and N leaching for a permanent grassland. SYMPHONY also shows that plant persistence depends on a fine adjustment of microbial mineralization of SOM to plant nutrient uptake. This fine adjustment was modeled by considering the destruction of SOM through PE and the interactions between two microbial functional groups: SOM-decomposers and SOM-builders. Moreover, consistent with recent observations, SYMPHONY explains how elevated CO2 induce modification of soil microbial communities leading to an intensification of SOM mineralization and a decrease in the soil C stock
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Böhm, Sven. "Assessing the variability of soil nitrogen mineralization." Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/321.
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Bohm, Sven. "Assessing the variability of soil nitrogen mineralization." Diss., Kansas State University, 2007. http://hdl.handle.net/2097/321.
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Doctor of Philosophy<br>Department of Agronomy<br>Charles W. Rice<br>Variable N fertilizer application recommendations would benefit from crediting the N that will be mineralized and available to the crop during the growing season. During the 1994 and 1995 growing season, the spatial and temporal pattern of N mineralization was assessed on two central Kansas corn fields. Net N mineralization was measured in the field using a buried bag and a resin core method. A 60 m sampling grid was established on the field and the N mineralization was measured at each grid point. The field N mineralization measured was then compared to three lab incubation (14 day anaerobic incubation, CO₂ evolved 1 day after rewetting, and N released on autoclaving) measurements to determine if the field N mineralization could be predicted by a laboratory test. Nitrogen mineralization in the field was highest in May and declined during the growing seasons. Patches of high N mineralization appeared and disappeared during the season, areas of high and low mineralization were not found in the same areas month after month. The semivariance of the laboratory incubations tended to be smoother near the origin than the field incubations, indicating that the field incubations were subject to more sources of variability (such as microclimatic variations) than the laboratory incubations.
Crop yields were not correlated with N mineralization in these fields. Soil moisture appeared to be more important to crop yields than the N contributed by mineralization. In these fields N mineralization does not need to be included in N fertilization recommendations unless the amount of fertilizer applied is much lower than in this study.
Finally, a method to estimate the initial δ¹³ C content of a soil is proposed. This method can be used if a location can be found that has had a continuous C₃, a continuous C₄crop and a C₃/ C₄rotation treatment.
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Herrmann, Anke. "Predicting nitrogen mineralization from soil organic matter - a chimera? /." Uppsala : Dept. of Soil Sciences, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a429.pdf.
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Tahir, Majid Mahmood. "Destino do carbono de raízes e parte aéreas de culturas de inverno enriquecidas com 13c em solo sob plantio direto." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/3369.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>Little is known about the decomposition and stabilization of shoots and intact roots derived carbon (C)
under no-tillage (no-till) field conditions. The present study was designed with following objectives:
1) evaluation of 13C pulse labeling method to label crop plants under field conditions for subsequent C
dynamics studies, 2) estimation of the actual rates of mineralization of intact roots and shoot residues,
decomposing simultaneously, and 3) finally to determine the fate of shoot vs root residues derived C in
soil, under no-till field conditions. The experiment was conducted at Federal University of Santa
Maria , Rio Grande de Sul, Brazil in 2013-2014 in an loam textured Typic Paleudalf. Wheat (Triticum
aestivum L.), pea (Pisum sativum L.) and vetch (Vicia sativa L.) plants were grown inside polyvinyl
chloride (PVC) cylinders and were pulse labeled weekly with 13C in the field until the flowering stage.
At plant harvest, the biomass of shoots and roots and chemical composition and isotopic enrichment
was determined. In order to achieve second objective, paired treatments were designed by combining
13C labeled shoots with unlabeled roots+soil and unlabeled shoots with 13C labeled roots+soil for each
crop, plus a control treatment. For the third objective, soil cylinders were excavated after 60, 180 and
365 days for the determination of distribution of shoot and root derived Cnew in soil aggregates. The
chemical composition of plant tissues (shoot and roots) were not modified by 13C labeling. The
maximum level of 13C enrichment in plants at harvest, was +495 in wheat, +426 in pea and
+378 in vetch plants. Our results though demonstrated heterogeneity of 13C among plant parts
particularly between stems and leaves however, it was far less than reported in other field and
controlled conditions experiments. The mineralization of roots+soil C was higher than shoot-C
residues for the three species (73 vs. 45 % initial C for wheat, 76 vs. 48 % for pea and 73 vs. 51 % for
vetch). Remaining 13C in root and soil organic matter (SOM) at day 180 indicated both a higher rate of
root-C decomposition and a higher rate of root- derived C in SOM compared to shoots. Greater
proportion of the shoot and root derived Cnew of three crops was associated with large macroaggregates
(>2000 μm) in 0-5 cm soil layer which declined with time. The content of root and shoot derived C
microaggregates (53 250 μm) increased gradually with time in all the three soil for all crops. After
365 days, 30% of the root derived C was present in soil compared to 5 % (average of three crops) of
the shoot derived C. The mean relative contribution of root vs shoot derived Cnew was 2.1 ranging from
1.5 (pea) to 2.5 (wheat). Our findings suggest that, crop residues location and contact with soil and, the
soil moisture and temperature, are important factors that significantly promoted roots decomposition
and root derived C in soil in situ, compared to shoots, erasing the consequences of their different
initial chemical composition. The 13CO2 labeling technique used under the field appeared to be a
practical approach with respect to resource demand and is suitable for in situ labeling. This work
provides a framework for further studies focusing on the interactions between aboveground and
belowground crop residues and environmental factors under no-till field conditions.<br>Pouco é conhecimento sobre a decomposição e a estabilização no solo do carbono (C) proveniente da parte
aérea e de raízes in situ em sistema de plantio direto (SPD). O presente estudo foi desenvolvido com os
seguintes objetivos: 1) avaliar o método de marcagem de plantas com 13C através da aplicação de pulsos de
13C no enriquecimento e distribuição do 13C nas plantas cultivadas em condições de campo para posterior
estudo da dinâmica de C; 2) estimar as taxas reais de mineralização do C de raízes in situ e da parte aérea
na superfície do solo; e 3) determinar o destino do C da parte aérea e de raízes no solo, em condições de
campo em SPD. O experimento foi conduzido na Universidade Federal de Santa Maria, Rio Grande do Sul,
Brasil, em 2013-2014 em um Argissolo vermelho distrófico arênico. Plantas de Trigo (Triticum aestivum
L.), ervilha (Pisum sativum L.) e ervilhaca (Vicia sativa L.) foram cultivadas em condições de campo
dentro de cilindros de PVC, nas quais foram aplicados semanalmente pulsos de 13C até o estágio de
floração. A biomassa da parte aérea e das raízes, a composição química e o enriquecimento isotópico foram
determinados no momento da colheita das plantas. A fim de alcançar o segundo objetivo, para cada cultura
foi montado tratamentos pareados combinando a parte aérea marcada com 13C com as raízes sem marcação
e a parte aérea não marcada com 13C com as raízes marcadas. Além desses foi utilizado um tratamento
controle. Para o terceiro objetivo, os cilindros com solo foram escavados depois de 60, 180 e 365 dias após
a instalação dos tratamentos pareados e realizada a determinação da distribuição nos agregados do Cnovo
derivado da parte aérea e das raízes. A composição química das plantas (parte aérea e raízes) não foi
modificada pela marcagem com 13C. O nível máximo de enriquecimento de 13C nas plantas, no momento
da colheita, foi de 495 no trigo, 426 na ervilha e 378 na ervilhaca. Os resultados demonstraram a
heterogeneidade na distribuição do 13C entre as partes da planta, particularmente entre caules e folhas, no
entanto, esse nível de heterogeneidade é inferior aos reportados na literatura para experimentos de campo e
em condições controladas. A mineralização de C das raízes das três espécies foi maior do que aquela
observada para os resíduos da parte aérea (73 x 45 % no trigo, 76 x 48 % na ervilha e 73 x 51 % na
ervilhaca). O 13C remanescente nas raízes e na matéria orgânica do solo (MOS) aos 180 dias indicou
elevada decomposição das raízes e alta taxa de C derivado das raízes na MOS comparado à parte aérea.
Maior proporção do Cnovo derivado da parte aérea e das raízes das três culturas foi associada aos
macroagregados (>2000 μm) na camada de 0-5 cm, a qual diminuiu com o passar do tempo. O C derivado
das raízes e da parte aérea nos microagregados (53 250 μm) aumentou gradualmente com o passar do
tempo em todas as camadas do solo para todas as culturas. Aos 365 dias, 30% do C das raízes estava
presente no solo, comparado aos 5% (média das três culturas) do C da parte aérea. A contribuição relativa
média do Cnovo derivado da raiz x parte aérea foi de 2,1 variando de 1,5 (ervilha) a 2,5 (trigo). Os resultados
do presente trabalho sugerem que a localização dos resíduos culturais, o contato com o solo e a umidade e a
temperatura do solo, são fatores importantes que promovem maior decomposição das raízes in situ e Cnovo
das raízes no solo, comparado com a parte aérea, reduzindo o efeito das diferenças na composição química
inicial. A técnica de enriquecimento das plantas através da aplicação de pulsos de 13C em condições de
campo parece ser viável em relação à demanda de recursos é adequada para a marcagem in situ. Este trabalho fornece informações de suporte para estudos futuros, com enfoque nas interações entre os resíduos culturais da parte aérea e raízes e os fatores ambientais em condições de campo em SPD.
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Hornibrook, Edward R. C. "Aspects of carbon mineralization in temperate zone freshwater wetlands." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21290.pdf.
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Yoo, Seung Youl. "Geochemical Clogging in Carbonate Mineralization on Carbon Dioxide Sequestration." 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/160987.
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Colocho, Hurtarte Luis Carlos. "Plant Nitrogen status driving soil organic matter mineralization in the rhizosphere." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/10440.
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Previous issue date: 2016-01-26<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Os fatores que regulam a dinâmica do Carbono (C) e Nitrogênio (N) do solo na rizosfera são ainda pouco compreendidos. A mineralização de C na rizosfera pode ser fortemente influenciada pelo estado nutricional da planta, a concentração de CO2 na atmosfera e a temperatura do ambiente, entre outros. Em este estudo, avaliamos o status nutricional de N em plantas de Eucalyptus spp. e sua influência na dinâmica do C e do N n a rizosfera. Realizamos um experimento usando um rhizobox dividido em dois compartimentos. No compartimento de cima plantas foram cultivadas e areia lavada e supridas com uma solução nutritiva contendo todos o nutrientes e a mesma solução porém sem N . No compartimento inferior o contato das raízes com o solo foi limitado usando uma membrana de nylon com abertura de 5 μm. Observamos uma maior razão raiz:parte aérea e maiores concentrações de CO2 no solo das plantas com deficiência de N. As raízes das plantas deficientes em N, apresentaram maiores concentrações em relação as plantas não deficientes em N, de citrato e tallose, e menores concentrações de sucrose e aminoácidos. A análise de C e N da fração de matéria orgânica ligada aos minerais , junto com os dados obtidos pela
termoquimolise indicam um aumento na mineralização de C e uma modificação na dinâmica do N. Devido a impossibilidade de contato físico direto com o solo, pela presença da membrana de nylon, a única forma de modificar o solo seria então pela exsudação de compostos pelas raízes. O contrastante conteúdo de aminoácidos e açúcares na raiz, junto com os dados do extrato da solução do solo e de mineralização de C, indica que a composição destes exsudatos diferiu em razão da deficiência de N. Enquanto as plantas deficientes em N exsudaram mais ácidos orgânicos, as plantas com ótimo status nutricional foram capazes de exsudar compostos energeticamente ricos. Os dados de δ13C da matéria orgânica ligada aos minerais indica que as plantas deficientes em N afetaram um maior volume de solo que as plantas supridas de N. Tudo isto mostra que, diferentes mecanismos de efeito priming foram dominantes, dependendo do status nutricional da planta. Em plantas deficiente de N, a mineralização de C no solo foi dominada pelo mecanismo chamado de “mineração de N”, enquanto no solo das plantas supridas de N o mecanismo dominante foi a “estequiometria microbiana”. Este trabalho demostra pela primeira vez, ao nosso saber, a atuação de diferentes mecanismos de efeito priming n a mesma planta, sobre diferente status de N . Assim ressaltando, a importância do manejo de nutrientes na dinâmica do C da rizosfera.<br>The factors that regulate the dynamics of soil Carbon (C) and Nitrogen (N) in the rhizosphere are still poorl y understood. The soil C mineralization in the rhizosphere ca n be heavil y influenced by plant’s nutritional status, atmospheric CO2 concentration and temperature, among others. In this study, we assess the influence of Eucalyptus spp. N status on the C and N dynamics in the rhizosphere. We performed an experiment us ing two compartment rhizobox. In the upper compartment, plants were cultivated in washed sand and supplied with a solution containing all nutrients or all nutrients but N. The lower compartment limited the contact of the roots with the soil using a 5 μm mesh nylon membrane. We observed a higher root-shoot ratio for the N deficient plants and an increase in its soil CO2 concentration. The roots of
the –N planted treatment had higher concentrations of citrate and tallose and lower concentration of sucrose and aminoacids, when compared to the +N planted treatment. The C and N anal ysis of the mineral associated organic matter fraction, together with the thermochemol ysis data showed an increase in C mineralization in both planted treatments and changes in N dynamics. As the roots had no physical contact with the soil due to the nylon membrane, the changes in the soil must have been consequence of root exudation. The contrasting sugar and aminoacid root content, together with the citrate concentration in soil solut ion extract and the C mineralization data, indicate that exudate composition changed due to the plants N status. The data indicates that the plants in the –N treatment exudated more organic acids than the plants of the +N treatment. Still the exudate comp osition of the plants with the +N treatment may had a higher energetic content and thus
affected differentl y the soil microbial communities. The δ13C data indicate that the N deficient plants affected a higher volume of soil than the plants of the +N treatment. All this together shows different priming mechanisms were dominant due to the plants N status. As the plants were N deficient, the mineralization of soil C was driven by the “N-mining” mechanism while in the soil of the +N planted treatment the dominant mechanism was “microbial stoichiometry”. This work demonstrates, to our knowledge, by the first time using the same plants, different priming mechanisms due to the plants N status. Thus highlighting, the importance of plants nutrient management in the rhizosphere C dynamics.
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Starr, Katherine. "Environmental and economic assessment of carbon mineralization for biogas upgrading." Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/129920.
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Durante los últimos años, la investigación y el desarrollo de tecnologías para la reducción de las emisiones de gases de efecto invernadero (GEI) en nuestro planeta ha incrementado. Varias soluciones se han propuesto, incluyendo la captura y secuestro de carbono (CCS en inglés). La aplicación de CCS se ha focalizado en las tecnologías de producción de energía a gran escala que utilizan combustibles fósiles. Recientemente, se ha trabajado en el uso de CCS en tecnologías de enriquecimiento de biogás. Esta práctica consiste en la eliminación del CO2 del biogás emitido por digestores anaeróbicos y vertederos con el fin de incrementar la concentración de CH4 en el biogás, generando así un potencial sustituto de gas natural.
Dos innovadoras tecnologías en desarrollo almacén además el CO2 eliminado en una forma sólida, a través de un proceso llamado mineralización de carbono. Este proceso utiliza óxido cálcico de los residuos industriales para fijar el CO2 en forma de carbonato cálcico. Idealmente estas tecnologías innovadoras de enriquecimiento deberían mostrar mayores beneficios ambientales en comparación con las tecnologías convencionales ya que almacenan inmediatamente el CO2. La primera tecnología analizada es la regeneración de alcalino (AwR) que consiste en el uso de una solución alcalina para eliminar el CO2 y que es regenerada mediante su exposición a un residuo industrial rico en CaO. La segunda tecnología es enriquecimiento de biogás con cenizas (BABIU), basada en la interacción directa del biogás con las cenizas resultantes de incineradores de residuos municipales. Esta tesis pretende determinar si estas tecnologías innovadoras muestran beneficios ambientales respecto a las tecnologías convencionales de enriquecimiento de biogás, mediante la aplicación de herramientas de la ecología industrial. El análisis de ciclo de vida, el análisis de flujos materiales y el análisis de exergía son aplicadas para el análisis ambiental y de recursos. Asimismo, la viabilidad a largo plazo de las tecnologías es examinada desde el punto de vista económico y material.
En general, los resultados indican que las tecnologías innovadoras no muestran un perfil ambiental notablemente mejor que las convencionales, especialmente para AwR donde el uso de la solución alcalina da lugar a un elevado impacto ambiental. Aún así, ambas tecnologías consiguen un significante ahorro de CO2 respecto a las tecnologías convencionales. Asimismo, dado que las dos tecnologías analizadas se encuentran en un período de prueba piloto, se identifican las potenciales mejoras para optimizar el perfil ambiental y económico, como incrementar la eficiencia de la regeneración de la solución alcalina en la tecnología AwR. El análisis económico realizado para AwR resaltó que reducir sus costes operacionales incrementaría la oportunidad de su implementación como negocio. Los resultados pueden ser usados tanto por promotores de estas innovadoras tecnologías para mejorar su viabilidad económica y ambiental a largo plazo, como por promotores y fabricantes de tecnologías similares, como aplicaciones de CCS o enriquecimiento de biogás.<br>Our world has been increasingly looking for solutions to reduce the greenhouse gas (GHG) emissions of our planet. Various solutions have been proposed, including carbon capture and sequestration (CCS). Focus for application of CCS has normally centered on large scale energy production that burns fossil fuel. Recently, developers have been working on applying CCS to biogas upgrading technology. This entails removing CO2 from biogas emitted from anaerobic digestors and landfills while also increasing the CH4 concentration to render the biogas suitable as natural gas substitute.
Two novel technologies under review also stores the removed CO2 in a solid form, through a process called carbon mineralization. This process uses calcium oxides found in industrial waste to fix CO2 by forming calcium carbonate. Ideally these novel upgrading technologies should have more environmental benefit over conventional ones based on the fact that they immediately store CO2, while conventional ones do not. The first technology is called alkaline with regeneration (AwR) and consists of using an alkaline solution to strip the CO2. The alkaline solution is then regenerated by exposing it to a waste rich in CaO. The second is called bottom ash for biogas upgrading (BABIU) which relies on a direct gas-solid phase interaction with bottom ash from municipal solid waste incinerators. This thesis examines whether or not these two novel technologies have an environmental benefit over conventional upgrading technologies, based on industrial ecology tools. Life cycle assessment, material flow analysis, and exergy analysis were applied for the environmental and resource assessments. The thesis also examines the long term feasibility of applying these technologies, both from a material and economic point of view.
Overall it was determined that the novel technologies generally do not have a better environmental performance over conventional technologies, especially AwR which was found to have a higher impact due to the use of the alkaline solution. Despite this, both novel technologies had significant CO2 savings over conventional technologies. As well since both novel processes are in the pilot plant stage it is possible to pinpoint what can be improved in order to increase the all around environmental benefit, for example by increasing the regeneration rate of the alkaline solution in AwR. The economic assessment was conducted on AwR and it was found that improving its operational costs would help create a business case for potential application. The results not only help the developers of the novel technologies to improve their long term environmental and economic viability but also can be used by developers and manufactures of similar technologies, such as other biogas upgrading or CCS technologies.
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Julies, Elsabé Mathilda. "Microbial ecology of anaerobic carbon mineralization in Namibian shelf sediments." kostenfrei, 2008. http://d-nb.info/98837935X/34.
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Harrison, Anna Lee. "Mechanisms of carbon mineralization from the pore to field scale : implications for carbon dioxide sequestration." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/51507.
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Innovative technologies to stabilize atmospheric CO₂ concentrations are essential in order to mitigate the harmful effects of anthropogenic greenhouse gas (GHG) emissions on the global climate system. Mineralization of carbon in solid, stable carbonate minerals through reaction of CO₂ with Mg-rich mining wastes is a promising CO₂ sequestration strategy that offers the potential to render certain mines GHG neutral. Here, the physical and chemical controls on rates of and capacity for CO₂ sequestration in systems representative of mine tailings are examined from the mineral-fluid interface to field scale using a combination of experimental techniques. These experimental data and existing field data are used to develop a comprehensive reactive transport model that captures the processes governing carbon mineralization in the shallow subsurface. Stirred batch reactor, microfluidic pore scale, and decimeter to meter scale column carbonation experiments using brucite [Mg(OH)2] revealed that the primary controls on carbonation include the rate of CO₂ supply, the distribution of the reactive phase, the mineral grain size/surface area, and the availability and distribution of water. The rate-limiting step during carbonation varied from CO₂ supply to mineral dissolution depending on the experimental variables. Surface passivation and water-limited reaction resulted in a highly non-geometric evolution of reactive surface area. The extent of reaction was also limited at high water content because viscous fingering of the gas streams supplied to the columns resulted in narrow zones of highly carbonated material, but left a large proportion of brucite unreacted. More robust predictions of the CO₂ sequestration rate and capacity that can be expected at the field scale are possible due to the incorporation of water consumption, water-limited reactivity, and surface passivation functions into the reactive transport code, MIN3P. This research imparts a better understanding of fundamental mechanisms and chemical processes relevant to CO₂ sequestration in mine tailings, with implications for mineral carbonation in other settings that have greater CO₂ sequestration capacity, such as shallow subsurface formations with similar mineralogy. Aspects of this research, such as water-limited reactivity, have broader implications for reactive transport processes in the vadose zone in general, including mineral weathering and groundwater remediation. Supplementary video material is available at: http://hdl.handle.net/2429/51487<br>Science, Faculty of<br>Earth, Ocean and Atmospheric Sciences, Department of<br>Graduate
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Al-Ismaily, Said Salim. "Nitrogen mineralization of manure-amended soil: Effects of salinity and moisture content." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/290018.
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Application of manure has been used to increase the nitrogen status of many arid and semi-arid agricultural soils, however, organic nitrogen contained in animal manures must be mineralized prior to utilization by crops. Nitrogen mineralization is, like other biological processes, affected by soil water status. This can be due to the direct influence of soil moisture and/or salt interactions on the nitrogen dynamics. It is critical to understand the interactive effects of salt and water on nitrogen in soils amended with organic fertilizer. Such knowledge may be used for improving and quantifying nitrogen use efficiency. Objectives of this study were (i) to examine the relative and interactive influences of soil osmotic and matric water potentials on nitrogen transformations in manure-amended and non-manured soils, (ii) to determine the extent of nitrogen mineralization over a range of soil water potentials, and (iii) to study the effect of manure addition on nitrogen dynamics in an agricultural desert soil. Gila fine sandy loam soil was treated by addition of varying amounts of distilled water, NaCl, and dairy manure and incubated at depth of 20 cm in 0.025 mm thickness Ziploc® bags. Ammonium nitrogen, nitrate nitrogen, gravimetric soil moisture content, and total soil water potential were measured weekly for 16 weeks. Our study showed a decrease in the amount of inorganic N released from both the non-manured and manure-amended soils at total soil water potentials of approximately -55 bars or less. Maximal amounts of inorganic-N were released at potentials of -23 to -3.5 bars. There was an accumulation in the amounts of NH₄-N released at potentials of -55 bars or less, presumably because of a reduction in net nitrification. The manure caused nitrogen immobilization especially during the early part of our study. Immobilization also occurred in non-manured soil, but this generally lasted only a few weeks. Immobilization was prolonged in soils with lower water potentials. Net N mineralization in the manure-amended soils was higher than in the non-manured soils when soil moisture content was at field capacity.
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Watts, Dexter Brown. "Mineralization in soils amended with manure as affected by environmental conditions." Auburn, Ala. :, 2007. http://repo.lib.auburn.edu/2007%20Spring%20Dissertations/WATTS_DEXTER_20.pdf.
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Stewart, Laura. "Carbon storage in an artificial soil." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/3420/.
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As we strive to find new technologies to dispose of our municipal solid waste, compost-like outputs (CLOs) are becoming more widely created. As a product of both aerobic and anaerobic digestion, they provide a potentially important carbon store and some have proven to enhance existing carbon stores when added to brownfield sites and agricultural land. However, the CO2 flux from this artificial soil is relatively high when compared to natural soils. The aerobic digestion process under which it is produced lasts only 9 days, producing a material which is still comparatively unstable and yet to mature. The CLO is laid in windrows where it is hoped that it will stabilise and mature; if the humification process at this stage can be optimised, would an even greater carbon store be achieved? This thesis seeks to answer this question, through the research into humification in both natural and artificial systems; through the measurement of CO2 flux to assess the stability of CLO over time; using adapted methodologies to gauge the maturity of this artificial soil by analysing the amount of humic acids present; by adding proposed catalysts to the material in fully factorial lysimeter studies; and by examining the affects of different physical environmental conditions under which CLO product humifies. The results of a series of experimental trials, undertaken over a three year period, are presented. Manganese-coated sand and char, both currently ‘waste’ products were both used as potential catalysts for the humification process of CLO. Temporal trends were seen in most samples using infra-red gas analysis, an alkali extraction technique, UV photospectrometry, fluorescence and a novel pseudo-thermogravimetric analysis. The waterlogging of the samples appeared to have an effect on the humification process and a great deal of concurrent data was seen upon the addition of Mn-coated sand and char to the CLO. Both appeared to have a stabilising effect on the CLO, reducing flux rate and increasing humification as compared to a control. An overriding theme present throughout this thesis is the heterogeneous and contaminated nature of the non-source-segregated CLO tested. It is therefore recommended that similar studies be undertaken on a purer, more homogenous CLO in order to assess whether promising results seen could be elucidated in order to gauge the efficacy of biochar and Mn in encouraging the production of humic substances. A field trial would allow the unified soil system to be considered, rather than the CLO alone.
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Attili, Viswatej. "Capture and mineralization of carbon dioxide from coal combustion flue gas emissions." Laramie, Wyo. : University of Wyoming, 2009. http://proquest.umi.com/pqdweb?did=1939354121&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Kocyigit, Rasim. "Partitioning of Carbon and Carbon Dioxide in plant-soil systems /." Search for this dissertation online, 2003. http://wwwlib.umi.com/cr/ksu/main.
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Yokobe, Tomohiro. "Linkage of Soil Fungal-to-Bacterial Dominance to Nitrogen Mineralization in Temperate Forests." Kyoto University, 2019. http://hdl.handle.net/2433/245325.
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Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(農学)<br>甲第22130号<br>農博第2376号<br>新制||農||1073(附属図書館)<br>学位論文||R1||N5238(農学部図書室)<br>京都大学大学院農学研究科森林科学専攻<br>(主査)教授 德地 直子, 教授 北島 薫, 准教授 舘野 隆之輔<br>学位規則第4条第1項該当
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Faulconer, R. Donald. "Organic amendment effects on carbon and nitrogen mineralization in an Appaplachian minesoil." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-03042009-041319/.
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da, Silva Cerozi Brunno, and Silva Cerozi Brunno da. "Phosphorus Dynamics, Mass Balance and Mineralization in Aquaponics Systems." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/620832.
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This study involves tracing inputs, partitioning, and outputs of phosphorus (P) through an aquaponics system. A mathematical model was developed to describe the dynamics of phosphorus in an aquaponics nutrient solution, and to maximize P use efficiency and minimize P waste. We assessed the influence of pH on the availability and speciation of phosphorus in an aquaponics nutrient solution. By using Visual MINTEQ, a freeware chemical equilibrium model for the calculation of element speciation, solubility equilibria, and sorption for natural waters, it was discovered that high pH values favor the formation of calcium phosphate complexes, decreasing the concentration of free phosphorus in aquaponics nutrient solutions. In addition, the mineralization of organic phosphorus in aquaponics systems was evaluated using treatments with phytase supplementation to fish diets, and incorporation of a microbial inoculant in the aquaponics nutrient solution. Overall, dietary phytase and microorganisms promoted phosphorus mineralization and enhanced phosphorus utilization in aquaponics systems. In the end, we conclude that aquaponics systems can keep the same growth performance and quality of vegetable crops grown in conventional systems when the availability and dynamics of phosphorus are well managed.
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White, Paul Mark Jr. "Enhancing soil carbon sequestration with plant residue quality and soil management." Diss., Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/222.
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Chen, Yujuan. "The Influence of Urban Soil Rehabilitation on Soil Carbon Dynamics, Greenhouse Gas Emission, and Stormwater Mitigation." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51240.
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Global urbanization has resulted in rapidly increased urban land. Soils are the foundation that supports plant growth and human activities in urban areas. Furthermore, urban soils have potential to provide a carbon sink to mitigate greenhouse gas emission and climate change. However, typical urban land development practices including vegetation clearing, topsoil removal, stockpiling, compaction, grading and building result in degraded soils. In this work, we evaluated an urban soil rehabilitation technique that includes compost incorporation to a 60-cm depth via deep tillage followed by more typical topsoil replacement. Our objectives were to assess the change in soil physical characteristics, soil carbon sequestration, greenhouse gas emissions, and stormwater mitigation after both typical urban land development practices and post-development rehabilitation. We found typical urban land development practices altered soil properties dramatically including increasing bulk density, decreasing aggregation and decreasing soil permeability. In the surface soils, construction activities broke macroaggregates into smaller fractions leading to carbon loss, even in the most stable mineral-bound carbon pool. We evaluated the effects of the soil rehabilitation technique under study, profile rebuilding, on soils exposed to these typical land development practices. Profile rebuilding incorporates compost amendment and deep tillage to address subsoil compaction. In the subsurface soils, profile rebuilding increased carbon storage in available and aggregate-protected carbon pools and microbial biomass which could partially offset soil carbon loss resulting from land development. Yet, urban soil rehabilitation increased greenhouse gas emissions while typical land development resulted in similar greenhouse gas emissions compared to undisturbed soils. Additionally, rehabilitated soils had higher saturated soil hydraulic conductivity in subsurface soils compared to other practices which could help mitigate stormwater runoff in urban areas. In our study, we found urban soil management practices can have a significant impact on urban ecosystem service provision. However, broader study integrating urban soil management practices with other ecosystem elements, such as vegetation, will help further develop effective strategies for sustainable cities.<br>Ph. D.
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Macdonald, Andrew James. "The effects of cover crops soil N transformations and losses from arable land." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326592.
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