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Full-Text Articles in Physical Sciences and Mathematics
Environmental And Climatic Constraints On Large-Scale Camelina Production In Eastern Arkansas, Benjamin Robert Tracy
Environmental And Climatic Constraints On Large-Scale Camelina Production In Eastern Arkansas, Benjamin Robert Tracy
Graduate Theses and Dissertations
Camelina sativa is a cold weather crop that is typically grown in semi-arid environments in the Western United States, usually as a spring crop, but sometimes during the winter. Research analyzing climate data and soil hydrology is important to better understand the environmental and terrain conditions necessary for Camelina farming wherever it is proposed for large-scale production. This study focused on various conditions and constraints pertaining to the potential for Camelina as a crop biofuel in Eastern Arkansas. Due to interest in the economic potential of crop biofuels in this area, and in particular the low input costs for Camelina, …
Willingness To Pay For Irrigation Water Under Scarcity Conditions, Tyler Robert Knapp
Willingness To Pay For Irrigation Water Under Scarcity Conditions, Tyler Robert Knapp
Graduate Theses and Dissertations
Reliance of Arkansas agricultural producers on groundwater for irrigation has led to depletion of the Mississippi River Valley alluvial aquifer. Without intervention, consequences include insufficient groundwater to meet irrigation demand as well as drawdown of the deeper Sparta Aquifer, upon which communities in eastern Arkansas rely for non-agricultural use. Among proposed solutions to combat groundwater decline is the construction of off-farm surface water infrastructure to meet the irrigation needs of producers. Despite the importance of irrigated agriculture to Arkansas, there is little know about the economic value of irrigation water to producers. Thus, we implement a double-bounded dichotomous choice contingent …
Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality, Jason Richard Burgess-Conforti
Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality, Jason Richard Burgess-Conforti
Graduate Theses and Dissertations
In 2013, only 37% of the 32 million Mg of flue gas desulfurization (FGD) by-products generated in the United States were reused beneficially. If FGD by-products could be used as a beneficial soil amendment, millions of megagrams may be diverted away from surface impoundments and landfills. The purpose of this research was to identify the liming characteristics of a high-Ca dry FGD (DFGD) by-product in comparison to a Class-C fly ash (FA) and reagent-grade CaCO3, and to evaluate the effects of land application to a managed grassland on runoff, plant, and soil quality. Liming characteristics were determined by measuring the …
Agro-Climatic Change, Crop Production And Mitigation Strategies-Case Studies In Arkansas, Usa And Kenya, John Westley Magugu
Agro-Climatic Change, Crop Production And Mitigation Strategies-Case Studies In Arkansas, Usa And Kenya, John Westley Magugu
Graduate Theses and Dissertations
Although climate change impacts vary geographically and temporally, studies at local levels are not readily available for stakeholders to better understand how their local communities would be affected and what remedial measures could be more effective in their local contexts. This dissertation has examined climate change and its impacts in two different local contexts: eastern Arkansas in the USA and Nyando in Kenya. The first part of this dissertation develops agro-meteorological indicators and examines the relationship between agro-meteorological indicators and crop yields in eastern Arkansas between 1960 and 2014. Results reveal that temperature based indicators were more strongly correlated to …
Eucalyptus In Kenya; Impacts On Environment And Society, Brandy M. Garrett Kluthe
Eucalyptus In Kenya; Impacts On Environment And Society, Brandy M. Garrett Kluthe
Graduate Theses and Dissertations
Eucalyptus trees were introduced to Kenya a little over a century ago. European colonization along with the development of a railway system increased the demand for a fast growing wood source. The expansion of the tree across the fertile lands in Kenya raises concerns about the environmental impact on ecosystems where it has been introduced. These concerns include degraded soils, loss of water resources, co-introduction of ectomycorrhizal species, and allelopathy. Economic benefits to local landowners were also explored as well as the potential for large Eucalyptus woodlots to maximize the sequestration of CO₂ from the atmosphere. This was examined through …
Evaluation Of Rusle 2 To Estimate Soil Loss From Pastures, Stasha Katrina Balkissoon
Evaluation Of Rusle 2 To Estimate Soil Loss From Pastures, Stasha Katrina Balkissoon
Graduate Theses and Dissertations
The accurate estimation of soil erosion by the Revised Universal Soil Loss Equation version 2 (RUSLE2) is critical for several conservation assessments, least of which is its use in the Phosphorus Index (PI) to identify and rank the vulnerability of agricultural fields to phosphorus (P) runoff. Earlier versions of RUSLE reported a soil loss overestimation, which were revised to give RUSLE2, where biomass production in different climatic regions was more accurately represented. RUSLE version 2.0, which contains the new vegetative biomass production routine, was evaluated using two performance indices, the Nash Sutcliffe Efficiency Index (NSE) and Index of Agreement (D) …
Dissemination And Persistence Of Plasmid Located, Integron Associated Antibiotic Resistant Genes In Wastewater Treatment Plant Effluent And Stream Water Bacteria, _ Suhartono
Graduate Theses and Dissertations
Transmissible plasmid-mediated integrons play important role in the persistence and dissemination of antibiotic resistance throughout the environment. Plasmids from 139 multi-antibiotic resistant Escherichia coli recovered from wastewater treatment plant effluent and upstream and downstream receiving stream water in Northwest Arkansas were extracted and profiled. Genes of class 1 and class 2 integrase (intI), mobilization (mob), sulfamethoxazole resistance (sul), and trimethoprim resistance (dfr) were detected using PCR and confirmed through DNA sequencing. Plasmids from almost half of the isolates (47%) were transmissible with mobF12 gene as the most frequently detected mobilization gene. Plasmid-borne class 1 with and without class 2 integrons …
Litter Conditioning Is Differentially Affected By Leaf Species, Phosphorus Enrichment, And Light Availability, Erin E. Scott
Litter Conditioning Is Differentially Affected By Leaf Species, Phosphorus Enrichment, And Light Availability, Erin E. Scott
Graduate Theses and Dissertations
Anthropogenic enrichment of nitrogen and phosphorus is one of the most pervasive and detrimental threats to aquatic ecosystems worldwide. In streams that rely on allochthonous basal food resources, such as leaves, nutrient pollution can result in altered food quality and decreased carbon (C) standing stocks. However, the magnitude and mechanisms of this change in quality are poorly understood. Laboratory microcosm studies were conducted to 1) quantify the response of litter C:P to a gradient of phosphorus (P) enrichment (0, 0.05, and 0.5 mg SRP/L) across leaf species with variable levels of degradability (sugar maple and oak), and 2) quantify the …
Modeling Greenhouse Gas Emissions And Net Return Implications For Cow-Calf Producers In The Ozark Highlands, Stephen Aaron Smith
Modeling Greenhouse Gas Emissions And Net Return Implications For Cow-Calf Producers In The Ozark Highlands, Stephen Aaron Smith
Graduate Theses and Dissertations
Cow-calf producers in the Ozark Highlands region are under continuous pressure to improve economic efficiency. Additionally, estimating greenhouse gas (GHG) emissions from cow-calf and forage production processes may become increasingly important as policy makers seek to mitigate or reduce agriculture's role in climate change. As such, this analysis had three objectives. Objective 1: Provide a model that could be used by cow-calf producers, extension agents, and researchers to evaluate GHG and net return (NR) repercussions when modifying site characteristics, production methods, and inputs. Objective 2: Develop a user guide such that the methodology for estimating cow-calf GHG emissions and NR …
Analyzing Spring Freeze Impacts On Deciduous Forest Productivity Using Modis Satellite Imagery, Karl Lintvedt
Analyzing Spring Freeze Impacts On Deciduous Forest Productivity Using Modis Satellite Imagery, Karl Lintvedt
Graduate Theses and Dissertations
The impacts of an April 2007 spring freeze event on the productivity of deciduous broadleaf forest were analyzed using geographic information system (GIS) tools. Forest productivity was modeled using the Enhanced Vegetation Index (EVI), as recorded by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor. Measures of spatial autocorrelation were used to quantify the degree of spatial congruence between a map depicting the severity of the freeze event, and maps modeling forest productivity throughout the year. The results show a geographic correlation between the unseasonably low minimum temperatures sustained during the freeze and the unusually low forest productivity that followed. …