Soil Science Commons^™

Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek

Masters Theses

Tidal marshes serve as important “blue carbon” ecosystems that accrete large amounts of carbon with limited area. While much attention has been paid to the spatial variability of sedimentation within salt marshes, less work has been done to characterize spatial variability in marsh carbon density. Driven by tidal inundation, surface topography, and sediment supply, soil properties in marshes vary spatially with several parameters, including marsh platform elevation and proximity to the marsh edge and tidal creek network. We used lidar to extract these morphometric parameters from tidal marshes to map soil organic carbon (SOC) at the meter scale. Fixed volume …

Evaluating The Relative Influence Of Soil Water Potential, Soil Moisture, And Vapor Pressure Deficit On Semi-Arid Vegetation Dynamics, Kayla R. Jamerson

Graduate Student Theses, Dissertations, & Professional Papers

Knowledge of vegetation’s response to soil water availability and atmospheric demand is critical to understanding the impact of climate change on semi-arid ecosystems. However, limited field-based research has been conducted to assess the relative importance of these drivers and previous research has simplified the assessment of soil water availability by relying on soil volumetric water content (VWC) as a primary control on plant growth, which, as opposed to soil water potential (Ψsoil), does not account for the effects of soil texture on plant available water. To address these gaps, we compared remotely sensed indicators of vegetation response to field based …

Hydrologic Controls On Phosphorus Speciation And Mobilization In A Subalpine Watershed (East River, Colorado), Lucia Isobel Arthen-Long

Masters Theses

The cycling of phosphorus (P) through floodplain environments is critical to ecosystem productivity and has significant implications on both water quality and soil fertility. P export from soils in response to saturation has been well documented, but the relative vulnerability of specific P pools to mobilization remains poorly constrained, as do the mechanisms mediating its release. The prediction of P availability in and export from mountainous floodplain soils is of great importance as global climate change is projected to significantly alter precipitation regimes in alpine systems. This study combined a thorough characterization of P distribution across a hillslope to floodplain …

Column Tests Of Nitrate Breakthrough Behavior In Subsurface Sediments To Understand Transport In The Root-Zone, Rebecca Sally Haworth, Emma Rose Goodwin

Natural Resources Management and Environmental Sciences

Nitrate has become an increasingly ubiquitous pollutant in surface and groundwater, posing a threat to hu- man health and ecosystems. Nitrogen is a necessary nutrient for plant growth and is limiting in many soils. As a result, farmers often add nitrogen to soil in a usable form such as nitrate, nitrite, or ammonia through the addition of fertilizer.

Extent Of Capillary Rise In Sands And Silts, Rachel Lynn Salim

Masters Theses

The values reported in literature for the height of capillary rise in fine sands, silts, and clays are contradictory. Most of the values were based on mathematical models, which used estimated rather than measured input data. This work measured capillary rise values in laboratory experiments in fine-grained sands and silts.

Two uniform sands with grains 0.35--0.7 mm in diameter and 0.3-0.6 mm in diameter, silt with an average grain size below 40 microns, and 0.35--0.7 mm sand coated with a water-repellant spray were carefully packed into two-inch diameter glass columns. These columns were placed into clear plastic tanks with water …

Soil Phosphorus Levels In Residential Lawns And Comparisons Among Four Land Uses In Springfield, Missouri, Timothy R. Davis

MSU Graduate Theses

Eutrophication of surface waters due to high phosphorus (P) concentrations is an important water quality concern in Greene County, Missouri. Phosphorus enrichment has been linked to a variety of non-point sources including runoff from both agricultural and urban land uses. Soil P has been shown to be a source of P in runoff. The differences in soil P among different land uses may provide insight into which land use contributes more P in runoff. This study examines the soil composition, geochemistry and total P concentration of surface soil (0-5cm) in four land uses in Greene County, Missouri. The land uses …