Call number: LD2668 .T4 1957 C37 / Master of Science

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 and is currently the only source for liquid renewable transportation fuels. Continued development of biomass as a renewable energy source is being driven in large part by the Energy Independence and Security Act of 2007 that mandates that by 2022 at least 36 billion gallons of fuel ethanol be produced, with at least 16 billion gallons being derived from cellulose, hemi-cellulose, or lignin. However, the production of biomass has drawbacks. The market for cellulosic bio-fuel feedstock is still under development, and being an innovative technique, there is a lack of production knowledge on the side of the producer. Some studies have been conducted that determine farmers’ willingness to produce switchgrass, however, they have been limited in geographic scope and additional research is warranted considering a broader area. Also, there have been production decision tools aimed at bio-mass, but these have either not been aimed at switchgrass specifically or have been missing key costs such as those incurred in storage. The overall objectives of this study are: 1.) to analyze the willingness of producers in the southeastern United States to plant switchgrass as a biofuel feedstock, 2.) to estimate the area of switchgrass they would be willing to plant at different switchgrass prices, 3.) to evaluate the factors that influence a producer’s decision to convert acreage to switchgrass, and 4.) to present a spreadsheet-based decision tool for potential switchgrass producers.

The renewable energy industry continues to expand at a rapid pace. New advances in cellulosic ethanol technologies have the potential to reduce our dependency on foreign oil. The evolution of these new biofuel markets could have significant effects on future production levels, market prices, and world trade levels for various agricultural commodities. Alternative scenarios involving new biofuel technologies, primary factor availability, and government policy will result in very different outcomes for the agricultural economy. The interactions of current and new biofuel technologies, including conventional ethanol production (from corn grain) and cellulosic ethanol production (from corn stover and switchgrass), and the agricultural economy were examined in a general equilibrium framework. Various outcomes were examined with attention primarily focused on (1) trade offs among competing uses of agricultural commodities, (2) changes in the output of major agricultural producers competing with the U.S., (3) effects on the livestock industry, (4) profitability of the agricultural industry, (5) changes in input costs, including land rents, and (6) changes in land use patterns. Results indicated that advances in cellulosic ethanol technology led to less grain ethanol production and more stover ethanol production in the United States. The production of switchgrass ethanol was not economically feasible under any scenario, which was expected due to the availability of lower priced corn stover. Overall, it was expected that a decrease in the costs of cellulosic ethanol production would lead to a higher increase in total U.S. ethanol production than actually occurred. As a result, the effects on the world economy were smaller than expected.

Switchgrass (Panicum virgatum L.) is a warm-season perennial bunchgrass native to North America. In addition to its importance as a forage grass, it has promise as a biofuel crop. However, its use is limited because the grass is difficult to establish. Improving seedling vigor is one approach for improving establishment. The objectives of this study were to: 1) select for increased seedling mass through half-sib family selection; 2) calculate an estimate of heritability for seedling mass; and 3) determine the mode of pollination of switchgrass. One cycle of selection was completed using a half-sib methodology. Seedling mass was determined in a series of growth chamber studies. The seed was produced in different space planted field nurseries in the College Station, TX area. Mean seedling weight of the base population (C0) was 0.014 gm seedling-1, while the mean seedling weight from the C1 cycle of selection was 0.029 gm seedling-1. Unfortunately, bulked seed from the base population was old and did not germinate well. Therefore, a new base population was recreated, and the C0 seedlings from this population were heavier than the C1 seedlings, 0.020 and 0.016 gm seedling-1, respectively. The calculated heritability estimate was H2 = 0.6. Since the C0 and C1 nurseries were not grown on the same soil type, the lack of a positive response for seedling weight may be due to the different soil types. However, it may require another cycle of selection to determine if seedling mass can be positively impacted via half-sib selection. The mode of pollination of the species was determined by 1) observing pollen germination and tube growth in the pistils using fluorescent microscopy and 2) determining seed set with selfed plants. When self-pollinated, the pollen tubes never grew into the ovaries but when cross-pollinated the tubes readily grew to the micropyle. Also, when switchgrass plants were self-pollinated, viable seed were not produced. These findings indicate that switchgrass is highly self-sterile because a self-incompatibility mechanism prevents the pollen tubes from growing into the ovary of the same genotype.

Nitrogen fertilization has the potential to significantly affect yield, nutrient concentration and removal and overall stand longevity of C4 grasses grown for bioenergy production. While most studies report that these grasses need little to no fertilizer inputs to maximize yield, no specific recommendations have been given for fertilizer requirements across a wide range of C4 perennial grass species, cultivars, harvest timings and N application rates. Two field trials were established in the summer of 2008 in Ridgetown and Elora, Ontario to compare 4 Miscanthus (M. sinensis and M. sacchariflorus crosses; Nagara-116 and Amuri-114, and Miscanthus x giganteus; M1 Select and Polish), 2 switchgrass (Panicum virgatum L.; Cave-in-rock and Shelter) and 2 big bluestem varieties (Andropogon gerardii Vitman; Prairie view and Southlow), 4 nitrogen fertilization rates (0, 40, 80, and 160 kg N ha-1) and 2 harvest timings (fall vs. spring harvest). Plots were harvested in the fall of 2009 and spring and fall of 2010. Yield response to N fertilization varied by location, species and year. In general, increasing N fertilization rates generated an increased yield response in all tested species. Different rates of N fertilization resulted in variable responses to N, P and K tissue concentrations and removal in switchgrass and Miscanthus. Tissue N concentrations and removal both increased with added N fertilization at both locations. In most cases N removal was the highest at the highest N application rate. Nitrogen concentrations were highest in the leaves and seed heads across species, N rates and locations. P and K concentrations and removal with increasing N fertilization in the whole plant and in individual plant parts did not follow clear trends in either Miscanthus or switchgrass in both locations. Delaying harvest to spring reduced yield at both locations by 35-42% and 62-65% for Miscanthus and switchgrass, respectively. Yield losses by delaying harvesting to the spring were increased with higher rates of N fertilization. Delaying harvesting decreased N, P and K concentration and removal in most grasses and locations.

Knowledge of nutrient accumulation and partitioning in plants is important to determine the optimum timing of harvesting during phytoremediation of biosolids. This research showed that a greater proportion of nitrogen (N) and phosphorus (P) absorbed by cattail and switchgrass was partitioned to the aboveground biomass (AGB), but this partition decreased after the onset of nutrient retranslocation to roots. Therefore, AGB should be harvested prior to retranslocation in order to optimize nutrient phytoextraction. Trace elements partitioned preferentially to the root biomass, indicating that AGB harvesting will have little impact on their phytoextraction. Net mineralized N concentration (Nmin) in biosolids from the primary lagoon cell was optimized near field capacity [60% water filled pore space (WFPS) but changed little under drier conditions (30% WFPS). Under near-saturation conditions (90% WFPS), net Nmin decreased with incubation time, likely due to reduced mineralization and denitrification. Available (Olsen) P concentration was not affected by moisture content.

Thesis (Ph.D.)--Michigan State University. Dept. of Crop and Soil Sciences, 2008. / Title from PDF t.p. (viewed on July 9, 2009) Includes bibliographical references. Also issued in print.

Belowground competition presents a threat to the production and sustainability of tree-grass ecosystems. Management scenarios designed to optimize the spatial and temporal distribution of soil resources will improve resource-use efficiency and promote greater co-production. We conducted three experiments to assess competition dynamics between loblolly pine and switchgrass. In a three-year field trial, loblolly pine and switchgrass were intercropped across varying competitive intensities. Interspecific competition decreased loblolly pine annual growth; however, establishing vegetation exclusion zones surrounding pines largely mitigated these effects. Switchgrass yields were less affected by interspecific competition compared to pines and land equivalency ratios indicated that with proper management co-production yields may exceed those of switchgrass monoculture. Switchgrass was a constant and significant competitor across all years while loblolly pine resource use was minimal in year 1 but increased in subsequent years. In a short-term greenhouse experiment, native soil was amended with biochar and inorganic N fertilizer and the effects of these amendments upon soil properties and switchgrass productivity were assessed. Biochar increased soil pH, total soil carbon, and soil moisture. However, N fertilization had negligible effects upon soil properties. Plant response to biochar was neutral to negative while N fertilization increased switchgrass foliar biomass but no interactive effects of the amendments were observed. Although the effects of biochar upon switchgrass production were trivial, its positive influence upon soil properties suggests a potential for mitigating competitive interactions. Finally, a field-scale study examined co-production of loblolly pine and switchgrass over two years in response to competition control, biochar, and N fertilizer. As expected, interspecific competition reduced soil resources and decreased plant productivity. Biochar increased total soil C and soil moisture levels but had relatively minor impacts upon other aspects of soil fertility or plant production. Nitrogen fertilization acidified soil pH and decreased total soil C and N but positively affected loblolly pine foliar N concentrations and switchgrass yields. A positive association between soil inorganic N and switchgrass yield suggests the species competitive influence may be increased with greater N supply.

The objective of this study is to a) develop the methodologies needed to measure moisture content in Switchgrass using electrical resistance meters, b) determine the effects of pressure and probe orientation on moisture content measurement using electrical resistance meters, c) generate moisture content calibration equations for electrical resistance meters using Switchgrass in the senescence growth stage, and d) characterize other methods to measure moisture content of Switchgrass in the windrow.

Lowland switchgrass (Panicum virgatum), big bluestem (Andropogon gerardii), indiangrass (Sorghastrum nutans), upland switchgrass (Panicum virgatum), little bluestem (Schizachyrium scoparium), beaked panicum (Panicum capillare), and purpletop (Tridens flavus) all show strong signs of seed dormancy which contributes to extremely poor field establishment. The objective of this work was to reduce seed dormancy by selecting individuals that exhibited reduced pre-stratification dormancy in laboratory tests. The classical breeding method of phenotypic recurrent selection was used to enhance germination. Of the three tall-stature species, lowland switchgrass made the greatest improvement in pre-stratification germination, followed by indiangrass and big bluestem. The four short stature species have shown various results after one cycle of selection at Starkville. A field emergence trial was also conducted to evaluate three cycles of breeding seed with five commercially available cultivars in which Cycle 3 seed produced more plants per hectare than any of the other cultivars or germplasm.