Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
University of Nebraska - Lincoln
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
- Keyword
-
- Endangered species (2)
- Prescribed fire (2)
- Remote sensing (2)
- Atrazine (1)
- Cattle (1)
-
- Decomposition (1)
- Dung (1)
- Economics of farmland (1)
- Ecosystem services (1)
- Farmland loss (1)
- GEOBIA (1)
- Grassland (1)
- Grazing (1)
- Image classification (1)
- Invasive species (1)
- Land cover (1)
- Land management (1)
- Legal farmland protection (1)
- Maize (1)
- Management practices (1)
- Nicrophorus americanus (1)
- Nitrogen (1)
- Nitrogen balance (1)
- Nutrient cycling (1)
- Producer data (1)
- Regime shifts (1)
- Subwatershed (1)
- Surface runoff (1)
- UAV (1)
- Urban sprawl (1)
Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison Ludwig
American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison Ludwig
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …
Impact Of Agricultural Land Use On Stream Nitrate, Phosphorus, And Sediment Concentrations At The Watershed And Field Scale, Brittany A. Kirsch
Impact Of Agricultural Land Use On Stream Nitrate, Phosphorus, And Sediment Concentrations At The Watershed And Field Scale, Brittany A. Kirsch
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Water quality is directly impacted by the landscape through which it travels. As such, land use, including summer annual and winter annual/perennial agriculture, has dramatic influence on the water quality of downstream aquatic and terrestrial ecosystems. I examined the impact of agricultural land use on water quality through two projects, one at a watershed scale and one at a field scale. In my first project, I investigated the impact of agricultural land use and climate on water quality in 13 HUC10 watersheds across Nebraska using public data from US Geological Survey (USGS), US Department of Agriculture National Agricultural Statistics Service …
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.
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 …
Benchmarking On-Farm Maize Nitrogen Balance In The Western U.S. Corn Belt, Fatima Amor Tenorio
Benchmarking On-Farm Maize Nitrogen Balance In The Western U.S. Corn Belt, Fatima Amor Tenorio
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
A nitrogen (N) balance, calculated as the difference between N inputs and grain-N removal, provides an estimate of the potential N losses. We used N balance with other N-related metrics (partial factor productivity for N inputs, and yield-scaled N balance), to benchmark maize yields in relation with N input use in the US Corn Belt. We first used experimental data on grain-N concentration (GNC) to assess variation in this parameter due to biophysical and management factors. Subsequently, we used N balance and N-related metrics to benchmark yields in relation with N inputs in irrigated and rainfed fields in Nebraska using …
A Web Based Real Time Nitrogen Leaching Calculator, Saeideh Samani, Babak Samani, Haishun Yang
A Web Based Real Time Nitrogen Leaching Calculator, Saeideh Samani, Babak Samani, Haishun Yang
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
While nitrogen (N) is an essential nutrient for corn, its leaching to ground water is an serious environmental issue and a hazard to public health. N leaching is closely linked to weather factors, especially rainfall. Prediction of N leaching in cropping systems is critical to improvement of crop management and reduction of N leaching. The objective of this project is to develop a web app that predicts in real-time mode N leaching across Nebraska using real-time weather data.
We are in the processing of developing the web app and expect a prototype to be running in 2017 cropping season. Field …
Multifunctional Rural Landscapes: Economic, Environmental, Policy, And Social Impacts Of Land Use Changes In Nebraska, Twyla M. Hansen, Charles A. Francis, J. Dixon Esseks, J. Allen Williams Jr.
Multifunctional Rural Landscapes: Economic, Environmental, Policy, And Social Impacts Of Land Use Changes In Nebraska, Twyla M. Hansen, Charles A. Francis, J. Dixon Esseks, J. Allen Williams Jr.
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
The conversion of farmland near cities to other human uses is a global trend that challenges our long-term capacity to provide food, fiber, and ecosystem services to a growing world population. If current trends continue in the United States, the population will reach 450 million by the year 2050. At the same time, an accelerating change in land use will reduce today’s two acres per person of farmland to less than one acre per person. This is scarcely enough to produce food for our domestic population, without any food available for export – even assuming advances in technology. We need …
Atrazine Runoff In The Blue River Basin: Geomorphology, Rainfall, And Agronomic Practices, Kundan Dhakal
Atrazine Runoff In The Blue River Basin: Geomorphology, Rainfall, And Agronomic Practices, Kundan Dhakal
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Atrazine concentrations in the Big Blue River Basin (BRB) in Nebraska and Kansas periodically exceed the U.S. EPA Maximum Contaminant Level (MCL) of 3 µg L-1. The present study is focused on watershed variables influencing surface runoff of atrazine. The assessment includes the impact of corn and sorghum planting progress (indicating atrazine application), rainfall, antecedent soil water content, and soil restrictive layer on stream-measured weekly atrazine load in independent BRB subwatersheds for 1997 - 2004. Maximum atrazine loading occurred after most of the corn had been planted but during sorghum planting from mid-May to early June, immediately following …