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Identification, Characterization, And Genetic Comparison Of Fusarium Species Isolated From Switchgrass (Panicum Virgatum L.), Tamara Annette Collins

Masters Theses

Fusarium spp. are ubiquitous, soilborne and seedborne pathogens that affect over 100 economically important plant hosts annually, resulting in billions of dollars in economic losses. They cause a variety of plant disease symptoms including, crown, root, and stem rots, wilts, and foliar necrosis. Furthermore, they produce harmful mycotoxins that are detrimental to the health of animals and humans. Members of this genus have been isolated from diseased tissues of switchgrass. The objective is to correctly identify and classify Fusarium isolates to species using both classic phenotypic characterization and current genetic technologies of DNA extraction and polymerase chain reaction and create …

Switchgrass Extractives Have Potential As A Value-Added Antimicrobial Against Plant Pathogens And Foodborne Pathogens, Alexander Ian Bruce

Masters Theses

Panicum virgatum (switchgrass), a perennial grass native to North America, is a leading biomass feedstock candidate for the manufacture of cellulosic ethanol. Switchgrass is considered a viable option for biofuel production due to its cheap production cost and ability to grow on marginal land. Biofuel derived from switchgrass has been shown to be very energy efficient, producing 540% more renewable energy versus nonrenewable energy expended. Switchgrass-derived biofuel is also estimated to have greenhouse gas emissions that are 94% lower than emissions from gasoline (Schmer et al 2008). Biofuels are created through biochemical processes that utilize various enzymes and microorganisms for …

Characterization Of Fusarium Species And Alternaria Alternata, And Their Effects On Switchgrass Health And Chemical Components, Sara Beth Collins

Masters Theses

Panicum virgatum L., readily referred to as Switchgrass, is a perennial warm-season bunch grass, used as an alternative energy source for biofuel production. There is insufficient research on switchgrass pathogens, and is expected that an increase in disease pressure will result as more land is reserved for this perennial crop. The purpose of this research was to identify and characterize pathogenic Alternaria alternata and Fusarium species on Switchgrass (Panicum virgatum L.), and to evaluate their impact on stand establishment and plant health. Molecular identifications of fungal isolates obtained from infected commercial switchgrass seed yielded eight species (A. alternata, …

A Simulation Model Of The “Bio-Depot” Concept In The Context Of Components Of Variance And The “Taguchi Loss Function”, Maximilian Platzer

Masters Theses

The research focuses on the simulation, statistical evaluation, costs, and continuous improvement of supply chains for bio-based materials. A significant challenge of using cellulosic feedstocks for biofuel or bioenergy production is the high per unit costs of final products, e.g., biofuels. The goal of the research is to provide practitioners with useful statistical methods and a simulation Excel template for evaluating the variance and costs associated with the supply chain of bio-based products. Statistical Process Control (SPC), components of variance, Taguchi Loss Function, and reliability block diagrams (RBD) are used in this thesis for the evaluation of the supply chain …

Modeling Water Quality For Switchgrass Crop Production: Implications For Bioenergy Sustainability In East Tennessee, Zachariah Tzvi Seiden

Masters Theses

With passing of the US Energy Independence and Security Act (EISA) of 2007, there has been considerable research conducted on the sustainability of bioenergy crop production in the United States; switchgrass has shown particular potential for bioenergy production in East Tennessee. Many studies evaluating the environmental impact switchgrass has on runoff and water quality use the Soil and Water Assessment Tool (SWAT) for watershed modeling. Because SWAT is a lumped watershed model, it evaluates the result of hydrological processes for each hydrologic response unit (HRU), without accounting for the physical interactions between these HRUs. The Water Erosion Prediction Project (WEPP) …

Economic And Environmental Optimization In The Supply Of Switchgrass In Tennessee, Jia Zhong

Masters Theses

The low efficiency of collection, storage and transportation in the switchgrass supply chain has hindered the commercialization of a switchgrass-based biofuel industry, even given its ecological and environmental advantages in carbon sequestrate, soil quality, water use, and pollution pressure. Thus, designing a switchgrass-based supply chain balancing both environmental and economic performance is important to expedite the development of the cellulosic biofuel industry to meet the national energy plan.

The objectives of this study are to 1) determine economic cost and multiple environmental outcomes in feedstock supply chains and 2) identify the relation between the economic and environmental performances. The first …

Diallel Analysis Of Biomass And Ethanol Yield In Leaves Versus Stems Of Lowland Switchgrass, Alexandria Christina Desantis

Masters Theses

Switchgrass (Panicum virgatum L.) is a warm season perennial grass used widely as a forage crop. This research seeks to address improving biomass yield and predicted ethanol yield through certain traits by the following objectives: (1) differences in average biomass and predicted ethanol yields from leaves versus stems, (2) genetic variance and heritability estimates of biomass and ethanol yield traits (3) general (GCA) and specific combining ability (SCA) among the five parents for biomass and ethanol yield, and (4) correlations between agronomic and morphological traits. Five parents with varying morphological traits were crossed in a diallel design, excluding selfs. …

Performance Of Beef Cattle Grazing Native Warm-Season Grasses In An Integrated Forage/Biofuels System In The Mid-South, William Matthew Backus

Masters Theses

Early season (ES) and full season (FS) grazing strategies were used to evaluate performance of stocker steers grazing native warm-season grasses (NWSG) in 2010, 2011 and 2012 in two experiments. Experiment one was conducted at the Research and Education Center (REC) at Ames Plantation near Grand Junction and experiment two was conducted at Highland Rim REC near Springfield in which Angus and Angus cross steers (268±25kg) were used in completely randomized design with three forage treatments: 1) switchgrass (Panicum virgatum L.); 2) a combination of big bluestem (Andropogon gerardii Vitman) and indiangrass (Sorghastrum nutans); and 3) …

Evaluation Of The Over-Expression Of A Miscanthus X Giganteus Ppdk (C4ppdk1) In Switchgrass (Panicum Virgatum) For Improved Cold Temperature C4 Photosynthesis, Mathew Christian Halter

Masters Theses

Switchgrass (Panicum virgatum) has been proposed as a potential biofuel feedstock to aid in the displacement of petroleum-based combustible fuels over the course of the next several decades. Improving the yield potential of this perennial grass is therefore of economic interest. Increased net ethanol yields can be achieved in cellulosic feedstocks via two means: 1. Improved sugar release from digestible cell wall materials, 2. Increased overall biomass yield. The latter is the subject of this study.

As a C4 photosynthetic plant, switchgrass is highly productive in the hot, humid climate of the southeastern United States. By bypassing the …

Optimal Location Of Cellulosic Ethanol Facilities And Their Impacts On Surface Water Quality In The Southeastern United States, Kevin Eric Cavasos

Masters Theses

Research suggests that by 2022, 10.5 billion of the 21 billion gallon annual production target for advanced biofuels mandated by the expanded 2007 Renewable Fuel Standard (RFS2) could originate in the Southeastern United States (US) (USDA 2010). This study applied a biorefinery siting and feedstock optimization model and a water quality model to examine the ex-ante impact of biorefinery locations on agricultural input use and nitrogen (N) loading into the region’s hydrological system. The objective of this research is to understand the potential implications of this level of cellulosic ethanol production and concomitant changes in land use on surface water …

Exploring The Potential To Penetrate The Energy Market For Tennessee-Produced Switchgrass, Fnu Shikha

Masters Theses

The need for alternative sources of energy which are renewable and environmentally friendly has focused attention on the development of biomass-based energy sector. Lignocellulosic energy crops such as switchgrass are considered potential feedstock for biomass-based energy because of wide range adaptability in conjunction with lower input requirements. However, the costs of the collection, storage, and transportation of the low density feedstock from farm to conversion facilities in the switchgrass supply chain pose a major barrier to the development of bioenergy sector.

The objective of the present study is to determine the optimal logistics configuration for Tennessee-produced switchgrass to penetrate the …

Genetic Variability For Biomass Yield, Yield Components, And Ethanol Yield Among Half-Sibs Of Switchgrass, Eifion Wyn Hughes

Masters Theses

For bioenergy crops to be an economical alternative to fossil fuels, rapid biological and technological advancements will need to occur. Some advancements can be accomplished by producing new switchgrass (Panicum virgatum L.) varieties with higher biomass and ethanol yields. The objective of this research was to quantify biomass and ethanol yield potential of four F₁ [F1] half-sib populations for future variety development as a bioenergy crop.

The four parental lines were PI 421999 (AR), PI 607837 (TX), PI 421552 (Cimarron), and Exp. # NSL-2001-1 (OK). Seed for one hundred and forty F₁ [F1] half-sib progeny were produced …

A Hydrological Analysis Of Switchgrass Land Cover In East Tennessee, Jordan Avery Hayes

Masters Theses

Energy needs and the recent installation of a cellulosic biofuel plant in Vonore, TN have created a demand for switchgrass in East Tennessee. Switchgrass has many strengths such as erosion protection, nutrient removal, and runoff mitigation. The Soil and Water Assessment Tool (SWAT) was selected to model the impact of transitioning traditional crops into switchgrass land cover. Field data was needed to properly calibrate the SWAT model for East Tennessee. The National Resources Conservation Service (NRCS) curve number (CN) was needed for runoff calibrations. This value was determined by both standard NRCS methods as well as an asymptotic method. The …

Preservation Of Nutrients In Cool- And Warm-Season Forages At Different Stages Of Maturity And Management, Jason Allen Shultz

Masters Theses

The overall goals of the studies described in this thesis were to investigate management practices of tall fescue and native warm-season grasses (NWSG) and find the best time to harvest and method to preserve forage quality. Study one investigated the effects of maturity on tall fescue and switchgrass and the effects of preservation method on forage quality. This study confirmed that maturity reduced forage quality in both tall fescue and switchgrass. Both tall fescue and switchgrass were successfully preserved as haylage or hay and did not differ in forage quality. Forages harvested before mid-May met the TDN and CP requirements …

Selected Costs And Benefits Of Protecting Vital Wildlife Habitats While Producing Biofuel, Benjamin Lewis Totty

Masters Theses

The objective of this study is to estimate selected costs and benefits of meeting the 2022 biofuel production mandates using switchgrass as the feedstock. This study involves the simulation of three scenarios to evaluate the cost of protecting and promoting biodiversity while producing switchgrass for biofuel. Two models are used in this study. The first, the Biofuels Facility Location Analysis Modeling Endeavor (BioFLAME), was developed at the University of Tennessee to study biorefinery location, feed stock source areas and costs associated with biofuel production. The second model was developed by the Nature Conservancy as part of Tennessee’s State Wildlife Action …

Factors Influencing The Feasibility Of Switchgrass Feedstocks: From A Biorefinery’S Perspective, Elizabeth Ann Humphreys

Masters Theses

Research suggests that biomass with high cellulose content like switchgrass is more efficient for producing ethanol than corn grain. The objective of this study is to evaluate factors influencing the economic feasibility of ethanol production from a biorefinery’s perspective using switchgrass as the only feedstock. The research conducted utilizes a model which considers switchgrass procurement costs, transportation costs, storage costs, dry matter loss, biorefinery construction costs, operating and maintenance costs, and ethanol production in determining the break-even price of ethanol. The break-even prices of ethanol estimated range from $2.02 to $2.45 per gallon. The sensitivity analysis demonstrated that when the …

The Epidemiology Of Puccinia Emaculata (Rust) In Switchgrass And Evaluation Of The Mycoparasite Sphaerellopsis Filum As A Potential Biological Control Organism For Switchgrass Rust., Jonathan Allen Black

Masters Theses

Switchgrass (Panicum virgatum L.) is a warm-season, perennial grass, whose native range includes the entire United States and north into Canada, excluding areas along the pacific coast. Recently, symptoms and signs of rust disease (Puccinia emaculata) have been observed on agronomic switchgrass, which include chlorosis of leaf tissue, necrosis, lodging, and plant death.

To evaluate disease progress of switchgrass rust, in four fields, individual leaves of twenty-five switchgrass plants were rated once per week for fifteen weeks over two growing seasons for disease severity. Rust was first observed on Julian day 166 and 152 in 2010 and …

Impact Of Switchgrass Bioenergy Feedstock Production On Soil Carbon Dioxide Flux And Below Ground Soil Organic Carbon Storage In East Tennessee, Leah Denise Soro

Masters Theses

Bioenergy production from switchgrass has shown promise in restoring degraded soils and helping to mitigate greenhouse gas (GHG) emissions. CO₂ loss and C-sequestration in soils are important topics for research to better understand the environmental impacts of bioenergy crops. The need for more thorough research of the carbon cycle in soils used for bioenergy production precipitated the primary interest of this study. The specific objectives of this study were 1) to measure SOC under switchgrass production in order to predict storage of carbon in soils based on previous cropping history, land management, soil physical characteristics, and time; and to …

Evaluation Of Capital Investment And Cash Flows For Alternative Switchgrass Feedstock Supply Chain Configurations, Jie Chen

Masters Theses

Biofuels have been widely recognized as a potential renewable energy source, and the United States’ government has been interested in producing ethanol from lignocellulosic biomass such as switchgrass. To evaluate whether lignocellulosic biomass based biofuels production is economically feasible, this paper estimated the capital investment outlays, operation costs, and net present value for investment in alternative switchgrass feedstock supply chain configurations in East Tennessee a 25 million gallon per year ethanol biorefinery. Two scenarios are analyzed in the study. The conventional hay harvest scenario includes the production, harvest, storage and transportation of biomass feedstocks from the fields to the biorefinery. …

Establishment And Persistence Of Legumes In Switchgrass Biomass And Forage/Biomass Production Systems, Kara Spivey Warwick

Masters Theses

Switchgrass, Panicum virgatum, is being developed as an economically and ecologically sustainable biomass crop. Nitrogen is considered one of the most limiting inputs of switchgrass. Alternatives to synthetic nitrogen fertilization may be nitrogen-fixing legumes interseeded into switchgrass. The objectives of this research were: (1) develop efficient legume management strategies for switchgrass production systems, (2) evaluate and identify cool and warm-season legumes that can be grown compatibly with switchgrass, (3) determine whether switchgrass yields are increased by legume N-fixation, and (4) determine N-fixation of common (Vicia sativa) and hairy vetch (Vicia villosa).

This study examined the …

Evaluation Of Pre-Processing And Storage Options In Biomass Supply Logistics: A Case Study In East Tennessee, Yuan Gao

Masters Theses

Biofuels have been widely recognized as a potential renewable energy source that can lessen the United States’ dependence on imported petroleum and enhance the domestic economy. Particularly, biofuels derived from lignocellulosic biomass (LCB) have been the focus in the development of a sustainable biofuels industry. However, technical barriers in the LCB feedstock supply chain have been one of the major challenges impeding the economic viability of this industry. To expedite the commercialization process of LCB-based biofuels production, this paper employed a spatial mixed-integer mathematical model to explore the optimal biomass logistic system for a switchgrass-based biofuels biorefinery in East Tennessee. …

Analysis Of Factors Affecting Farmers’ Willingness To Adopt Switchgrass Production In The Southern United States And An Excel Spreadsheet-Based Decision Tool For Potiential Switchgrass Producers, Donald Joshua Qualls

Masters Theses

The increased need for and scarcity of hydrocarbon energy pushes the search and extraction of reserves toward more technically difficult deposits and less efficient forms of hydrocarbon energy. The increased use of hydrocarbons also predicates the increased emission of detrimental chemicals in our surrounding environment. For these reasons, there is a need to find feasible sources of renewable energy that could prove to be more environmentally friendly.

One possible source that meets these criteria is biomass, which in the United States is the largest source of renewable energy as it accounts for over 3 percent of the energy consumed domestically …

Consumer Willingness To Pay For E85, Denise A. Skahan

Masters Theses

Concerns regarding energy security, resource sustainability, and environmental protection have heightened interests in renewable fuels and sparked the research and development of ethanol as a transportation fuel. This study examines consumers’ willingness to pay for ethanol from various potential feedstocks; corn, switchgrass and wood wastes. Data was collected via a survey of fuel consumers across the United States in 2009. Results show that consumers have a preference for E85 (a fuel blend with 85 percent ethanol and 15 percent gasoline) from corn, switchgrass and wood wastes compared to E0 (gasoline) and a preference for E85 from switchgrass and wood wastes, …

Economic Impacts Of Production, Storage, Transport, And Conversion Of Switchgrass For Cellulosic Ethanol In Tennessee, Adam David Fulton

Masters Theses

The goal of this study is to evaluate the introduction of cellulosic ethanol conversion plants using switchgrass as the feedstock and how it impacts the economies of two Tennessee regions. Switchgrass feedstock production, storage, and transportation costs are estimated for one plant in West Tennessee and one plant in East Tennessee. In each region, the location for a cellulosic ethanol conversion plant and the acreage required to meet a 61.8 million-gallon/year capacity are specified. The costs associated with switchgrass production and cellulosic ethanol conversion are then entered into IMPLAN to estimate the economic impacts of one cellulosic ethanol plant in …

Analysis Of Bioenergy Crops As A Production Alternative For A Representative East Tennessee Beef And Crop Farm, Andrew Preston Griffith

Masters Theses

The United States has increased its emphasis on energy independence and has developed legislation that promotes the development of alternative energy sources. One potential energy source being studied is the perennial cellulosic feedstock switchgrass. Switchgrass is currently being produced for experimental purposes and not on a commercial scale. The first objective of this research was to evaluate, under risk, the switchgrass contract incentives that could encourage a representative farmer in Monroe County, Tennessee to produce switchgrass. The second objective was to evaluate, under risk, the contract type and terms that would induce a representative farmer to produce switchgrass. Net returns …

Economic Analysis Of Delivering Switchgrass To A Biorefinery From Both The Farmers' And Processor's Perspectives, Chenguang Wang

Masters Theses

Switchgrass for bioenergy production will require substantial storage. The first paper evaluates costs of various baling and on-farm storage systems by simulating the final delivered costs to the biorefinery under two representative soil types in East Tennessee and West Tennessee. Influences of the volatilities of switchgrass yield, diesel fuel price and nitrogen fertilizer price on delivered costs are considered. Results show that rectangular bales minimize cost if switchgrass is processed immediately after harvest. However, round bales minimize cost if switchgrass is stored without protection for 200 days before being transported to the biorefinery. The second paper evaluates from the processors' …