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- Department of Biological Systems Engineering: Papers and Publications (29)
- Daugherty Water for Food Global Institute: Faculty Publications (3)
- Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research (3)
- Great Plains Research: A Journal of Natural and Social Sciences (2)
- Nebraska Water Center: Faculty Publications (2)
Articles 1 - 30 of 40
Full-Text Articles in Engineering
Soybean Crop Coefficients Under Different Seeding Rates And Full And Limited Irrigation And Rainfed Management, Suat Irmak, Rupinder Sandhu
Soybean Crop Coefficients Under Different Seeding Rates And Full And Limited Irrigation And Rainfed Management, Suat Irmak, Rupinder Sandhu
Department of Biological Systems Engineering: Papers and Publications
The effects of soybean seeding rates on evapotranspiration (ETc) and grassand alfalfa-reference crop coefficients (Kco and Kcr) were investigated under five seeding rates (185,250, 247,000, 308,750, 370,500 and 432,250 seeds ha-1) (62, 82, 103, 124 and 144% of the recommended seeding rate of 300,000 seeds ha-1 in the experimental region) and different irrigation strategies (i.e. full irrigation treatment [FIT], limited irrigation of 75% FIT and 50% FIT and rainfed treatment). Kco and Kcr values were developed for each soybean growth stage. The seasonal ETc ranged from 460 mm for …
Toward Automated Irrigation Management With Integrated Crop Water Stress Index And Spatial Soil Water Balance, Sandeep Bhatti, Derek M. Heeren, Susan A. O’Shaughnessy, Christopher M. U. Neale, Jacob Larue, Steve Melvin, Eric Wilkening, Geng Bai
Toward Automated Irrigation Management With Integrated Crop Water Stress Index And Spatial Soil Water Balance, Sandeep Bhatti, Derek M. Heeren, Susan A. O’Shaughnessy, Christopher M. U. Neale, Jacob Larue, Steve Melvin, Eric Wilkening, Geng Bai
Department of Biological Systems Engineering: Papers and Publications
Decision support systems intended for precision irrigation aim at reducing irrigation applications while optimizing crop yield to achieve maximum crop water productivity (CWP). These systems incorporate on-site sensor data, remote sensing inputs, and advanced algorithms with spatial and temporal characteristics to compute precise crop water needs. The availability of variable rate irrigation (VRI) systems enables irrigation applications at a sub-field scale. The combination of an appropriate VRI system along with a precise decision support system would be ideal for improved CWP. The objective of this study was to compare and evaluate two decision support systems in terms of seasonal applied …
Toward Automated Irrigation Management With Integrated Crop Water Stress Index And Spatial Soil Water Balance, Sandeep Bhatti, Derek M. Heeren, Susan A. O’Shaughnessy, Christopher M. U. Neale, Jacob Larue, Steve Melvin, Eric Wilkening, Geng Bai
Toward Automated Irrigation Management With Integrated Crop Water Stress Index And Spatial Soil Water Balance, Sandeep Bhatti, Derek M. Heeren, Susan A. O’Shaughnessy, Christopher M. U. Neale, Jacob Larue, Steve Melvin, Eric Wilkening, Geng Bai
Department of Biological Systems Engineering: Papers and Publications
Decision support systems intended for precision irrigation aim at reducing irrigation applications while optimizing crop yield to achieve maximum crop water productivity (CWP). These systems incorporate on-site sensor data, remote sensing inputs, and advanced algorithms with spatial and temporal characteristics to compute precise crop water needs. The availability of variable rate irrigation (VRI) systems enables irrigation applications at a sub-field scale. The combination of an appropriate VRI system along with a precise decision support system would be ideal for improved CWP. The objective of this study was to compare and evaluate two decision support systems in terms of seasonal applied …
The Effect Of Relative Humidity On Eddy Covariance Latent Heat Flux Measurements And Its Implication For Partitioning Into Transpiration And Evaporation, Weijie Zhang, Martin Jung, Mirco Migliavacca, Rafael Poyatos, Diego G. Miralles, Tarek S. El-Madany, Marta Galvagno, Arnaud Carrara, Nicola Arriga, Andreas Ibrom, Ivan Mammarella, Dario Papale, Jamie R. Cleverly, Michael Liddell, Georg Wohlfahrt, Christian Markwitz, Matthias Mauder, Eugenie Paul-Limoges, Marius Schmidt, Sebastian Wolf, Christian Brümmer, M. Altaf Arain, Silvano Fares, Tomomichi Kato, Jonas Ardö, Walter Oechel, Chad Hanson, Mika Korkiakoski, Sébastien Biraud, Rainer Steinbrecher, Dave Billesbach, Leonardo Montagnani, William Woodgate, Changliang Shao, Nuno Carvalhais, Markus Reichstein, Jacob A. Nelson
The Effect Of Relative Humidity On Eddy Covariance Latent Heat Flux Measurements And Its Implication For Partitioning Into Transpiration And Evaporation, Weijie Zhang, Martin Jung, Mirco Migliavacca, Rafael Poyatos, Diego G. Miralles, Tarek S. El-Madany, Marta Galvagno, Arnaud Carrara, Nicola Arriga, Andreas Ibrom, Ivan Mammarella, Dario Papale, Jamie R. Cleverly, Michael Liddell, Georg Wohlfahrt, Christian Markwitz, Matthias Mauder, Eugenie Paul-Limoges, Marius Schmidt, Sebastian Wolf, Christian Brümmer, M. Altaf Arain, Silvano Fares, Tomomichi Kato, Jonas Ardö, Walter Oechel, Chad Hanson, Mika Korkiakoski, Sébastien Biraud, Rainer Steinbrecher, Dave Billesbach, Leonardo Montagnani, William Woodgate, Changliang Shao, Nuno Carvalhais, Markus Reichstein, Jacob A. Nelson
Department of Biological Systems Engineering: Papers and Publications
While the eddy covariance (EC) technique is a well-established method for measuring water fluxes (i.e., evaporation or 'evapotranspiration’, ET), the measurement is susceptible to many uncertainties. One such issue is the potential underestimation of ET when relative humidity (RH) is high (>70%), due to low-pass filtering with some EC systems. Yet, this underestimation for different types of EC systems (e.g. open-path or closed-path sensors) has not been characterized for synthesis datasets such as the widely used FLUXNET2015 dataset. Here, we assess the RH-associated underestimation of latent heat fluxes (LE, or ET) from different EC systems for 163 sites in …
The Combined Impact Of Redcedar Encroachment And Climate Change On Water Resources In The Nebraska Sand Hills, Yaser Kishawi, Aaron R. Mittelstet, Zablon Adane, Nawaraj Shrestha, Paolo Nasta
The Combined Impact Of Redcedar Encroachment And Climate Change On Water Resources In The Nebraska Sand Hills, Yaser Kishawi, Aaron R. Mittelstet, Zablon Adane, Nawaraj Shrestha, Paolo Nasta
Department of Biological Systems Engineering: Papers and Publications
The Nebraska Sand Hills (NSH) is considered a major recharge zone for the High Plains Aquifer in the central United States. The uncontrolled expansion of the eastern redcedar (Juniperus Virginiana) under climate warming is posing threats to surface water and groundwater resources. The combined impact of land use and climate change on the water balance in the Upper Middle Loup River watershed (4,954 km2) in the NSH was evaluated by simulating different combination of model scenarios using the Soil Water Assessment Tool (SWAT) model. A total of 222 climate models were ranked according to the aridity …
Behavior Of Completely Automated Evapotranspiration Estimation (Eemetric), Atiqullah Atif
Behavior Of Completely Automated Evapotranspiration Estimation (Eemetric), Atiqullah Atif
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Evapotranspiration (ET) is the second-largest component in the water balance equation, globally consuming 70% of the earth’s annual precipitation. Accurate and consistent estimation of ET is essential for ensuring water resources sustainability, proper management, planning, and regulations of water resources. Though a 100% accurate estimation of ET may not be feasible with the current technology, there are proven techniques that give us estimates of ET we can heavily rely on. Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) is a widely used surface energy balance model that produces relatively accurate ET maps utilizing remote sensing data and requires skilled …
Dynamics Of Crop Evapotranspiration Of Four Major Crops On A Large Commercial Farm: Case Of The Navajo Agricultural Products Industry, New Mexico, Usa, Koffi Djaman, Komlan Koudahe, Ali T. Mohammed
Dynamics Of Crop Evapotranspiration Of Four Major Crops On A Large Commercial Farm: Case Of The Navajo Agricultural Products Industry, New Mexico, Usa, Koffi Djaman, Komlan Koudahe, Ali T. Mohammed
Department of Biological Systems Engineering: Papers and Publications
Crop evapotranspiration (ETa) is the main source of water loss in farms and watersheds, and with its effects felt at a regional scale, it calls for irrigation professionals and water resource managers to accurately assess water requirements to meet crop water use. On a multi-crop commercial farm, different factors affect cropland allocation, among which crop evapotranspiration is one of the most important factors regarding the seasonally or annually available water resources for irrigation in combination with the in-season effective precipitation. The objective of the present study was to estimate crop evapotranspiration for four major crops grown on the Navajo Agricultural …
Crop Response To Thermal Stress Without Yield Loss In Irrigated Maize And Soybean In Nebraska, Sandeep Bhatti, Derek M. Heeren, Steven R. Evett, Susan A. O'Shaughnessy, Daran Rudnick, Trenton E. Franz, Yufeng Ge, Christopher M.U. Neale
Crop Response To Thermal Stress Without Yield Loss In Irrigated Maize And Soybean In Nebraska, Sandeep Bhatti, Derek M. Heeren, Steven R. Evett, Susan A. O'Shaughnessy, Daran Rudnick, Trenton E. Franz, Yufeng Ge, Christopher M.U. Neale
Department of Biological Systems Engineering: Papers and Publications
Thermal sensing provides rapid and accurate estimation of crop water stress through canopy temperature data. Canopy temperature is highly dependent on the transpiration rate of the leaves. It is usually assumed that any reduction in crop evapotranspiration (ET) leads to crop yield loss. As a result, an increase in canopy temperature due to a decrease in crop ET would indicate crop yield loss. This research evaluated the hypothesis that crop water stress could be detected using canopy temperature measurements (increased leaf temperature) from infrared thermometers (IRTs) before incurring crop yield loss. This would be possible in a narrow range when …
Real-Time Irrigation Scheduling Of Maize Using Degrees Above Non-Stressed (Dans) Index In Semi-Arid Environment, Hope Njuki Nakabuye, Daran Rudnick, Kendall C. Dejonge, Tsz Him Lo, Derek M. Heeren, Xin Qiao, Trenton E. Franz, Abia Katimbo, Jiaming Duan
Real-Time Irrigation Scheduling Of Maize Using Degrees Above Non-Stressed (Dans) Index In Semi-Arid Environment, Hope Njuki Nakabuye, Daran Rudnick, Kendall C. Dejonge, Tsz Him Lo, Derek M. Heeren, Xin Qiao, Trenton E. Franz, Abia Katimbo, Jiaming Duan
Department of Biological Systems Engineering: Papers and Publications
Irrigation scheduling methods have been used to determine the timing and amount of water applied to crops. Scheduling techniques can include measurement of soil water content, quantification of crop water use, and monitoring of crop physiological response to water stress. The aim of this study was to evaluate the performance of a simplified crop canopy temperature measurement (CTM) method as Irrigation Principles. Soil and Water Conservation Engineera technique to schedule irrigation for maize. Specifically, the Degrees Above Non-Stressed (DANS) index, which suggests water stress when canopy temperature exceeds the non-stressed canopy temperature (Tcns), was determined by estimating T …
Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale
Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale
Daugherty Water for Food Global Institute: Faculty Publications
Evapotranspiration (ET) provides a strong connection between surface energy and hydrological cycles. Advancements in remote sensing techniques have increased our understanding of energy and terrestrial water balances as well as the interaction between surface and atmosphere over large areas. In this study, we computed surface energy fluxes using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm and a simplified adaptation of the CIMEC (Calibration using Inverse Modeling at Extreme Conditions) process for automated endmember selection. Our main purpose was to assess and compare the accuracy of the automated calibration of the SEBAL algorithm using two different sources of meteorological …
Effects Of Surface Heterogeneity Due To Drip Irrigation On Scintillometer Estimates Of Sensible, Latent Heat Fluxes And Evapotranspiration Over Vineyards, Hatim M. E. Geli, José González-Piqueras, Christopher M. U. Neale, Claudio Balbontín, Isidro Campos, Alfonso Calera
Effects Of Surface Heterogeneity Due To Drip Irrigation On Scintillometer Estimates Of Sensible, Latent Heat Fluxes And Evapotranspiration Over Vineyards, Hatim M. E. Geli, José González-Piqueras, Christopher M. U. Neale, Claudio Balbontín, Isidro Campos, Alfonso Calera
Daugherty Water for Food Global Institute: Faculty Publications
Accurate estimates of sensible (H) and latent (LE) heat fluxes and actual evapotranspiration (ET) are required for monitoring vegetation growth and improved agricultural water management. A large aperture scintillometer (LAS) was used to provide these estimates with the objective of quantifying the effects of surface heterogeneity due to soil moisture and vegetation growth variability. The study was conducted over drip-irrigated vineyards located in a semi-arid region in Albacete, Spain during summer 2007. Surface heterogeneity was characterized by integrating eddy covariance (EC) observations of H, LE and ET; land surface temperature (LST) and normalized difference vegetation index (NDVI) data from Landsat …
Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale
Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale
Daugherty Water for Food Global Institute: Faculty Publications
Evapotranspiration (ET) provides a strong connection between surface energy and hydrological cycles. Advancements in remote sensing techniques have increased our understanding of energy and terrestrial water balances as well as the interaction between surface and atmosphere over large areas. In this study, we computed surface energy fluxes using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm and a simplified adaptation of the CIMEC (Calibration using Inverse Modeling at Extreme Conditions) process for automated endmember selection. Our main purpose was to assess and compare the accuracy of the automated calibration of the SEBAL algorithm using two different sources of meteorological …
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
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). …
Actual Evapotranspiration And Crop Coefficients Of Irrigated Lowland Rice (Oryza Sativa L.) Under Semiarid Climate, Koffi Djaman, Daran R. Rudnick, Yonnelle D. Moukoumbi, Abdoulaye Sow, Suat Irmak
Actual Evapotranspiration And Crop Coefficients Of Irrigated Lowland Rice (Oryza Sativa L.) Under Semiarid Climate, Koffi Djaman, Daran R. Rudnick, Yonnelle D. Moukoumbi, Abdoulaye Sow, Suat Irmak
Department of Biological Systems Engineering: Papers and Publications
Lowland irrigated rice is the predominant crop produced in the Senegal River Valley characterized by very low annual rainfall, high temperatures, and low relative humidity. The Senegal River is shared by Senegal, Mali, Mauritania, and Guinea, and serves as the main source of irrigation water for the adopted double rice cropping system. Developing appropriate resource management strategies might be the key factor for the sustainability of rice production in the region. This study aims to estimate rice seasonal evapotranspiration (ETa), irrigation water requirement, and to develop rice growth stage specific crop coefficients (Kc) to improve rice water productivity. Field experiments …
Integration Of Remote Sensing And Proximal Sensing For Improvement Of Field Scale Water Management, Foad Foolad
Integration Of Remote Sensing And Proximal Sensing For Improvement Of Field Scale Water Management, Foad Foolad
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Water is one of the most precious natural resources, and sustainable water resources development is a significant challenge facing water managers over the coming decades. Accurate estimation of the different components of the hydrologic cycle is key for water managers and planners in order to achieve sustainable water resources development. The primary goal of this dissertation was to investigate techniques to combine datasets acquired by remote and proximal sensing and in-situ sensors for the improvement of monitoring near surface water fluxes. This dissertation is separated into three site-specific case studies. First study, investigated the feasibility of using inverse vadose zone …
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
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 Biological Systems Engineering: Papers and 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 (Kcbrf) 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 …
Evaluation Of Variable Rate Irrigation Using A Remote-Sensing-Based Model, John Burdette Barker, Derek M. Heeren, Christopher M.U. Neale, Daran Rudnick
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 Biological Systems Engineering: Papers and 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 …
Crop Evapotranspiration, Irrigationwater Requirement And Water Productivity Of Maize From Meteorological Data Under Semiarid Climate, Koffi Djaman, Michael O'Neill, Curtis K. Owen, Daniel Smeal, Komlan Koudahe, Margaret West, Samuel Allen, Kevin Lombard, Suat Irmak
Crop Evapotranspiration, Irrigationwater Requirement And Water Productivity Of Maize From Meteorological Data Under Semiarid Climate, Koffi Djaman, Michael O'Neill, Curtis K. Owen, Daniel Smeal, Komlan Koudahe, Margaret West, Samuel Allen, Kevin Lombard, Suat Irmak
Department of Biological Systems Engineering: Papers and Publications
Under the semiarid climate of the Southwest United States, accurate estimation of crop water use is important for water management and planning under conservation agriculture. The objectives of this study were to estimate maize water use and water productivity in the Four Corners region of New Mexico. Maize was grown under full irrigation during the 2011, 2012, 2013, 2014 and 2017 seasons at the Agricultural Science Center at Farmington (NM). Seasonal amounts of applied irrigation varied from 576.6 to 1051.6 mm and averaged 837.7 mm and the total water supply varied from 693.4 to 1140.5 mm. Maize actual evapotranspiration was …
Bias And Other Error In Gridded Weather Data Sets And Their Impacts On Estimating Reference Evapotranspiration, Philip A. Blankenau
Bias And Other Error In Gridded Weather Data Sets And Their Impacts On Estimating Reference Evapotranspiration, Philip A. Blankenau
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Gridded weather data sets are increasingly used in a variety of hydrologic and agricultural applications due to their complete spatial and temporal coverage. One application of gridded data sets is the estimation of evapotranspiration (ET). Several operational remote sensing (RS) approaches for estimating ET, such as the SEBAL, METRIC and EEFlux models, require estimates of reference ET (ETref), where ETref is expected ET from a hypothetical reference crop of clipped grass or alfalfa. Gridded weather data provide for the computation of ETref in all areas of a remote sensing image, and therefore potentially remove the need for dense weather station …
Trend Analysis In Rainfall, Reference Evapotranspiration And Aridity Index In Southern Senegal: Adaptation To The Vulnerability Of Rainfed Rice Cultivation To Climate Change, Komlan Koudahe, Koffi Djaman, Ansoumana Bodian, Suat Irkmak, Mamadou Sall, Lamine Diop, Alpha B. Balde, Daran Rudnick
Trend Analysis In Rainfall, Reference Evapotranspiration And Aridity Index In Southern Senegal: Adaptation To The Vulnerability Of Rainfed Rice Cultivation To Climate Change, Komlan Koudahe, Koffi Djaman, Ansoumana Bodian, Suat Irkmak, Mamadou Sall, Lamine Diop, Alpha B. Balde, Daran Rudnick
Department of Biological Systems Engineering: Papers and Publications
Rainfall and evapotranspiration are two vital elements for food production under rainfed agriculture. This study aims at investigating the combined changes in these variables in the form of aridly index in the southern Senegal. The temporal trends in annual and monthly (from May to October) aridity index, rainfall and evapotranspiration are examined and adaptation strategies to the vulnerability of rainfed rice cultivation to the changes are developed. The results show a significant decreasing trend in annual rainfall at all study locations for the period 1922-2015. When analyzing the trends in sub-periods, there are two clear patterns in the annual rainfall …
Spatial And Temporal Changes In Maize And Soybean Grain Yield, Precipitation Use Efficiency, And Crop Water Productivity In The U.S. Great Plains, Meetpal S. Kukal, S. Irmak
Spatial And Temporal Changes In Maize And Soybean Grain Yield, Precipitation Use Efficiency, And Crop Water Productivity In The U.S. Great Plains, Meetpal S. Kukal, S. Irmak
Department of Biological Systems Engineering: Papers and Publications
Sustainable agricultural utilization of the limited water resources demands improvements in understanding the changes in crop water productivity (CWP) in space and time, which is often presented as a potential solution to relieve the growing pressure on fresh water resources. In addition, crop yield needs to be studied in relation to precipitation received annually and during the growing season for its contribution to reduce irrigation water requirements, which is quantified through precipitation use efficiency (PUE). Hence, systematic quantifications, mapping, and analyses of large-scale CWP and PUE levels are needed. This study aims to quantify long-term (1982-2013) information on grain yield, …
Development And Assessment Of A Groundwater Sustainability Index In Climatically Diverse Groundwater Irrigated Regions In Nebraska, Maria A. Mulet Jalil
Development And Assessment Of A Groundwater Sustainability Index In Climatically Diverse Groundwater Irrigated Regions In Nebraska, Maria A. Mulet Jalil
Department of Biological Systems Engineering: Dissertations and Theses
The aim of this research was to evaluate the impact of regional change in ET on groundwater level changes and the assessment and development of a groundwater sustainability index for climatically diverse regions across Nebraska during 2000-2014. Irrigation in the selected regions is predominantly supplied by groundwater. The hypothesis is that groundwater use can become sustainable if the regional evapotranspiration (ET) is managed so that it equals the ET of vegetation that is native to the region. Site locations were Box Butte, Chase, Dundy, Holt LNNRD and York Counties and 3 ecosystems were evaluated: native vegetation, dryland and irrigated cropping …
The Spatial Sensitivity Analysis Of Evapotranspiration Using Penman-Monteith Method At Grid Scale, Sivarajah Mylevaganam, Chittaranjan Ray
The Spatial Sensitivity Analysis Of Evapotranspiration Using Penman-Monteith Method At Grid Scale, Sivarajah Mylevaganam, Chittaranjan Ray
Nebraska Water Center: Faculty Publications
The need to allocate the existing water in a sustainable manner, even with the projected population growth, has made to assess the consumptive use or evapotranspiration (ET), which determines the irrigation demand. As underscored in the literature, Penman-Monteith method which is a combination of aerodynamic and energy balance method is widely used and accepted as the method of estimation of ET. However, the application of Penman-Monteith relies on many climate parameters such as relative humidity, solar radiation, temperature, and wind speed. Therefore, there exists a need to determine the parameters that are most sensitive and correlated with dependent variable ( …
A Spatial Evapotranspiration Tool At Grid Scale, Sivarajah Mylevaganam, Chittaranjan Ray
A Spatial Evapotranspiration Tool At Grid Scale, Sivarajah Mylevaganam, Chittaranjan Ray
Nebraska Water Center: Faculty Publications
The drastic decline in groundwater table and many other detrimental effects in meeting irrigation demand, and the projected population growth have force to evaluate consumptive use or evapotranspiration (ET), the rate of liquid water transformation to vapor from open water, bare soil, and vegetation, which determines the irrigation demand. As underscored in the literature, Penman- Monteith method which is based on aerodynamic and energy balance method is widely used and accepted as the method of estimation of ET. However, the estimation of ET is oftentimes carried out using meteorological data from climate stations. Therefore, such estimation of ET may vary …
Long-Term Patterns Of Air Temperatures, Daily Temperature Range, Precipitation, Grass-Reference Evapotranspiration And Aridity Index In The Usa Great Plains: Part I. Spatial Trends, Meetpal S. Kukal, Suat Irmak
Long-Term Patterns Of Air Temperatures, Daily Temperature Range, Precipitation, Grass-Reference Evapotranspiration And Aridity Index In The Usa Great Plains: Part I. Spatial Trends, Meetpal S. Kukal, Suat Irmak
Department of Biological Systems Engineering: Papers and Publications
Due to their substantial spatio-temporal behavior, long-term quantification and analyses of important hydrological variables are essential for practical applications in water resources planning, evaluating the water use of agricultural crop production and quantifying crop evapotranspiration patterns and irrigation management vs. hydrologic balance relationships. Observed data at over 800 sites across the Great Plains of USA, comprising of 9 states and 2,307,410 km2 of surface area, which is about 30% of the terrestrial area of the USA, were used to quantify and map large-scale and long-term (1968-2013) spatial trends of air temperatures, daily temperature range (DTR), precipitation, grass-reference evapotranspiration (ET …
Evaluation Of A Hybrid Remote Sensing Evapotranspiration Model For Variable Rate Irrigation Management, J. Burdette Barker, Christopher M. U. Neale, Derek M. Heeren
Evaluation Of A Hybrid Remote Sensing Evapotranspiration Model For Variable Rate Irrigation Management, J. Burdette Barker, Christopher M. U. Neale, Derek M. Heeren
Department of Biological Systems Engineering: Papers and Publications
Accurate generation of spatial irrigation prescriptions is essential for implementation and evaluation of variable rate irrigation (VRI) technology. A hybrid remote sensing evapotranspiration (ET) model was evaluated for use in developing irrigation prescriptions for a VRI center pivot. The model is a combination of a two-source energy balance model and a reflectance based crop coefficient water balance model. Spatial ET and soil water depletion were modeled for a 10 km2 area consisting of rainfed and irrigated maize fields in eastern Nebraska for 2013. Multispectral images from Landsat 8 Operational Land Imager and Thermal Infrared Sensor were used as model …
Vulnerability Of Crops And Native Grasses To Summer Drying In The U.S. Southern Great Plains, Naama Raz-Yaseef, Dave P. Billesbach, Marc L. Fischer, Sebastien C. Biraud, Stacey A. Gunter, James A. Bradford, Margaret S. Torn
Vulnerability Of Crops And Native Grasses To Summer Drying In The U.S. Southern Great Plains, Naama Raz-Yaseef, Dave P. Billesbach, Marc L. Fischer, Sebastien C. Biraud, Stacey A. Gunter, James A. Bradford, Margaret S. Torn
Department of Biological Systems Engineering: Papers and Publications
The Southern Great Plains are characterized by a fine-scale mixture of different land-cover types, predominantly winter-wheat and grazed pasture, with relatively small areas of other crops, native prairie, and switchgrass. Recent droughts and predictions of increased drought in the Southern Great Plains, especially during the summer months, raise concern for these ecosystems. We measured ecosystem carbon and water fluxes with eddy-covariance systems over cultivated cropland for 10 years, and over lightly grazed prairie and new switchgrass fields for 2 years each. Growing-season precipitation showed the strongest control over net carbon uptake for all ecosystems, but with a variable effect: grasses …
Surface Energy Balance, Evapotranspiration, And Surface Coefficients During Non-Growing Season In A Maize-Soybean Cropping System, Lameck O. Odhiambo, Suat Irmak
Surface Energy Balance, Evapotranspiration, And Surface Coefficients During Non-Growing Season In A Maize-Soybean Cropping System, Lameck O. Odhiambo, Suat Irmak
Department of Biological Systems Engineering: Papers and Publications
Surface energy balance components, including actual evapotranspiration (ET), were measured in a reducedtill maize-soybean field in south central Nebraska during three consecutive non-growing seasons (2006/2007, 2007/2008, and 2008/2009). The relative fractions of the energy balance components were compared across the non-growing seasons, and surface coefficients (Kc) were determined as a ratio of measured ET to estimated alfalfa (ETr) and grass (ETo) reference ET (ETref). The non-growing season following a maize crop had 25% to 35% more field surface covered with crop residue as compared to the non-growing seasons following soybean crops. Net …
Soybean Yield, Evapotranspiration, Water Productivity, And Soil Water Extraction Response To Subsurface Drip Irrigation And Fertigation, Suat Irmak, James E. Specht, Lameck O. Odhiambo, J. M. Rees, K. G. Cassman
Soybean Yield, Evapotranspiration, Water Productivity, And Soil Water Extraction Response To Subsurface Drip Irrigation And Fertigation, Suat Irmak, James E. Specht, Lameck O. Odhiambo, J. M. Rees, K. G. Cassman
Department of Biological Systems Engineering: Papers and Publications
Soybean [Glycine max (L.) Merr.] yield, irrigation water use efficiency (IWUE), crop water use efficiency (CWUE), evapotranspiration water use efficiency (ETWUE), and soil water extraction response to eleven treatments of full, limited, or delayed irrigation versus a rainfed control were investigated using a subsurface drip irrigation (SDI) system at a research site in south-central Nebraska. The SDI system laterals were 0.40 m deep in every other row middle of 0.76 m spaced plant rows. Actual evapotranspiration (ETa) was quantified in all treatments and used to schedule irrigation events on a 100% ETa replacement basis in all but …
Maize Evapotranspiration, Yield Production Functions, Biomass, Grain Yield, Harvest Index, And Yield Response Factors Under Full And Limited Irrigation, Koffi Djaman, Suat Irmak, William R. Rathje, Derrel L. Martin, Dean E. Eisenhauer
Maize Evapotranspiration, Yield Production Functions, Biomass, Grain Yield, Harvest Index, And Yield Response Factors Under Full And Limited Irrigation, Koffi Djaman, Suat Irmak, William R. Rathje, Derrel L. Martin, Dean E. Eisenhauer
Department of Biological Systems Engineering: Papers and Publications
South-central Nebraska is one of the most extensively irrigated areas in the U.S., with over 65,000 active irrigation wells, and maize is the major agronomical crop produced. Maize production in this region requires supplementary irrigation for maximum productivity. Effective on-farm implementation of full and limited irrigation practices for potential improvements of crop productivity requires knowledge of locally developed crop yield response to water functions. In this study, the effects of full and limited irrigation practices on maize (Zea mays L.) plant height, leaf area index (LAI), grain yield and biomass production, actual crop evapotranspiration (ETa), yield production functions, …