Using Swat To Enhance Watershed-Based Plans To Meet Numeric Water Quality Standards,
2016
University of Nebraska-Lincoln
Using Swat To Enhance Watershed-Based Plans To Meet Numeric Water Quality Standards, Aaron R. Mittelstet, Daniel E. Storm, Michael J. White
Department of Agricultural and Biological Systems Engineering: Faculty Publications
The number of states that have adopted numeric nutrient water-quality standards has increased to 23, up from ten in 1998. One state with both stream and reservoir phosphorus (P) numeric water-quality standards is Oklahoma. There were two primary objectives of this research: (1) determine if Oklahoma was meeting the stream and reservoir numeric water-quality standards in the Illinois River and Eucha–Spavinaw watersheds, respectively and (2) identify various combinations of management practices required to meet the water-quality standards. A Soil and Water Assessment Tool (SWAT) model was developed for each watershed. After runoff and P calibration and validation, each model was …
Temporal Dynamics Of Maize Plant Growth, Water Use, And Leaf Water Content Using Automated High Throughput Rgb And Hyperspectral Imaging,
2016
University of Nebraska-Lincoln
Temporal Dynamics Of Maize Plant Growth, Water Use, And Leaf Water Content Using Automated High Throughput Rgb And Hyperspectral Imaging, Yufeng Ge, Geng Bai, Vincent Stoerger, James C. Schnable
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Automated collection of large scale plant phenotype datasets using high throughput imaging systems has the potential to alleviate current bottlenecks in data-driven plant breeding and crop improvement. In this study, we demonstrate the characterization of temporal dynamics of plant growth and water use, and leaf water content of two maize genotypes under two different water treatments. RGB (Red Green Blue) images are processed to estimate projected plant area, which are correlated with destructively measured plant shoot fresh weight (FW), dry weight (DW) and leaf area. Estimated plant FW and DW, along with pot weights, are used to derive daily plant …
Pumpage Reduction By Using Variable Rate Irrigation To Mine Undepleted Soil Water,
2016
University of Nebraska-Lincoln
Pumpage Reduction By Using Variable Rate Irrigation To Mine Undepleted Soil Water, Tsz Him Lo, Derek M. Heeren, Derrel Martin, Luciano Mateos, Joe D. Luck, Dean E. Eisenhauer
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Conventional irrigation schedules are typically based on portions of the field where root zones hold the least available soil water. This leaves undepleted available water in areas with larger water holding capacities. The undepleted water could be used through variable-rate irrigation (VRI) management; however, the benefits of VRI without in-field mapping are unexamined. In this research, the field-averaged amount of undepleted available soil water in the root zone was calculated from the NRCS Soil Survey Geographic database for 49,224 center-pivot irrigated fields in Nebraska. Potential reductions in pumpage from mining undepleted available water were then estimated. Results of the analysis …
Analytical Solution For Speed To Achieve A
Desired Operating Point For A Given Fan Or Pump,
2016
University of Nebraska-Lincoln
Analytical Solution For Speed To Achieve A Desired Operating Point For A Given Fan Or Pump, Michael F. Kocher, Jeyamkondan Subbiah
Department of Agricultural and Biological Systems Engineering: Faculty Publications
The Affinity Laws for fans (and pumps) provide a way of determining new fan or pump speed given fan or pump performance curve data and a desired operating point (combination of flow rate and pressure) that does not fall on the curve. However, the affinity law calculations require using a point on the curve (hereafter referred to as the “basic point”) to determine the new speed. Most references regarding the Affinity Laws do not give a clear description of the method for determining the “basic point”, and improper selection of this point can affect the results considerably. This article describes …
In-Field Fuel Use And Load States Of Agricultural Field Machinery,
2016
University of Nebraska-Lincoln
In-Field Fuel Use And Load States Of Agricultural Field Machinery, Santosh Pitla, Joe D. Luck, Jared Werner, Nannan Lin, Scott A. Shearer
Department of Agricultural and Biological Systems Engineering: Faculty Publications
The ability to define in-field tractor load states offers the potential to better specify and characterize fuel consumption rate for various field operations. For the same field operation, the tractor experiences diverse load demands and corresponding fuel use rates as it maneuvers through straight passes, turns, suspended operation for adjustments, repair and maintenance, and biomass or other material transfer operations. It is challenging to determine the actual fuel rate and load states of agricultural machinery using force prediction models, and hence, some form of in-field data acquisition capability is required. Controller Area Networks (CAN) available on the current model tractors …
Inter-Row Robot Navigation Using 1d Ranging Sensors,
2016
University of Nebraska–Lincoln
Inter-Row Robot Navigation Using 1d Ranging Sensors, Tyler A. Troyer, Santosh Pitla, Ethan Nutter
Department of Agricultural and Biological Systems Engineering: Faculty Publications
In this paper a fuzzy logic navigation controller for an inter-row agricultural robot is developed and evaluated in laboratory settings. The controller receives input from one-dimensional (1D) ranging sensors on the robotic platform, and operated on ten fuzzy rules for basic row-following behavior. The control system was implemented on basic hardware for proof of concept and operated on a commonly available microcontroller development platform and open source software libraries. The robot platform used for experimentation was a small tracked vehicle with differential steering control. Fuzzy inferencing and defuzzification, step response and cross track error were obtained from the test conducted …
Tractor Hydraulic Power Data Acquisition System,
2016
University of Nebraska-Lincoln
Tractor Hydraulic Power Data Acquisition System, J. B.W. Roeber, Santosh Pitla, Michael F. Kocher, Joe D. Luck, Roger M. Hoy
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Tractor hydraulic power is used on a wide range of agricultural implements; however, the availability of operational hydraulic data at points other than full engine throttle position is limited. Operators could utilize this hydraulic data to maximize field efficiency and minimize machinery costs when determining suitable machinery for field operations. A field usable hydraulic test apparatus capable of measuring tractor hydraulic pressure and flow rate data was developed. The goal of this study was to determine if a hydraulic flow and pressure measurement device could be installed on the rear of a tractor to provide implement hydraulic power consumption at …
Quantifying The Fate Of Agricultural Nitrogen In An Unconfined
Aquifer: Stream-Based Observations At Three Measurement
Scales,
2016
University of Nebraska-Lincoln
Quantifying The Fate Of Agricultural Nitrogen In An Unconfined Aquifer: Stream-Based Observations At Three Measurement Scales, Troy E. Gilmore, David P. Genereux, D. Kip Solomon, John E. Solder, Briant A. Kimball, Helena Mitasova, Francois Birgand
Department of Agricultural and Biological Systems Engineering: Faculty Publications
We compared three stream-based sampling methods to study the fate of nitrate in groundwater in a coastal plain watershed: point measurements beneath the streambed, seepage blankets (novel seepage-meter design), and reach mass-balance. The methods gave similar mean groundwater seepage rates into the stream (0.3–0.6 m/d) during two 3–4 day field campaigns despite an order of magnitude difference in stream discharge between the campaigns. At low flow, estimates of flowweighted mean nitrate concentrations in groundwater discharge ([NO-3 ]FWM) and nitrate flux from groundwater to the stream decreased with increasing degree of channel influence and measurement scale, i.e., …
Groundwater Transit Time Distribution And Mean From
Streambed Sampling In An Agricultural Coastal Plain Watershed, North Carolina, Usa,
2016
University of Nebraska-Lincoln
Groundwater Transit Time Distribution And Mean From Streambed Sampling In An Agricultural Coastal Plain Watershed, North Carolina, Usa, Troy E. Gilmore, David P. Genereux, D. Kip Solomon, John E. Solder
Department of Agricultural and Biological Systems Engineering: Faculty Publications
We measured groundwater apparent age (s) and seepage rate (v) in a sandy streambed using point-scale sampling and seepage blankets (a novel seepage meter). We found very similar MTT estimates from streambed point sampling in a 58 m reach (29 years) and a 2.5 km reach (31 years). The TTD for groundwater discharging to the stream was best fit by a gamma distribution model and was very similar for streambed point sampling in both reaches. Between adjacent point-scale and seepage blanket samples, water from the seepage blankets was generally younger, largely because blanket samples contained a fraction of ‘‘young’’ stream …
Comparing Various Hardware/Software Solutions And Conversion Methods For Controller Area Network (Can) Bus Data Collection,
2016
University of Nebraska–Lincoln
Comparing Various Hardware/Software Solutions And Conversion Methods For Controller Area Network (Can) Bus Data Collection, Samuel E. Marx, Joe D. Luck, Santosh Pitla, Roger M. Hoy
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Various hardware and software solutions exist for collecting Controller Area Network (CAN) bus data. Digital data accuracy could vary based upon different data logging methods (e.g., hardware/software timing, processor timing, etc.). CAN bus data were collected from agricultural tractors using multiple data acquisition solutions to quantify differences among collection methods and demonstrate potential data accumulation rates. Two types of data were observed for this study. The first, CAN bus frame data, represents data collected for each line of hex data sent from an ECU. One issue with frame data is the resulting large file sizes, therefore a second logging format …
Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance,
2016
Adjunct Professor, Biological Systems Engineering
Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance, John E. Gilley, Aaron J. Sindelar, Brian L. Woodbury
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Vegetative filter strips located at the bottom of a hillslope have been shown to substantially reduce nutrients and sediment in runoff. Cropland areas could serve a similar function. However, little scientifically derived information is available to help identify the setback distances required to effectively reduce the transport of contaminants in runoff. The objective of this study was to determine the effects of setback distance and runoff rate on the concentrations and mass transport rates of selected constituents following land application of beef cattle manure to a no-till cropland area. The study site had a residue cover of 8.84 Mg ha-1 …
Impact Of Scale/Resolution On Evapotranspiration
From Landsat And Modis Images,
2016
University of Nebraska-Lincoln
Impact Of Scale/Resolution On Evapotranspiration From Landsat And Modis Images, Vivek Sharma, Ayse Kilic, Suat Irmak
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Understanding the role of landscape heterogeneity and its influence on the scaling behavior of surface fluxes as observed by satellite sensors with different spatial resolutions is a critical need to investigate. In this study, the effects of pixel scales on ETc estimation and other parameters that are used to calculate ETc were investigated over different vegetation surfaces in south central Nebraska, USA. Surface Energy Balance System (SEBS) was used to estimate spatially distributed ETc by combining ground-based meteorological data for Landsat and MODIS imagery. The estimated surface energy fluxes were compared and validated to the measured Bowen Ratio Energy Balance …
Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance,
2016
USDA, Agricultural Research Service
Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance, John E. Gilley, Aaron J. Sindelar, Bryan L. Woodbury
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Vegetative filter strips located at the bottom of a hillslope have been shown to substantially reduce nutrients and sediment in runoff. Cropland areas could serve a similar function. However, little scientifically derived information is available to help identify the setback distances required to effectively reduce the transport of contaminants in runoff. The objective of this study was to determine the effects of setback distance and runoff rate on the concentrations and mass transport rates of selected constituents following land application of beef cattle manure to a no-till cropland area. The study site had a residue cover of 8.84 Mg ha …
262. Direct Measure Of Cervical Interbody Forces In Vivo: Load Reversal After Plating,
2016
Rensselaer Polytechnic Institute
262. Direct Measure Of Cervical Interbody Forces In Vivo: Load Reversal After Plating, Eric H. Ledet, Josh Peterson, Rebecca A. Wachs, Mary Beth M. Grabowsky, Joseph C. Glennon, Darryl J. Dirisio
Department of Agricultural and Biological Systems Engineering: Faculty Publications
BACKGROUND CONTEXT: Biomechanics play an important role in spine fusion, but the in vivo biomechanics of the cervical spine are not well characterized and the in vivo biomechanics after spinal arthrodesis have never been studied. Load sharing facilitates fusion, but overloading of interbody implants can lead to subsidence and failure. In vitro studies have demonstrated that anterior plating significantly alters mechanical loading in the cervical spine. The instantaneous axis of rotation is shifted anteriorly and loading is reversed relative to an uninstrumented spine; the interbody space is compressed during extension and unloaded during flexion. However, this has never been tested …
Moisture Insensitive Prediction Of Soil Properties From Vnir Reflectance
Spectra Based On External Parameter Orthogonalization,
2016
University of Nebraska - Lincoln
Moisture Insensitive Prediction Of Soil Properties From Vnir Reflectance Spectra Based On External Parameter Orthogonalization, Nuwan K. Wijewardane, Yufeng Ge, Cristine L.S. Morgan
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Moisture is the single most important factor that affects soil reflectance spectra, particularly for field applications. Interest in using soil VNIR spectral libraries, which are commonly based on dry ground soils, to predict soils in the intact field-moist condition (in situ VNIR) is growing. External parameter orthogonalization (EPO) has been proposed as a useful method that links dry ground VNIR models to field moist scans. The goal of this study is to test EPO on a wider set of soil properties and four different modeling techniques, namely, Partial Least Squares Regression (PLS), Artificial Neural Network (ANN), Random Forest (RF), and …
Neural Encoding Of Saltatory Pneumotactile
Velocity In Human Glabrous Hand,
2016
University of Nebraska - Lincoln
Neural Encoding Of Saltatory Pneumotactile Velocity In Human Glabrous Hand, Hyuntaek Oh, Rebecca Custead, Yingying Wang, Steven M. Barlow
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Neurons in the somatosensory cortex are exquisitely sensitive to mechanical stimulation of the skin surface. The location, velocity, direction, and adaptation of tactile stimuli on the skin's surface are discriminable features of somatosensory processing, however the representation and processing of dynamic tactile arrays in the human somatosensory cortex are poorly understood. The principal aim of this study was to map the relation between dynamic saltatory pneumatic stimuli at discrete traverse velocities on the glabrous hand and the resultant pattern of evoked BOLD response in the human brain. Moreover, we hypothesized that the hand representation in contralateral Brodmann Area (BA) 3b …
Analyses, Calibration And Validation Of Evapotranspirationmodels To Predict Grass-Reference Evapotranspiration In Thesenegal River Delta,
2016
Africa Rice Center
Analyses, Calibration And Validation Of Evapotranspirationmodels To Predict Grass-Reference Evapotranspiration In Thesenegal River Delta, Koffi Djaman, Hossein Tabari, Alpha B. Balde, Lamine Diop, Koichi Futakuchi, Suat Irmak
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Study region: Grass-reference evapotranspiration estimation by the Penman-Monteithmethod (PM-ETo) requires a number of climate variables which are not always availableat all weather stations. Different alternative ETo equations have been developed and theirutilization for various local climate conditions requires analyses of their accuracy as com-pared to the standardized Penman-Monteith method. There is a significant lack of data andinformation on this topic in the Senegal River Delta (SRD). Study focus: The objective of this study was to evaluate, calibrate and validate six EToequations ((Trabert, Mahringer, Penman1948, Albrecht, Valiantzas1 and Valiantzas2) forthe SRD. Although all six equations showed good agreement with the PM-ETo …
A Multi-Sensor System For High Throughput Field Phenotyping In Soybean
And Wheat Breeding,
2016
University of Nebraska - Lincoln
A Multi-Sensor System For High Throughput Field Phenotyping In Soybean And Wheat Breeding, Geng Bai, Yufeng Ge, Waseem Hussain, P. Stephen Baenziger, George L. Graef
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Collecting plant phenotypic data with sufficient resolution (in both space and time) and accuracy represents a long standing challenge in plant science research, and has been a major limiting factor for the effective use of genomic data for crop improvement. This is particularly true in plant breeding where collecting large-scale field-based plant phenotypes can be very labor intensive and costly. In this paper we reported a multi-sensor system for high throughput phenotyping in plant breeding. The system comprised five sensor modules (ultrasonic distance sensors, thermal infrared radiometers, NDVI sensors, portable spectrometers, and RGB web cameras) to measure crop canopy traits …
Recalibration Methodology To Compensate For Changing Fluid Properties In An Individual Nozzle Direct Injection Systems,
2016
University of Nebraska-Lincoln
Recalibration Methodology To Compensate For Changing Fluid Properties In An Individual Nozzle Direct Injection Systems, Joe D. Luck, S. A. Shearer, B. D. Luck, M. P. Sama
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Limited advancement of direct injection pesticide application systems has been made in recent years, which has hindered further commercialization of this technology. One approach to solving the lag and mixing issues typically associated with injection-based systems is high-pressure individual nozzle injection. However, accurate monitoring of the chemical concentrate flow rate can pose a challenge due to the high pressure, low flow, and changing viscosities of the fluid. A methodology was developed for recalibrating high-pressure chemical concentrate injectors to compensate for fluid property variations and evaluate the performance of this technique for operating injectors in an open-loop configuration. Specific objectives were …
A Multi-Scale Comparison Of Modeled And Observed Seasonal
Methane Emissions In Northern Wetlands,
2016
Lawrence Berkeley National Laboratory
A Multi-Scale Comparison Of Modeled And Observed Seasonal Methane Emissions In Northern Wetlands, Xiyan Xu, William J. Riley, Charles D. Koven, Dave P. Billesbach, Rachel Y.-W. Chang, Roisin Commane, Eugenie S. Euskirchen, Sean Hartery, Yoshinobu Harazono, Hiroki Iwata, Kyle C. Mcdonald, Charles E. Miller, Walter C. Oechel, Benjamin Poulter, Naama Raz-Yaseef, Colm Sweeny, Margaret Torn, Steven C. Wofsy, Zhen Zhang, Donatella Zona
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Wetlands are the largest global natural methane (CH4) source, and emissions between 50 and 70° N latitude contribute 10–30% to this source. Predictive capability of land models for northern wetland CH4 emissions is still low due to limited site measurements, strong spatial and temporal variability in emissions, and complex hydrological and biogeochemical dynamics. To explore this issue, we compare wetland CH4 emission predictions from the Community Land Model 4.5 (CLM4.5-BGC) with siteto regional-scale observations. A comparison of the CH4 fluxes with eddy flux data highlighted needed changes to the model’s estimate of aerenchyma area, which …
