Digital Commons Network^™

Hydrologic And Water Quality Impacts From Perennial Crop Production On Marginal Lands, Qingyu Feng

Open Access Dissertations

Marginal lands are proposed as a viable option for producing biofeedstocks as these lands are not heavily engaged in agricultural production or may not be suitable for intensive row-crop food/feed production. However, meeting biofeedstock production goals will require large amount of marginal lands and the unintended consequences of producing biofeedstocks on marginal lands are not fully clear. The overall goal of this study was to evaluate the productivity of biofeedstocks on marginal lands and the potential impacts on hydrologic and water quality processes from the land use conversion.

This study was conducted in the Upper Mississippi River Basin (UMRB). First, …

A Comparative Analysis Of Sorghum And Maize As Bioenergy Feedstock For The Us Midwest: Compositional Attributes And System Nitrogen Dynamics, Monique K. Long

Open Access Dissertations

The comparative production potential among annual cropping systems grown as bioenergy feedstock in the Eastern Cornbelt of the US Midwest is generally unknown. Two field experiments were conducted to evaluate the compositional attributes, agronomic and economic efficiencies, and environmental impacts of sorghum (Sorghum bicolor M.) and maize (Zea mays L.) as they relate to bioethanol production and nitrogen (N). A 3 site-year fertilizer rate study (0, 67, 135 and 202 kg N ha-1) comparing five distinct sorghum hybrids/lines and a maize hybrid, was conducted to evaluate yields, carbohydrate pools, and associated theoretical ethanol (EtOH) yields. Post-harvest, dried stover was analyzed …

Effects Of Biomass Harvest On Eastern Red-Backed Salamanders, Patrick J. Ruhl

Open Access Theses

In a typical forest harvest, the volume of coarse woody debris (CWD) increases from nonmerchantable material (i.e., tree-tops, limbs, and small-diameter trees) left on the forest floor. Biomass harvesting removes much of this material for bioenergy production. When removed, ecosystem services associated with CWD, such as seedbed substrate, nutrient cycling, and essential wildlife habitat, is reduced. Woodland salamanders have strict microhabitat and soil moisture requirements that make them especially sensitive to timber harvest practices, particularly those that remove CWD, a primary habitat for the group.

I monitored the abundance of Eastern red-backed salamanders ( Plethodon cinereus ) in response to …

Developing An Unstructured Model To Investigate The Effect Of Ethanol On Product Yields For Glucose And Xylose Cofermentation In Saccharomyces Cerevisiae 424a (Lnh-St), Shane D. Clingenpeel

Open Access Theses

Production of bio-ethanol from lignocellulose requires the efficient fermentation of glucose and xylose, even in the presence of inhibitors. The desired product, ethanol itself, will inhibit the fermentation. A further understanding of how ethanol affects the organism is critical to overcoming its inhibition.

This thesis evaluated the effect of ethanol on the cofermentation of glucose and xylose in two different cases. The first case had an unstructured model created for Saccharomyces cerevisiae 424A (LNH-ST), a genetically modified strain of yeast capable of cofermenting glucose and xylose. The differential equations were based around sugar consumption, and the product yields were investigated …

Swat Model Simulation Of Bioenergy Crop Impacts In A Tile-Drained Watershed, Chelsie Marie Werling Boles

Open Access Theses

Tile drains are an important component of agricultural production in the Midwest, and their inclusion in modeling studies is important in watersheds where they are a principal hydrologic pathway. The new tile drainage simulation method in the Soil Water Assessment Tool (SWAT) was parameterized and tile flow results were compared with reviewed literature. Streamflow, sediment, and nutrient outputs were compared to measured values and simulated crop yields were examined with respect to average county yields. Plant growth stressors were examined to account for differences between simulated and published yields. The bioenergy crop switchgrass (Panicum virgatum) was applied over …