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- Department of Agronomy and Horticulture: Faculty Publications (4)
- Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research (3)
- United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications (3)
- Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research (1)
- School of Natural Resources: Dissertations, Theses, and Student Research (1)
Articles 1 - 12 of 12
Full-Text Articles in Life Sciences
Characterization Of Physical And Biochemical Traits In Wheat And Corn Plants Using High Throughput Image Analysis, Kantilata Thapa
Characterization Of Physical And Biochemical Traits In Wheat And Corn Plants Using High Throughput Image Analysis, Kantilata Thapa
Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research
Plant phenotyping has been recognized as a rapidly growing field of research due to the labor-intensive, destructive, and time-consuming nature of traditional phenotyping methods. These phenotyping bottlenecks can be addressed by advancements in image-based phenotyping like RGB and hyperspectral imaging for the assessment of plant traits important for breeding purposes. This study aims (1) to characterize the physical and biochemical traits of wheat and corn plants using RGB and hyperspectral imaging in the greenhouse, and (2) to estimate leaf nitrogen (N), phosphorus (P), and potassium (K) content using hyperspectral imaging and an analytical spectral device (ASD spectrometer) and compare the …
Next-Generation Technologies Unlock New Possibilities To Track Rangeland Productivity And Quantify Multi-Scale Conservation Outcomes, Caleb P. Roberts, David E. Naugle, Brady W. Allred, Victoria M. Donovan, Dillon T. Fogarty, Matthew O. Jones, Jeremy D. Maestas, Andrew C. Olsen, Dirac L. Twidwell Jr
Next-Generation Technologies Unlock New Possibilities To Track Rangeland Productivity And Quantify Multi-Scale Conservation Outcomes, Caleb P. Roberts, David E. Naugle, Brady W. Allred, Victoria M. Donovan, Dillon T. Fogarty, Matthew O. Jones, Jeremy D. Maestas, Andrew C. Olsen, Dirac L. Twidwell Jr
Department of Agronomy and Horticulture: Faculty Publications
Historically, relying on plot-level inventories impeded our ability to quantify large-scale change in plant biomass, a key indicator of conservation practice outcomes in rangeland systems. Recent technological advances enable assessment at scales appropriate to inform management by providing spatially comprehensive estimates of productivity that are partitioned by plant functional group across all contiguous US rangelands. We partnered with the Sage Grouse and Lesser Prairie-Chicken Initiatives and the Nebraska Natural Legacy Project to demonstrate the ability of these new datasets to quantify multi-scale changes and heterogeneity in plant biomass following mechanical tree removal, prescribed fire, and prescribed grazing. In Oregon’s sagebrush …
Regional Plant Community Differences In The Nebraska Sandhills, Travis Millikan
Regional Plant Community Differences In The Nebraska Sandhills, Travis Millikan
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
The Nebraska Sandhills is very valuable to the state of Nebraska, representing one of the most in-tact and largest grassland ecosystems in temperate regions in the world. Rangeland managers must understand plant community dynamics across the Sandhills to better inform management decisions. The first objective of this study was to evaluate plant community variability on upland Sands ecological sites across different precipitation zones in the Nebraska Sandhills. The second objective of our study was to utilize the Rangeland Analysis Platform (RAP) to examine spatial and temporal variability in biomass production and cover on pastures of ranches analyzed in the first …
Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell
Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
This study is focused on the population of federally-endangered American burying beetles in south-central Nebraska. It is focused on changes in land cover over time and at several levels of spatial scale, and how management efforts are impacting both the beetle and a changing landscape. Our findings are applicable to a large portion of the Great Plains, which is undergoing the same shift from grassland to woodland, and to areas where the beetle is still found.
Improving On Modis Mcd64a1 Burned Area Estimates In Grassland Systems: A Case Study In Kansas Flint Hills Tall Grass Prairie, Rheinhardt Scholtz, Jayson Prentice, Yao Tang, Dirac Twidwell
Improving On Modis Mcd64a1 Burned Area Estimates In Grassland Systems: A Case Study In Kansas Flint Hills Tall Grass Prairie, Rheinhardt Scholtz, Jayson Prentice, Yao Tang, Dirac Twidwell
Department of Agronomy and Horticulture: Faculty Publications
Uncertainty in satellite-derived burned area estimates are especially high in grassland systems, which are some of the most frequently burned ecosystems in the world. In this study, we compare differences in predicted burned area estimates for a region with the highest fire activity in North America, the Flint Hills of Kansas, USA, using the moderate resolution imaging spectroradiometer (MODIS) MCD64A1 burned area product and a customization of the MODIS MCD64A1 product using a major ground-truthing effort by the Kansas Department of Health and Environment (KDHE-MODIS customization). Local-scale ground-truthing and the KDHE-MODIS product suggests MODIS burned area estimates under predicted fire …
Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate …
Wheat Height Estimation Using Lidar In Comparison To Ultrasonic Sensor And Uas, Wenan Yuan, Jiating Li, Madhav Bhatta, Yeyin Shi, P. Stephen Baenziger, Yufeng Ge
Wheat Height Estimation Using Lidar In Comparison To Ultrasonic Sensor And Uas, Wenan Yuan, Jiating Li, Madhav Bhatta, Yeyin Shi, P. Stephen Baenziger, Yufeng Ge
Department of Agronomy and Horticulture: Faculty Publications
As one of the key crop traits, plant height is traditionally evaluated manually, which can be slow, laborious and prone to error. Rapid development of remote and proximal sensing technologies in recent years allows plant height to be estimated in more objective and efficient fashions, while research regarding direct comparisons between different height measurement methods seems to be lagging. In this study, a ground-based multi-sensor phenotyping system equipped with ultrasonic sensors and light detection and ranging (LiDAR) was developed. Canopy heights of 100 wheat plots were estimated five times during a season by the ground phenotyping system and an unmanned …
Remote Estimation Of Nitrogen And Chlorophyll Contents In Maize At Leaf And Canopy Levels, Michael Schlemmer, Anatoly A. Gitelson, James S. Schepers, Richard B. Ferguson, Y. Peng, J. Shanahan, Donald Rundquist
Remote Estimation Of Nitrogen And Chlorophyll Contents In Maize At Leaf And Canopy Levels, Michael Schlemmer, Anatoly A. Gitelson, James S. Schepers, Richard B. Ferguson, Y. Peng, J. Shanahan, Donald Rundquist
Department of Agronomy and Horticulture: Faculty Publications
Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were determined using the red-edge chlorophyll index with R2 of 0.74 and 0.94, respectively. Results showed that at the canopy level, Chl and N contents can be accurately retrieved using green and red-edge Chl …
Chlorophyll-Based Approach For Remote Estimation Of Crop Gross Primary Production: From In Situ Measurements To Satellite Imagery, Yi Peng
School of Natural Resources: Dissertations, Theses, and Student Research
The synoptic and accurate quantification of crop gross primary production (GPP) is essential for studying carbon budgets in croplands and monitoring crop status. The objective of this dissertation is to develop a quantitative technique to estimate crop GPP using remotely sensed data collected from close range to satellite altitudes. In this study, a model based on a recently developed paradigm, which relates crop GPP to a product of total crop chlorophyll content and incident radiation affecting vegetation photosynthesis, was justified for the remote estimation of GPP in crops. The model was tested with ground-observed incoming photosynthetically active radiation (PARin …
Evapotranspiration Information Reporting: I. Factors Governing Measurement Accuracy, Richard G. Allen, Luis S. Pereira, Terry A. Howell, Marvin E. Jensen
Evapotranspiration Information Reporting: I. Factors Governing Measurement Accuracy, Richard G. Allen, Luis S. Pereira, Terry A. Howell, Marvin E. Jensen
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
More and more evapotranspiration models, evapotranspiration crop coefficients and associated measurements of evapotranspiration (ET) are being reported in the literature and used to develop, calibrate and test important ET process models. ET data are derived from a range of measurement systems including lysimeters, eddy covariance, Bowen ratio, water balance (gravimetric, neutron meter, other soil water sensing), sap flow, scintillometry and even satellite-based remote sensing and direct modeling. All of these measurement techniques require substantial experimental care and are prone to substantial biases in reported results. Reporting of data containing measurement biases causes substantial confusion and impedance to the advancement of …
Improving In-Season Nitrogen Recommendations For Maize Using An Active Sensor, J. Schmidt, D. Beegle, Q. Q. Zhu, R. Sripada
Improving In-Season Nitrogen Recommendations For Maize Using An Active Sensor, J. Schmidt, D. Beegle, Q. Q. Zhu, R. Sripada
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
An active crop canopy reflectance sensor could be used to increase N-use efficiency in maize (Zea mays L.), if temporal and spatial variability in soil N availability and plant demand are adequately accounted for with an in-season N application. Our objective was to evaluate the success of using an active canopy sensor for developing maize N recommendations. This study was conducted in 21 farmers’ fields from 2007 to 2009, representing the maize production regions of east central and southeastern Pennsylvania, USA. Four blocks at each site included seven sidedress N rates (0–280 kgNha−1) and one at-planting N …
Responsive In-Season Nitrogen Management For Cereals, J.F. Shanahan, N. R. Kitchen, W. R. Raun, James S. Schepers
Responsive In-Season Nitrogen Management For Cereals, J.F. Shanahan, N. R. Kitchen, W. R. Raun, James S. Schepers
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Current nitrogen (N) management strategies for worldwide cereal production systems are characterized by low N use efficiency (NUE), environmental contamination, and considerable ongoing debate regarding what can be done to improve N fertilizer management. Development of innovative strategies that improve NUE and minimize off-field losses is crucial to sustaining cereal-based farming. In this paper, we review the major managerial causes for low NUE, including (1) poor synchrony between fertilizer N and crop demand, (2) uniform field applications to spatially variable landscapes that commonly vary in crop N need, and (3) failure to account for temporally variable influences on crop N …