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2020

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Articles 151 - 175 of 175

Full-Text Articles in Engineering

Ground And Aerial Robots For Agricultural Production: Opportunities And Challenges, Santosh Pitla, Sreekala Bajwa, Santosh Bhusal, Tom Brumm, Tami M. Brown-Brandl, Dennis R. Buckmaster, Isabella Condotta, John Fulton, Todd J. Janzen, Manoj Karkee, Mario Lopez, Robert Moorhead, Michael Sama, Leon Schumacher, Scott Shearer, Alex Thomasson Jan 2020

Ground And Aerial Robots For Agricultural Production: Opportunities And Challenges, Santosh Pitla, Sreekala Bajwa, Santosh Bhusal, Tom Brumm, Tami M. Brown-Brandl, Dennis R. Buckmaster, Isabella Condotta, John Fulton, Todd J. Janzen, Manoj Karkee, Mario Lopez, Robert Moorhead, Michael Sama, Leon Schumacher, Scott Shearer, Alex Thomasson

Department of Biological Systems Engineering: Papers and Publications

Crop and animal production techniques have changed significantly over the last century. In the early 1900s, animal power was replaced by tractor power that resulted in tremendous improvements in field productivity, which subsequently laid foundation for mechanized agriculture. While precision agriculture has enabled site-specific management of crop inputs for improved yields and quality, precision livestock farming has boosted efficiencies in animal and dairy industries. By 2020, highly automated systems are employed in crop and animal agriculture to increase input efficiency and agricultural output with reduced adverse impact on the environment. Ground and aerial robots combined with artificial intelligence (AI) techniques …


Representing Organic Matter Thermodynamics In Biogeochemical Reations Via Substrate-Explicit Modeling, Hyun-Seob Song, James C. Stegen, Emily B. Graham, Joon-Yong Lee, Vanessa A. Garayburu-Caruso, William C. Nelson, Xingyuan Chen, J. David Moulton, Timothy D. Scheibe Jan 2020

Representing Organic Matter Thermodynamics In Biogeochemical Reations Via Substrate-Explicit Modeling, Hyun-Seob Song, James C. Stegen, Emily B. Graham, Joon-Yong Lee, Vanessa A. Garayburu-Caruso, William C. Nelson, Xingyuan Chen, J. David Moulton, Timothy D. Scheibe

Department of Biological Systems Engineering: Papers and Publications

Predictive biogeochemical modeling requires data-model integration that enables explicit representation of the sophisticated roles of microbial processes that transform substrates. Data from high-resolution organic matter (OM) characterization are increasingly available and can serve as a critical resource for this purpose, but their incorporation into biogeochemical models is often prohibited due to an over-simplified description of reaction networks. To fill this gap, we proposed a new concept of biogeochemical modeling—termed substrate-explicit modeling—that enables parameterizing OM-specific oxidative degradation pathways and reaction rates based on the thermodynamic properties of OM pools. Based on previous developments in the literature, we characterized the resulting kinetic …


Teacher Level Factors And Student Achievement In A Cyber-Enabled Engineering Education Professional Development Program, Wei Zakharov, Johannes Strobel, Heidi A. Diefes-Dux Jan 2020

Teacher Level Factors And Student Achievement In A Cyber-Enabled Engineering Education Professional Development Program, Wei Zakharov, Johannes Strobel, Heidi A. Diefes-Dux

Department of Biological Systems Engineering: Papers and Publications

This study investigates the impact of an elementary engineering education teacher professional development program on student learning. The results show a significant increase in students’ knowledge in science from pre- to post-test as well as in engineering design from grade two to grade four. Further, the study uses multilevel modeling to quantitatively analyze the impact of differences among teachers on the engineering design achievement of their students. Different predictive relationships between demographic and social capital factors at the teacher level and student achievement are identified and implications for educational policymaking and practices are discussed.


An Automated Seepage Meter For Streams And Lakes, Douglas Kip Solomon, Eric Humphrey, Troy E. Gilmore, David P. Genereux, Vitaly A. Zlotnik Jan 2020

An Automated Seepage Meter For Streams And Lakes, Douglas Kip Solomon, Eric Humphrey, Troy E. Gilmore, David P. Genereux, Vitaly A. Zlotnik

Department of Biological Systems Engineering: Papers and Publications

We describe a new automatic seepage meter for use in soft bottom streams and lakes. The meter utilizes a thin‐walled tube that is inserted into the streambed or lakebed. A hole in the side of the tube is fitted with an electric valve. Prior to the test, the valve is open and the water level inside the tube is the same as the water level outside the tube. The test starts with closure of the valve, and the water level inside the tube changes as it moves toward the equilibrium hydraulic head that exists at the bottom of the tube. …


Automatic Wheat Lodging Detection And Mapping In Aerial Imagery To Support High-Throughput Phenotyping And In-Season Crop Management, Biquan Zhao, Jiating Li, P. Stephen Baenziger, Vikas Belamkar, Yufeng Ge, Jian Zhang, Yeyin Shi Jan 2020

Automatic Wheat Lodging Detection And Mapping In Aerial Imagery To Support High-Throughput Phenotyping And In-Season Crop Management, Biquan Zhao, Jiating Li, P. Stephen Baenziger, Vikas Belamkar, Yufeng Ge, Jian Zhang, Yeyin Shi

Department of Biological Systems Engineering: Papers and Publications

Latest advances in unmanned aerial vehicle (UAV) technology and convolutional neural networks (CNNs) allow us to detect crop lodging in a more precise and accurate way. However, the performance and generalization of a model capable of detecting lodging when the plants may show different spectral and morphological signatures have not been investigated much. This study investigated and compared the performance of models trained using aerial imagery collected at two growth stages of winter wheat with different canopy phenotypes. Specifically, three CNN-based models were trained with aerial imagery collected at early grain filling stage only, at physiological maturity only, and at …


Predicting Total Petroleum Hydrocarbons In Field Soils With Vis–Nir Models Developed On Laboratory-Constructed Samples, Nuwan K. Wijewardane, Yufeng Ge, Natasha Sihota, Thomas Hoelen, Toni Miaso, David C. Weindorf Jan 2020

Predicting Total Petroleum Hydrocarbons In Field Soils With Vis–Nir Models Developed On Laboratory-Constructed Samples, Nuwan K. Wijewardane, Yufeng Ge, Natasha Sihota, Thomas Hoelen, Toni Miaso, David C. Weindorf

Department of Biological Systems Engineering: Papers and Publications

Accurate quantification of petroleum hydrocarbons (PHCs) is required for optimizing remedial efforts at oil spill sites. While evaluating total petroleum hydrocarbons (TPH) in soils is often conducted using costly and time-consuming laboratory methods, visible and near-infrared reflectance spectroscopy (Vis–NIR) has been proven to be a rapid and cost-effective field-based method for soil TPH quantification. This study investigated whether Vis–NIR models calibrated from laboratory-constructed PHC soil samples could be used to accurately estimate TPH concentration of field samples. To evaluate this, a laboratory sample set was constructed by mixing crude oil with uncontaminated soil samples, and two field sample sets (F1 …


Setback Distance Impacts On Transport And Antibiotic Resistance Phenotypes Of Fecal Indicators, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Daniel N. Miller, Xu Li, Amy M. Schmidt Schmidt Jan 2020

Setback Distance Impacts On Transport And Antibiotic Resistance Phenotypes Of Fecal Indicators, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Daniel N. Miller, Xu Li, Amy M. Schmidt Schmidt

Department of Biological Systems Engineering: Papers and Publications

Although the land application of livestock manure has numerous agronomic benefits, runoff from manured fields can degrade water quality. Setbacks instruct a minimum distance be maintained between manure application and surface waters. They are commonly used to manage nutrient contamination of surface waters; however, their utility for reducing microbial inputs remains unclear. Here we evaluated the efficacy of five setback distances in no-till wheat (Triticum aes- tivum L.) residue plots for reducing runoff fecal indicator concentrations from swine manure-amended fields. Also, since there is increasing interest in the use of water quality indicators to monitor antibiotic resistance in environmental sys- …


Within-Field Variability In Granular Matrix Sensor Data And Its Implications For Irrigation Scheduling, T. Lo, H.C. Pringle Iii, Daran Rudnick, Geng Bai, L. Jason Krutz, D.M. Gholson, Xin Qiao Jan 2020

Within-Field Variability In Granular Matrix Sensor Data And Its Implications For Irrigation Scheduling, T. Lo, H.C. Pringle Iii, Daran Rudnick, Geng Bai, L. Jason Krutz, D.M. Gholson, Xin Qiao

Department of Biological Systems Engineering: Papers and Publications

Even when located within the same field, multiple units of the same soil moisture sensor rarely report identical values. Such within-field variability in soil moisture sensor data is caused by natural and manmade spatial heterogeneity and by inconsistencies in sensor construction and installation. To better describe this variability, daily soil water tension values from 14-23 sets of granular matrix sensors during the middle part of four soybean site-years in the Mississippi Delta were analyzed. The soil water tension data were found to follow approximately normal distributions, to exhibit moderately high temporal rank stability, and to show strong positive correlation between …


High‐ And Low‐Molecular‐Weight Chitosan Act As Adjuvants During Single‐Dose Influenza A Virus Protein Vaccination Through Distinct Mechanisms, Anna T. Lampe, Eric Farris, Deborah M. Brown, Angela K. Pannier Jan 2020

High‐ And Low‐Molecular‐Weight Chitosan Act As Adjuvants During Single‐Dose Influenza A Virus Protein Vaccination Through Distinct Mechanisms, Anna T. Lampe, Eric Farris, Deborah M. Brown, Angela K. Pannier

Department of Biological Systems Engineering: Papers and Publications

The investigation of new adjuvants is essential for the development of efficacious vaccines. Chitosan (CS), a derivative of chitin, has been shown to act as an adjuvant, improving vaccine‐induced immune responses. However, the effect of CS molecular weight (MW) on this adjuvanticity has not been investigated, despite MW having been shown to impact CS biological properties. Here, two MW variants of CS were in- vestigated for their ability to enhance vaccine‐elicited immune responses in vitro and in vivo, using a single‐dose influenza A virus (IAV) protein vaccine model. Both low‐ molecular‐weight (LMW) and high‐molecular‐weight (HMW) CS‐induced interferon regulatory factor pathway …


Antibiotic Resistance Gene Profile Changes In Cropland Soil After Manure Application And Rainfall, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Heidi Waldrip, Lana Castleberry, Amy Schmidt Jan 2020

Antibiotic Resistance Gene Profile Changes In Cropland Soil After Manure Application And Rainfall, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Heidi Waldrip, Lana Castleberry, Amy Schmidt

Department of Biological Systems Engineering: Papers and Publications

Land application of manure introduces gastrointestinal microbes into the environ- ment, including bacteria carrying antibiotic resistance genes (ARGs). Measuring soil ARGs is important for active stewardship efforts to minimize gene flow from agri- cultural production systems; however, the variety of sampling protocols and target genes makes it difficult to compare ARG results between studies. We used polymerase chain reaction (PCR) methods to characterize and/or quantify 27 ARG targets in soils from 20 replicate, long-term no-till plots, before and after swine manure application and simulated rainfall and runoff. All samples were negative for the 10 b-lactamase genes assayed. For tetracycline resistance, …


Interrelationships Between Water Use Efficiency And Light Use Efficiency In Four Row Crop Canopies, Meetpal S. Kukal, Suat Irmak Dr. Jan 2020

Interrelationships Between Water Use Efficiency And Light Use Efficiency In Four Row Crop Canopies, Meetpal S. Kukal, Suat Irmak Dr.

Department of Biological Systems Engineering: Papers and Publications

Quantitative evidence of light use efficiency (LUE) controls on water use effi- ciency (WUE) is lacking, especially comparatively across row crops. Field research experiments (2016–2018) were set up for maize (Zea mays L.), soybean [Glycine max (L.) Merr.], sorghum [Sorghum bicolor (L.) Moench], and winter wheat (Triticum aestivum L.), under optimal growth conditions in dry sub-humid conditions. Overall, LUE was able to explain 52% of variance in WUE, and were related as WUE = 1.73 LUE, although crop-specific variation was observed. High- est sensitivity of WUE to changes in LUE was found in sorghum, followed by soybean, winter wheat, and …


Innovative Extension Methods In The U.S. To Promote Irrigation Water Management, Daran Rudnick, Matt Stockton, Saleh Taghvaeian, Jason Warren, Michael D. Dukes, Amy Kremen, Christopher G. Henry, Jonathan Aguilar, Brenda Ortiz, Allan A. Andales, Chuck A. Burr, Xin Qiao, Wei‑Zhen Liang, Steven Walthour, Steve H. Amosson Jan 2020

Innovative Extension Methods In The U.S. To Promote Irrigation Water Management, Daran Rudnick, Matt Stockton, Saleh Taghvaeian, Jason Warren, Michael D. Dukes, Amy Kremen, Christopher G. Henry, Jonathan Aguilar, Brenda Ortiz, Allan A. Andales, Chuck A. Burr, Xin Qiao, Wei‑Zhen Liang, Steven Walthour, Steve H. Amosson

Department of Biological Systems Engineering: Papers and Publications

Promotion and adoption of irrigation water management (IWM) technology, tools, and best management practices are important as water availability concerns are addressed. Traditional extension programs have relied on lecture presentations, field tours, fact sheets, and on-station demonstrations to promote IWM practices and tools. However, these platforms tend not to provide the experience and opportunity for growers to identify and become comfortable with innovative solutions, such as new technology. To address these challenges and to appeal to an ever-changing client base, innovative and locally relevant extension and outreach programs have been devised to engage and educate growers. This article describes some …


Accumulation And Release Of Nutrients By Immersed Stalks Collected On Selected Dates Following Harvest, John E. Gilley, David B. Marx Jan 2020

Accumulation And Release Of Nutrients By Immersed Stalks Collected On Selected Dates Following Harvest, John E. Gilley, David B. Marx

Department of Biological Systems Engineering: Papers and Publications

The concentrations of phosphorus (P) and nitrogen (N) in runoff from cropland areas may be influenced by accumulation and release of P and N by stalk residues. A laboratory study was conducted to measure the effects of time since harvest and immersion period on accumulation and release of P and N by corn, soybean, and wheat stalks. Experimental variables included type of stalk material (corn, soybean, and wheat), time since harvest (six residue collection dates over an approximate 1-year period), and stalk immersion period (25 s (0.42 min), 250 s (4.2 min), 2500 s (42 min), 25,000 s (6.9 h), …


Field Assessment Of Interreplicate Variability From Eight Electromagnetic Soil Moisture Sensors, Tsz Him Lo, Daran Rudnick, Jasreman Singh, Hope Njuki Nakabuye, Abia Katimbo, Derek M. Heeren, Yufeng Ge Jan 2020

Field Assessment Of Interreplicate Variability From Eight Electromagnetic Soil Moisture Sensors, Tsz Him Lo, Daran Rudnick, Jasreman Singh, Hope Njuki Nakabuye, Abia Katimbo, Derek M. Heeren, Yufeng Ge

Department of Biological Systems Engineering: Papers and Publications

Interreplicate variability—the spread in output values among units of the same sensor subjected to essentially the same condition—can be a major source of uncertainty in sensor data. To investigate the interreplicate variability among eight electromagnetic soil moisture sensors through a field study, eight units of TDR315, CS616, CS655, HydraProbe2, EC5, 5TE, and Teros12 were installed at a depth of 0.30 m within 3 m of each other, whereas three units of AquaSpy Vector Probe were installed within 3 m of each other. The magnitude of interreplicate variability in volumetric water content (θv) was generally similar between a static …


Irrigation-Yield Production Functions And Irrigation Water Use Effciency Response Of Drought-Tolerant And Non-Drought-Tolerant Maize Hybrids Under Different Irrigation Levels, Population Densities, And Environments, Suat Irmak, Ali T. Mohammed, William Kranz, C. D. Yonts, Simon Van Donk Jan 2020

Irrigation-Yield Production Functions And Irrigation Water Use Effciency Response Of Drought-Tolerant And Non-Drought-Tolerant Maize Hybrids Under Different Irrigation Levels, Population Densities, And Environments, Suat Irmak, Ali T. Mohammed, William Kranz, C. D. Yonts, Simon Van Donk

Department of Biological Systems Engineering: Papers and Publications

Irrigation-yield production functions (IYPFs), irrigation water use effciency (IWUE), and grain production per unit of applied irrigation of non-drought-tolerant (NDT) and drought-tolerant (DT) maize (Zea mays L.) hybrids were quantified in four locations with different climates in Nebraska [Concord (sub-humid), Clay Center (transition zone between sub-humid and semi-arid); North Platte (semi-arid); and, Scottsbluff (semi-arid)] during three growing seasons (2010, 2011, and 2012) at three irrigation levels (fully-irrigated treatment (FIT), early cut-off (ECOT), and rainfed (RFT)) under two plant population densities (PPDs) (low-PPD; 59,300 plants ha-1; and, high-PPD, 84,000 plants ha-1). Overall, DT hybrids’ performance was …


Development And Application Of A Performance And Operational Feasibility Guide To Facilitate Adoption Of Soil Moisture Sensors, Meetpal S. Kukal, Suat Irmak, Kiran Sharma Jan 2020

Development And Application Of A Performance And Operational Feasibility Guide To Facilitate Adoption Of Soil Moisture Sensors, Meetpal S. Kukal, Suat Irmak, Kiran Sharma

Department of Biological Systems Engineering: Papers and Publications

Soil moisture sensors can be effective and promising decision-making tools for diverse applications and audiences, including agricultural managers, irrigation practitioners, and researchers. Nevertheless, there exists immense adoption potential in the United States, with only 1.2 in 10 farms nationally using soil moisture sensors to decide when to irrigate. This number is much lower in the global scale. Increased adoption is likely hindered by lack of scientific support in need assessment, selection, suitability and use of these sensors. Here, through extensive field research, we address the operational feasibility of soil moisture sensors, an aspect which has been overlooked in the past, …


Prediction Of Neighbor-Dependent Microbial Interactions From Limited Population Data, Joon-Yong Lee, Shin Haruta, Souichiro Kato, Hans C. Bernstein, Stephen R. Lindemann, Dong-Yup Lee, Jim K. Fredrickson, Hyun-Seob Song Jan 2020

Prediction Of Neighbor-Dependent Microbial Interactions From Limited Population Data, Joon-Yong Lee, Shin Haruta, Souichiro Kato, Hans C. Bernstein, Stephen R. Lindemann, Dong-Yup Lee, Jim K. Fredrickson, Hyun-Seob Song

Department of Biological Systems Engineering: Papers and Publications

Modulation of interspecies interactions by the presence of neighbor species is a key ecological factor that governs dynamics and function of microbial communities, yet the development of theoretical frameworks explicit for understanding context-dependent interactions are still nascent. In a recent study, we proposed a novel rule-based inference method termed the Minimal Interspecies Interaction Adjustment (MIIA) that predicts the reorganization of interaction networks in response to the addition of new species such that the modulation in interaction coefficients caused by additional members is minimal. While the theoretical basis of MIIA was established through the previous work by assuming the full availability …


Site-Specific Irrigation Management In A Sub-Humid Climate Using A Spatial Evapotranspiration Model With Satellite And Airborne Imagery, Sandeep Bhatti, Derek M. Heeren, J. Burdette Barker, Christopher M. U. Neale, Wayne Woldt, Mitchell S. Maguire, Daran Rudnick Jan 2020

Site-Specific Irrigation Management In A Sub-Humid Climate Using A Spatial Evapotranspiration Model With Satellite And Airborne Imagery, Sandeep Bhatti, Derek M. Heeren, J. Burdette Barker, Christopher M. U. Neale, Wayne Woldt, Mitchell S. Maguire, Daran Rudnick

Department of Biological Systems Engineering: Papers and Publications

Variable Rate Irrigation (VRI) considers spatial variability in soil and plant characteristics to optimize irrigation management in agricultural fields. The advent of unmanned aircraft systems (UAS) creates an opportunity to utilize high-resolution (spatial and temporal) imagery into irrigation management due to decreasing costs, ease of operation, and reduction of regulatory constraints. This research aimed to evaluate the use of UAS data for VRI, and to quantify the potential of VRI in terms of relative crop and water response. Irrigation treatments were: (1) VRI using Landsat imagery (VRI-L), (2) VRI using UAS imagery (VRI-U), (3) uniform (U), and (4) rainfed (R). …


Cover Crop Productivity And Subsequent Soybean Yield In The Western Corn Belt, Katja Koehler-Cole, Roger W. Elmore, Humberto Blanco-Canqui, Charles A. Francis, Charles Shapiro, Christopher A. Proctor, Sabrina J. Ruis, Derek M. Heeren, Suat Irmak, Richard Ferguson Jan 2020

Cover Crop Productivity And Subsequent Soybean Yield In The Western Corn Belt, Katja Koehler-Cole, Roger W. Elmore, Humberto Blanco-Canqui, Charles A. Francis, Charles Shapiro, Christopher A. Proctor, Sabrina J. Ruis, Derek M. Heeren, Suat Irmak, Richard Ferguson

Department of Biological Systems Engineering: Papers and Publications

Cover crops (CC) in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotations may prevent N loss and provide other ecosystem services but CC productivity in the western Corn Belt is limited by the short growing season. Our objective was to assess CC treatment and planting practice effects on CC biomass, spring soil nitrate concentrations, and soybean yield at two rainfed sites in eastern and one irrigated site in south-central Nebraska over 4 years. Cover crop treatments (cereal rye [Secale cereale L.] [RYE] and a mix of rye, legume, and brassica species [MIX]) were planted …


Effects Of Farrowing Stall Layout And Number Of Heat Lamps On Sow And Piglet Production Performance, Suzanne M. Leonard, Hongwei Xin, Tami M. Brown-Bandl, Brett C. Ramirez, Somak Dutta, Gary A. Rohrer Jan 2020

Effects Of Farrowing Stall Layout And Number Of Heat Lamps On Sow And Piglet Production Performance, Suzanne M. Leonard, Hongwei Xin, Tami M. Brown-Bandl, Brett C. Ramirez, Somak Dutta, Gary A. Rohrer

Department of Biological Systems Engineering: Papers and Publications

Most farrowing facilities in the United States use stalls and heat lamps to improve sow and piglet productivity. This study investigated these factors by comparing production outcomes for three different farrowing stall layouts (traditional, expanded creep area, expanded sow area) and use of one or two heat lamps. Data were collected on 427 sows and their litters over one year. Results showed no statistical differences due to experimental treatment for any of the production metrics recorded, excluding percent stillborn. Parity one sows had fewer piglets born alive (p < 0.001), lower percent mortality (p = 0.001) and over-lay (p = 0.003), and a …


Calibration Of A Common Shortwave Multispectral Camera System For Quantitative Agricultural Applications, J. Burdette Barker, Wayne Woldt, Brian Wardlow, Christopher Michael Usher Neale, Mitchell S. Maguire, Bryan Leavitt, Derek M. Heeren Jan 2020

Calibration Of A Common Shortwave Multispectral Camera System For Quantitative Agricultural Applications, J. Burdette Barker, Wayne Woldt, Brian Wardlow, Christopher Michael Usher Neale, Mitchell S. Maguire, Bryan Leavitt, Derek M. Heeren

Department of Biological Systems Engineering: Papers and Publications

Unmanned aerial systems (UAS) for collecting multispectral imagery of agricultural fields are becoming more affordable and accessible. However, there is need to validate calibration of sensors on these systems when using them for quantitative analyses such as evapotranspiration, and other modeling for agricultural applications. The results of laboratory testing of a MicaSense (Seattle, WA, USA) RedEdge™ 3 multispectral camera and MicaSense Downwelling Light Sensor (irradiance sensor) system using a calibrated integrating sphere were presented. Responses of the camera and irradiance sensor were linear over many light levels and became non-linear at light levels below expected real-world, field conditions. Simple linear …


Influence Of Watershed Characteristics On Streambed Hydraulic Conductivity Across Multiple Stream Orders, Olufemi P. Abimbola, Aaron R. Mittelstet, Troy E. Gilmore, Jesse T. Korus Jan 2020

Influence Of Watershed Characteristics On Streambed Hydraulic Conductivity Across Multiple Stream Orders, Olufemi P. Abimbola, Aaron R. Mittelstet, Troy E. Gilmore, Jesse T. Korus

Department of Biological Systems Engineering: Papers and Publications

Streambeds are critical hydrological interfaces: their physical properties regulate the rate, timing, and location of fluxes between aquifers and streams. Streambed vertical hydraulic conductivity (Kv) is a key parameter in watershed models, so understanding its spatial variability and uncertainty is essential to accurately predicting how stresses and environmental signals propagate through the hydrologic system. Most distributed modeling studies use generalized Kv estimates from column experiments or grain-size distribution, but Kv may include a wide range of orders of magnitude for a given particle size group. Thus, precisely predicting Kv spatially has remained conceptual, experimental, …


Effect Of Urea Fertilizer Deep Placement Days After Transplanting Using Brri Prilled Urea Applicator On Transplanted Boro Rice Yield, Muhammad Rashed Al Mamun, K. Naher, Md Towfiqur Rahman, Md Anwar Hossen Jan 2020

Effect Of Urea Fertilizer Deep Placement Days After Transplanting Using Brri Prilled Urea Applicator On Transplanted Boro Rice Yield, Muhammad Rashed Al Mamun, K. Naher, Md Towfiqur Rahman, Md Anwar Hossen

Department of Biological Systems Engineering: Papers and Publications

Rice is the most important crop in the developing countries of Asia. In the south and south-east Asia, rain-fed and irrigated transplanted rice occupies nearly two-thirds of the rice-growing area and produces more than 80% of the rough rice. In these areas, prilled urea conventionally applied by farmers is very insufficient in the transplanted rice field, where severe losses occur (up to 60% of applied N) via NH3volatilization, denitrification, leaching, and runoff. Considering loss minimization, an experiment was conducted during the Boro season at Bangladesh Agricultural Development Corporation (BADC) in Sylhet to evaluate the performance of BRRI Prilled …


Effect Of Rotary Blade Modification On Residue Retention Into Conservation Agriculture Practices, Md Talash Mahmud, Md Towfiqur Rahman, Md Mosharraf Hossain, Muhammad Ashik-E-Rabbani Jan 2020

Effect Of Rotary Blade Modification On Residue Retention Into Conservation Agriculture Practices, Md Talash Mahmud, Md Towfiqur Rahman, Md Mosharraf Hossain, Muhammad Ashik-E-Rabbani

Department of Biological Systems Engineering: Papers and Publications

Conservation Agriculture (CA) has been a promising technique for better crop production. Manual seeding with conventional tillage practice is laborious and time consuming. However, Strip tillage (ST) method incorporating seeding machines minimizes human drudgery and optimizes the crop yield. Many problems associated with ST have been rectified e.g. tiny furrow backfill, inaccuracy of seed and fertilizer placement, leading to poor germination and curtailed outcomes. This article focused on the effects of residue retention for the rotary blades design on a versatile multi-crop planter (VMP). Four types of rotary blades of VMP differed by 15o increment of tip angles were …


A Framework For Sustainable Procurement Practice In The Irish Construction Industry, Duga Jamus Ewuga Jan 2020

A Framework For Sustainable Procurement Practice In The Irish Construction Industry, Duga Jamus Ewuga

Doctoral

The Architectural, Engineering and Construction (AEC) sector has been called upon to develop innovative strategies to drive sustainability. Despite the efforts and commitments made, their performance is still observed to be low, this has been linked to the low level of understanding of practitioners. Also noted was the lack of interest by firms due to the uncertainty of the benefits of committing to long term investments. Nevertheless, academic literature and reports have stated that firms nowadays utilise their procurement mechanism to drive their sustainability practice. However, there is a gap in understanding how construction firms adopt and embed sustainability in …