Physical Sciences and Mathematics Commons^™

Will Saf Turbocharge The Corn Ethanol Market?, Richard Perrin, Lilyan Fulginiti, Felipe Miranda De Souza Almeida

Cornhusker Economics

The long-run outlook for the corn ethanol industry is questionable, due to a transition to electric and hybrid vehicles. One source of hope for the long run is the potential demand for producing Sustainable Aviation Fuel (SAF). SAF is a key component in the United States Aviation Climate Action Plan, a path to net-zero greenhouse gas (GHG) emissions in the aviation industry by 2050. Demand for ethanol for SAF offers hope to the ethanol industry, but it depends a great deal on policy decisions that are being made now. Here we sketch out this story.

Based on the information available …

Field Research Report: Results From The Enreec Vri Field For The 2021, 2022, And 2023 Crop Seasons, Derek M. Heeren, Ali T. Mohammed, Eric Wilkening, Christopher M. U. Neale, Alan L. Boldt, Ankit Chandra, Precious Nneka Amori, Ivo Z. Goncalves, Yeyin Shi, Guillermo R. Balboa

Department of Biological Systems Engineering: Conference Presentations and White Papers

Long-term irrigation management research has been conducted from 2014 to 2023 for corn and soybean at the Eastern Nebraska Research, Extension, and Education Center (ENREEC) Variable Rate Irrigation (VRI) Field located in subhumid east-central Nebraska (in the Lower Platte North Natural Resources District). The objective of this report was to present the overall results from the VRI Field for 2021 to 2023. Across the three growing seasons, there were the following irrigation treatments: Best Management Practice (BMP), 50% BMP, 125% BMP, rainfed, Spatial ET Modeling Interface (SETMI), SDD1, SDD2, machine-learning-based Cyber-Physical System (CPS), a student team recommended rate, and industry …

Perennializing Marginal Croplands: Going Back To The Future To Mitigate Climate Change With Resilient Biobased Feedstocks, Salvador Ramirez Ii, Marty R. Schmer, Virginia L. Jin, Robert B. Mitchell, Catherine E. Stewart, Jay Parsons, Daren D. Redfearn, John J. Quinn, Gary E. Varvel, Kenneth P. Vogel, Ronald F. Follett

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Managing annual row crops on marginally productive croplands can be environmentally unsustainable and result in variable economic returns. Incorporating perennial bioenergy feedstocks into marginally productive cropland can engender ecosystem services and enhance climate resiliency while also diversifying farm incomes. We use one of the oldest bioenergy-specific field experiments in North America to evaluate economically and environmentally sustainable management practices for growing perennial grasses on marginal cropland. This long-term field trial called 9804 was established in 1998 in eastern Nebraska and compared the productivity and sustainability of corn (Zea mays L.)—both corn grain and corn stover—and switchgrass (Panicum virgatum …

Assessing The Morphological And Physiological Traits Of Smooth Brome Pastures Under Long Term Grazing And Nutrient Enrichment In Eastern Nebraska, Hassan Shehab

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

Climate change together with the increase in demands for food, feed, fuel, and fiber are becoming a threat to sustainability and resilience of agriculture and pasture lands. Bromus inermis (smooth bromegrass) dominates pastures for cattle grazing in Eastern Nebraska, US, where it is planted in monocultures, and is considered high quality forage because of its palatability and high nutritional value for cattle, especially under intensive management practices. Sustainable management of these pastures is key to long-term resilience. This study aims to assess the performance of smooth bromegrass pastures to the combined effects of long-term management practices (since 2005) of fertilization …

Human Dimensions Of Woody Encroachment Management In Nebraska, Emily Rowen

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

Woody plant encroachment (WPE) is a social-ecological problem that will challenge conservation professionals and agricultural producers to adapt their management strategies. This research first examined WPE from the perspective of individual conservation professionals through an online survey. Conservation professionals’ attitudes about adaptation to vegetation transitions, such as WPE, were of interest because these attitudes are one measure of how prepared this group is to respond to WPE. Hypothesized predictors of adaptation attitude were tested through linear regression modeling. These predictors included ecological change, observation of WPE, or risk perception. It was found that risk perception was the strongest predictor of …

Game-Theoretic Approaches To Optimal Resource Allocation And Defense Strategies In Herbaceous Plants, Molly R. Creagar

Department of Mathematics: Dissertations, Theses, and Student Research

Empirical evidence suggests that the attractiveness of a plant to herbivores can be affected by the investment in defense by neighboring plants, as well as investment in defense by the focal plant. Thus, allocation to defense may not only be influenced by the frequency and intensity of herbivory but also by defense strategies employed by other plants in the environment. We incorporate a neighborhood defense effect by applying spatial evolutionary game theory to optimal resource allocation in plants where cooperators are plants investing in defense and defectors are plants that do not. We use a stochastic dynamic programming model, along …

Evaluation Of Native Plant Communities On Nebraska Game And Parks Commission State Parks, Robert F. Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This report evaluates the Native Plant Communities on Nebraska Game and Parks Commission State Parks East Region, also known as Region 3, which includes much of northeast and extreme eastern Nebraska, including portions of the lower Niobrara, Elkhorn and Platte Rivers and nearly the entire east border formed by the Missouri River. Fifteen state-listed threatened and endangered species have been recorded within the boundaries of Region 3 within the last twenty years. Several of these occupy habitats within major river channels.

Surveyed areas which contained habitat for legally protected species include Dead Timber State Recreation Area, Indian Cave State Park, …

Deficit Irrigation Management For Irrigated Corn In Nebraska: Economically Viable?, Lia Nogueira, Cory Walters, Emily O'Donnell, Wesley Peterson, Suat Irmak

Cornhusker Economics

In this study we determine the economic value of deficit irrigation management using both technological and methodological advancements. The use of soil moisture probes represents the technological improvement. We provide improvements in the methodology as follows. Regarding data, we employ a field-size study, instead of plots, where the irrigation decision is determined by the moisture level in the soil measured through a soil moisture probe. Regarding the understanding of the yield response to water, although we examine the commonly used quadratic function, we improve upon this specification by also examining an alternative response function, the linear response stochastic plateau. Our …

Carbon Farming: A Preliminary Economic Analysis Of Carbon Credits For No-Till And Cover Crops, Drew Havens, Richard K. Perrin, Lilyan E. Fulginiti

Cornhusker Economics

Summary Based on experimental data about the amount of carbon sequestered and estimated implementation costs, our preliminary results show that the average cost of sequestering carbon via no-till (about $22 per ton of CO₂e) appears to be much lower than the $51 per ton social value of sequestering that ton. In contrast, our preliminary results show that the average costs of sequestration via adoption of cover crops is much higher, about $60 per ton. Depending on how accurate soil carbon models are in predicting sequestration on individual fields to qualify them for enrollment, reimbursement costs for planting cover …

Assessing Functional Biodiversity For The Future Of Plants, Planet, And People, Ali Loker

Doctor of Plant Health Program: Dissertations and Student Research

Biodiversity plays a critical role in supporting life in global ecosystems and its links to ecosystem services and sustainability are recognized by scientific and non-scientific communities. Growing awareness of the importance of biodiversity is accelerated by discussions of its loss, and how to design interventions to conserve and mitigate a biodiversity crisis. Stakeholders are funding and implementing assessment strategies at various scales to help direct conservation efforts. There is also growing interest in measuring and communicating biodiversity outcomes.

Functional biodiversity characterizes the multiplicity of life forms into groups based on their diverse contributions to natural and agro-ecosystems. Assessing functional biodiversity …

Teaching Agroecology: Preparing Students For Navigating Uncharted Territory, Charles A. Francis, Steve Gliessman

Department of Agronomy and Horticulture: Faculty Publications

Agroecologists understand that farming and food systems are more complex than the aggregation of their components. This realization drives our choices of learning strategies and activities that will prepare students for complexity and uncertainty. Our quest for a just, sustainable, and nutritious food system adequate to equitably serve everyone on the planet today and into the future is an enormous challenge. An undertaking of this magnitude will be met only with major adjustments informed by thoughtful teaching and practicing problem solving skills through a new educational lens. The principles of agroecology help us focus this lens on the wicked problems …

The Impact Of Policy Design On Willingness To Pay For Ecosystem Services From Prairie Strips, Karina Schoengold, Badri Khanal, Taro Mieno, Lisa Schulte Moore

Cornhusker Economics

Ecosystem services from farmland conservation are public good benefits. The value of these benefits is primarily measured using methods that determine the willingness to pay (WTP) for those benefits. Prairie strips, a farmland conservation practice, provide ecosystem services such as improved water quality, soil health, and biodiversity (Schulte et al., 2017). The state of Iowa is a major corn producer and contributes significant amounts of nitrogen and phosphorous to the Gulf of Mexico (Alexander et al., 2008). The development of conventional agricultural systems has also resulted in a significant loss of biodiversity, including a dominant land cover of tallgrass prairie. …

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

USDA Forest Service / UNL Faculty Publications

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …

Review Of Spiders Of North America, By Sarah Rose, Michael L. Draney

The Prairie Naturalist

A field guide to spiders, the dominant terrestrial predator group, has long been a desire for North American naturalists, biologists, and spider fans, but not surprisingly, the first “real” field guide has been a long time coming. The diversity of spiders, with over 50,000 known species globally (World Spider Catalog 2022) and around 4,000 in North America north of Mexico (Rose 2022), is well beyond the diversity of more traditional field guide targets such as birds (about 1,000 species north of Mexico; American Birding Association 2022) or butterflies (about 725 species north of Mexico; North American Butterfly Association 2022). Also, …

Review Of The Duck Factory: A History Of Waterfowl In North Dakota, By Mike Jacobs And Erik Fritzell, Douglas Johnson

The Prairie Naturalist

It was by geological accident that North Dakota became the heart of duck production in the continental United States. When the Wisconsin glaciation retreated some 11,000 years ago, it left an uneven layer of glacial till over much of North Dakota and nearby states and provinces, an area termed the Prairie Pothole Region. Large blocks of ice in the glacial till eventually melted and formed depressions that became wetlands, or prairie potholes. These were embedded in a matrix of soil that, with millennia of growth by deep-rooted prairie plants, became rich topsoil. The wetlands, surrounded by luxuriant grassland, were ideal …

Second Twenty-Five Year Index: Volumes 26–50, 1994–2018, Jane E. Austin

The Prairie Naturalist

The first 50 years of the Prairie Naturalist reside on the shelves of libraries and personal collections. The articles and notes published over those years provide invaluable knowledge about Great Plains biota, communities, conservation, and landscape ecologies. Awareness of the wealth of information in those 50 print volumes has been limited, relying on references from other published papers or the limited number of articles that have been made available online by authors. This index serves as resource for individuals to digitally tap into the information published since 1994. This index, together with the first 25-year index, serves to complement the …

Regenerating Agroecosystems By Overcoming Human Exceptionalism In Designing For Increased Equity Of Benefits From Ecoservices, Ali Loker, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Our commentary explores three critical issues related to ecosystem services. First is how ecoservices are currently designed and implemented primarily for human benefit without concern for how these impact other species. We conclude that awareness of this imbalance is the first step toward meaningful change. Second we observe that human exceptionalism guides most decisions, and ask whether we can overcome this mind-set to embrace ecoregeneration and design of resilient and mutually beneficial agroecosystems. Our attitude toward the challenge and moving toward greater humility about human roles that guide management decisions in the ecosystem is a requisite for change. Third we …

Gaia Contributions To Agroecology By James Lovelock (1919-2022), Steve Gliessman, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

In writing about the history of agroecology we too often ignore the valuable contributions of British scientist James Lovelock who recently died on his 103rd birthday. A prolific inventor and influential theorist, Lovelock is best known for the Gaia hypothesis first proposed during his innovative work in the 1960s with the United States National Aeronautics and Space Administration. He suggested that ‘the biosphere has a regulatory effect on the Earth’s environment that acts to sustain life’ as written in Gaia: A New Look at Life on Earth (Lovelock 1979). Lovelock further proposed that humans have strongly impacted the planet’s capacity …

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 …

Review Of Methods For Ecological Research On Terrestrial Small Mammals, By Robert Mccleery, Lynda R. Lafond

The Prairie Naturalist

Small mammals are used in ecological studies throughout the world, yet the subject has lacked a clear reference that included upto- date methods pertaining to passive detection, molecular, and statistical approaches. In Methods for Ecological Research on Terrestrial Small Mammals, McCleery and his coauthors build on previous research references (Braun 2005, Sutherland 2006, Krebs 2014, Silvy 2020) and present methodologies specific to the study of small mammals that are applicable globally. Written as an asset for novice and experienced small mammal researchers alike, Methods for Ecological Research on Terrestrial Small Mammals is organized in a logical format, providing readers …

Review Of Loon Lessons: Uncommon Encounters With The Great Northern Diver, By James D. Paruk, Kristin Bianchini

The Prairie Naturalist

Gavia immer Brunnich (Common Loon) is a bird that has captivated bird watchers, wildlife enthusiasts, campers, cottagers, and others interested in the natural world for centuries. The loon also features prominently in Native American mythology. For many, the loon symbolizes the wildness of the north, and it is often used as a sentinel of lake health. Indeed, the Common Loon has inspired a wealth of literature, both scientific and popular, describing this species’ ecology, behavior, and fitness in the face of environmental changes. To this literature, Loon Lessons: Uncommon Encounters with the Great Northern Diver adds a complete and accurate …

Hyperseed: An End-To-End Method To Process Hyperspectral Images Of Seeds, Tian Gao, Anil Kumar Nalini Chandran, Puneet Paul, Harkamal Walia, Hongfeng Yu

School of Computing: Faculty Publications

High-throughput, nondestructive, and precise measurement of seeds is critical for the evaluation of seed quality and the improvement of agricultural productions. To this end, we have developed a novel end-to-end platform named HyperSeed to provide hyperspectral information for seeds. As a test case, the hyperspectral images of rice seeds are obtained from a high-performance line-scan image spectrograph covering the spectral range from 600 to 1700 nm. The acquired images are processed via a graphical user interface (GUI)-based open-source software for background removal and seed segmentation. The output is generated in the form of a hyperspectral cube and curve for each …

Comparing Machine Learning Techniques With State-Of-The-Art Parametric Prediction Models For Predicting Soybean Traits, Susweta Ray

Department of Statistics: Dissertations, Theses, and Student Work

Soybean is a significant source of protein and oil, and also widely used as animal feed. Thus, developing lines that are superior in terms of yield, protein and oil content is important to feed the ever-growing population. As opposed to the high-cost phenotyping, genotyping is both cost and time efficient for breeders while evaluating new lines in different environments (location-year combinations) can be costly. Several Genomic prediction (GP) methods have been developed to use the marker and environment data effectively to predict the yield or other relevant phenotypic traits of crops. Our study compares a conventional GP method (GBLUP), a …

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 …

The Prairie Naturalist, Vol. 52, Issue 2, December 2020

The Prairie Naturalist

Comparing Native Bee Communities on Reconstructed and Remnant Prairie in Missouri • Joseph LaRose, Elisabeth B. Webb, and Deborah Finke

Patterns and Potential Causes of Changing Winter Bird Distributions in South Dakota • David L. Swanson, Reza Goljani Amipkhiz, and Mark D. Dixon

Greater prairie-chickens and sharp-tailed grouse have similarly high nest survival in the Nebraska Sandhills • Larkin A. Powell, Walter H. Schacht, Julia P. Ewalt, and Katie R. McCollum

Captive Ring-necked Pheasant Response to Very High Experimental Doses of Lead • Travis J. Runia and Alex J. Solem

Trends in a Greater Prairie Chicken Population Established by Translocation …

Differences In Soil Water Changes And Canopy Temperature Under Varying Water × Nitrogen Sufficiency For Maize, Tsz Him Lo, Daran Rudnick, Kendall C. Dejonge, Geng Bai, Hope Njuki Nakabuye, Abia Katimbo, Yufeng Ge, Trenton E. Franz, Xin Qiao, Derek M. Heeren

West Central Research and Extension Center, North Platte

Crop nitrogen (N) status is known to affect crop water status and crop water use. To investigate further the N effects on soil water changes and on canopy temperature, three water levels × four N levels were imposed on two growing seasons of maize in west central Nebraska, USA. Soil water changes were measured using a neutron probe, whereas canopy temperature was measured using infrared thermometers on a ground-based mobile platform. At all water levels, soil water losses over monthlong intervals were generally greater as N levels increased. Given equal water levels, early afternoon canopy temperatures were usually lower with …

A Survey Of Dairy-Goat Keeping In Zanzibar, Tiffanie Stone, Charles A. Francis, L. O. Eik

Department of Agronomy and Horticulture: Faculty Publications

Dairy goats with improved genetics for milk production were recently introduced onto small-scale farms in Zanzibar through governmental and non-governmental projects. These projects were meant to support small-scale farmers by improving both income and household nutrition through milk production. No follow up had been conducted to understand what effects dairy goat keeping had on these small-scale farms, or how they could be improved. A survey of 193 dairy goat farmers in Zanzibar was conducted, including 30% and 60% of all dairy goat farmers on Unguja and Pemba, the two largest islands, respectively. The objective was to understand the impact keeping …

Optimal Allocation Of Two Resources In Annual Plants, David Mcmorris

Department of Mathematics: Dissertations, Theses, and Student Research

The fitness of an annual plant can be thought of as how much fruit is produced by the end of its growing season. Under the assumption that annual plants grow to maximize fitness, we can use techniques from optimal control theory to understand this process. We introduce two models for resource allocation in annual plants which extend classical work by Iwasa and Roughgarden to a case where both carbohydrates and mineral nutrients are allocated to shoots, roots, and fruits in annual plants. In each case, we use optimal control theory to determine the optimal resource allocation strategy for the plant …

Soil Chemical Properties After 12 Years Of Tillage And Crop Rotation, Maysoon M. Mikha, Gary Hergert, Xin Qiao, Bijesh Maharjan

Panhandle Research and Extension Center

Crop rotation in combinationwith tillage can improve productivity, enhance economical return, and reduce soil erosion. The objective of this study was to evaluate the impact of moldboard plow (MP), strip tillage (ST), no-tillage (NT), and crop rotations on: (1) crop yield; (2) soil chemical properties; and (3) particulate organic matter (POM). The study was initiated in 2007 at the University of Nebraska-Lincoln Panhandle Research and Extension Center near Scottsbluff, NE. Crops in rotation were corn (C; Zea mays L.) and dry bean (DB; Phaseolus vulgaris L.) organized in a 3-yr rotation (C–DB–C) and a 4-yr rotation with the addition of …

The Prairie Naturalist, Vol. 52, Issue 1, June 2020

The Prairie Naturalist

EDITOR’S NOTE • Jane E. Austin, Ph.D., Editor-in-Chief

Factors Associated with Larval Freshwater Drum Annual Peak Density in a Nebraska Irrigation Reservoir • Brett T. Miller, Brian C. Peterson, Keith D. Koupal, and Casey W. Schoenbeck

Small mammal communities in grasslands at the Grand Forks Air Force Base, North Dakota, USA • Lynda R. Lafond, Elizabeth H. Rave, and Kathryn A. Yurkonis

Evaluation of Four Larval Fish Sampling Methods in a Large Midwestern River • Nathan J. Lederman, Anthony R. Sindt, Douglas J. Dieterman, John D. Krenz, and Shannon J. Fisher

Wood Frogs (Rana sylvatica) in Southwestern Roberts …