Civil and Environmental Engineering Commons^™

Cover Crops Have Negligible Impact On Soil Water In Nebraska Maize–Soybean Rotation, J. Burdette Barker, Derek M. Heeren, Katja Koehler-Cole, Charles Shapiro, Humberto Blanco-Canqui, Roger W. Elmore, Christopher A. Proctor, Suat Irmak, Charles A. Francis, Tim M. Shaver, Ali T. Mohammed

Department of Agricultural and Biological Systems Engineering: Faculty Publications

One perceived cost of integrating winter cover cropping in maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation systems is the potential negative impact on soil water storage available for primary crop production. The objective of this 3-year study was to evaluate the effects of winter cover crops on soil water storage and cover crop biomass production following no-till maize and soybean rotations. Locations were near Brule (west-central), Clay Center (south-central), Concord (northeast), and Mead (east-central), Nebraska, United States. Treatments included crop residue only (no cover crop) and a multi-species cover crop mix, both broadcast-seeded before …

Plant Community Composition, Floristic Quality, And Establishment Of Roadside Revegetation In Nebraska, Usa, Jonathan M. Soper

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Roadside revegetation poses a challenge and opportunity for biodiversity conservation, as the land area occupied by roadsides is not expected to decline in the future. In the context of roadside revegetation activities in rural regions dominated by agricultural land uses, revegetation efforts can establish plant communities that offer unique species that would otherwise be absent on the landscape. To determine the efficacy of roadside revegetation efforts in 1) providing plant communities of high biodiversity value and 2) meeting the expectations of roadside revegetation managers for establishment, we quantified botanical composition, floristic quality, and success in seeding efforts to meet manager …

Tradeoffs In Model Performance And Effort For Long-Term Phosphorus Leaching Based On In Situ Field Data, Ryan P. Freiberger, Derek M. Heeren, Dean E. Eisenhauer, Aaron R. Mittelstet, Guillermo Baigorria

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Phosphorus and N are critical nutrients for agriculture but are also responsible for surface water enrichment that leads to toxic algal growth. Although P loading to surface waters has traditionally been thought to occur primarily in surface runoff, contributions from subsurface transport can also be significant. The primary objectives of this research were to evaluate several methods of representing macropore flow and transport in a finite element model using plot-scale infiltration and leaching data and to compare several models of various levels of complexity to simulate long-term P leaching. To determine flow and transport parameters, single- and dual-porosity models in …

Portable Flux Tower Deployments Field Campaign Report, M. S. Torn, L Kuepper, S. C. Biraud, D. P. Billesbach

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Contents

Acronyms and Abbreviations...................................................................... iii

1.0 Summary ....................................................... 1

2.0 Results ........................................... 1

3.0 Publications and References ................................................. 2

4.0 Lessons Learned .................................................................... 2

U.S. Agro-Climate In 20th Century: Growing Degree Days, First And Last Frost, Growing Season Length, And Impacts On Crop Yields, Meetpal Singh Kukal, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Significant air temperature changes have occurred globally during the 20th century, which are spatially variable to a considerable degree and these changes can have substantial implications in agroecosystem productivity. The agroclimate indicators that are responsible in these contexts are first fall frost (FFF), last spring frost (LSF), climatological growing season (CGS) length, and heat accumulation (growing degree days, GDD). We explore spatial and temporal trends associated with these indices across the continental U.S. (CONUS) during 1900–2014 using datasets collected at 1218 sites. On average, FFF has been occurring later (by 5.4 days century⁻¹), and LSF has been occurring …

Adam J. Liska: Curriculum Vitae, Adam Liska

Adam Liska Papers

Associate Professor, George Dempster Smith Chair of Industrial Ecology, Departments of Biological Systems Engineering and Agronomy & Horticulture, University of Nebraska-Lincoln 236 L.W. Chase Hall, Lincoln, NE 68583-0726, Ph: (402) 472-8744, e-mail: [email protected]

Ph.D. 2003 Biology (magna cum laude), Max Planck Institute of Molecular Cell Biology & Genetics, Technische Universität Dresden, Dresden, Germany

Investigating Initial Interactions Between Silver Nanoparticles And Wastewater, Casey Gibson

Biological and Agricultural Engineering Undergraduate Honors Theses

The use of nanoparticles (NPs) has increased exponentially in the last 15-20 years, especially in the consumer market. NPs are currently found in over 1800 commercial products, including cosmetics, clothing, packaging, and toys. As a result, NPs can enter the environment via wastewater (WW) streams, leading to new challenges in WW treatment. This study focuses on the initial fate of silver nanoparticles (AgNPs) in WW. The AgNP interaction including aggregation and dissolution in both synthetic and real WW were studied. Real WW was collected from the primary-clarifier, secondary-clarifier, and effluent WW streams at two local WW treatment plants (Westside and …

Chloride Salt Inhibition On Lipid Production In Wastewater-Grown Algae For Biofuel Production, Will Richardson

Biological and Agricultural Engineering Undergraduate Honors Theses

Algae are increasingly being recognized as useful organisms for many applications in today’s world. Their ability to remove nitrogen, phosphorus, and trace metals from water while adding oxygen to water makes them an attractive tertiary treatment technology in municipal wastewater treatment facilities. At the same time, algae produce lipids and carbohydrates that are useful for biofuel production, and they are not a human food crop unlike many biofuel feedstocks. In this study the effect of increased chloride concentrations in wastewater was assessed on the ability of two species of algae, Chlorella vulgaris and Scenedesmus dimorphus, to function as a …

Assessing Auto-Flocculation Of Microalgae In Wastewater Treatment, Alexander Parr

Biological and Agricultural Engineering Undergraduate Honors Theses

Biofuels produced from algae have the prospect to provide a cheap, carbon neutral alternative to fossil fuels. However, the high cost for harvesting algae limits its wide application, as the preferred algae strains for biofuel production are typically unicellular microalgae that do not settle in water very well. Recently, researchers have been focusing on developing a biological method to achieve the sedimentation of algae through flocculation. A recent study has concluded that introducing microalgae that self-flocculates increases the recovery of the desired microalgae, similar to the effect of using coagulant to flocculate the algae. This option can potentially be more …

Development Of A Digital Rain-Sensing Irrigation Pump Controller And An Android Enabled Bluetooth Paddlewheel Flowmeter, Jayendra Mishra

Graduate Theses and Dissertations

For better irrigation efficiency, it is recommended that farmers track their water consumption to avoid over-irrigating. However, it is difficult to implement this as it is labor intensive to supervise pumps manually and available technologies require high investment. Therefore, a rain sensing pump controller for 3-phase electric irrigation pumps and a stand-alone portable Android enabled paddlewheel flowmeter has been developed to test their feasibility.

The pump timer is a retrofit device for irrigation pump panels. The controller allows an irrigator to start and stop the pump with less supervision. An infrared rain sensor is integrated with the controller to measure …

Evaluation Of A Hybrid Reflectance-Based Crop Coefficient And Energy Balance Evapotranspiration Model For Irrigation Management, J. Burdette Barker, Christopher M. U. Neale, Derek M. Heeren, Andrew E. Suyker

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Accurate generation of spatial soil water maps is useful for many types of irrigation management. A hybrid remote sensing evapotranspiration (ET) model combining reflectance-based basal crop coefficients (K_cbrf) and a two-source energy balance (TSEB) model was modified and validated for use in real-time irrigation management. We modeled spatial ET for maize and soybean fields in eastern Nebraska for the 2011-2013 growing seasons. We used Landsat 5, 7, and 8 imagery as remote sensing inputs. In the TSEB, we used the Priestly-Taylor (PT) approximation for canopy latent heat flux, as in the original model formulations. We also used the …

Climate-Driven Crop Yield And Yield Variability And Climate Change Impacts On The U.S. Great Plains Agricultural Production, Meetpal Singh Kukal, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climate variability and trends affect global crop yields and are characterized as highly dependent on location, crop type, and irrigation. U.S. Great Plains, due to its significance in national food production, evident climate variability, and extensive irrigation is an ideal region of investigation for climate impacts on food production. This paper evaluates climate impacts on maize, sorghum, and soybean yields and effect of irrigation for individual counties in this region by employing extensive crop yield and climate datasets from 1968–2013. Variability in crop yields was a quarter of the regional average yields, with a quarter of this variability explained by …

The Role Of Dense Slurry In Achieving Zero Liquid Discharge, D.M. Timmons, Istvan Kovacsics

Coal Combustion and Gasification Products Journal Archive

The Coal Combustion Residual (CCR) and Effluent Limitations Guidelines (ELGs) rules pose significant technical and economic challenges for ash management and for treatment and discharge of flue gas desulfurization (FGD) wastewater at coal-fired power plants. Beneficial use is always a priority for ash, but only about half is being reused on a national basis, and the rest is destined for disposal. The U.S. Environmental Protection Agency identified biological treatment as the baseline treatment technology for FGD wastewater in the ELGs. However, it is becoming evident that bioreactors exhibit high capital and operating costs, occupy significant space, and are sensitive to …

Comparison Of Three Regionalization Techniques For Predicting Streamflow In Ungaged Watersheds In Nebraska, Usa Using Swat Model, Michael W. Van Liew, Aaron R. Mittelstet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study compared three approaches, regional averaging, nearest neighbor, and donor techniques, to regionalize parameters in the Soil and Water Assessment Tool (SWAT) on eleven watersheds located in the Dissected Plains, Plains, and Rolling Hills Landforms in the eastern portion of the State of Nebraska, USA. Within the Rolling Hills Landform, three watersheds were randomly selected as calibration watersheds while two were randomly selected as validation watersheds. Two watersheds were randomly selected as calibration watersheds while one was randomly selected as a validation watershed within each of the Dissected Plains and Plains Landforms. The seven calibration watersheds were used to …

Compressibility Of Fly Ash Under Ko Loading: Strain Rate Effects In Constant Rate Of Strain Testing, Jaime A. Mercado, Luis G. Arboleda-Monsalve, Tarunjit S. Butalia, Pedro J. Amaya

Coal Combustion and Gasification Products Journal Archive

Coal combustion processes produce large volumes of fly ash. The compressibility of fly ash was studied using moist tamping and drypluviation methods to achieve different void ratios before subjecting the material to compressive oedometric Ko loading (i.e., zero lateral deformation throughout the test). The class F fly ash used in this research was produced at a Midwest U.S. power plant. The material was initially characterized with hydrometer and specific gravity tests, and maximum and minimum realizable void ratios were determined. The compressibility characteristics of the fly ash material were studied at four strain rates, 1%/h, 10%/h, 40%/h, and 100%/h, and …

Influence Of Flow Rate On Leachability, John L. Daniels, Gautham P. Das

Coal Combustion and Gasification Products Journal Archive

The leaching potential of coal fly ash is often approximated with laboratory-based methods that expose columns of compacted material to synthetic precipitation. While this procedure can simulate aspects of the field condition, it remains difficult to replicate site-specific thermodynamic and kinetic constraints on geochemical processes. This article explores one aspect that contributes to the field/laboratory disparity, namely, the influence of flow rate and intermittency. Seven column-based leaching experiments were conducted with the same ash but with different flow rates and intermittency (i.e., infiltration pulsing), and results were evaluated in terms of aqueous sodium, calcium, and chromium concentrations in the effluent. …

Kinetic And Thermodynamic Parameters For The Adsorption Of Methylene Blue Using Fly Ash Under Batch, Column, And Heap Leaching Configurations, J.H. Potgieter, S. Pearson, C. Pardesi

Coal Combustion and Gasification Products Journal Archive

In this article, the use of fly ash, a low-cost adsorbent, for the removal of a toxic cationic dye, methylene blue (MB), from aqueous solution has been investigated. Fly ash is a waste by-product generated from coal combustion. Contrary to many other reported investigations, the fly ash was not treated prior to the experiments for this investigation. The study was done in order to ascertain the viability of using the waste material to remove cationic dyes from wastewater. While MB adsorption has been described often in batch studies, batch, column, and heap leaching studies were carried out under the same …

Universal And Excavatable Controlled Low Strength Material Using High Loss On Ignition Fly Ash And Limestone Screenings†, James T. Locum, L.K. Crouch, Daniel Badoe

Coal Combustion and Gasification Products Journal Archive

Limestone screenings and high loss on ignition (LOI) fly ash are by-products that are stockpiling because of their unintentional production and the negative effects when utilized in portland cement concretes. The research objective was to investigate whether these by-products could produce controlled low strength materials (CLSMs) meeting the three types of Tennessee Department of Transportation (TDOT) 204.06 flowable fill specifications. TDOT defines these CLSMs as the following: general use, excavatable, and early strength. Each type is required to have an inverted slump flow of not less than 15 inches (38.1 cm) while meeting ASTM International D6024 at 24 hours. Because …

2018 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 …

Effects Of Subsurface Drainage Systems On Water And Nitrogen Footprints Simulated With Rzwqm2, Kristina J. Craft, Matthew J. Helmers, Robert W. Malone, Carl H. Pederson, Linda R. Schott

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Developing drainage water management (DWM) systems in the Midwest to reduce nitrogen (N) transport to the northern Gulf of Mexico hypoxic zone requires understanding of the long-term performance of these systems. Few studies have evaluated long-term impacts of DWM, and the simulation of controlled drainage (CD) with the Root Zone Water Quality Model (RZWQM) is limited, while shallow drainage (SD) has not been examined. We tested RZWQM using nine years (2007-2015) of field data from southeast Iowa for CD, SD, conventional drainage (DD), and undrained (ND) systems and simulated the long-term (1971-2015) impacts. RZWQM accurately simulated N loss in subsurface …

A Tunable, Three-Dimensional In Vitro Culture Model Of Growth Plate Cartilage Using Alginate Hydrogel Scaffolds, Alek G. Erickson, Taylor D. Laughlin, Sarah M. Romereim, Catherine N. Sargus-Patino, Angela K. Pannier, Andrew T. Dudley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Defining the final size and geometry of engineered tissues through precise control of the scalar and vector components of tissue growth is a necessary benchmark for regenerative medicine, but it has proved to be a significant challenge for tissue engineers. The growth plate cartilage that promotes elongation of the long bones is a good model system for studying morphogenetic mechanisms because cartilage is composed of a single cell type, the chondrocyte; chondrocytes are readily maintained in culture; and growth trajectory is predominately in a single vector. In this cartilage, growth is generated via a differentiation program that is spatially and …

Hydraulic Properties Of Baled Switchgrass And Miscanthus, Drew F. Schiavone, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

This study characterized the hydraulic properties within baled switchgrass ( Panicum virgatum L., variety Alamo) and miscanthus (Miscanthus x giganteus), thereby enabling a better understanding of moisture changes in baled biomass during on-farm storage and/or high-solids bioconversion. Fully saturated bales were drained by gravity, and the moisture content was determined over 60 h. The average initial moisture content ranged between 55.9% and 71.9% (w.b.) for switchgrass and between 60.5% and 73.9% (w.b.) for miscanthus bales depending on the dry bale density. As the bale drained by gravity, rapid leaching of water was observed within the first 0.1 h, …

Detection Of Multi-Tomato Leaf Diseases (Late Blight, Target And Bacterial Spots) In Different Stages By Using A Spectral-Based Sensor, Jinzhu Lu, Reza Ehsani, Yeyin Shi, Ana Isabel De Castro, Shuang Wang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Several diseases have threatened tomato production in Florida, resulting in large losses, especially in fresh markets. In this study, a high-resolution portable spectral sensor was used to investigate the feasibility of detecting multi-diseased tomato leaves in different stages, including early or asymptomatic stages. One healthy leaf and three diseased tomato leaves (late blight, target and bacterial spots) were defined into four stages (healthy, asymptomatic, early stage and late stage) and collected from a field. Fifty-seven spectral vegetation indices (SVIs) were calculated in accordance with methods published in previous studies and established in this study. Principal component analysis was …

Evaluation Of Variable Rate Irrigation Using A Remote-Sensing-Based Model, John Burdette Barker, Derek M. Heeren, Christopher M.U. Neale, Daran Rudnick

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Improvements in soil water balance modeling can be beneficial for optimizing irrigation management to account for spatial variability in soil properties and evapotranspiration (ET). A remote-sensing-based ET and water balance model was tested for irrigation management in an experiment at two University of Nebraska-Lincoln research sites located near Mead and Brule, Nebraska. Both fields included a center pivot equipped with variable rate irrigation (VRI). The study included maize in 2015 and 2016 and soybean in 2016 at Mead, and maize in 2016 at Brule, for a total of 210 plot-years. Four irrigation treatments were applied at Mead, including: VRI based …

Integration Of Hydrogeophysical Datasets And Empirical Orthogonal Functions For Improved Irrigation Water Management, Catherine E. Finkenbiner, Trenton E. Franz, Justin P. Gibson, Derek M. Heeren, J. D. Luck

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Precision agriculture offers the technologies to manage for infield variability and incorporate variability into irrigation management decisions. The major limitation of this technology often lies in the reconciliation of disparate data sources and the generation of irrigation prescription maps. Here the authors explore the utility of the cosmic-ray neutron probe (CRNP) which measures volumetric soil water content (SWC) in the top ~ 30 cm of the soil profile. The key advantages of CRNP is that the sensor is passive, non-invasive, mobile and soil temperature-invariant, making data collection more compatible with existing farm operations and extending the mapping period. The objectives …

Dynamic Rops Test For Tractors Over 6,000 Kilograms, Caleb M. Lindhorst, Roger M. Hoy, Santosh Pitla, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

OECD static tests (Codes 4, 6, 7, and 8) for agricultural rollover protective structures (ROPS) have become accepted standards for evaluating the ability of these structures to protect the operator during tractor rollover events. The strength properties of some materials typically used in ROPS change because of cold weather embrittlement at low temperatures. The static ROPS tests lack the ability to evaluate the strength of these structures during cold weather. The use of the dynamic ROPS test is well noted as a means for proving cold weather embrittlement resistance properties. Unfortunately, application of the OECD dynamic ROPS test (Code 3) …

The Open Source Gaitor Suite For Rodent Gait Analysis, Brittany Y. Jacobs, Emily H. Lakes, Alex J. Reiter, Spencer P. Lake, Trevor R. Ham, Nic D. Leipzig, Stacy L. Porvasnik, Christine E. Schmidt, Rebecca A. Wachs, Kyle D. Allen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Locomotive changes are often associated with disease or injury, and these changes can be quantified through gait analysis. Gait analysis has been applied to preclinical studies, providing quantitative behavioural assessment with a reasonable clinical analogue. However, available gait analysis technology for small animals is somewhat limited. Furthermore, technological and analytical challenges can limit the effectiveness of preclinical gait analysis. The Gait Analysis Instrumentation and Technology Optimized for Rodents (GAITOR) Suite is designed to increase the accessibility of preclinical gait analysis to researchers, facilitating hardware and software customization for broad applications. Here, the GAITOR Suite’s utility is demonstrated in 4 models: …

Greenhouse Gas Emissions From Beef Feedlot Surface Materials As Affected By Diet, Moisture, Temperature, And Time, Bryan L. Woodbury, John E. Gilley, David B. Parker, Bobbi S. Stomer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A laboratory study was conducted to measure the effects of diet, moisture, temperature, and time on greenhouse gas (GHG) emissions from feedlot surface materials (FSM). The FSM were collected from open-lot pens where beef cattle were fed either a dry-rolled corn (DRC) diet containing no wet distillers grains with solubles (WDGS) or a DRC diet containing 35% WDGS. The FSM were collected, air-dried or mixed with 3.0 L of water to represent dry or wet conditions, and then incubated at temperatures of 5°C, 15°C, 25°C, or 35°C. Static flux chambers were used to quantify GHG emissions over a 14-day period. …

Surface Detention On Cropland, Rangeland, And Conservation Reserve Program Areas, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

One of the factors contributing to overland flow on upland areas is water stored temporarily in a thin sheet on the soil surface as surface detention. This study was conducted to quantify surface detention on selected cropland, rangeland, and Conservation Reserve Program (CRP) sites. Surface detention was determined from the recession portion of runoff hydrographs corresponding with the period when rainfall had ceased but runoff continued. The hydrographs were generated from six previously reported rainfall simulation studies conducted on paired 3.7 m wide  10.7 m long plots on which approximately 128 mm of rainfall was applied. Surface detention values …

Evaluation Of The Accuracy Of Machine Reported Can Data For Engine Torque And Speed (J1939), Rodney A. Rohrer, Joe D. Luck, Santosh K. Pitla, Roger M. Hoy

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Most modern off-road machinery use embedded electronic controllers connected to a controller area network (CAN) to broadcast machine information for on-board processes and diagnostics. Commercially available tools can record CAN data for a variety of research and commercial uses. For agricultural tractors, there is an opportunity to create advanced test procedures that are more representative of field operations and that could supplement existing machine performance tests, such as the OECD Code 2 Standard Code for the Official Testing of Agricultural and Forestry Tractor Performance. CAN parameters provide an efficient way to collect tractor performance data during field operations. However, the …