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Bioresource and Agricultural Engineering Commons

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2011

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Full-Text Articles in Bioresource and Agricultural Engineering

The Economics And Logistics Of The Dual Harvest Of Grain And Biomass In A Single-Pass, Matthew T. Wold Dec 2011

The Economics And Logistics Of The Dual Harvest Of Grain And Biomass In A Single-Pass, Matthew T. Wold

Department of Biological Systems Engineering: Dissertations and Theses

Significant interest has developed in using cellulosic resources, especially crop residues, to create biofuels. Collecting these residues in a single-pass of the harvester across the field has the potential to be a low cost option. Two models have been developed; the first characterizes the in-field logistics of single-pass crop residue collection, the second the economics. These models allow the user to easily examine a wide variety of both grain-only and single-pass residue collection harvest cases. A variety of possible residue collection cases have been examined, and their effects both on harvester field capacity and harvest cost compared to grain-only harvest …


Velocity Contour Weighting Method. Ii: Evaluation In Trapezoidal Channels And Roughness Sensitivity, Daniel Howes, Brett F. Sanders Nov 2011

Velocity Contour Weighting Method. Ii: Evaluation In Trapezoidal Channels And Roughness Sensitivity, Daniel Howes, Brett F. Sanders

BioResource and Agricultural Engineering

The Velocity Contour Weighting Method (VCWM) was developed in Part I to accurately estimate the cross-sectional average velocity of a prismatic channel flow using acoustic Doppler velocity meter (ADVM) measurements of centerline velocity. Here, the VCWM is validated by its successful application to 25 different concrete-lined trapezoidal channels used for irrigation water delivery. At each site, the cross-sectional distribution of velocity is measured by an acoustic Doppler velocimeter (ADV), which is moved horizontally and vertically through a sampling grid. Multiple tests at some sites led to a total of 51 sets of cross-sectional measurements. ADVM measurements are simulated by interpolating …


Velocity Contour Weighting Method. I: Algorithm Development And Laboratory Testing, Daniel J. Howes, Brett F. Sanders Nov 2011

Velocity Contour Weighting Method. I: Algorithm Development And Laboratory Testing, Daniel J. Howes, Brett F. Sanders

BioResource and Agricultural Engineering

An algorithm is developed for real-time estimation of the cross-sectional average velocity of a channel flow by using an upward-looking pulsed wave acoustic Doppler velocity meters (ADVM). The Velocity Contour Weighting Method (VCWM) is applicable to gradually varied flows in prismatic channels and requires little to no calibration. VCWM estimates the average velocity as a weighted average of ADVM bin velocities. Weights are based on the velocity distribution sampled by the ADVM. Collectively, the VCWM is able to adapt to a wide range of channel geometry and roughness features. Expressions for the velocity weights are developed by first applying a …


Irrigation Engineering In Seismic Zones - Mexicali Valley, Mexico, Alan Dennis Gracia, Charles M. Burt, Mario Paredes Vallejo Nov 2011

Irrigation Engineering In Seismic Zones - Mexicali Valley, Mexico, Alan Dennis Gracia, Charles M. Burt, Mario Paredes Vallejo

BioResource and Agricultural Engineering

On April 4, 2010 an earthquake of Richter magnitude 7.2 occurred with an epicenter south of Mexicali within the irrigated zone of Mexicali Valley. Extensive damage occurred to main and lateral canal structures, plus to field irrigation systems and the main drainage network. This paper describes the engineering for a new major irrigation water conveyance system to service the most heavily impacted zone of 80,000 acres. Considerations included identification of the causes of the damage, selection of canal versus pipeline, relocation costs of people along new routes, and improved flexibility of water delivery. Major investigations regarding soils, topography, etc. were …


Agricultural Irrigation Using Municipal Effluent, Charles M. Burt Nov 2011

Agricultural Irrigation Using Municipal Effluent, Charles M. Burt

BioResource and Agricultural Engineering

The paper describes the development of a design and management plan for disposing of secondary effluent originating in the urban communities. It highlights the differences in approach that a public utility must take, versus a typical agricultural irrigation application. Costs and requirements for municipal effluent irrigation are many times greater. The complexity of regulations and agency procurement procedures relegates the actual irrigation system design to a relatively small role in the total project.


The Genome Portal Of The Department Of Energy Joint Genome Institute, Igor V. Grigoriev, Henrik Nordberg, Igor Shabalov, Andrea Aerts, Mike Cantor, David Goodstein, Alan Kuo, Simon Minovitsky, Roman Nikitin, Robin A. Ohm, Robert Otillar, Alex Poliakov, Igor Ratnere, Robert Riley, Tatyana Smirnova, Daniel Rokhsar, Inna Dubchak Nov 2011

The Genome Portal Of The Department Of Energy Joint Genome Institute, Igor V. Grigoriev, Henrik Nordberg, Igor Shabalov, Andrea Aerts, Mike Cantor, David Goodstein, Alan Kuo, Simon Minovitsky, Roman Nikitin, Robin A. Ohm, Robert Otillar, Alex Poliakov, Igor Ratnere, Robert Riley, Tatyana Smirnova, Daniel Rokhsar, Inna Dubchak

US Department of Energy Publications

The Department of Energy (DOE) Joint Genome Institute (JGI) is a national user facility with massive-scale DNA sequencing and analysis capabilities dedicated to advancing genomics for bioenergy and environmental applications. Beyond generating tens of trillions of DNA bases annually, the Institute develops and maintains data management systems and specialized analytical capabilities to manage and interpret complex genomic data sets, and to enable an expanding community of users around the world to analyze these data in different contexts over the web. The JGI Genome Portal (http://genome.jgi.doe.gov) provides a unified access point to all JGI genomic databases and analytical tools. A user …


History Of The Biological Systems Engineering Program In Nebraska, University Of Nebraska-Lincoln, William E. Splinter Oct 2011

History Of The Biological Systems Engineering Program In Nebraska, University Of Nebraska-Lincoln, William E. Splinter

Tractor Testing Development and Research Documents

The Farm Machinery/Agricultural Engineering/Biological Systems Engineering program current and former faculty members at the University of Nebraska, as demonstrated here, has made a statewide, national, and worldwide impact on the efficient production of food. The quality of this recognition is evidenced best by peer professionals through recognized ASABE awards received by Nebraska alumni or professors. Since its inception in 1909 and until 2010, there have been 10 national presidents, 19 gold medal recipients and 33 named national award recipients. Currently there are 31 ASABE Fellows and two members of the National Academy of Engineering. This national recognition comes as a …


The Irrigation Sector Shift From Construction To Modernization: What Is Required For Success?, Charles M. Burt Oct 2011

The Irrigation Sector Shift From Construction To Modernization: What Is Required For Success?, Charles M. Burt

BioResource and Agricultural Engineering

External pressures related to environmental protection, commodity prices, energy availability, larger populations, and climate change have combined to require an immediate and substantial improvement in agricultural irrigation performance. Worldwide progression towards modernized irrigation projects has been uneven and slower than desired, but decades of irrigation modernization development have clarified certain requirements for success, as well as illuminated indicators of project failure. Of particular importance are required shifts within the state and national irrigation bureaucracies, as well as universities.


High Ethanol Titers From Cellulose By Using Metabolically Engineered Thermophilic, Anaerobic Microbes, D. Aaron Argyros, Shital A. Tripathi, Trisha F. Barrett, Stephen R. Rogers, Lawrence F. Feinberg, Daniel G. Olson, Justin M. Foden, Bethany B. Miller, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza Sep 2011

High Ethanol Titers From Cellulose By Using Metabolically Engineered Thermophilic, Anaerobic Microbes, D. Aaron Argyros, Shital A. Tripathi, Trisha F. Barrett, Stephen R. Rogers, Lawrence F. Feinberg, Daniel G. Olson, Justin M. Foden, Bethany B. Miller, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza

Dartmouth Scholarship

This work describes novel genetic tools for use in Clostridium thermocellum that allow creation of unmarked mutations while using a replicating plasmid. The strategy employed counter-selections developed from the native C. thermocellum hpt gene and the Thermoanaerobacterium saccharolyticum tdk gene and was used to delete the genes for both lactate dehydrogenase (Ldh) and phosphotransacetylase (Pta). The Δldh Δpta mutant was evolved for 2,000 h, resulting in a stable strain with 40:1 ethanol selectivity and a 4.2-fold increase in ethanol yield over the wild-type strain. Ethanol production from cellulose was investigated with an engineered coculture of organic acid-deficient engineered strains of …


Stage-Dependent Transient Storage Of Phosphorus In Alluvial Floodplains, Derek M. Heeren, Garey A. Fox, Ronald B. Miller, Daniel E. Storm, Amanda K. Fox, Chad J. Penn, Todd Halihan, Aaron R. Mittelstet Sep 2011

Stage-Dependent Transient Storage Of Phosphorus In Alluvial Floodplains, Derek M. Heeren, Garey A. Fox, Ronald B. Miller, Daniel E. Storm, Amanda K. Fox, Chad J. Penn, Todd Halihan, Aaron R. Mittelstet

Department of Biological Systems Engineering: Papers and Publications

Models for contaminant transport in streams commonly idealize transient storage as a well-mixed but immobile system. These transient storage models capture rapid (near-stream) hyporheic storage and transport, but do not account for large-scale, stage-dependent interaction with the alluvial aquifer. The objective of this research was to document transient storage of phosphorus (P) in coarse gravel alluvium potentially influenced by large-scale, stage-dependent preferential flow pathways (PFPs). Long-term monitoring was performed at floodplain sites adjacent to the Barren Fork Creek and Honey Creek in northeastern Oklahoma. Based on results from subsurface electrical resistivity mapping which was correlated to hydraulic conductivity data, observation …


Bankfull Hydraulic Geometry Relationships For The Inner And Outer Bluegrass Regions Of Kentucky, Carmen Agouridis, Ruth Roseann Brockman, Stephen R. Workman, Lindell E. Ormsbee, Alex Fogle Sep 2011

Bankfull Hydraulic Geometry Relationships For The Inner And Outer Bluegrass Regions Of Kentucky, Carmen Agouridis, Ruth Roseann Brockman, Stephen R. Workman, Lindell E. Ormsbee, Alex Fogle

Biosystems and Agricultural Engineering Faculty Publications

Bankfull hydraulic geometry relationships relate bankfull stream dimensions, such as cross-sectional area, width, mean depth, mean velocity, width to depth ratio, and slope to bankfull discharge. These relationships can assist in determining a design discharge for stream restoration and management projects. This study assessed 27 stable streams located in the Inner Bluegrass and Outer Bluegrass regions of Kentucky. Reaches were selected based on the presence of a U.S. Geological Survey gage, as well as other conditions such as presence of readily identifiable bankfull indicators, stability indices, and site accessibility. Bankfull channel dimensions and discharges were determined, and hydraulic geometry relationships …


Bioenergy Feedstock-Specific Enrichment Of Microbial Populations During High-Solids Thermophilic Deconstruction, Amitha P. Reddy, Martin Allgaier, Steven W. Singer, Terry C. Hazen, Blake A. Simmons, Philip Hugenholtz, Jean S. Vandergheynst Sep 2011

Bioenergy Feedstock-Specific Enrichment Of Microbial Populations During High-Solids Thermophilic Deconstruction, Amitha P. Reddy, Martin Allgaier, Steven W. Singer, Terry C. Hazen, Blake A. Simmons, Philip Hugenholtz, Jean S. Vandergheynst

US Department of Energy Publications

Thermophilic microbial communities that are active in a high-solids environment offer great potential for the discovery of industrially relevant enzymes that efficiently deconstruct bioenergy feedstocks. In this study, finished green waste compost was used as an inoculum source to enrich microbial communities and associated enzymes that hydrolyze cellulose and hemicellulose during thermophilic high-solids fermentation of the bioenergy feedstocks switchgrass and corn stover. Methods involving the disruption of enzyme and plant cell wall polysaccharide interactions were developed to recover xylanase and endoglucanase activity from deconstructed solids. Xylanase and endoglucanase activity increased by more than a factor of 5, upon four successive …


Effects Of Sprinkler, Partial Sprinkler/Drip, And Drip Only Irrigation On Strawberry Transplants 2010-2011, Stuart Styles Aug 2011

Effects Of Sprinkler, Partial Sprinkler/Drip, And Drip Only Irrigation On Strawberry Transplants 2010-2011, Stuart Styles

BioResource and Agricultural Engineering

The purpose of the project is to develop an analysis of the current irrigation practices of the strawberry growers on the Central Coast of California. The primary research evaluation is during the establishment of transplants where sprinklers are typically used even though drip irrigation is available. Growers have been selected from Oxnard, Santa Maria, and Watsonville to provide a good cross section of the different strawberry growing areas.

The specific objectives of the project are to: (1) set up a research areas and control plots on a demonstration scale, (2) determine the key factors that affect the problems in early …


Extrusion And Alkali Extrusion Of Corn Stover To Improve Enzyme Saccharification, Shujing Zhang Aug 2011

Extrusion And Alkali Extrusion Of Corn Stover To Improve Enzyme Saccharification, Shujing Zhang

Department of Biological Systems Engineering: Dissertations and Theses

Biomass pretreatment constitutes an important part in the whole process of bioethanol production. The main goals of pretreatment include improving cellulose accessibility to enzyme, enhancing sugar yields from hemicellulose, achieving low capital and energy costs, as well as low sugar degradation and low chemical requirements. Extrusion, as a continuous and high throughput pretreatment method, requires much less chemical compared to traditional alkali pretreatment. In this research, twin-screw extrusion was evaluated for its effect with regard to promoting sugar yields from corn stover. Also, the underlying factors contributing to this improvement were examined. It was found that extrusion with no chemicals …


Testing Fuel Efficiency Of Tractors With Both Continuously Variable And Standard Geared Transmissions, Christopher N. Howard, Michael F. Kocher, Roger M. Hoy, Erin E. Blankenship Aug 2011

Testing Fuel Efficiency Of Tractors With Both Continuously Variable And Standard Geared Transmissions, Christopher N. Howard, Michael F. Kocher, Roger M. Hoy, Erin E. Blankenship

Department of Biological Systems Engineering: Conference Presentations and White Papers

A John Deere 8295R IVT tractor with a continuously variable transmission (CVT) and a John Deere 8295R PowerShift (PST) tractor (Waterloo, Iowa) with a standard geared transmission (GT) were tested for fuel consumption at three different travel speeds with six different load levels applied per speed. The JD 8295R PST tractor was tested both at full throttle (FT) and shifted up two gears and throttled back (SUTB) to achieve the same travel speed as at full throttle conditions. For each travel speed with each transmission mode, fuel consumption was determined to be linearly related to drawbar power. Linear regression results …


Streambank Erosion And Instability Induced By Groundwater Seepage, Taber L. Midgley, Garey A. Fox, Glenn V. Wilson, Derek M. Heeren, Andrew Simon, Eddy J. Langendoen Aug 2011

Streambank Erosion And Instability Induced By Groundwater Seepage, Taber L. Midgley, Garey A. Fox, Glenn V. Wilson, Derek M. Heeren, Andrew Simon, Eddy J. Langendoen

Department of Biological Systems Engineering: Papers and Publications

Excessive sediment is one of the most common surface water pollutants. It diminishes water quality and destroys aquatic habitat. Streambank erosion is known to be a major source of sediment in streams and rivers, contributing as much as 80% of the total sediment load in some watersheds. Little work has been done to study the effects of seepage on streambank erosion and failure. Prior research, primarily in the laboratory under well-defined and controlled conditions, has examined seepage as a mechanism for bank erosion, but more needs to be done to validate conclusions derived from the laboratory with field data. This …


Biofilter Media Characterization Using Water Sorption Isotherms, Guilherme Del Nero Maia, George B. Day, Richard S. Gates, Joseph L. Taraba Jul 2011

Biofilter Media Characterization Using Water Sorption Isotherms, Guilherme Del Nero Maia, George B. Day, Richard S. Gates, Joseph L. Taraba

Biosystems and Agricultural Engineering Faculty Publications

Compost material has been used extensively as a gas‐phase biofilter media for contaminant gas treatment in recent years. One of the biggest challenges in the use of this type of material is adequate control of compost moisture content and understanding its effect on the biofiltration process. The present work provides a methodology for characterization of biofilter media under low moisture conditions. Results indicated that low levels of equilibrium moisture content (EMC) were obtained for high levels of equilibrium relative humidity (ERH), i.e., 99% ERH produced EMC of approximately 20% (dry basis) at 25° C. Most bacteria struggle to survive in …


Twin-Screw Extrusion Processing Of Distillers Dried Grains With Solubles (Ddgs)-Based Yellow Perch (Perca Flavescens) Feeds, Ferouz Y. Ayadi, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan, Michael L. Brown Jul 2011

Twin-Screw Extrusion Processing Of Distillers Dried Grains With Solubles (Ddgs)-Based Yellow Perch (Perca Flavescens) Feeds, Ferouz Y. Ayadi, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan, Michael L. Brown

Natural Resource Management Faculty Publications

Increases in global aquaculture production, compounded with limited availabilities of fish meal for fish feed, has created the need for alternative protein sources. Twinscrew extrusion studies were performed to investigate the production of nutritionally balanced feeds for juvenile yellow perch (Perca flavescens). Five isocaloric (~3.06 kcal/g) ingredient blends, adjusted to a target protein content of 36.7% db, were formulated with 0%, 10%, 20%, 30%, and 40% distillers dried grains with solubles (DDGS) at an initial moisture content of 5–7%db, with appropriate amounts of fish meal, fish oil, whole wheat flour, corn gluten meal, and vitamin and mineral premixes. …


Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa Jul 2011

Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa

Department of Biological Systems Engineering: Dissertations and Theses

Human activities such as conversion of natural ecosystem to croplands and urban-centers, deforestation and afforestation impact biophysical properties of land surface such as albedo, energy balance, and surface roughness. Alterations in these properties affect the heat and moisture exchanges between the land surface and atmospheric boundary layer. The objectives of this research were; (i) to quantitatively identify the High plains’ regional climate change in temperatures over the period 1895 to 2006, (ii) detect the signatures of anthropogenic forcing of LULC changes on the regional climate change of the High Plains, and (iii) examine the trends in evolving regional latent heat …


Transport Of Trace Elements In Runoff From Unamended And Pond‐Ash Amended Feedlot Surfaces, Jason R. Vogel, John E. Gilley, Gary L. Cottrell, Brian L. Woodbury, Elaine D. Berry, Roger Eigenberg Jul 2011

Transport Of Trace Elements In Runoff From Unamended And Pond‐Ash Amended Feedlot Surfaces, Jason R. Vogel, John E. Gilley, Gary L. Cottrell, Brian L. Woodbury, Elaine D. Berry, Roger Eigenberg

Department of Biological Systems Engineering: Papers and Publications

The use of pond ash (fly ash that has been placed in evaporative ponds for storage and subsequently dewatered) for feedlot surfaces provides a drier environment for livestock and furnishes economic benefits. However, pond ash is known to have high concentrations of trace elements, and the runoff water‐quality effects of feedlot surfaces amended with pond ash are not well defined. For this study, two experimental units (plots) were established in eight feedlot pens. Four of the pens contained unamended soil surfaces, and the remaining four pens had pond‐ash amended surfaces. Before each test, unconsolidated surface material was removed from four …


A Look At 20th Century Droughts, Vijay P. Singh, Ashok K. Mishra Jun 2011

A Look At 20th Century Droughts, Vijay P. Singh, Ashok K. Mishra

2011 Symposium on Data-Driven Approaches to Droughts

Droughts exercise a profound effect on the social and economic fabric of nations. Many nations of the world experienced droughts encompassing the full spectrum of severity, areal extent and duration. The result has been that the economic development was hampered and many countries have not yet recouped fully from the ravages of droughts. The first decade of the 21st century has also witnessed varying degrees of droughts across the globe. Therefore, we ask the following questions: (a) Do droughts affect every part of the world? (b) Are there similarities in major droughts around the world? (c) Are climate change and …


Drought Regionalization Of Brazos River Basin Using An Entropy Approach, Deepthi Rajsekhar, Ashok Mishra, Vijay P. Singh Jun 2011

Drought Regionalization Of Brazos River Basin Using An Entropy Approach, Deepthi Rajsekhar, Ashok Mishra, Vijay P. Singh

2011 Symposium on Data-Driven Approaches to Droughts

Assessment and understanding of past climate is an important step for drought mitigation and water resources planning. In this study, stream flows imulation obtained from the variable infiltration capacity(VIC) model was used for drought characterization, and subsequently regionalization was done based on the annual severity level, for the Brazos basin in Texas over a time span of 1949-2000. It is important to study drought characteristics with in a regional context. Hence, identification of homogenous drought regions is a prerequisite, so that the drought characteristics can be studied with in each of these regions. In this study, the concept of entropy …


A Simple Method To Improve Autonomous Gps Positioning For Tractors, Jaime Gomez-Gil, Sergio Alonso-Garcia, Francisco Javier Gómez-Gil, Tim Stombaugh May 2011

A Simple Method To Improve Autonomous Gps Positioning For Tractors, Jaime Gomez-Gil, Sergio Alonso-Garcia, Francisco Javier Gómez-Gil, Tim Stombaugh

Biosystems and Agricultural Engineering Faculty Publications

Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. …


Strawberries: Effects Of Modifying Irrigation Methods For Transplant Establishment, Stuart Styles, Lynn Groundwater, Curtis Lutje May 2011

Strawberries: Effects Of Modifying Irrigation Methods For Transplant Establishment, Stuart Styles, Lynn Groundwater, Curtis Lutje

BioResource and Agricultural Engineering

In 2009, the Cal Poly Irrigation Training and Research Center began a multi-year analysis of the current irrigation practices of strawberry growers on the Central Coast of California. Specifically, the project examines the impacts of salinity on young strawberry transplants and the current practice of sprinkler use during the establishment of transplants for salinity control in areas where drip irrigation is available. The overall goal of the project is to study current practices and determine any conditions where growers can minimize or eliminate sprinkler use on strawberries, thereby conserving water, saving pumping costs, and reducing runoff. Results from the first …


Implementation And Field Calibration Pipeline Doppler Meters In Northern California, Stuart Styles May 2011

Implementation And Field Calibration Pipeline Doppler Meters In Northern California, Stuart Styles

BioResource and Agricultural Engineering

The Tehama-Colusa Canal Authority (TCCA) has been using SonTek Doppler flow meters at approximately 30 installations for about 3 years. TCCA is located in northern California with its headquarters in Willows. The Cal Poly ITRC compared the accuracy of the flow measurement readings from the new Doppler flow meters to the venturi meters that were installed by the US Bureau of Reclamation (USBR). The venturis were used as the historical standard for flow measurement for TCCA. TCCA has opted to move away from the existing technology for a variety of reasons, especially due to the issue concerning access requirements for …


Characteristics Of Irrigation Pump Performance In Major Irrigated Areas Of California, Charles Burt May 2011

Characteristics Of Irrigation Pump Performance In Major Irrigated Areas Of California, Charles Burt

BioResource and Agricultural Engineering

Pumping data was collected from over 15,000 well and non-well pumps throughout the Sacramento, Salinas, and San Joaquin Valley groundwater basins of California. Each of these basins is divided into a number of subbasins. A map of the general layout is shown below (gray lines outside of basins represent county lines; gray lines inside basins represent subbasins).

Data was analyzed by basin and subbasin for well pumps and non-well pumps. For each pump type, averages were calculated based on:

  • The whole basin
  • Overall pumping plant efficiency (OPPE)
  • kWh/AF
  • Subbasins

General conclusions were drawn for each set of averages, and a …


Irrigation System Components And Potentials For Energy Conservation, Charles M. Burt May 2011

Irrigation System Components And Potentials For Energy Conservation, Charles M. Burt

BioResource and Agricultural Engineering

On-site electricity conservation in irrigation can be accomplished through a series of general steps. The primary focus of the agricultural energy conservation programs of the utilities has been to improve the efficiency of the pumping plant. In general, the electric utilities have provided or subsidized pump testing, along with some form of rebate for replacement or repair of pumps. There are, of course, other irrigation-related aspects of energy conservation. However, this report focuses on on-site electricity conservation in the field.


Nutrient Runoff Following Manure Application, Chance Thayer May 2011

Nutrient Runoff Following Manure Application, Chance Thayer

Department of Biological Systems Engineering: Dissertations and Theses

A field study was completed to measure the effects of varying flow rate on nutrient transport following the application of varying amounts of beef cattle manure to plots containing either no-residue or a wheat residue cover. Beef cattle manure was applied and incorporated into the soil in May 2010 to meet zero, one, two, four or eight year corn phosphorus requirements. Simulated rainfall events were applied in June and July 2010. The presence of a crop residue cover significantly increased the transport of dissolved phosphorus, total phosphorus, NO3-N, NH4-N, and total nitrogen in runoff but decreased …


Analysis Of Site-Specific Adjustment Applied To On-The-Go Soil Sensing Data For Agronomic Use, Allison K. Jonjak May 2011

Analysis Of Site-Specific Adjustment Applied To On-The-Go Soil Sensing Data For Agronomic Use, Allison K. Jonjak

Department of Biological Systems Engineering: Dissertations and Theses

Successful variable-rate applications of agricultural inputs such as lime rely on the quality of input data. Systematic grid soil sampling is the most common method used for creating variable rate prescription maps. The insufficient number of point measurements usually obtained using this method has been primarily responsible for the typical inaccuracies seen in lime prescription maps. To increase sampling density, on-the-go sensing technology was developed for the mapping of soil pH and other relevant attributes. In this study, five fields in eastern Nebraska were mapped using both on-thego sensing technology and systematic grid sampling. Ten calibration points per field were …


Application Of Gis And Geographically Weighted Regression To Evaluate The Spatial Non‐Stationarity Relationships Between Precipitation Vs. Irrigated And Rainfed Maize And Soybean Yields, Vivek Sharma, Ayse Kilic, Isa Kabenge, Suat Irmak May 2011

Application Of Gis And Geographically Weighted Regression To Evaluate The Spatial Non‐Stationarity Relationships Between Precipitation Vs. Irrigated And Rainfed Maize And Soybean Yields, Vivek Sharma, Ayse Kilic, Isa Kabenge, Suat Irmak

Department of Biological Systems Engineering: Papers and Publications

Understanding the relationship between the spatial distribution of precipitation and crop yields on large scales (i.e., county, state, regional) while accounting for the spatial non‐stationarity can help managers to better evaluate the long‐term trends in agricultural productivity to make better assessments in food security, policy decisions, resource assessments, land and water resources enhancement, and management decisions. A relatively new technique, geographically weighted regression (GWR), has the ability to account for spatial non‐stationarity with space. While its application is growing in other scientific disciplines (i.e., social sciences), the application of this new technique in agricultural settings has not been practiced. The …