Bioresource and Agricultural Engineering Commons^™

Improving In-Stream Nutrient Routines In Water Quality Models Using Stable Isotope Tracers: A Review And Synthesis, Alexandria K. Jensen, William I. Ford, James F. Fox, Admin Husic

Biosystems and Agricultural Engineering Faculty Publications

Water quality models serve as an economically feasible alternative to quantify fluxes of nutrient pollution and to simulate effective mitigation strategies; however, their applicability is often questioned due to broad uncertainties in model structure and parameterization, leading to uncertain outputs. We argue that reduction of uncertainty is partially achieved by integrating stable isotope data streams within the water quality model architecture. This article outlines the use of stable isotopes as a response variable within water quality models to improve the model boundary conditions associated with nutrient source provenance, constrain model parameterization, and elucidate shortcomings in the model structure. To assist …

Three-Dimensional Modeling Of Nitrate-N Transport In Vadose Zone: Roles Of Soil Heterogeneity And Groundwater Flux, Simin Akbariyeh, Shannon L. Bartelt-Hunt, Daniel D. Snow, Xu Li, Zhenghong Tang, Yusong Li

Department of Civil and Environmental Engineering: Faculty Publications

Contamination of groundwater from nitrogen fertilizers in agricultural lands is an important environmental and water quality management issue. It is well recognized that in agriculturally intensive areas, fertilizers and pesticides may leach through the vadose zone and eventually reach groundwater. While numerical models are commonly used to simulate fate and transport of agricultural contaminants, few models have considered a controlled field work to investigate the influence of soil heterogeneity and groundwater flow on nitrate-N distribution in both root zone and deep vadose zone.

In this work, a numerical model was developed to simulate nitrate-N transport and transformation beneath a center …

A Multi-Criteria And Dynamic Sustainability Assessment Of Crop Rotation Alternatives, Saturnina Fabian Nisperos

Computational Modeling & Simulation Engineering Theses & Dissertations

With the food security challenge faced by nations globally, agriculture sustainability has been a significant consideration for concerned agencies. Sustainability assessments are significant tools in providing support to stakeholders in their crop production planning. Agricultural sustainability assessment, however, is complex and it involves numerous criteria that can be conflicting. Limitations on crop rotation sustainability assessment methods include: non-dynamic assessment; lack of regard to cover crops and to the individual crop production preferences of farmers; and focused only on single-year and single-crop rotation. We sought to address these limitations by developing a multi-criteria and dynamic sustainability assessment model that considers the …

Use Of Long Term Weather Data And Spatially Delineated Field Attributes To Predict Water And Energy Conservation From Variable Rate Irrigation, Sahil Sharma

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The declining levels of the Ogallala aquifer calls for more judicious use of water. Studies have shown that VRI has the potential for water savings. But adoption of VRI is still very low. The major reason is lack of information on the returns from the VRI systems and its feasibility in different fields. Also, a quantification of the required reduction in prices of VRI is necessary. So, an economic return analysis of VRI strategies was done to compare it to uniform irrigation management (UIM) using a water balance model based on long term weather data and field properties for a …

A Risk-Based Method For Estimating The Carbon Sequestration Budget For A Mixed Hardwood Forest, Erin Cooper

Chemical Engineering Undergraduate Honors Theses

Carbon Dioxide (CO₂) levels in the atmosphere have risen from approximately 310 ppm in the 1950’s to over 400 ppm as of 2015. This rise in CO₂ has likely resulted in the observed warming trend of the earth’s atmosphere in the same time frame, causing significant concern in the scientific community. Several mitigation strategies have arisen to combat the upward trend of CO₂ emissions in recent decades, among them being carbon sequestration- the process of capturing CO₂ from the atmosphere and holding it for an extended period of time. This study used the U.S. Forest …

Biofuels From Crop Residue: Soil Organic Carbon And Climate Impacts In The Us And India, Adam Liska

Adam Liska Papers

The transformation of crop residue to soil organic carbon and CO₂ is a conserved process that occurs globally. Due to the mathematics of carbon intensity calculations found in government regulations, the amount of CO₂ emitted from crop residue per unit of energy in biofuel is largely independent of the amount of residue removed and the location of its removal, as shown by results from the US and India.

Soil organic carbon (SOC) levels are at equilibria determined by carbon inputs from plant material (+I_c) and loss from oxidation to CO₂

Are the US results relevant …

Catalytic Oxidation And Depolymerization Of Lignin In Aqueous Ionic Liquid, Lalitendu Das, Siquan Xu, Jian Shi

Biosystems and Agricultural Engineering Faculty Publications

Lignin is an integral part of the plant cell wall, which provides rigidity to plants, also contributes to the recalcitrance of the lignocellulosic biomass to biochemical and biological deconstruction. Lignin is a promising renewable feedstock for aromatic chemicals; however, an efficient and economic lignin depolymerization method needs to be developed to enable the conversion. In this study, we investigated the depolymerization of alkaline lignin in aqueous 1-ethyl-3-methylimidazolium acetate [C₂C₁Im][OAc] under oxidizing conditions. Seven different transition metal catalysts were screened in presence of H₂O₂ as oxidizing agent in a batch reactor. CoCl₂ and …

Reducing Equifinality Using Isotopes In A Process-Based Stream Nitrogen Model Highlights The Flux Of Algal Nitrogen From Agricultural Streams, William I. Ford, James F. Fox, Erik Pollock

Biosystems and Agricultural Engineering Faculty Publications

The fate of bioavailable nitrogen species transported through agricultural landscapes remains highly uncertain given complexities of measuring fluxes impacting the fluvial N cycle. We present and test a new numerical model named Technology for Removable Annual Nitrogen in Streams For Ecosystem Restoration (TRANSFER), which aims to reduce model uncertainty due to erroneous parameterization, i.e., equifinality, in stream nitrogen cycle assessment and quantify the significance of transient and permanent removal pathways. TRANSFER couples nitrogen elemental and stable isotope mass‐balance equations with existing hydrologic, hydraulic, sediment transport, algal biomass, and sediment organic …

Development Of A Water Quality Status And Trend Detection Tool*, Ruchir Aggarwal, Valeria Mijares, Margaret W. Gitau

The Summer Undergraduate Research Fellowship (SURF) Symposium

Water Quality Index (WQI) models have been developed since the early 1970s. They present a means by which water quality status and trends can be compared across time and space on the basis of a composite value computed using existing water quality data. There is a need for a tool that can bring the different water quality parameters together and calculate the WQIs so as to facilitate data use in predictive modeling and water quality management. We are developing a software tool that can be used by water quality managers and others with different technical backgrounds to calculate WQI of …

A Comparative Analysis Of Feed And Environmental Factors On Broiler Growth In The United States, Alexandra Gulli

Graduate Theses and Dissertations

Broiler production in the United States has become an important industry within the last half century. As the demand for poultry continues to increase and the concern of climate change also increases, it will become an important part of the industry to become more sustainable. This study uses a feed optimization model, a broiler growth model, and a life cycle assessment (LCA) to determine how feed ingredients and the barn environment can affect the broiler’s growth and production emissions. A multi-criteria ration optimization model is used to produce feeds based on carbon footprint and cost. A growth model is used …

Nuclear Weapons In A Changing Climate: Probability, Increasing Risks, And Perception, Adam Liska, Tyler R. White, Eric Holley, Robert J. Oglesby

Adam Liska Papers

Many people tend to think that the outcome of any nuclear weapons use today will result in an escalatory situation with apocalyptic outcomes for the countries involved. Yet many factors are increasing the probability of the limited use of nuclear weapons (e.g., 1 to 20 warheads) in a range of conflict scenarios. Previous atmospheric model simulations of regional nuclear conflicts employing many relatively small bombs have been estimated to cause a global “nuclear autumn,” with great reductions in agricultural productivity, stratospheric ozone loss, and spread of hazardous radioactive fallout. The totality of these effects would result in widespread damage …

Streambank Erosion Mapping On The Nottoway River Using Gps-Based Above-Water Video, Emine Fidan

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

This project concerns the development of streambank erosion maps on military installations utilizing GPS-based above-water video mapping and image georeferencing techniques. The river mapped was the Nottoway River at the Fort Pickett military installation on October 10-11, 2015. Kayak-mounted above-water cameras were utilized to capture georeferenced images of streambank erosion. These GIS-based erosion classifications were utilized to develop erosion maps for determining streambank erosion conditions along the river. Areas of high erosion were identified as about two percent of the river (2167 ft. of streambank length). These maps allow for the opportunity to revisit the sites to determine changes in …

Development Of A Methodology To Determine Antibiotic Concentrations In Water Samples Using High-Pressure Liquid Chromatography, Tahnee Qualls, Carmen T. Agouridis, Manish Kulshrestha

Biosystems and Agricultural Engineering Faculty Publications

Antibiotic concentrations are typically measured using solid-phase extraction along with liquid chromatography, but this process is not practical due to a large number of man hours involved. The use of a lyophilizer with high-pressure liquid chromatography (HPLC) is an accurate and cost-effective method of analyzing antibiotics in water samples. An initial antibiotic analysis methodology was developed with the goal of concentrating antibiotics in water samples for greater detection; however, it was observed that the methodology required additional refinement to improve accuracy, particularly when manure was present in the water samples. Based on prior tetracycline antibiotic research, we hypothesized that sample …

Geometry-Based Mass Grading Of Mango Fruits Using Image Processing, M. A. Momin, Md Towfiqur Rahman, M. S. Sultana, C. Igathinathane, A. T. M. Ziauddin, T. E. Grift

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Mango (Mangifera indica) is an important, and popular fruit in Bangladesh. However, the post-harvest processing of it is still mostly performed manually, a situation far from satisfactory, in terms of accuracy and throughput. To automate the grading of mangos (geometry and shape), we developed an image acquisition and processing system to extract projected area, perimeter, and roundness features. In this system, images were acquired using a XGA format color camera of 8-bit gray levels using fluorescent lighting. An image processing algorithm based on region based global thresholding color binarization, combined with median filter and morphological analysis was developed …

Using The Vehicle Routing Problem To Reduce Field Completion Times With Multiple Machines, Hasan Seyyedhasani, Joseph S. Dvorak

Biosystems and Agricultural Engineering Faculty Publications

The Vehicle Routing Problem (VRP) is a powerful tool used to express many logistics problems, yet unlike other vehicle routing challenges, agricultural field work consists of machine paths that completely cover a field. In this work, the allocation and ordering of field paths among a number of available machines has been transformed into a VRP that enables optimization of completion time for the entire field. A basic heuristic algorithm (a modified form of the common Clarke-Wright algorithm) and a meta-heuristic algorithm, Tabu Search, were employed for optimization. Both techniques were evaluated through computer simulations in two fields: a hypothetical basic …

Contemporary And Future Characteristics Of Precipitation Indices In The Kentucky River Basin, Somsubhra Chattopadhyay, Dwayne R. Edwards, Yao Yu

Biosystems and Agricultural Engineering Faculty Publications

Climatic variability can lead to large-scale alterations in the hydrologic cycle, some of which can be characterized in terms of indices involving precipitation depth, duration and frequency. This study evaluated the spatiotemporal behavior of precipitation indices over the Kentucky River watershed for both the baseline period of 1986–2015 and late-century time frame of 2070–2099. Historical precipitation data were collected from 16 weather stations in the watershed, while future rainfall time-series were obtained from an ensemble of 10 Coupled Model Intercomparison Project Phase 5 (CMIP5) global circulation models under two future emission pathways: Representative Concentration Pathways (RCP) 4.5 and 8.5. Annual …

Remediating 1,4-Dioxane-Contaminated Water With Slow-Release Persulfate And Zerovalent Iron, Ann Kambhu, Megan Gren, Wei Tang, Steve D. Comfort, Clifford Harris

Nebraska Water Center: Faculty Publications

1,4-dioxane is an emerging contaminant that was used as a corrosion inhibitor with chlorinated solvents. Metal-activated persulfate can degrade dioxane but reaction kinetics have typically been characterized by a rapid decrease during the first 30 min followed by either a slower decrease or no further change (i.e., plateau). Our objective was to identify the factors responsible for this plateau and then determine if slow-release formulations of sodium persulfate and Fe⁰ could provide a more sustainable degradation treatment. We accomplished this by conducting batch experiments where Fe⁰-activated persulfate was used to treat dioxane. Treatment variables included the timing …

The Irreversible Momentum Of Clean Energy, Barack Obama

United States Department of Energy: Publications

The release of carbon dioxide (CO₂) and other greenhouse gases (GHGs) due to human activity is increasing global average surface air temperatures, disrupting weather patterns, and acidifying the ocean. Left unchecked, the continued growth of GHG emissions could cause global average temperatures to increase by another 4°C or more by 2100 and by 1.5 to 2 times as much in many midcontinent and far northern locations. Although our understanding of the impacts of climate change is increasingly and disturbingly clear, there is still debate about the proper course for U.S. policy—a debate that is very much on display …

2017 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman

Nebraska Department of Environmental Quality: Reports

The Nebraska Department of Environmental Quality (NDEQ) is charged with monitoring, assessing, and to the extent possible, managing the state’s water resources. The purpose of this work is to protect and maintain high quality water and encourage or execute activities to improve poor water quality. Monitoring is done on nearly 17,000 miles of flowing rivers and streams, more than 134,000 acres of surface water in lakes and reservoirs, as well as the vast storage of groundwater in Nebraska’s aquifers.

Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 2. Stand Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this study was to explore the relationships between stand-level photochemical reflectance index (PRI) and canopy structure/ pigment pools, as well as light use efficiency (LUE) of photosynthetically active vegetation focusing on seasonal or ontogenetic time frames. PRI was originally designed as a means of assessing the xanthophyll cycle and LUE over short (e.g. diurnal) time frames, and few studies have explored the drivers of PRI over longer, seasonal time frames, particularly in crops having different photosynthetic pathways or canopy structures. Consequently, our purpose was to understand and quantify the drivers of PRI responses over seasonal time scales …

Automated Calibration Of Electrochemical Oxygen Sensors For Use In Compost Bedded Pack Barns, John T. Evans, Michael P. Sama, Joseph L. Taraba, George B. Day

Biosystems and Agricultural Engineering Faculty Publications

The objective of this study was to develop an automated calibration process for a galvanic cell type oxygen sensor. The manufacturer recommended a two-point calibration at room temperature; however, testing revealed that the response was not linear when both the temperature and oxygen concentrations varied. Thus, additional points were needed to generate a representative calibration equation and to reduce the sensor prediction interval. The calibration process needed to be capable of automatically recording sensor response (voltage) at an array of temperatures and oxygen concentrations. Calibration gases were used to precisely control the oxygen concentration inside a small manifold, and an …

Ammonia And Carbon Dioxide Emissions Of Three Laying-Hen Housing Systems As Affected By Manure Accumulation Time, Timothy A. Shepherd, Hongwei Xin, John P. Stinn, Morgan D. Hayes, Yang Zhao, Hong Li

Biosystems and Agricultural Engineering Faculty Publications

Laying-hen housing design and management are the most significant factors affecting the generation and release of gaseous ammonia to the atmosphere. Transitioning the hen housing type from traditional high-rise (where manure is stored within the house for about one year) to modern manure-belt style (where manure is removed every 1 to 4 d and placed into long-term storage) has significantly improved in-barn air quality and reduced farm-level ammonia emissions. As a direct result of the advantages, 100% of new construction for U.S. egg production incorporates manure-belt systems that regularly remove manure from the houses. However, manure-belt system designs (e.g., active …

Evaluation Of Flocculation, Sedimentation, And Filtration For Dewatering Of Scenedesmus Algae, Nicholas A. Rhea, Jack Groppo, Czarena Crofcheck

Biosystems and Agricultural Engineering Faculty Publications

Algae can be used as a feedstock for agricultural fertilizers, livestock and poultry feeds, anaerobic digestion, and biofuel production. For each end product, the requirements for moisture content (or solids content) vary, such that a desirable water removal strategy needs to be adaptable to varying levels of water removal. Flocculation, sedimentation, and filtration were evaluated as possible strategies for thickening and dewatering of algae. The goal of this study was to validate that algae cells treated by such means could be processed by vacuum belt filters and to determine the conditions under which the solids content could be increased to …

Effects Of Biochar Treatment Of Municipal Biosolids And Horse Manure On Quality Of Runoff From Fescue Plots, Rachel Williams, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Land-applied horse manure and municipal biosolids can increase nutrient and bacteria concentrations in runoff. Biochar has been demonstrated to have beneficial impacts on nutrient retention and runoff quality when used to treat other land-applied organic soil amendments (e.g., poultry manure). The objective of this study was to evaluate the effects of biochar addition to horse manure and municipal biosolids on runoff concentrations of nutrients and fecal coliforms. Biochar was added at 5% to 8% (wet basis) to horse manure and biosolids that were applied to 2.4 m x 6.1 m fescue plots followed by application of simulated rainfall (102 mm …

Modeling Streamflow And Water Quality Impacts Of Grassland Establishment, Conversion, And Management In Skunk Creek Watershed, Jiyeong Hong

Electronic Theses and Dissertations

Grassland is a valuable natural resource with many environmental benefits, which include erosion control, wildlife habitat promotion, water quality protection, and flood prevention. Conversion of grassland to cultivated cropland has been linked to environmental quality concerns. The goal of this study was to model the impacts of grassland establishment, depletion, and management on hydrology and water quality in Skunk Creek watershed in eastern South Dakota. The specific objectives are to quantify the impacts of grassland conversion and selected management regimes on streamflow and water quality, and explore the optimum grassland establishment location within a watershed to achieve water quality benefits. …

Using Remote Sensing To Estimate Crop Water Use To Improve Irrigation Water Management, Arturo Reyes-Gonzalez

Electronic Theses and Dissertations

Irrigation water is scarce. Hence, accurate estimation of crop water use is necessary for proper irrigation managements and water conservation. Satellite-based remote sensing is a tool that can estimate crop water use efficiently. Several models have been developed to estimate crop water requirement or actual evapotranspiration (ETa) using remote sensing. One of them is the Mapping EvapoTranspiration at High Resolution using Internalized Calibration (METRIC) model. This model has been compared with other methods for ET estimations including weighing lysimeters, pan evaporation, Bowen Ratio Energy Balance System (BREBS), Eddy Covariance (EC), and sap flow. However, comparison of METRIC model outputs to …

A Demonstration Study Of Drainage Water Management In Eastern South Dakota, Ashik Sahani

Electronic Theses and Dissertations

Subsurface drainage is a common water management practice for improving crop production in poorly drained soils; however, the practice is associated with several environmental concerns such as nutrient losses to downstream surface waters. These environmental concerns from subsurface drainage have prompted interest in drainage water management strategies such as controlled drainage. This study assessed the agronomic and environmental impacts of drainage water management in eastern South Dakota by using two demonstration plots for controlled and conventional drainage. Drain flow, nitrate and dissolved phosphorous concentration in drain water, shallow groundwater, crop yield, residual soil nitrate, soil moisture and temperature, soil penetration …

Nebraska Public Water Supply Program Summary Report 2017

Nebraska Department of Environmental Quality: Reports

The United States Environmental Protection Agency (EPA) established the Public Water System Supervision (PWSS) Program under the authority of the 1974 Safe Drinking Water Act (SDWA). Under the SDWA and the 1986 Amendments, EPA sets national limits on contaminant levels in drinking water to ensure that the water is safe for human consumption. These limits are known as Maximum Contaminant Levels (MCLs) and Maximum Residual Disinfectant Levels (MRDLs). For some regulations, EPA establishes treatment techniques in lieu of an MCL to control unacceptable levels of contaminants in water.

2017 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …

Fourth-Generation Fan Assessment Numeration System (Fans) Design And Performance Specifications, Michael P. Sama, George B. Day, Laura M. Pepple, Richard S. Gates

Biosystems and Agricultural Engineering Faculty Publications

The Fan Assessment Numeration System (FANS) is a measurement device for generating ventilation fan performance curves. Three different-sized FANS currently exist for assessing ventilation fans commonly used in poultry and livestock housing systems. All FANS consist of an array of anemometers inside an aluminum shroud that traverse the inlet or outlet of a ventilation fan. The FANS design has been updated several times since its inception and is currently in its fourth-generation (G4). The current design iteration (FANS-G4) is reported in this article with an emphasis on the hardware and software control, data acquisition systems, and operational reliability. Six FANS-G4 …