Physical Sciences and Mathematics Commons^™

Pronghorn Survival And Resource Selection In Western Nebraska's Agriculturally Dominated Landscape, Katie Piecora

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska’s pronghorn population has been stable over the last decade, yet their presence on the landscape remains a contentious subject amongst private landowners. Conversion of grassland for crop production and increased anthropogenic activity has drastically altered pronghorn behavior throughout their current range, however basic ecology and resource use by pronghorn in Nebraska remains poorly understood. Establishing baseline population metrics and seasonal patterns of resource use for this population at the eastern periphery of the species range is critical to guide management actions. We deployed GPS collars on 110 adult pronghorn to quantify survival, mortality risk, and seasonal resource selection in …

The Last Drought Frontier: Building A Drought Index For The State Of Alaska, Olivia Campbell

School of Natural Resources: Dissertations, Theses, and Student Research

Drought is characterized by periods of below average precipitation. There are five major types of drought recognized in the literature: meteorological, hydrological, agricultural, socioeconomic, and ecological. A relatively new concept in the drought literature is “snow drought.” A key part of the definition of drought is that it is not always accompanied by extreme heat. This means drought can occur even in cold climates, cold seasons, and higher latitudes and altitudes, like Alaska. Drought is a natural part of climate variability, but Alaska’s climate is changing faster than any other state in the United States. Alaska is no stranger to …

Movements And Resource Selection Of Wild Pigs Associated With Growth Stages Of Corn, Bethany A. Friesenhahn, Randall W. Deyoung, Michael J. Cherry, Humberto L. Perotto-Baldivieso, Kurt C. Vercauteren, Nathan P. Snow

USDA Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are one of the most successful invasive species globally and are often implicated in agricultural damage. This damage is expected to increase as ranges of wild pigs expand, impacting the human food supply and increasing costs of food production. Our objective was to evaluate movement behaviors of wild pigs relative to resource availability and landscape features in an agriculture-dominated landscape, with a goal of informing management practices for reducing damage to corn. We monitored hourly movements of adult wild pigs relative to corn crops using GPS collars during the 2019 and 2020 growing seasons (Feb–Sept) in …

Resilience Theory And Coerced Resilience In Agriculture, S. M. Sundstrom, D. G. Angeler, C. R. Allen

School of Natural Resources: Documents and Reviews

No abstract provided.

Multi-Criteria Evaluation Model For Classifying Marginal Cropland In Nebraska Using Historical Crop Yield And Biophysical Characteristics, Andrew Laws

School of Natural Resources: Dissertations, Theses, and Student Research

Marginal cropland is suboptimal due to historically low and variable productivity and limiting biophysical characteristics. To support future agricultural management and policy decisions in Nebraska, U.S.A, it is important to understand where cropland is marginal for its two most economically important crops: corn (Zea mays) and soybean (Glycine max). As corn and soybean are frequently planted in a crop rotation, it is important to consider if there is a relationship with cropland marginality. Based on the current literature, there exists a need for a flexible yet robust methodology for identifying marginal land at different scales, which …

Irrigation’S Impact On A Precipitation Event During Grainex In Nebraska, Usa, Daniel Whitesel

School of Natural Resources: Dissertations, Theses, and Student Research

Numerous precipitation events were observed during the Great Plains Irrigation Experiment (GRAINEX). However, the precipitation event that was observed the morning of 23 July 2018 is the focus of this thesis. Six experiments were conducted which involved increasing or decreasing soil moisture by 5% increments over the irrigated cropland. An additional experiment, which changed the irrigated land use to grassland, showed precipitation increases. It was found that regardless of strength of irrigation, average precipitation decreased. Average precipitation decreased by up to 72% when irrigation increased compared to the control simulation and decreased by up to 85% when irrigation decreased compared …

Biochar: Properties And Potential Benefits For Agricultural Soil In Rwanda, Andromede Uwase

Honors Theses

Physical and chemical soil degradation is becoming a major challenge for agricultural productivity in Rwanda, which is the most important part of the country’s economy. The wide spreading soil degradation in Rwanda is mainly a result of naturally poor soils coupled with unsustainable soil management leading to, for example, accelerated soil erosion, acidification, nutrient loss, compaction, and to decreasing yields. Biochar, as an end product of pyrolysis of biomass in the absence of oxygen, has been proposed as a soil amendment in remediation strategies because of its positive effects on soil productivity relevant parameters such as soil pH, structure, nutrient …

Rodents In Agriculture: A Broad Perspective, Gary Witmer

USDA Wildlife Services: Staff Publications

The largest taxonomic group of mammals is rodents, with over 2200 species known around the world [1]. More recently, it was stated that over 2500 species exist [2]. Many species exist on all continents, with the exception of Antarctica. Rodents have adapted to all ecosystems of the world, including tundra, alpine, temperate forests, grasslands, arid regions, and aquatic systems. They provide many ecosystem functions, including soil aeration and mixing, seed and spore dispersal, vegetation succession, and being an important food source for predatory animals. Some species of rodents are even consumed by people in some parts of the world. Most …

Towards A More Comprehensive Understanding Of Wild Pig (Sus Scrofa) Impacts On Agricultural Producers: Insights From A Texas Case Study, Keith M. Carlisle, Nicole Didero, Sophie Mckee, Julie Elser, Stephanie A. Shwiff

USDA Wildlife Services: Staff Publications

This research investigates the impacts of invasive wild pigs (Sus scrofa Linneaus) on agricultural producers in Texas, with the aim of identifying and describing all categories of wild pig impacts and quantifying the extent of producers’ over- or underestimation of their total wild pig-related costs in 2018, as compared to calculations based upon data subsequently provided by the producers about individual wild pig-related costs and losses. Based on interviews with 23 producers in 16 Texas counties, we identified more than 20 discrete categories of negative impacts and negligible positive impacts associated with wild pigs. Among them were categories that have …

Recharge Assessment In The Context Of Expanding Agricultural Activity: Urucuia Aquifer System, Western State Of Bahia, Brazil, Glauco Z.S. Eger, Gerson C. Silva Junior, Eduardo A.G. Marques, Bernardo R.C. Leão, Diana G.T.B. Da Rocha, Troy E. Gilmore, Luís G.H. Do Amaral, Juremá A.O. Silva, Christopher Neale

Conservation and Survey Division

Groundwater recharge rate estimation is crucial to sustainable development of aquifers in intensely pumped regions, such as the Urucuia Aquifer System (UAS). A sedimentary aquifer in Western Bahia, Brazil, that underlies one of the major agricultural areas of the country where there has been major growth of irrigated areas. This study seeks to evaluate the recharge component of the water budget in the UAS area, based on three complementary techniques. The double-ring infiltrometer test was used to evaluate surface infiltration capacity, an important control on recharge. Water level data from wells (2011–2019 period, 19 wells) in the Brazilian Geological Survey’s …

Power-Over-Tether Unmanned Aerial System Leveraged For Trajectory Influenced Atmospheric Sensing, Daniel Rico

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

The use of unmanned aerial systems (UASs) in agriculture has risen in the past decade and is helping to modernize agriculture. UASs collect and elucidate data previously difficult to obtain and are used to help increase agricultural efficiency and production. Typical commercial off-the-shelf (COTS) UASs are limited by small payloads and short flight times. Such limits inhibit their ability to provide abundant data at multiple spatiotemporal scales. In this thesis, we describe the design and construction of the tethered aircraft unmanned system (TAUS), which is a novel power-over-tether UAS configured for long-term, high throughput atmospheric monitoring with an array of …

Impacts Of Irrigated Agriculture On The Near Surface And Planetary Boundary Layer Atmosphere: Results From The Great Plains Irrigation Experiment (Grainex), Emilee Lachenmeier

School of Natural Resources: Dissertations, Theses, and Student Research

Modification of natural prairie grasslands into irrigated and rainfed agriculture in the Great Plains produced significant impacts on regional weather and climate including temperatures, precipitation, energy fluxes, and the planetary boundary layer (PBL) atmosphere. The Great Plains Irrigation Experiment (GRAINEX) during the 2018 growing season collected data over irrigated and non-irrigated crop fields to further understand these impacts. The data were collected during two intensive observation periods (IOPs) in early June (IOP 1: 30 May – 13 June of 2018) and late July (IOP 2: 16 July – 30 July of 2018). The data analyzed include latent (LE) and sensible …

Nitrate Dynamics And Source Within Nested Watersheds Of An Agricultural Stream, Nebraska, Usa, Galen Richards

School of Natural Resources: Dissertations, Theses, and Student Research

Nitrate concentrations have been increasing throughout the globe, primarily due to heightened agricultural activity. Nitrate concentrations in Bazile Creek, located in Northeastern Nebraska, have been steadily rising since the early 2000s. Groundwater nitrate concentrations within the Bazile Creek watershed are high (> 10 mg/L nitrate-N), and there is strong connectivity between groundwater and surface water systems. This study aimed to better understand temporal nitrate concentration variability within the watershed through sampling tributaries and the main channel during baseflow conditions. Nitrate source was also investigated though the use of dual δ¹⁵N and δ¹⁸O nitrate isotopes, with samples …

Spatial And Temporal Patterns Of Bat Activity In A Southeast Nebraska Agricultural Landscape, Christopher Fill

School of Natural Resources: Dissertations, Theses, and Student Research

Intensive agriculture is associated with biodiversity loss and species decline. Yet wild species, such as bats, may provide critical ecosystem services to agriculture, even in transformed landscapes. In the United States, bats have been estimated to save the agricultural industry billions of dollars per year. However, white-nose syndrome and habitat loss have led to the decline of many bat species in North America, including the federally threatened northern long-eared bat, Myotis septentrionalis.

To better evaluate the effectiveness of these pest-controlling services, and to increase understanding of bat foraging behavior in these extreme landscapes, I deployed 11 grids of 24 detectors, …

Comprehensive And Agricultural Greenhouse Gas Emissions Inventories For Nebraska And The Midwest As Baselines For Climate Change Mitigation, Eric R. Holley

School of Natural Resources: Dissertations, Theses, and Student Research

Climate change is the paramount challenge of today for a sustainable future. Mitigation of greenhouse gas (GHG) emissions is necessary to reduce the associated risks and impacts on society. Using the EPA’s SIT and literature review, comprehensive GHG-emissions inventories were developed for the state of Nebraska over 25 years (1990-2015) and agricultural GHG emissions inventories were developed for the Midwest U.S for one year (2016). Nebraska’s net emissions increased from 56.2 million metric tons of carbon dioxide equivalent (MMtCO₂e) in 1990 to 87.4 MMtCO₂e in 2016. Agriculture was found to be the sector with the most …

Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray

Daugherty Water for Food Global Institute: Faculty Publications

This study combines empirical predictive and economics models to estimate the cost of remediation for domestic wells exceeding suggested treatment thresholds for nitrates. A multiple logistic regression model predicted the probability of well contamination by nitrate, and a life cycle costing methodology was used to estimate costs of nitrate contamination in groundwater in two areas of Nebraska. In south-central Nebraska, 37% of wells were estimated to be at risk of exceeding a threshold of 7.5 mg/L as N, and 17% were at risk of exceeding 10 mg/L as N, the legal limit for human consumption in the United States. In …

Assessing Agricultural Risk Management Using Historic Crop Insurance Loss Data Over The Ogallala Aquifer, Julian Reyes, Emile Elias, Erin M.K. Haacker, Amy Kremen, Lauren Parker, Caitlin Rottler

Department of Earth and Atmospheric Sciences: Faculty Publications

Much of the agricultural production in the Ogallala Aquifer region relies on groundwater for irrigation. In addition to declining water levels, weather and climate-driven events affect crop yields and revenues. Crop insurance serves as a risk management tool to mitigate these perils. Here, we seek to understand what long-term crop insurance loss data can tell us about agricultural risk management in the Ogallala. We assess patterns and trends in crop insurance loss data from the U.S. Department of Agriculture Risk Management Agency. Indemnities, or insurance payments, totaled $22 billion from 1989–2017 for the 161 counties that overlie the Ogallala Aquifer. …

Timing And Extent Of Crop Damage By Wild Pigs (Sus Scrofa Linnaeus) To Corn And Peanut Fields, C. M. Boyce, Kurt C. Vercauteren, James C. Beasley

USDA Wildlife Services: Staff Publications

The global expansion of wild pigs over the last few decades has resulted in an increase in extent and distribution of damages to crops, placing a growing strain on agricultural producers and land managers. Despite the extent of wild pig damage to agriculture, there is little data regarding timing and spatial variability of damage to corn (Zea mays Linnaeus) and we found no data regarding the effect of these factors on peanuts (Arachis hypogaea Linnaeus). Our objective was to determine the timing and extent of wild pig damage to corn and peanut fields, as well as the extent …

Movement Behavior Of Radio-Tagged European Starlings In Urban, Rural, And Exurban Landscapes, Page E. Klug, H. Jeffrey Homan

USDA Wildlife Services: Staff Publications

Since their intentional introduction into the United States in the 1800s, European starlings (Sturnus vulgaris) have become the fourth most common bird species and a nuisance bird pest in both urban and rural areas. Managers require better information about starling movement and habit-use patterns to effectively manage starling populations and the damage they cause. Thus, we revisited 6 radio-telemetry studies conducted during fall or winter between 2005 and 2010 to compare starling movements (n = 63 birds) and habitat use in 3 landscapes. Switching of roosting and foraging sites in habitat-sparse rural landscapes caused daytime (0900–1500 hours) …

Drought Impacts Assessment In Brazil - A Remote Sensing Approach, Denis Mariano

School of Natural Resources: Dissertations, Theses, and Student Research

Climate extremes are becoming more frequent in Brazil; studies project an increase in drought occurrences in many regions of the country. In the south, drought events lead to crop yield losses affecting the value chain and, therefore, the local economy. In the northeast, extended periods of drought lead to potential land degradation, affecting the livelihood and hindering local development. In the southern Amazon, an area that experienced intense land use change (LUC) in the last, the impacts are even more complex, ranging from crop yield loss and forest resilience loss, affecting ecosystem health and putting a threat on the native …

Seasonality Of Nitrogen Balances In A Mediterranean Climate Watershed, Oregon, Us, Jiajia Lin, Jana E. Compton, Scott G. Leibowitz, George Mueller-Warrant, William Matthews, Stephen H. Schoenholtz, Daniel M. Evans, Rob A. Coulombe

United States Environmental Protection Agency: Staff Publications

We constructed a seasonal nitrogen (N) budget for the year 2008 in the Calapooia River Watershed (CRW), an agriculturally dominated tributary of the Willamette River (Oregon, U.S.) under Mediterranean climate. Synthetic fertilizer application to agricultural land (dominated by grass seed crops) was the source of 90% of total N input to the CRW. Over 70% of the stream N export occurred during the wet winter, the primary time of fertilization and precipitation, and the lowest export occurred in the dry summer. Averaging across all 58 tributary subwatersheds, 19% of annual N inputs were exported by streams, and 41% by crop …

Quantitative Appraisal Of Non-Irrigated Cropland In South Dakota, Shelby Riggs

Honors Theses

This appraisal attempts to remove subjectivity from the appraisal process and replace it with quantitative analysis of known data to generate a fair market value of the subject property. Two methods of appraisal were used, the income approach and the comparable sales approach. For the income approach, I used the average cash rent for the region, the current property taxes for the subject property, and a capitalization rate based on Stokes' (2018) capitalization rate formula to arrive at my income-based valuation. For the comparable sales approach, I utilized Stokes' (2018) research in optimization modeling to estimate a market value for …

The Impact Of Land Use On Nitrate-N Movement And Storage In The Vadose Zone Of The Hastings’ Whpa, Craig Adams

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska has one of the largest agricultural economies in the United States and relies heavily on irrigation and fertilizer application to maintain crop yields. Over-irrigation and continuous application of nitrogen (N) in many areas has led to accumulation of nitrate-N in soils and sediments throughout the state’s vadose zone. Because nitrate-N is both persistent and mobile, groundwater concentrations in many areas of Nebraska and other agriculturally intensive states are increasing. Nitrate-N contamination of public and private drinking water supplies that utilize groundwater are of particular concern. Vadose zone sampling is an important method for rapidly assessing the effect of changing …

Provision Of Climate Services For Agriculture: Public And Private Pathways To Farm Decision-Making, Tonya Haigh, Vikram Koundinya, Chad Hart, Jenna Klink, Maria Lemos, Amber Saylor Mase, Linda Prokopy, Ajay Singh, Dennis Todey, Melissa Widhalm

School of Natural Resources: Faculty Publications

No abstract provided.

Factors Influencing Farmers Adoption Of Best Management Practices: A Review And Synthesis, Tingting Liu, Randall J.F. Bruins, Matthew T. Heberling

School of Natural Resources: Faculty Publications

No abstract provided.

A Framework For Tracing Social–Ecological Trajectories And Traps In Intensive Agricultural Landscapes, Daniel R. Uden, Craig R. Allen, Francisco Munoz-Arriola, Gengxin Ou, Nancy Shank

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Charting trajectories toward sustainable agricultural development is an important goal at the food–energy–water–ecosystem services (FEWES) nexus of agricultural landscapes. Social–ecological adaptation and transformation are two broad strategies for adjusting and resetting the trajectories of productive FEWES nexuses toward sustainable futures. In some cases, financial incentives, technological innovations, and/or subsidies associated with the short-term optimization of a small number of resources create and strengthen unsustainable feedbacks between social and ecological entities at the FEWES nexus. These feedbacks form the basis of rigidity traps, which impede adaptation and transformation by locking FEWES nexuses into unsustainable trajectories characterized by control, stability, and efficiency, …

Avian Diversity, Abundance, And Nest Success Among Managed Prairies And Agricultural Plots In Oklahoma And Texas, Phillip J. Leonard, Douglas R. Wood, Wayne E. Meyer

The Prairie Naturalist

Over the last 50 years, grassland birds experienced rapid declines due to habitat loss and degradation as a result of agricultural practices. Our objective was to document the diversity, abundance, and nest success of bird communities using managed prairie and agricultural plots at the Tishomingo National Wildlife Refuge (NWR) in southern Oklahoma and Hagerman NWR in northern Texas. From April 1 to July 15, 2013–2014, point count surveys, nest searches, nest monitoring, and vegetation sampling were conducted among three habitat treatments: managed prairie, unharvested wheat, and fallow agricultural plots. Species richness values for potential nesting species were higher in managed …

The Future Of Evapotranspiration: Global Requirements For Ecosystem Functioning, Carbon And Climate Feedbacks, Agricultural Management, And Water Resources, Joshua B. Fisher, Forrest S. Melton, Elizabeth M. Middleton, Christopher Hain, Martha C. Anderson, Richard G. Allen, Matthew Mccabe, Simon Hook, Dennis Baldocchi, Philip A. Townsend, Ayse Kilic, Kevin Tu, Diego Miralles, Johan Perret, Jean-Pierre Lagouarde, Duane Waliser, Adam J. Purdy, Andrew French, David Schimel, James S. Famiglietti, Graeme Stephens, Eric F. Wood

Department of Earth and Atmospheric Sciences: Faculty Publications

The fate of the terrestrial biosphere is highly uncertain given recent and projected changes in climate. This is especially acute for impacts associated with changes in drought frequency and intensity on the distribution and timing of water availability. The development of effective adaptation strategies for these emerging threats to food and water security are compromised by limitations in our understanding of how natural and managed ecosystems are responding to changing hydrological and climatological regimes. This information gap is exacerbated by insufficient monitoring capabilities from local to global scales. Here, we describe how evapotranspiration (ET) represents the key variable in linking …

Temporal Migration Shifts In The Aransas-Wood Buffalo Population Of Whooping Cranes (Grus Americana) Across North America, Joel G. Jorgensen, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Birds are altering the phenology of critical life history events, including migration, in response to the effects of global climate change. Whooping Cranes (Grus americana) are one of the most critically endangered birds in the world. Their remnant population, referred to as the Aransas-Wood Buffalo Population, numbers between 300-400 individuals and migrates between the U.S. Gulf of Mexico coast and north-central Canada twice each year. Previous analyses suggested Whooping Crane migration was temporally constant in spring and fall. New analyses of observations spanning 1942-2016 show Whooping Crane migration is now occurring earlier in spring by approximately 22 days …

Aquacrop-Os: An Open Source Version Of Fao’S Crop Water Productivity Model, T. Foster, N. Brozovic, A. P. Butler, C. M. U. Neale, D. Raes, P. Steduto, E. Fereres, T. C. Hsiao

Daugherty Water for Food Global Institute: Faculty Publications

Crop simulation models are valuable tools for quantifying crop yield response to water, and for devising strategies to improve agricultural water management. However, applicability of the majority of crop models is limited greatly by a failure to provide open-access to model source code. In this study, we present an open-source version of the FAO AquaCrop model, which simulates efficiently water-limited crop production across diverse environmental and agronomic conditions. Our model, called AquaCrop-OpenSource (AquaCrop-OS), can be run in multiple programming languages and operating systems. Support for parallel execution reduces significantly simulation times when applying the model in large geospatial frameworks, for …