Physical Sciences and Mathematics Commons^™

Rice Biomass Response To Various Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH4PO4⋅6H2O), may provide a sustainable alternative to rapidly decreasing rock phosphate reserves. Struvite can be generated via chemical and/or electrochemical precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice cultivar (Gemini 214, RiceTec) grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)] in a P-deficient silt …

Environmental And Agronomic Evaluation Of Struvite In Rice Production Systems, Diego Della Lunga

Graduate Theses and Dissertations

Furrow-irrigation constitutes an alternative water regime that has been increasingly adopted in Arkansas. Among the management of nutrients in furrow-irrigated systems, phosphorus (P) represents a substantial challenge. The environmental sustainability of rice (Oryza sativa) production systems needs to be evaluated across different water regimes and fertilizer-P sources. Therefore, the objectives of the following studies were to: i) evaluate season-long carbon dioxide (CO2) and methane (CH4) emissions and global warming potential (GWP) under different tillage treatments [i.e., conventional tillage (CT) and no-tillage (NT)] and at different site positions (i.e., up-, mid-, down-slope) along the predominant slope of a production-scale, furrow-irrigated rice …

Tree-Ring Reconstruction Of Ouachita River Streamflow, Keaton Cade Jenkins-Joyce

Graduate Theses and Dissertations

The Ouachita River drains the Ouachita Mountains and Upper Coastal Plain in Arkansas and Louisiana. The Ouachita River is used for navigation, power generation, recreation, water supply, and wastewater treatment. The river has been prone to low flows during drought and extreme flooding, which were principal justifications for the construction of three large multipurpose dams on the stream. It is likely that the use of the Ouachita River will be stressed by future population growth, economic expansion, and climate change. For this study, tree-ring chronologies from various locations in and near the Ouachita River drainage basin were used to reconstruct …

Patterns In Winter Stonefly Distribution Along A River Continuum And Land-Use Gradient In Northwest Arkansas Streams, Zachary Tipton

Graduate Theses and Dissertations

Freshwater ecosystems are facing a crisis with extinction rates of aquatic species exceeding those of their terrestrial counterparts by up to fivefold. This decline is predominantly attributed to evolving land use patterns within watersheds, leading to chemical and physical transformations in freshwater habitats. Northwest Arkansas (NWA) represents one of the fastest-growing regions in the United States, undergoing substantial shifts in land use. Consequently, the status of aquatic life in this region remains uncertain. Addressing this concern, the latest Arkansas Wildlife Action Plan emphasizes the necessity of distribution and population data to guide conservation efforts for Species of Greatest Conservation Need …

Stream Restoration Effectiveness In Mullins Creek In Fayetteville, Arkansas, Amadeo Scott

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Lotic waterways are vital for habitat, food, water, and flood protection, but urbanization poses a major threat to their integrity. Runoff from urban surfaces leads to pollution, flashiness, loss of biodiversity, and other symptoms, also known as Urban Stream Syndrome (USS). To combat USS, streams can be restored, but most restorations are not monitored so their long-term effectiveness is unknown. This study quantitatively evaluated a decade-old stream restoration in Fayetteville, Arkansas, to assess its effectiveness in combating USS and achieving set restoration goals, and to gain insights for future restoration projects. Restoration goals included decreasing erosion and sedimentation, increasing pool …

Evaluation Of Hydrogeochemical Characteristics Of San Joaquin, Tulare, And Mojave Aquifers, Southern California, Maedeh Hassanvand

Graduate Theses and Dissertations

Before making attempts to enhance and manage the quality of water, a thorough understanding of these processes is necessary since the chemical quality of groundwater is impacted by a number of linked processes. This would be more important in arid and semiarid regions like the southern part of California where more rely on groundwater for agriculture and drinking water uses than the other states. As a result, fundamental knowledge of the governing processes of groundwater chemistry is required for effective water resource management. Thus, this study is primarily concerned with three aspects in Mojave, Tulare, and San Joaquin aquifers: The …

Constituent Loads And Trends In The Upper Illinois River Watershed: A Nonpoint Source Management Program Priority Watershed, Erin M. Grantz, Brian E. Haggard

Technical Reports

The Arkansas Department of Agriculture - Natural Resources Division (ANRD) has identified the Upper Illinois River Watershed (UIRW; 11110103), a hydrologic unit code (HUC) 8 watershed, located in Northwest Arkansas for prioritization by the Nonpoint Source (NPS) Management Program. URIW encompasses the Illinois River from its headwaters to the state line with Oklahoma and has been the subject of interstate disputes over water quality for decades. Nonpoint source pollution concerns in UIRW are excess nutrients from agriculture and sediment from changes in land use/land cover (LULC).

Local, state, and national groups, including the NPS Source Management Program, have invested in …

Constituent Loads And Trends In The Upper White River Basin: A Nonpoint Source Management Program Priority Watersheds, Erin M. Grantz, Brian E. Haggard

Technical Reports

The Arkansas Department of Agriculture – Natural Resources Division (ANRD) has identified the Upper White River Basin (UWRB; HUC 11010001) a hydrologic unit code (HUC) 8 watersheds, located in Northwest Arkansas, for prioritization by the Nonpoint Source (NPS) Management Program. UWRB includes Beaver Lake in its borders, the drinking water source for 1 in 6 Arkansans. Nonpoint source pollution concerns in these watersheds are excess nutrients from agriculture and sediment from changes in land use/land cover (LULC).

Local, state, and national groups, including the NPS Source Management Program, have invested in education, best management practices, and streambank restoration in the …

Life Cycle Assessment Of Novel Electrochemical Struvite Recovery In Municipal Wastewater Treatment At The Plant And U.S. Watershed Scales, Karla Morrissey

Graduate Theses and Dissertations

As the supply of phosphorus decreases, nutrient recovery in municipal wastewater treatment has become an important area of research. Recovery methods for phosphorus-containing fertilizers, such as struvite, and other products are currently being developed and assessed for their efficiency and economic feasibility. Potential environmental impacts from nutrient recovery are also being assessed as design for the environment is important, especially with regards to the eutrophying potential of phosphorus in phosphorus-limited freshwater aquatic systems. Life cycle assessment (LCA) is a tool that can be used to estimate potential environmental impacts of a product or service focusing on its entire life cycle. …

Orbital Mapping Of Seasonal And Yearly Changes In Co2 And Water Ice On The Southern Polar Cap Of Mars, Victoria Michell Ann Karnes

Graduate Theses and Dissertations

This research exhibits a new foundation for the rates of change in CO2 and water ice on the southern polar cap of Mars, where the annual precipitation cycles are known to fluctuate seasonally between the north and south pole, based on observations from the Compact Reconnaissance Imaging Spectrometer (CRISM). The conventional belief is that both CO2 ice and water ice on the southern polar cap condenses and evaporates over the course of a Martian year (MY), condensing during the Martian spring and summer and evaporating during the Martian fall and winter. With this theory in mind, CO2 and water ice …

The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt

Graduate Theses and Dissertations

Sustainable intensification of rice farming is crucial to meeting human food needs while reducing environmental impacts. Rice produces 8% of all anthropogenic CH4, which is a potent greenhouse gas. CH4 emissions can potentially be reduced by cultivation practices that minimize the number of days the fields are saturated, such as dry-seeding instead of water-seeding and irrigation using the alternate wetting and drying (AWD) technique instead of delayed, continuous flooding (DF). Ratoon cropping, wherein a second crop of rice is grown from the harvested stubble of the first crop, can be used to produce additional yield with minimal labor, but may …

Watershed Prioritization To Reduce Nutrient Export: A Framework For The State Of Arkansas Based On Ambient Water Quality Monitoring Data, Erin Grantz, Brian E. Haggard

Technical Reports

The annual formation of the Northern Gulf of Mexico hypoxic zone is driven by nutrient loading from the Mississippi-Atchafalaya River Basin (MARB). Member States of The Mississippi River/Gulf of Mexico Hypoxia Task have developed statewide strategies to identify priorities and opportunities for nutrient export reduction in the MARB. In 2014, the State of Arkansas joined the Task Force and initiated an Arkansas Nutrient Reduction Strategy (ANRS), which currently prioritizes ten Hydrologic Unit Code 8 (HUC-8) watersheds (ANRD, 2014). These priority watersheds were not selected based on measured in-stream nutrient concentrations or trends, which impedes quantitative assessment, goal setting, and linking …

Defining Critical Or Hydrologic Conditions As Sampled During The Joint Study, Brian E. Haggard, Erin Grantz, J. T. Scott

Technical Reports

The “Joint Study” was conducted to fulfill the obligations of the second “Statement of Joint Principles and Actions” agreed to by the states of Arkansas and Oklahoma. The “Joint Study” affirmed the magnitude of Oklahoma’s Scenic River total phosphorus (TP) criteria (i.e., 0.037 mg/L), but it added the new caveat of applying the criteria to “critical conditions.” The primary purpose of this paper was to define “critical conditions” based on the range in base flow proportions (BFP) of total streamflow on days that were sampled in the “Joint Study,” where BFP is base flow discharge divided by total stream flow …

Cyanobacterial And Microcystin Response To Nutrient Additions At Lake Fayetteville Throughout The 2021 Growing Season, Lillie Haddock

Graduate Theses and Dissertations

Harmful Algal Blooms (HABs) are becoming a global concern due to their increasing distribution, frequency, intensity, and the occurrence of toxins. While it is known that eutrophication influences algal blooms, there is less known about what triggers these HABs to produce toxins, especially microcystin. In this study, we conducted 21 community bioassays at Lake Fayetteville, a hypereutrophic reservoir in Fayetteville, Arkansas, from April-November 2021 to examine how the addition of phosphorous and nitrogen influence cyanobacteria concentrations, microcystin concentrations, and microcystin toxin production. These experiments included a control, nitrogen (1.0 mg/L as KNO3), low phosphorus (0.025 mg/L as K2HPO4), high phosphorus …

Exploring The Effects Of Varied Land Use On Elemental Concentrations Within Streams, Logan Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

It is well documented that human activity influences the chemistry of surrounding waters. As such, it is possible that there is a link between land use within a watershed and the chemical composition of the stream. The objectives of this study are to determine if varied land use does affect the concentrations of macronutrients and trace elements present in the streams of Northwest Arkansas, and if so, to determine what extent urban and agricultural development are responsible for these changes. Water samples were collected across 19 streams in the Northwest Arkansas region between January and March of 2022. Water samples …

Temporal Changes In Surface Water Availability: Patterns Of Seasonal Shift On Water Stress In The Conterminous Us Under A Changing Climate, Quinn Montana

Graduate Theses and Dissertations

The argument could be made that there is nothing more valuable on the planet than water. Our lives depend upon it. Climate change is already having an impact on the United States (US) and water stress will be one of the problems we increasingly face in coming decades. Regional research has shown that one or another part of the conterminous US (CONUS) is expected to experience an annual deficit or a surplus in runoff. Further studies have looked at changing patterns over the CONUS as a whole. Other research has focused on a particular season. This work addresses a gap …

Arkansas Bulletin Of Water Research - Issue 2021-2022, Erin Grantz, Lillie Haddock, Brian E. Haggard

Arkansas Bulletin of Water Research

The Arkansas Bulletin of Water Research (Bulletin) is a publication of the Arkansas Water Resources Center (AWRC). We publish the Bulletin to communicate the major findings of research funded by the Water Resources Research Act Section 104(b) in Arkansas. This research is relevant to Arkansas water stakeholders, and the Bulletin provides an easily searchable and aesthetically engaging access option.

This is the fourth publication of the Bulletin. This issue contains final reports from research projects that were funded by the 104(b) program in fiscal years 2019 and 2020. The articles in this issue can be cited as an AWRC publication. …

Optimization Of Nitrogen Removal Rate In One-Stage Reactor Through Partial Nitrification Anammox Process During Direct Treatment Of Poultry Litter Wastewater, Yiting Xiao

Graduate Theses and Dissertations

Anammox is an increasingly common process used for the treatment of reject water and even mainstream wastewater due to its low oxygen demand. However, anammox is not commonly utilized in the direct treatment of poultry litter because of the high organic content, which would inhibit the anammox process. Thus, this project is aimed at optimizing the nitrogen removal rate through partial nitrification anammox process (PN/A) to treat synthetic poultry litter wastewater. Nitrogen removal efficiencies will therefore be improved through optimizing the combination of three operating parameters including hydraulic retention time (HRT), dissolved oxygen (DO) concentration, and carbon to nitrogen (C/N) …

Use Patterns And Influencing Factors Of Irrigation Best Management Practices In The Lower Mississippi River Basin, Merri E. Day

Graduate Theses and Dissertations

This study uses the 2016 Irrigation Survey from Arkansas, Louisiana, and Mississippi to document the use of irrigation best management practices (IBMPs), analyze use patterns, and use quantitative methods to determine factors that influence producers’ decisions regarding IBMPs. IBMPs included in the survey can be grouped as: field management practices (zero-grade leveling, precision-grade leveling, end blocking, warped surface, and deep tillage), water flow control practices (computerized pipe-hole selection, multiple-inlet irrigation, surge irrigation, alternate wetting and drying, cutback irrigation, flow meters, and pump timers), water recovery/storage practices (tail-water recovery system and on-farm storage reservoir), and advanced irrigation scheduling practices (soil moisture …

Data Analytics For Sustainable Food And Agriculture Systems, Megan Lord Reavis

Graduate Theses and Dissertations

The increasing concentration of anthropogenic greenhouse gases in the atmosphere is altering the climate, posing a serious threat to global agriculture and food security. Agriculture and food production contribute a quarter of all GHG emissions produced, so there is a critical need to limit emissions in this area while increasing food production to feed the anticipated 10 billion people by 2050. To address the needs of the future, data-driven solutions are needed to guide decision-making and provide support for actionable climate mitigation and survival strategies. Research efforts must be focused on analyzing problems on multiple scales, identifying new ways to …

Identification Of Phosphorous Loading Point Source Facilities To 303(D) Listed Nutrient Impaired Waters Through Watershed Delineation Using Arcgis For Life Cycle Assessment Applications, John Zimmerman

Chemical Engineering Undergraduate Honors Theses

The work done for this project is part of a larger “life cycle assessment (LCA) of novel electrochemical phosphorus recovery technology at the wastewater treatment plant and U.S. watershed scales” (Morrissey 2019). The goal of that LCA is to determine “environmental impacts of implementing electrochemical struvite recovery at the wastewater treatment plant, U.S watershed, and global scales” (Morrissey 2019). This project’s goal is to identify locations deemed more sensitive to eutrophication impacts. The results will be used as part of the life cycle inventory (LCI) accounting for geographically explicit phosphorus flows. The waters identified as impaired were sourced from the …

The Pandemic, Climate Change And Farm Subsidies, Allen H. Olson, Edward J. Peterson

Journal of Food Law & Policy

Many people believe that once the COVID-19 pandemic has passed, life will return to the way it was. This belief is both unrealistic and dangerous. It is unrealistic because the virus will be around for years if not indefinitely. The timeframe for the worst of the pandemic will depend on our ability to administer effective vaccines worldwide and the public’s willingness to accept continued social distancing in the meantime. The damage done to public health, the economy and individuals is already substantial and will get worse. Recovery will be slow and incomplete. The belief that life will return to the …

Nutrient Sources, Loads And Trends Vary Spatially And Temporally Within The Poteau River Watershed And Lake Wister, Oklahoma, Abbie Lasater

Graduate Theses and Dissertations

Excess inputs of nutrients and sediments jeopardize drinking water sources, aquatic life habitats, and aesthetic quality of freshwater resources for recreation. The purpose of this dissertation was to analyze long-term water quality trends and loads in the Upper Poteau River Watershed (UPRW) and the Lake Wister Watershed (LWW), and analyze internal phosphorus (P) loads in Lake Wister, Oklahoma. Additionally, this dissertation sought to review the literature for methods of prioritizing subwatersheds for watershed management using watershed models, implement a cost efficient method to remotely monitor streamflow and estimate constituent loads in small-scale watersheds, and finally, to validate the Soil Water …

Sediment Phosphorus Release At Lake Fayetteville, Summer 2020, Brian E. Haggard, Abbie L. Lasater, Morgan B. Dulin, Bradley J. Austin

Technical Reports

The purpose of this project was to evaluate the release of dissolved phosphorus (P) from bottom sediment at Lake Fayetteville, and the potential use of aluminum sulfate (Al2(SO4)3) to remediate the P stored and released by bottom sediments. Intact sediment cores (n=18) were taken at three locations, named inlet, mid and dam sites at Lake Fayetteville. The cores were incubated with 1 L of overlying water with light excluded and bubbled with air (half, aerobic treatment) and N2 (other half, anaerobic). Water samples were pulled and analyzed for soluble reactive P (SRP), and that water was replaced with filtered lake …

Investigative Study Of Microalgal And Electrochemical Wastewater Treatment Systems And Modeling Of The Wafer-Enhanced Electrodeionization Using Supervised Learning, Humeyra Betul Ulusoy Erol

Graduate Theses and Dissertations

Wastewater has a serious impact on environment and public health due to its high concentration of nutrients and toxic contaminants. Without proper treatment, excess nutrients discharged in wastewater can cause a damage to the ecosystem such as undesirable pH shifts, cyanotoxin production, and low dissolved oxygen concentrations.

Main objectives of this dissertation work were to investigate i) the biofuel potential of P. cruentum when grown in swine wastewater, ii) the influence of four most commonly used ion exchange resins on the system efficiency and selectivity for the removal of sodium, calcium, and magnesium ions, and iii) the modeling of wafer-enhanced …

The Influence Of Peer Irrigators On The Extensive And Intensive Margin Of Irrigation Techniques, Victoria Bailey

Graduate Theses and Dissertations

We examine how irrigation techniques in use by family and friends influence the use and share of land utilizing different irrigation techniques by Arkansas producers. A bivariate sample selection model simultaneously estimates how farm characteristics determine the use and explain the share of a farm that utilizes an irrigation technique. We find that the irrigation techniques in use by family and friends do affect the irrigation techniques a producer uses and the share of acres utilizing different irrigation techniques. A producer with a family or friend that uses end-blocking irrigation is 41% more likely to use end-blocking themselves. Having a …

Characterization Of Problematic Red Clay Soils In Arkansas For The Purpose Of Onsite Wastewater System Placement, Bailey Darnell

Graduate Theses and Dissertations

Distinguishing between red-clay soils that are non-expansive and can reduce and red-clay soils developing in problematic red parent material, which are expansive, but also non-reducing, is key for proper on-site wastewater system placement. The Arkansas Department of Health allows for the placement of on-site wastewater systems in certain red-clay soils that have the potential to reduce, but only in the Ozark Highlands [Major Land Resource Area (MLRA) 116A], which is referred to as the red-soil exception. There is currently little scientific data to support the geographic restriction of the red-soil exception. The objectives of this study were to: i) confirm …

Long-Term Changes In Soil Surface Properties As Affected By Management Practices In A Wheat-Soybean, Double-Crop System, Machaela Morrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Long-term agricultural sustainability and productivity are controlled by the integrative effects of different management practices on the soil. Many Arkansas producers use the double-crop system to grow soybeans [Glycine max (L.) Merr] and wheat (Triticum aestivum L.). Studying combinations of different, non-traditional, alternative agricultural techniques may help producers better understand the long-term implications of various management practice options on sustainability and productivity. The objective of this study was to evaluate the effects of agricultural management practices, including residue level, tillage, irrigation, and burning, and soil depth on the change in various soil properties from 2010 to 2020 in …

Low Impact Development: Low-Maintenance Design To Encourage Residential Adoption Of Sustainable Systems, Haley Ellis

Biological and Agricultural Engineering Undergraduate Honors Theses

Residential adoption of low-impact development (LID) technology can positively impact downstream watershed hydrology by reducing total volumetric discharge from the residential site. This reduction can provide economic, environmental, and social benefits for the residents as well as the community at large. Additionally, homeowners are often affected by stormwater related issues, like flooding or washout, that could be easily mitigated with a sustainably engineered LID structure or network. Engineering for sustainability often includes the blending of several objectives to provide greater overall benefit. This thesis compares the outflow characteristics of three low-maintenance residential LID design scenarios differing in rain garden soil …

Estimating Irrigation In Rice Fields With A Water Balance Approach, Kristen Trinh

Biological and Agricultural Engineering Undergraduate Honors Theses

Global food production must increase to meet the demand associated with increased population growth, so irrigation water use will continue to rise. Therefore, it is important to monitor water usage particularly when an irrigation flowmeter is unavailable. A field water balance was created for a selection of rice fields in East-central Arkansas under observation in 2018 and 2019. From those, irrigation inputs are deduced from the water balance alone. First, each field had sensors that collected water table level (WTL) data. Next, other water inputs and outputs such as precipitation and evapotranspiration (ET) were collected from two modeled sources. The …