Physical Sciences and Mathematics Commons^™

A Study Of Short-Season Winter Cover Crops For Organic High Tunnel Production Systems, Luke Riley Freeman

Graduate Theses and Dissertations

This two-year study investigated short-season winter cover crops to improve soil quality and growth of subsequent vegetable crops in an organic high tunnel production system. Five winter cover crop treatments including a nontreated control, Austrian winter peas (Pisum arvense), bell beans (Vicia faba), mustard (Brassica juncea cv. Kodiak), and Daikon radish (Raphanus sativus var. longipinnatus) were grown in a high tunnel in a randomized complete block design from mid-November to mid-March, mowed and incorporated into the soil, and followed by a succession of vegetable crops including tomato (Lycopersicon lycopersicum, cv. ‘Plum Dandy’) and broccoli (Brassica oleracea var. italica, cv. ‘Bay …

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 …

A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly

Graduate Theses and Dissertations

Groundwater depletion, a subject of growing concern for a significant portion of Arkansas, may lead to future economic challenges for the Arkansas Delta region. The Mississippi River Valley Alluvial Aquifer is the uppermost aquifer and features the largest groundwater capacity in the Mississippi Embayment Aquifer System. The Mississippi River Valley Alluvial Aquifer, commonly referred to as the “alluvial aquifer”, spans 53,000〖 km〗^2 underlying portions of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Illinois, and Tennessee. As the alluvial aquifer trends southward for approximately 250 miles alongside the Mississippi River, its geographical extent ranges from 50 to 125 miles wide. There is a …

Gastrointestinal Health As A Stimulus For Native American Attraction To Medicinal Asteraceae And Further Implications For Human Evolution, Christopher David Stiegler

Graduate Theses and Dissertations

The Asteraceae, or the daisy family, is the largest family of flowering plants in the world, and its ethnobotanical, medical, and economic value is readily apparent cross-culturally. The aim of this thesis is to examine why constituent genera of the Aster family have remained such an integral part of human medicinal plant knowledge, and thereby to reveal any potential physiological, biological, or evolutionary mechanisms underlining human patterns of use regarding the Asteraceae. The present study focuses specifically on Native American plant knowledge made available by the expansive database in the works Daniel Moerman (Moerman 2003). Frequencies of plant use and …

The Impact Of Climate Change In Bangladesh On The Rice Market And Farm Households, Mst Ashrafun Nahar

Graduate Theses and Dissertations

Bangladesh is trying to achieve self-sufficiency in domestic rice production but climate change effects on agricultural production makes it challenging to attain the goal. The country is highly vulnerable to the effects of climate change since it is the major cause to rise in sea level, more warm summer, and happening food and cyclone in the country.

This study develops an Aggregate Farm Household Model to analyze the impact of potential land loss and yield reduction from climate change on production, consumption, prices, welfare, and the ability of government to achieve self-sufficiency in rice production. The model is calibrated to …

Implications For The North American Lower Crustal 7.Xx Km/S Layer From An Exhumed Crustal Root, Western Canadian Shield, Calvin Everette Johnson

Graduate Theses and Dissertations

Studies of the Thorsby magnetic low, the southern extent of the 2,800 km-long Snowbird

Tectonic Zone (STZ) in Alberta, Canada, show pronounced lower crustal seismic reflectivity and preservation of a crustal root. These features may be correlative to the well-exposed central STZ, where two lower crustal tectonic events have been identified at 2.6-2.55 Ga and 1.92-1.89 Ga. High-resolution cross-sections of the central STZ reveal the late-stage interaction of Paleoproterozoic intracontinental thrust and strike-slip shear zones responsible for juxtaposing ca. >20,000 km2 of lower continental crust (0.9-1.5 GPa) with middle continental crust (0.5 GPa) (Mahan and Williams, 2005; Dumond et al., …

Lidar-Assisted Extraction Of Old Growth Baldcypress Stands Along The Black River Of North Carolina, Weston Pierce Murch

Graduate Theses and Dissertations

The remnants of ancient baldcypress forests continue to grow across the Southeastern United States. These long lived trees are invaluable for biodiversity along riverine ecosystems, provide habitat to a myriad of animal species, and augment the proxy climate record for North America. While extensive logging of the areas along the Black River in North Carolina has mostly decimated ancient forests of many species including the baldcypress, conservation efforts from The Nature Conservancy and other partners are under way. In order to more efficiently find and study these enduring stands of baldcypress, some of which are estimated to be more than …

Spread Trading In Corn Futures Market, Ryan D. Napier

Graduate Theses and Dissertations

The non-linear relationship between old crop – new crop year spreads in corn futures market and stock-to-use (S-U) ratios published by the United States Department of Agriculture is analyzed. Using a non-linear logarithmic smooth transition regression (LSTR) model, we capture asymmetric market behaviors in high and low S-U regimes. Capturing this relationship and understanding the non-linear aspects of the relationship is of interest of grain merchandizers and speculators in the market. A spread trading strategy is simulated for the sample period, January 1985 through April 2015, to determine if the non-linear relationship is a profitable arbitrage opportunity in the market.

Geospatial Analysis Of Droughts, Rice And Wheat Production, And Agrarian Vulnerability: A District-Level Study Of The Self-Calibrated Palmer Drought Severity Index In India, Aaron Michael Shew

Graduate Theses and Dissertations

Droughts have affected more people than any other natural disaster in the last century, causing billions in economic damages and millions of deaths. As the Sea Surface Temperatures (SST) have heated in the Indian Ocean, drought patterns across South Asia have changed; the Indian monsoon has become more volatile and less predictable. In this study, monthly self-calibrated Palmer Drought Severity Index (sc-PDSI) data for the time period between 1950 and 2009 were interpolated to India’s districts; then the data were analyzed for changes in frequency and severity. The data were further evaluated using Anselin’s Local Moran’s I Statistic to elicit …