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Peat soils are known to be a significant source of atmospheric greenhouse gasses. However, the releases of methane and carbon dioxide gasses from peat soils are currently not well understood, particularly since the timing of the releases are poorly constrained. Furthermore, most research work performed on peatlands has been focused on temperate to sub-arctic peatlands, while recent works have suggested that gas production rates from low-latitude peat soils are higher than those from colder climates. The purpose of the work proposed here is to introduce an autonomous Ground Penetrating Radar (GPR) method for investigating the timing of gas releases from peat soils at the lab scale utilizing samples originating from Maine and the Florida Everglades, and at the field scale in a Maine peatland. Geophysical data are supported by direct gas flux measurements using the flux chamber method enhanced by timelapse photography, and terrestrial LiDAR (TLS) monitoring surface deformation. / by William J. Wright. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Includes bibliographical references. The beneficial effects of tillage are often negated in Australian soils by poor aggregate structural stability. If irrigation or rain falls on exposed freshly tilled soil, crusting or harsetting often develops on drying. Rainfall intensity, kinetic energy, rate of wetting, antecedent water content and soil management history have been implicated in aggregate breakdown.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Three drainage experiments were conducted on a newly developed organic soil where three cultural methods were superimposed. Measurements of carrot yields, subsidence, water table fluctuations, subsurface drain performance, hydraulic conductivity and soil bulk density were made. Rotovating the soil produced higher carrot yields than plowing or disking during the first year. The seven-year subsidence totalled 515 mm and depended mostly on organic soil depth. Hydraulic conductivity values did not change after five years of drainage. Bulk density of the top 0.20 m increased by 71% in 6 years, whereas the values down the profile increased between 3.3 and 16.2%. / The effect of two water table depths (WTD), 0.6 and 0.9 m, in an organic soil on soil water tension, subsidence swelling and carrot yields was studied in undisturbed cores in the greenhouse. Carrot yields were reduced by the 0.9 m WTD. Subsidence with the 0.9 m WTD was more than double that of the 0.6 m WTD. Raising the water table near the surface caused the soil to swell. / Hydraulic conductivity, bulk density, fiber content and drainable porosity were measured in undisturbed organic soil profiles. Values from all four properties decreased with increasing depth.

This thesis utilizes a combination of landform and soil data and a GIS model to analyze previous subsurface reconnaissance data within the Tipton Till Plain region of Indiana. Survey areas are analyzed according to their location within drainages as well as on their individual surface and subsurface soil characteristics. Additionally, measurements of the valley width at the investigation area and upstream are collected and considered. Soils are also analyzed as a ratio of their individual impermeability in relation to the impermeability of upstream soils. Soil taxonomy and drainage characteristics are analyzed along with the effects stream order and proximity to water have on the potential for an area to contain buried deposits. The conclusion drawn is that comparisons of the permeability of individual drainage basins in relation to the larger drainage basin is not a reliable method of predicting the potential for site burial. The relationship between the valley width at the point of investigation in relation to valley width upstream was analyzed with a weak correlation between valley width stability and the potential for buried deposits. Soil drainage and taxonomic classification analysis appear to show where buried deposits are not likely to be encountered. The analyses of stream order and proximity to water did not reveal any significant differences in the potential for encountering buried deposits. It is recommended that the current guidelines for recommending subsurface investigation should be followed more strictly. / Department of Anthropology

Includes bibliographical references. / xxiv, 177 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The beneficial effects of tillage are often negated in Australian soils by poor aggregate structural stability. If irrigation or rain falls on exposed freshly tilled soil, crusting or hardsetting often develops on drying. Rainfall intensity, kinetic energy, rate of wetting, anticedent water contentand soil management history have been implicated in aggregate breakdown. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science, 1995

Thesis (Ph.D.)--University of Western Australia, 2007.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references). Also available on the Internet.