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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 38 for “"nitrogen mineralization"”.
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Assessing the variability of soil nitrogen mineralization
… 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 …
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Carbon and nitrogen mineralization in temperate forest soils at low temperatures
In the past, carbon (C) and nitrogen (N) mineralization in temperate forest soils was often considered negligible at low temperatures during the dormant season, which is questioned by recent findings. Climate models predict warmer winters but little is known about the temperature sensitivity of C …
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Organic amendment effects on carbon and nitrogen mineralization in an Appalachian minesoil
… minesoils based on the accumulation and mineralization of carbon and nitrogen pools. A factorial experiment was established in 1987; treatments (5 cm of a Jefferson series topsoil, 8 cm of whole-tree woodchips, and an unamended control) were assigned to lysimeters filled with blasted …
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Estimating the Contributions of Soil and Cover Crop Nitrogen Mineralization for Corn
Current Virginia nitrogen (N) fertilizer recommendations do not include site-specific estimates of N supply from cover crops (CCs) or soil organic matter (SOM). Recent research successfully predicted the contribution of N from SOM and CCs to corn (Zea mays L.) in Pennsylvania. The objective of this …
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Seasonal, biogeochemical, and microbial response of soils to simultaneous warming and nitrogen additions
<p>Climate warming and nitrogen deposition are global environmental threats that could alter soil microbial communities and the biogeochemical processes they perform. Few studies have examined interactive effects of elevated temperatures and nitrogen inputs. Many studies have also not considered …
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Dynamics and Characterization of Soil Organic Matter on Mine Soils 16 Years after Amendment with Topsoil, Sawdust, and Sewage Sludge
… content, aggregate stability, and mineralizable nitrogen, (ii) to determine the effects of these key soil quality variables on plant productivity, and (iii) to determine the comparative ability of trees and herbaceous plants to persist and to conserve or maintain mine soil quality. In 1982, a …
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Water and available nitrogen as co-determinants of a mesic savanna in Kruger National Park, South Africa
… as it triggers many ecosystem processes such as nitrogen mineralization. This rainfall is however extremely variable with cycles of wet and dry years. The impacts of rainfall variability on N mineralization rates and tree-grass dynamics are not well known. This study seeks to provide a …
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The impact of harvesting and site preparation on nutrient dynamics, soil erosion and stream water quality in the Virginia Piedmont
… areas following site preparation. Available nitrogen reserves decreased substantially in the shear, pile, disc treatment area but increased in the chop and burn and shear-disc treatment areas following site preparation. Increased soil moisture and temperature following disturbance stimulated …
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An investigation of nitrogen cycling processes in a coastal fynbos ecosystem in the South Western Cape Province, South Africa
… drastically reduced. Nutrients, in particular nitrogen and phosphorus, have been identified as being of crucial importance in the structure and functioning of fynbos ecosystems because of the nutrient poor substrates upon which this vegetation type exists. This study has concentrated on the …
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A mathematical model of the nitrogen cycle in a constructed wetland
… wetland theory to predict the fate of nitrogen runoff in a constructed wetland. The model utilizes nitrogen concentrations of influent water as system inputs. The model is three-dimensional, one dimensional in time, and two dimensional in space. The physical domain of the model …
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Soil Carbon and Nitrogen Dynamics Across the Hillslope-Riparian Interface in Adjacent Watersheds with Contrasting Cellulosic Biofuel Systems
… 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 …
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An investigation of the duration of phosphorous fertilization effects on phosphorous and nitrogen cycling patterns of Pinus elliottii plantations in the southern Cape
… investigated by examining soil phosphorus and nitrogen turnover and litterfall in a 8, 20 and 25 year old plantation age sequence. Each stand contained plots fertilized with between 30-60 kg ha-1 superphosphate at establishment and an equal number of control (unfertilized) plots. At the oldest …
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Influence of soil water regime on nitrogen availability and plant competition in wet meadows
… context, this thesis explores the involvement of nitrogen availability, an often limiting resource which may be dependent on soil water regime. Laboratory and mesocosm experiments alongside field observations were undertaken to explore the interrelationships between water regime, nitrogen …
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Spatial Variability of Corn Response to Nitrogen Fertilizer: Implications for Variable Rate Fertilization
… recognized that corn yield and its response to nitrogen fertilizer varies within fields. New technologies allow varying the rate of nitrogen fertilizer within fields, but the adoption of this technology is limited due to a lack of recommendations developed for this management strategy. The …
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The role of red-backed salamanders in ecosystems
… affected litter or wood decomposition rates, nitrogen mineralization, nitrification, or acorn germination. Nor did salamanders affect the densities of predatory litter-dwelling macroinvertebrates. However, there was considerable variability in the density of salamanders among plots, even …
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Biogeochemical and ecological responses to warming climate in High Arctic polar deserts
… which was consistent with the decreases in gross nitrogen mineralization by 30–48% and in carbon dioxide (CO2) emissions by 19–38%. Similarly, diapiric frost boils slowed net methane (CH4) emissions. With higher archaeal amoA abundance, diapiric frost boils had a higher magnitude of the emissions …
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Municipal wastewater effects on nitrogen cycling in a mature hardwood forest
… of N transformation processes in the soil. Nitrogen mineralization and nitrification increased as irrigation increased. Denitrification rates were not affected by irrigation; the process of denitrification did not constitute a significant N output from the forest system. The additional soil …
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Forest Harvesting Disturbance and Site Preparation Effects on Soil Processes and Vegetation in a Young Pine Plantation
… soil biological activity, which increased nitrogen mineralization in excess of pine demand. When non-crop vegetation was chemically controlled, mineralization rates increased due to increases in surface soil temperatures. With less vegetation on the site, the amount of nitrogen sequestered …
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CARBON AND NITROGEN CYCLING IN GIANT CANE (ARUNDINARIA GIGANTEA (WALT.) MUHL.) RIPARIAN ECOSYSTEMS
… Phase two determined the pools and cycling of nitrogen and carbon in canebrakes and compared those to nearby agricultural and forested riparian areas. Phase three quantified the N2O and CO2 fluxes from canebrakes and adjacent forested areas. Phase four included methods to quantify nutrient …
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The value of Mopane worms: quantifying ecosystem services in terms of nutrient cycling in semi-arid regions of Limpopo
… frass to nutrient cycling by determining the nitrogen mineralization rates of frass compared to that of mopane leaves. We used search engines such as African Journals Online (AJOL), Google Scholar, and Web of Knowledge. The online databases were searched using the following keywords, 'mopane …
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