Agriculture Commons^™

Design And Plan Of A Modified Hydroponic Shipping Container For Research, John A. Houtman

Open Access Theses

As the world’s population continues to increase, food production will need to increase in order to meet the predicted rise in food demand. However, with increased pressure on cropland available from environmental effects and urbanization, new innovative methods of crop production need to be researched in order to increase agricultural production with limited land. This research focuses on the design of a single form of urban agriculture that is considered Zfarming and has the potential to produce quality urban agricultural produce through ground-based measures. This project produced detailed step-by-step analysis of the design process, develop variability within the modified hydroponic …

Evaluating The Two-Stage Ditch As A New Best Management Practice, Andi Hodaj

Open Access Dissertations

A two-stage ditch involves modifications of a traditional drainage ditch to resemble more the features of a natural stream. The idea is to create or simulate extended benches on both sides of the ditch that would develop naturally over a period of time in a stream because of geomorphological processes. Previous research in Indiana and Ohio has shown that two-stage ditches offer the potential to reduce sediment load and extend the interaction time between water and vegetation on the benches allowing larger uptake of nutrients from the vegetation on the extended benches, and increasing the denitrification rates in the bench …

Investigating U.S. Resident Perceptions Of Corporate Social Responsibility In Food And Agriculture, Carissa Jae Morgan

Open Access Theses

Corporations are prioritizing corporate social responsibility (CSR) activities by investing in and actively promoting their social practices. In the U.S. of the modern food supply chain creates a unique challenge for corporations to address concerns about social issues of consumers and non-consumers alike. This study is motivated by the need to better understand individuals’ perceptions of CSR as it pertains to the food supply chain. In April 2015 an online survey collected information from 1,201 U.S. residents with the objective of investigating individuals’ perceptions of relative importance of eight prominent CSR areas relevant to food and agriculture. Demographic, household consumption, …

Enhancing Bioethanol Fermentation Through Removal Of Acetic Acid Using Liquid-Liquid Extraction, Mahdieh Aghazadeh

Open Access Dissertations

The concern for the ever growing human population as well as the depletion of fossil fuel resources and their impact on global warming have long been motivations for the researchers to investigate means for sustainable producing carbon-neutral energy. Second-generation biofuel refers to liquid fuels that are produced from non-food resources and reduce the total greenhouse gas emission by at least 60 %. Acetic acid has been shown to be one of the most ubiquitous fermentation inhibitors in a bioethanol production facility which slows down the bioethanol production and reduces its yield through inhibition of the ethanol producing microorganisms. The use …

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, …

Modifying A Cow-Calf Biophysical Simulation Model For Analyses Of Alternative Enterprises, Jennifer L. Lutes

Graduate Theses and Dissertations

Cow-calf producers in the United States, tasked with providing beef calves for the beef industry, have had a multitude of difficulties to overcome in recent years. Producers in northwest Arkansas were negatively impacted by high hay prices coupled with low beef cattle market prices due to severe drought experienced in portions of 2010, 2011, and 2012. During this time they also faced high grain prices, due to a record low harvest, combined with portions of the corn harvest diverted from human and animal feed to ethanol production. Tight lending policies of this time, reminiscent of the housing market crash in …

Life Cycle Assessment Of Alternative Swine Management Practices, Prathamesh Avadhut Bandekar

Graduate Theses and Dissertations

Life Cycle Assessments (LCAs) are quantitative analyses of complex systems for evaluation of impacts and risk associated with management decisions. LCAs can be effective tools for determining comparative advantages of management strategies across specific impact concern. In this study, life cycle assessments of pork production management alternatives was performed. The alternative management practices included in this study were production of entire males (boars), use of pens for gestation housing, immunocastration, production without growth promoting antimicrobials, production without growth promoting and preventive antimicrobials, and production without ractopamine. These LCAs evaluated the impact of each management strategy on greenhouse gas emission (GHG), …

Nitrate Removal From Subsurface Drainage By Denitrifying Bioreactor, Erin Chichlowski

Open Access Theses

Denitrifying bioreactors are an edge-of-field best management practice that reduce nitrate in runoff and subsurface drainage waters with minimum surface foot print and management requirements. The objectives of this study included evaluating a 173 m3 wood chip bioreactor for nitrate reduction and removal rates, the effects on phosphorus, and the impacts of the bioreactor's physical characteristics on effective nitrate reduction During periods of flow, weekly water samples were collected for lab analysis of nitrate+nitrite (nitrate-N), total nitrogen (TN), soluble reactive phosphorus (SRP), and total phosphorus (TP) and measurements were made of water temperature, dissolved oxygen, pH, oxidation reduction potential, temperature, …

Uncertainty, Irreversibility, And Investment In Secondgeneration Biofuels, Tanner Joseph Mccarty

Open Access Theses

The present study formalizes and quantifies the importance of uncertainty for investment in a corn-stover based cellulosic biofuel plant. Using a real options model we recover prices of gasoline that would trigger entry into the market and calculate the portion of that entry trigger price required to cover cost and the portion that corresponds to risk premium. We then discuss the effect of managerial flexibility on the entry risk premium and the prices of gasoline that would trigger mothballing, reactivation, and exit. Results show that the risk premium required by plants to enter the second-generation biofuel market is likely to …

Field To Flight: A Techno-Economic Analysis Of Stover To Aviation Biofuels Supply Chain, Amanda C. Bittner

Open Access Theses

Greenhouse gas emissions have been a growing concern. The transportation sector contributes to one-third of GHG emissions in the United States from fossil fuel burning. The Renewable Fuel Standard set a requirement for 16 billion gallons (ethanol equivalent) of cellulosic biofuels to be used in the market. Aviation biofuels can help to meet both of these problems as well as improve U.S. energy security.

Investment in the biofuel industry carries a lot of risk. The biofuel industry is run by the private sector, but can be incentivized by government. Cellulosic biofuels carry even more risk than first generation biofuels, because …

Shrinkage Prediction During Pasta Dehydration, Gina Michelle Bressani

Open Access Theses

Shrinkage models from different fields of study were reviewed. Pasta was used as a model to further develop the hypothesis of predicting shrinkage in terms of the rate of relaxation and the rate of moisture loss. An extended literature review of pasta properties, such as isotherms, diffusivity, glass transition, rheological properties, and shrinkage was conducted. Isotherm and glass transition models were developed from the literature data acquired. Creep was tested with a 25 mm-diameter flat plate at 20 to 40°C at varying moisture content. Viscoelastic properties for the Burgers model for creep were determined, where higher moisture content samples resulted …

Determinants Of Energy Efficiency Across Countries, Guolin Yao

Open Access Theses

With economic development, environmental concerns become more important. Economies cannot be developed without energy consumption, which is the major source of greenhouse gas emissions. Higher energy efficiency is one means of reducing emissions, but what determines energy efficiency?

In this research we attempt to find answers to this question by using cross-sectional country data; that is, we examine a wide range of possible determinants of energy efficiency at the country level in an attempt to find the most important causal factors. All countries are divided into three income groups: high-income countries, middle-income countries, and low-income countries. Energy intensity is used …

Environmental Tradeoffs In Bioenergy Production And Agricultural Practices, Alicia Lynn English

Open Access Dissertations

The focus of this dissertation is the environmental tradeoffs of stover removal within the Corn Belt. The environmental tradeoffs considered are mainly concerned with managing soil erosion and soil quality. The analysis layers soil characteristics, management strategies and per acre costs using an integrated RUSLE2/WEPS model and an economic optimization model to illuminate a lower bound supply response. Different assumptions were tested in regards to sustainability, prices, and market integration for five states and 18,760 soil types throughout the Corn Belt. Sustainability was defined to limit soil erosion from wind and water to 5 tons/acre/year and the soil organic matter …

Using The Ceres-Maize Model To Create A Geographically Explicit Grid Based Estimate Of Corn Yield Under Climate Change Scenarios, Ryan Zachary Johnston

Graduate Theses and Dissertations

The CERES-Maize model was evaluated in its capacity to predict both regional maize yield and water use within the United States Department of Agriculture (USDA) Economic Research Service (ERS) Region 1 between the years 1997-2007. A grid based, geospatially explicit method was developed to express the various rainfed and irrigated maize cultivars grown across the region. Overall, the calibrated model compared well for both physiological and yield parameters, producing significant linear relationships (p

The calibrated and validated CERES-Maize model was used to predict potential evapotranspiration and yield under three IPCC weather scenarios for the year 2050 to evaluate crop production …

Measuring The Energy Required To Dry Rice In Commercial Rice Dryers, Maria Alejandra Billiris

Graduate Theses and Dissertations

The objective of this research was to quantify and assess the energy use and efficiency of commercial cross-flow dryers when drying rice using a range of drying and ambient conditions. First, equations that predict the theoretical energy required to dry rice from any given initial moisture content to a desired final moisture content were developed for several rice cultivars using a semi-theoretical approach to obtain a basis for comparison to calculate energy efficiency. Theoretical energy requirements, expressed as the energy required per unit mass of water removed, increased exponentially as initial moisture content decreased. Additionally, medium-grains required more energy to …