Physical Sciences and Mathematics Commons^™

Reintroducing Hemp (Rongony) In The Material Palette Of Madagascar: A Study On The Potential Of Hemp Clay Components And Its Impact On Social And Ecological Communities., Henintsoa Thierry Andrianambinina

Masters Theses

When mentioning the word hemp, especially in the local language of Madagascar, the literal translation does not set it apart from marijuana, as they are both called “rongony” - creating the stigma around hemp as the negative stereotype of marijuana. However, the material has been used by the ancestors of Madagascar, as well as across cultures, in its fibrous form to produce fabrication like textile goods and packaging. During colonization, the prohibition of hemp intensified, and since then, any activity related to either of these plants is prohibited and will end in severe punitive measures. This thesis explores the strengths …

Impact Of Cover Crop Species Diversity On Soil Nutrient Availability And Crop Productivity, Amanda Kramer

Masters Theses

Cover crops provide multiple environmental benefits that improve both soil and water quality; however, farmers only utilize them on approximately 5% of harvested U.S. cropland. Low adoption rates are attributed to yield impact concerns, seed and planting costs, and lack of advocacy. This study, which began in October 2019, assessed the effects of nitrogen rate and cover crop diversity on weed biomass, soil coverage, in-situ residue decomposition, soil nitrogen and phosphorus availability, and cash crop yield to better understand the costs and benefits of cover crop adoption at two locations in Tennessee (Milan and Spring Hill). Treatments were replicated 4 …

The Use Of Biological Soil Health Indicators To Quantify The Benefits Of Cover Crops, Alexander Wu

Masters Theses

Soils provide many essential functions that support the world. With a decline in soil health, these functions also decrease in efficiency, and can threaten the health of billions of people around the world. Typically, soil health tests do not use biological indicators, however microbes drive and perform vital functions to increase soil health. One way to increase soil health is through the use of cover crops to reduce soil erosion during fallow periods, increasing soil organic matter, as well as collecting nutrients from soil into their biomass. These cover crops are then terminated through various methods such as herbicides, disk …

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 …

Concept Validation: Collecting Composite Samples To Understand The Presence Of Per- And Polyfluoroalkyl Substances (Pfas) In Michigan Forested Areas, Nicole Renee Sanabria

Masters Theses

This research discusses the results of a state-wide study conducted by The Michigan Department of Environment, Great Lakes, and Energy to assess the presence of PFAS in shallow soils of state-owned forested areas in Michigan utilizing a composite sampling method. One sample collected from each of Michigan’s 83 counties reveals the presence of PFAS in all but one sample, with total PFAS concentrations ranging from non-detect to 2.016 μg/kg (dry weight). PFOS is generally detected at the highest concentrations, ranging from non-detect to 0.88 μg/kg, followed by PFBA, with concentrations ranging from non-detect to 0.69 μg/kg, and PFOA, with concentrations …

Manganese Geochemistry And Plant Availability In Response To Agricultural Practices, Ashleigh R. Montgomery

Masters Theses

Manganese (Mn) is an essential micronutrient for all organisms. In soils, Mn forms determine availability to plants. Most Mn research has been conducted in forest ecosystems and Mn cycling in agricultural systems is understudied. Therefore, the objective of the experiment is to understand the effect of different agricultural management strategies on Mn cycling and plant availability. First, a greenhouse experiment was conducted to determine the effect of different application rates of two Mn fertilizers (MnSO₄ and MnEDTA) on soil geochemical properties and growth of corn (Zea mays) and soybean (Glycine max). The fertilizers were applied to …

The Characterization Of Dynamic Soil Properties And Their Relation To Soil Organic Carbon In East Tennessee Soils, Shannon Marissa Newell

Masters Theses

Quantifying how dynamic soil properties (DSPs) are affected by different management regimes is essential for understanding how these vital resources can be better managed. The Dewey soil series is a critical soil series in East Tennessee. For this study, the University of Tennessee, Knoxville (UTK) worked alongside the National Cooperative Soil Survey (NCSS) in an effort to better understand the dynamics of the Dewey soil series through a wide range of DSP data. To accomplish this, Dewey soil was collected from five sites which are considered representative of five management regimes: well-managed cropland (WMC), poorly-managed cropland (PMC), well-managed pasture (WMP), …

Evaluation Of Microbiometer As A Tool To Estimate Soil Health In A West Tennessee Cotton Crop, Daniel T. Sain

Masters Theses

Healthy soils are critical for optimized yields and sustainability in agriculture. Soil health testing can provide valuable information on how management practices are affecting soil health. In west Tennessee, existing soil health tests were unable to discern between significant differences in management practices. A new soil health test called microBIOMETER® has been developed by Prolific Earth Sciences® (Montgomery, NY). MicroBIOMETER® utilizes a new methodology for estimating microbial biomass and uses that estimate as a soil health score. This test has not been validated for use in west Tennessee. This research was focused on the validation of microBIOMETER® in a continuous …

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 …

Cover Crop Treatment Impacts On Selected Soil Health Indicators In Two Tennessee Long-Term No-Till Corn-Soybean Rotations, Adam A. Zimmerman

Masters Theses

Soil hydraulic conductivity (K_sat) and soil microbial biomass carbon (SMB-C) estimates in Tennessee no-till corn (Zea mays L.) and soybean (Glycine max L.) rotation systems may be changed with cover crops. This study assessed differences in K_sat rates and SMB-C values under common cover crop treatments of two no-till corn and soybean rotation systems in west and middle Tennessee. Wheat (Triticum aestivum L.), cereal rye (Secale cereale L.), wheat/crimson clover (Trifolium incarnatum L.), cereal rye/crimson clover, a five species mix (containing cereal rye, crimson …

Influence Of Living Plant Roots And Mycorrhizal Hyphae On Soil Hydraulic Properties, Katelyn M. Marcacci

Masters Theses

The interrelationships between vegetation, soil, and water are fundamental in evaluating the projected impacts of global climate change. Many predictive models require soil hydraulic parameters as inputs. As most hydraulic parameter datasets are for repacked soil, the influence of vegetation on hydraulic parameters is not thoroughly understood. Living roots and mycorrhizal fungi cause physicochemical alterations in soils. Quantifying how vegetation influences soil hydraulic parameters is necessary to more accurately simulate soil water dynamics in climate models.

Laboratory experiments were conducted to test if the presence of roots and roots inoculated with mycorrhizal fungi have a significant effect on the saturated …

Root-Driven Weathering Impacts On Mineral-Organic Associations Over Pedogenic Time Scales, Mariela Garcia Arredondo

Masters Theses

Plant roots are critical weathering agents in deep soils, yet the impact of resulting mineral transformations on the vast deep soil carbon (C) reservoir are largely unknown. Root-driven weathering of primary minerals may cause the formation of reactive secondary minerals, which protect mineral-organic associations (MOAs) for centuries or millennia. Conversely, root-driven weathering may also transform secondary minerals, potentially enhancing the bioavailability of C previously protected in MOAs. Here we examined the impact of root-driven weathering on MOAs and their capacity to store C over pedogenic time scales. I compared soil that experienced root-driven weathering, resulting in the formation of discrete …

Impacts Of Plant-Microbe Interactions On Seedling Performance In A Riparian Forest Invaded By Lonicera Maackii, Taylor E. K. Strehl

Masters Theses

Soil microbes have profound impacts on plant growth and survival and can either promote or inhibit plant dominance. Exotic plants are often strongly invasive because they have escaped their natural enemies, potentially including antagonistic soil microbes. I examined how the invasive shrub Lonicera maackii and a common native tree, Acer negundo, responded to soil microbial communities to determine the role of soil microbes in regulating invasion success. This was done by growing both species with microbes from invaded (L. maackii) and uninvaded (A. negundo) soils collected from three locations within a riparian forest. Seedlings were …

Mineral And Redox Controls On Soil Carbon Cycling In Seasonally Flooded Soils, Rachelle Lacroix

Masters Theses

Soils contain nearly three times the amount of carbon (C) than the atmosphere, with C turnover times ranging from centuries to millennia. Although wetland soils represent a relatively small portion of the terrestrial landscape, they account for an estimated 20-30% of the global C reservoir. Seasonally flooded soils are likely the most vulnerable wetlands to climate change, as changing temperature and precipitation patterns are expected to alter the timing and duration of flooding. Seasonal variations in soil moisture are recognized as a critical control on soil C stocks and CO₂emissions. However, the relative influence of associated changes in …

Influence Of Algae On Soil Saturated Hydraulic Conductivity: An In Situ Treatment Option For Reducing Infiltration Beneath Unlined Algae Cultivation Ponds, Molly Brianne Pattullo

Masters Theses

Commercial production of algal biofuels is currently limited by high capital costs, including the cost of installation and maintenance of plastic pond liners, which mitigate seepage of cultivation fluids and control the release of salts and nutrients into the subsurface beneath outdoor algae cultivation ponds. However, studies of animal waste settling lagoons show that underlying soils ranging from sands to clay loams can exhibit reduced hydraulic conductivity within days to weeks after construction, reducing the need for plastic liners. The mechanisms of the hydraulic conductivity reductions, or “soil sealing”, are physical rearrangement of soil particles, buildup of fines, and the …

Opportunities In Sustainability: Maize Seeders For The Developing World And Alternative Fertilizers In The United States, Rebecca Mattingly Harman

Masters Theses

Sustainable agricultural systems are needed for both large and small-scale farmers the world over. Central to the sustainability of these systems is the availability of cheap and effective seeders for smallholder farmers and effective utilization of less energy intensive nitrogen sources. In the first two chapters, this thesis considers maize seeders for smallholder use in a Conservation Agriculture system. To sustain the smallholder sector, soil fertility and soil erosion must be addressed and a Conservation Agriculture model seeks to improve soil conditions in agriculture. The technologies available to smallholder farmers, though, need to be tested in a no-till system before …

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 …

An Examination Of Fertilizer Use Efficiency And Irrigation Management In Tennessee Agricultural Production, Timothy James Grant

Masters Theses

Understanding the effect of supplemental irrigation and timing of nitrogen availability on yield of cotton is pertinent to the success of Tennessee cotton producers. Response to irrigation and nitrogen source is likely to vary across greatly differing soil types. This research indicated the need for higher amounts of water and earlier irrigation initiation to optimize yields in coarse-textured, low water holding capacity soils. Deep silt loam soils did not respond to irrigation in two wet years. Delaying nitrogen availability via use of a polymer coated urea fertilizer generally either lowered or did not affect yield. Delaying nitrogen availability was less …

Naturally-Occurring Metals Concentrations In Michigan Soils: A 2015 Survey, Zachary Lowell Spotts

Masters Theses

Closure of hazardous waste sites can be aided through the use of a soil background survey for metals. Data for these studies come from either field sampling or publicly available environmental files. Previous studies were conducted in Michigan, known as the Michigan Background Soil Survey (MBSS). The current update is a refinement and improvement of the 2005 update. New data was collected from publicly available environmental files and other sources. Both the current update and the 2005 update differentiated data by soil type and glacial lobe. GIS analysis was used to observe spatial distribution of the data and to determine …

The Effects Of Industrial Biomass Gasification Ash As A Soil Amendment On The Earthworm Eisenia Fetida, Michael J. Blackowicz

Masters Theses

Soil application of solid residues from thermal conversion of biomass (i.e. combustion and pyrolysis) has become a topic of interest in recent years. However, there exists a gap in the literature with regard to soil application of gasification residues and their effects on soil health and soil macroorganisms. This study investigates the effects of three different ashes (hardwood oak/hickory, hardwood willow, corn stover), collected from industrial biomass gasification reactors (University of Minnesota Morris, Eastern Illinois University), as a soil amendment on the composting worm Eisenia fetida. Additionally, ash samples were analyzed for total polycyclic aromatic hydrocarbons (PAHs) and potentially toxic …

Investigating The Effects Of Urbanization On Residual Forest Soils In Knox Co., Tennessee, Benjamin Lee Reichert

Masters Theses

As the process of urbanization advances across the country, so does the importance of urban forests, which include both trees and the soils in which they grow. Soil microbial biomass, which plays a critical role in nutrient transformation in urban ecosystems, is affected by factors such as soil type and the availability of water, carbon, and nitrogen. However, the microbial dynamics of urban forest soils remain largely unknown. A key mechanistic link between plant species diversity and ecosystem function is heterotrophic microbial communities that inhabit the soil and mediate principal processes that control ecosystem carbon (C) and nitrogen (N) cycling. …

Measuring Carbon Dioxide (Co2) Flux Of Agricultural Practices In Sub-Saharan Africa, Debra Blumberg O'Dell

Masters Theses

Agriculture has an important role in addressing two of the world’s most pressing problems: meeting global food demand and mitigating climate change. If agriculture is not practiced sustainably it will fail to meet future food demand and likely intensify the pace of global climate change. There are some agricultural practices, such as Conservation Agriculture, that can produce food sustainably and have the potential to mitigate climate change. However it is not clear which agricultural practices contribute to climate mitigation and by how much. By measuring the carbon dioxide (CO2) emissions of specific agricultural practices, the ability of practices to sequester …

Activated Carbon Preconditioning To Reduce Contaminant Leaching In Cement-Based Stabilization Of Soils, Renee Elizabeth Crane

Masters Theses

Powdered activated carbon (PAC) is often added with cement to enhance the stabilization and solidification (S/S) of materials contaminated with organic compounds. Adsorption of organic contaminants onto PAC can reduce leaching of organic contaminants. Simultaneous addition of PAC and cement reduces soil handling costs, but cement hydration reactions coat PAC with Ca(OH)2 before contaminants can be adsorbed onto PAC. Laboratory studies were done on four aged, contaminated soils from manufactured gas plant sites to compare the performance of S/S treatment with simultaneous addition of PAC and cement vs. cement addition after preconditioning with PAC to enhance contaminant adsorption. Performance was …

Using Soil Organic Matter As An Iron Chelate To Enhance The Efficiency Of Modified Fenton Oxidition Of Diesel Fuel In Arctic Soils, Mary K. Sherwood

Masters Theses

Laboratory experiments were conducted to investigate the use of modified fenton chemistry on the treatment of three soils from the Canadian arctic, all with abundant soil organic matter, iron and manganese oxides, and diesel fuel contamination. The purpose of these studies was to (I) to assess modified fenton chemistry as a treatment option for petroleum-contaminated arctic soils, and (2) to evaluate the impact of soil organic matter on the modified fenton treatment of soils. Modified fenton treatment was compared for reactions in which ethylenediaminetetraacetate was added as a chelate vs. reactions in which the native soil organic matter was the …

Adsorption Of Antimony By Birnessite And The Impact Of Antimony On The Electrostatic Surface Properties Of Variable-Charge Soil Minerals, Kalyn Alaine Vergeer

Masters Theses

Antimony (Sb) is a toxin that can be found in high concentrations in the soil due to anthropogenic sources. Antimony exists in soil as Sb(V) in the monovalent antimonate hydroxyanion. The adsorption mechanisms of Sb(V) are not well-characterized. The objective of this study was to further elucidate Sb(V) adsorption mechanisms by examining the impact of adsorption on surface charging characteristics of gibbsite, goethite, birnessite, and kaolinite. Also examined was Sb(V), SO₄ [sulfate], and PO₄ [phosphate] adsorption by birnessite. Electrophoretic mobility and potentiometric titrations were employed to examine the ζ-potential [zeta-potential] and net proton surface charge density as a …

Chemical Characterization And Anion Exchange Properties Of A West Tennessee Loess Soil, Jessica Lynn Ottinger

Masters Theses

Loess soils of west Tennessee may potentially contain large amounts of subsoil metal oxides (Fe, Al, and Mn) which may retain and restrict the movement of conservative anions, such as nitrate (NO₃). The potential utilization of large quantities of flue gas desulfurization (FGD) gypsum on these soils may displace subsoil NO₃, releasing it to adversely impact sensitive aquatic environments. This research examines the depth distribution of Fe-, Al, and Mn-oxyhydroxides, pH, particle size distribution, and of the cation and anion exchange capacity and exchange phase composition to identify depths that have the greatest potential for anion …

Adsorption Of Hexavalent Chromium On Hydrous Manganese Oxide, Andrew K. Macleod

Masters Theses

Hexavalent chromium is a very common contaminant most often associated with industrial processes, it is quite mobile in the subsurface and a better understanding of its mobility and interactions with soil constituents will help ongoing remediation efforts.

Hydrous manganese oxides (HMO) are a very common soil constituent and thus would be likely to interact with Cr(VI) in contaminated shallow subsurface environments. The goal of this study is to develop a working model that can improve predictions of Cr(VI) mobility in natural systems. A diffuse double layer surface complexation model (DLM) was developed by deriving reaction stoichiometries and stability constants for …

Characterization Of Wetting Front Geometry And Fluid Migration In The Vadose Zone Using Surface Time-Lapse Seismic First-Arrival Tomography, Rachel Elizabeth Storniolo

Masters Theses

Characterizing and quantifying vadose zone parameters and processes are critical for assessing environmental, agricultural, and engineering problems. The shallow subsurface is essential to the geologic and hydrologic cycles because it supports agriculture and ecosystems, influences water resources, and acts as a repository for contaminants. Fluid migration in the vadose zone is dependent on a number of soil characteristics (e.g. soil type and saturation). Quantifying parameters is often the primary goal of hydrological fluid-flow investigations; however, the values calculated can be misrepresentative of the subsurface due to anisotropic features. Hydraulic conductivity (K), the most common quantitative parameter used to describe fluid …

Composted Biosolids As A Soil Cover On Steep Slopes, Justin Lee Fisher

Masters Theses

Municipal sewage disposal and soil erosion control from highly disturbed sites are both large scale issues of environmental concern. Composted biosolids (CBS) and shredded wood have the potential to be applied as soil cover to address both disposal and erosion issues. There is a lack of information on the use of these products on steep slopes, typical of construction sites. The objective of this study was to evaluate the use of CBS for reducing erosion and establishing vegetation on a cherty, slightly compacted, Fullerton Series sub-soil embankment, with an average slope of 46.5 percent. The study was conducted at the …

Effect Of Landscape Position And Dairy Manure Addition On Bioavailable Forms Of Soil Phosphorus Using Enzyme Hydrolysis, Themis Mahalia Stone

Masters Theses

Bioavailable phosphorus (P) has traditionally been measured as inorganic orthophosphate (PO₄) while organic P (P_o) has been considered of limited relevance to short-term biological consumption. However, enzymes secreted by bacteria and fungi which serve to mineralize P_o are ubiquitous in the environment and may contribute significant bioavailable P over time. In order to assess environmentally-relevant, potentially bioavailable P in soils with added dairy wastes, microcosms of identical soil series but differing management histories and landscape positions were incubated at 24 C° for three weeks. Subsamples were taken weekly from microcosms and analyzed by: 1) Mehlich-3 …