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Full-Text Articles in Physical Sciences and Mathematics
Impact Of Cover Crop Species Diversity On Soil Nutrient Availability And Crop Productivity, Amanda Kramer
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 …
Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris
Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris
All Theses
Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 105 and 2.14 x106 years (Hu, 2010). Considering these characteristics, 99Tc and 237Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …
Spatial Geochemical Changes In Central And East Texas Soils Over Time Resulting From Human Decomposition, Isabela Marisol Overturf
Spatial Geochemical Changes In Central And East Texas Soils Over Time Resulting From Human Decomposition, Isabela Marisol Overturf
CMC Senior Theses
Human decomposition is studied to aid forensic investigations and better understand the impact of cemeteries on urban resources like soil and groundwater. The purpose of this study was to identify changes in soil geochemistry at and around a human grave to search for lateral nutrient movement and possibly identify new patterns in elemental concentrations that could be used in estimating post-mortem intervals (PMIs). At the Forensic Anthropology Research Facility (FARF) at Texas State San Marcos, soil samples were collected from a shallow grave over the course of 54 days to conduct analysis for organic matter content, texture, pH, and bulk …
Environmental Assessment Of Arsenic And Mercury Levels At The Garfield Mill Site, Calico, California, Steven Gregory Thorp
Environmental Assessment Of Arsenic And Mercury Levels At The Garfield Mill Site, Calico, California, Steven Gregory Thorp
Electronic Theses, Projects, and Dissertations
Environmental impacts of mining at Calico, California, are poorly understood in comparison to the details of its history of silver production. Human health risks associated with arsenic from the lode rock, as well as mercury from the silver milling process, include central nervous system damage, organ failure, and death. To quantify the potential human health risk and manage remediation of this site, tailings from the Garfield Mill site were digitally mapped and chemically analyzed by portable x-ray fluorescence, which permitted volumetric estimates of total mill tailings and the arsenic and mercury budget, as well as identification of anomalies in the …
Seasonal Soil Carbon Fluxes In Transitioning Agricultural Soils In Central Washington State: Relations To Land-Use, Environmental Factors And Soil Carbon-Nitrogen Characteristics, Brandon Kautzman
All Master's Theses
Changing agricultural land-use practices to increase soil carbon sequestration contributes to climate change mitigation and improved food security by moving CO2 from the atmosphere into soil as soil organic carbon (SOC). In 2016, a farm in Thorp, Washington, Spoon Full Farm, began converting land historically farmed using conventional methods of tillage and synthetic fertilizers to conservation farming methods with direct seeding and organic soil amendments with a goal of sequestering carbon in the soil. This project evaluates relationships of soil CO2 respiration and net ecological exchange (NEE) with land-use types, seasonal environmental factors (air temperature, relative humidity, soil …
Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik
Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik
Honors Theses and Capstones
The expansion of local agriculture in the New England region is putting increased pressure on farmers to expand their arable land base. While clear-cutting is a traditional method of converting forested land to agriculture, it is known for having adverse ecological impacts. To minimize these impacts, farmers can create a silvopasture which incorporates a portion of the original forest canopy into pastures or crop fields. This study evaluates the impact of land-use changes for agriculture on soil nitrogen (N) retention. In particular, this study investigates the differences in soil N turnover, gaseous loss, and aqueous loss among an established forest, …
Isolation From Soil Microorganisms That Are Inhibitory To Wheat Seeding Pathogens, Kynita Wilson-Humphrey
Isolation From Soil Microorganisms That Are Inhibitory To Wheat Seeding Pathogens, Kynita Wilson-Humphrey
McCabe Thesis Collection
Many diseases caused by bacteria, viruses, or fungi are responsible for the ruin of a great number of crops annually. At present, many of these crops are being treated for diseases by synthetic or man-made chemicals. Some of the chemicals have been proved to have adverse effects on the environment, including humans and animals. Very few non-chemical means are available to farmers at this time to control these pathogens. This is due to the fact that many of the means of control have little effect against the pathogens or diseases. This research attempts to isolate microorganisms from the soil which …