Agriculture Commons^™

Patch Mow Grazing: Investigating The Effects Of Mowing On Forage Nutritive Value, The Biomass–Nutritive Value Relationship, And Herbivore Selection, Trace R. Stauble

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Herbivore foraging behavior plays a critical role in shaping grassland structural heterogeneity, with selection often driven by forage biomass and nutritive value. Currently, it is thought that herbivores primarily select areas that are greater in nutritive value, and low in biomass. More specifically, disturbances like fire and grazing have been thoroughly studied showing that recently burned and grazed areas are not only higher in nutritive value but disproportionately selected by herbivores in comparison to undisturbed areas. However, most studies address only narrow ranges of defoliation, comparing intensely defoliated sites (< 10 cm) to those that are either not defoliated or have experienced a much longer time since defoliation, thereby decreasing grazing pressure as biomass increases. However, one of the most widely used methods of defoliation in grasslands, mowing, hasn’t been thoroughly studied for its effects on nutritive value, and how it impacts herbivore selection. Our study aimed to (1) evaluate how mowing treatments—i.e., short (5 cm), medium (18 cm), and tall (>30 cm, unmown)—affect nutritive value and herbivore selection, (2) assess …

Cover Crop Influence On Arthropod Biodiversity And Soil–Water Dynamics In A Semi-Arid Maize–Soybean Sequence Of The Nebraska High Plains, Carlos Eduardo De Oliveira Martins

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

With the expansion of cover crop (CC) use in semi-arid regions, producers in the Nebraska High Plains are increasingly interested in understanding how CCs influence both beneficial arthropods and soil-water within maize-soybean (Zea mays L., Glycine max [L.] Merr.) rotations. Integrating CCs in these systems can enhance soil water availability and beneficial insect activity, but potential trade-offs include higher early-season water use by CCs and the risk of increasing potential pest populations. This thesis addresses these questions through two complementary studies conducted under field conditions near Brule, Nebraska. The first study evaluated the effects of a multi-species CC mixture …

Post-Fire Soil Health Assessment Of The Grasslands And Woodlands In The Semi-Arid Nebraska Sandhills, Stephanie M. Lugo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands in the Nebraska Sandhills are shaped by natural wildfires, which help maintain the structure and function of native grasslands. In recent decades, afforestation with ponderosa pine and eastern redcedar has introduced new woodlands that altered the region’s fire dynamics and raised important questions about the effects of wildfire on different vegetation types. As wildfires become more frequent, understanding their impacts on soil health in grasslands and woodlands becomes increasingly important. This study examines the short-term effects of the 2022 Bovee Fire on physical, chemical, and biological soil properties in native grasslands and ponderosa pine and eastern redcedar afforested woodlands. …

Characterizing The Relationship Between Parturition In Beef Cattle And The Lunar Phase And Meteorological Factors., Caroline E. Chambers

Honors College Theses

For beef cattle, parturition is one of the most critical stages in the reproductive process. It is crucial that farmers understand the factors that may influence the timing of parturition. There is a persistent preconception that the onset of parturition is influenced by the lunar phase and weather factors. The objective of this study is to characterize the association between parturition in beef cattle, the lunar phase, and/or different weather factors such as barometric pressure and temperature. Cattle records were obtained from Chambers Family Farm in Cumberland Furnace, TN. Data was collected from 142 calvings from January 2017 to October …

Hyperspectral Indicators And Characterization Of Glyphosate-Induced Stress In Common Lambsquarters (Chenopodium Album L.), Mario Andrés Soto Valencia

Graduate Theses and Dissertations

Hyperspectral sensing enables detection of herbicide stress in weeds, but practical use requires strategies for redundancy control, rating variability management, and evaluator bias mitigation. This thesis evaluates common lambsquarters (Chenopodium album) under glyphosate exposure, aiming to identify key wavelengths, construct vegetation indices, and improve injury modeling. Greenhouse experiments used dimensionality reduction methods (principal component analysis, Relief F, Bayesian discriminant analysis) to isolate 34 unique wavelengths from about 3,200 bands. Calibration data were collected 14 days after treatment (DAT) to support wavelength selection and model development, while data from 27 DAT were used for independent validation. Class comparisons across six statistically …

Bedstraw Eradication Program 2024-25: Annual Report To Grain Growers, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity published reports

The Bedstraw Eradication Program operates under the Biosecurity and Agricultural Management Industry Funding Scheme (Grains) Regulations 2010.

Approved Plans developed annually for each infested property in consultation with the Grains, Seeds and Hay Industry Management Committee (GSHIMC), the Department of Primary Industries and Regional Development (DPIRD) and the landholders detail management actions, estimated costs and timeframes of agreed actions.

Skeleton Weed Program 2024-25: Annual Report To Grain Growers, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity published reports

Skeleton weed is a major pest of grain crops and can significantly reduce grain crop yields by competing for moisture and nutrients (mainly nitrogen), due to its deep perennial root system.

Skeleton weed is a declared plant in WA under section 22 of the Biosecurity and Agriculture Management Act (2007) and is assigned to control category 2 (Eradication) for the whole of the State, except in the Narembeen and Yilgarn Shires, where it is category 3 (Management).

Modelling indicates that under a nil management scenario, the cost to WA broadacre agriculture will be approximately $19.2 million per year after twenty …

Leptinotarsa Texana Schaeffer And Gargaphia Arizonica Drake & Carvalho As Potential Biocontrol Agents For The Noxious Weed Solanum Elaeagnifolium Cav, Samikshya Subedi, Stephanie L. Kasper, Alexis Racelis, Greg Lefoe, Rupesh R. Kariyat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Silverleaf nightshade (Solanum elaeagnifolium Cav.; SLN) is a perennial forb native to the southern United States, Mexico and South America that has become a serious agricultural weed across the world. Biological control has emerged as a significant alternative for the management of (SLN) due to the challenges and high costs associated with chemical and mechanical controls. In this study, we used a combination of field and laboratory studies to (1) explore the fundamental and realized host ranges of two North American insects, Leptinotarsa texana Schaeffer and Gargaphia arizonica Drake & Carvalho and (2) assess their suitability as potential biological …

Nutrient Utilization Efficiency And Antioxidant Profile Of Bc2 Abaca (Musa Textilis Née) Hybrids, Roberto Barba Jr, Antonio Lalusin

The Philippine Agricultural Scientist

Abaca (Musa textilis Née) is an important fiber crop widely recognized for its superior tensile strength, yet its productivity remains constrained by nutrient inefficiency, poor cropping management, and climatic stresses under manual production systems. Efficient nutrient utilization and an understanding of antioxidant compositions are practically relevant to the productivity of the abaca fiber crop. However, despite the crop’s economic importance, limited studies have examined nutrient uptake dynamics and internal utilization efficiency related to fiber synthesis. This study aimed to demonstrate the nutrient utilization efficiency and antioxidant profiles of BC₂ abaca hybrids in relation to fiber yield and quality. Fiber …

Evaluating Metamitron Efficacy For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) Management In Sugarbeet Across The Central High Plains, Abraham Akuoko

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Herbicide-resistant (HR) Palmer amaranth (Amaranthus palmeri S. Watson) is regarded as one of the most prominent weeds within sugarbeet fields across the Central High Plains, with limited chemical control options. Although a few herbicides are available, their use is restrictive due to crop injury concerns and can only be applied at or after the 2–4 true leaf (TL) growth stage, which will provide no control for already emerged weeds. However, Palmer amaranth often emerges between sugarbeet planting and the 2 TL sugarbeet growth stage. Consequently, as of 2023, there were no herbicide options to control Palmer amaranth in sugarbeet …

Fragmentation In The U. S. Fed Cattle Market: Implications For Price Transparency And Discovery, Taralee M. Hudson

Department of Agricultural Economics: Dissertations, Theses, and Student Research

The U.S. fed cattle market is one plagued by recurring stakeholder concern. Market participants frequently raise questions about the transparency of fundamental information under existing reporting frameworks, and the extent to which Private Negotiation, the dominant trading institution, effectively facilitates price discovery. Although extensive research has sought to address these issues, much of it has failed to account for the market’s increasingly fragmented structure. This thesis is comprised of three chapters that collectively examine price transparency and discovery through the lens of market fragmentation. Each chapter presents research related to the fed cattle market and is intended to stand …

The Economics Of Us Row Crop Production With Large-Scale Autonomous Machines, Joshua Strine, Chad Fiechter, James Lowenberg-Deboer

Department of Agricultural Economics Faculty Publications

Labor challenges are underpinning large multinational farm machine manufacturers' development of autonomy solutions for their large-scale machine offerings. This study simulates a linear optimization model to examine the economics of large-scale autonomous machines for a rotational maize and soybean farm in the Midwest US. Results support the hypothesis that autonomous machines can be economically viable for farms facing severe labor shortages. However, under current technology and pricing structures, conventional mechanization remains the most profitable option for farms with reliable labor. Critical factors shaping the competitiveness of autonomy include subscription fees, field efficiency, and human supervision requirements. As these factors evolve, …

Farm Efficiency And Precision Agriculture Technology, Chad Fiechter, Brady Brewer, Jennifer Ifft, Michael Boehlje

Department of Agricultural Economics Faculty Publications

Precision agriculture technology (PAT) is often viewed as a potential driver of future efficiency gains in farming. Using within-farm variation from an unbalanced panel of Kansas farms, this study examines the impact of PAT bundles on efficiency in generating gross revenue. On average, we find little evidence that these technologies improve efficiency. However, among less efficient farms, several bundles are linked to notable efficiency gains, underscoring the importance of accounting for farm heterogeneity.

Two Essays On Agricultural Trade Policy And Total Factor Productivity, Hanifi Otgun

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation consists of two essays: the first examines the welfare and trade implications of the 2016–2017 drought in Brazil and the subsequent temporary import ban on Robusta coffee; the second examines how trade openness influences agricultural total factor productivity across 26 NUTS-2 regions in Türkiye from 2013 to 2020.

The first essay focuses on Brazil, a major Robusta coffee producer and exporter that faced a significant drought in 2016–17, reducing Robusta output. In response, the government initially allowed one million 60-kg bags of Robusta coffee to be imported. An import ban was imposed shortly afterward due to lobbying by …

Assessing Crop Rotation Productivity, Soil Health, And Fertility, And Economic Performance, To Enhance Semi-Arid High Plains Cropping Systems Sustainability, Ezequiel Maria Villamil

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Sustainable crop production in the semi-arid High Plains of Nebraska faces challenges from limited precipitation, high interannual variability, and economic risk. This dissertation investigates the long-term productivity, water use, soil health, and economic sustainability of dryland crop rotations, with emphasis on the role of pulses as alternatives to fallow.

Chapter 1 analyzes nearly three decades (1995–2023) of on-farm data from the High Plains Agricultural Laboratory (Sidney, Nebraska) to compare seven crop rotations, including wheat, corn, millet, sunflower, and field peas. Results showed that wheat–corn–fallow (W–C–F) consistently outperformed traditional wheat–fallow (W–F) and more intensified four-year rotations, providing the highest grain yields, …

Serum Concentrations Of Inflammatory Markers And Selected Nutrient Metabolites In Holstein And Jersey Cows Across The Transition Period, Avery Orr

Master's Theses

The transition period, spanning the weeks surrounding parturition, requires dairy cows to undergo synchronized metabolic, endocrine, and immunological adjustments that support the onset of lactation but also heighten disease susceptibility. Although individual inflammatory or metabolic biomarkers have been extensively studied, the integrated immunometabolic dynamics that occur across this period and the difference between breeds is not fully understood. The objective of this study was to characterize longitudinal patterns in key nutrient metabolites and inflammatory markers in Holstein and Jersey cows and assess how these systems interact across the transition period.

A total of 63 Holstein and Jersey cows were sampled …

Characterizing The Germination Process And Establishing Best Practices For Seed Propagation Of Tamaulipan Thornscrub Species For Habitat Restoration, Saroj Dhakal

Theses and Dissertations

Tamaulipan thornscrub is an imperiled plant community of southern Texas and northeastern Mexico. Given its importance for biodiversity conservation, stakeholders have been involved in restoration programs using seedlings grown from wild seeds. However, stakeholders often report that insufficient seedling supply is a challenge. To address knowledge gaps in seed germination behavior limiting seedling production, this study was conducted on 18 Tamaulipan thornscrub species, identified by growers as difficult to germinate. Seeds of all studied species are orthodox except Amyris texana, which have recalcitrant properties. Nine species have physical dormancy that was successfully addressed with mechanical and/or chemical scarification. Other species …

Collective Agency And Community Resilience Among Farmworkers In The Lower Rio Grande Valley, Angel Velazquez

Theses and Dissertations

This research assesses how farmworkers in the Lower Rio Grande Valley of Texas use everyday practices to build resilience and adapt to changes in their lives. I apply two interconnected theories, White’s (2017, 2019) framework of collective agency and community resilience and Castro and Sen’s (2022) framework of everyday adaptation actions, to study these practices. I conducted 19 semi-structured interviews with Latino farmworkers and professionals who work with local farmworker organizations in the Rio Grande Valley (RGV) of Texas. Interview transcripts were analyzed to determine if and how Latino farmworkers in the RGV can work towards community resilience and implement …

Determination Of An Effective Natural Boxelder Bug (Boisea Trivittata) Repellent, Reyna Chavez

Theses and Dissertations

This study investigates the use of ecofriendly repellant alternatives to pest management to control boxelder bugs (Boisea trivittata). This bug gathers by the thousands on warm surfaces of exterior suburban homes during early fall and late spring. I determined bug repellency to turmeric oil (Curcuma longa), catnip (Nepeta cataria), citronella (Cymbopogon nardus), and lavender (Lavandula angustifolia). The treatments consisted of essential oils containing 20% methanol. All treatments demonstrated repellency of Boxelder bugs. Citronella was the most effective and had the highest level of repellency range of 90-99%. Catnip was the least effective with a repellency range of 63-82%.

Citrullus Amarus Drought Tolerance: An Above And Below Ground Analysis, Ben A. Hyland

All Theses

Ever rising environmental temperatures threaten global food security by worsening severity and increasing the occurrence of drought. Commercially cultivated watermelon (Citrullus lanatus), have reduced drought tolerance due to a narrow genetic base caused by breeding for desirable traits such as sweetness, size, and flesh/rind color. Comparatively, the crop wild relative desert watermelon variety (Citrullus amarus), while more drought tolerant than their commercially cultivated relatives (C. lanatus), still require large amounts of water to grow and produce reliable fruit yields. Watermelon root morphology plays a key role in their ability to tolerate drought, with more …

National-Scale Open Cattle Feedlot Detection Using Deep Learning And High-Resolution Aerial Images: Spatial Distribution And Animal Welfare Analysis, Uilson Ricardo Venancio Aires, Vitor Souza Martins, Dakota Hester, Thainara Lima, Lucas Borges Ferreira

Research Data

Open cattle feedlots are a major form of beef production infrastructure in the United States, characterized by outdoor confinement, high animal densities, and regulated feeding practices. Despite their economic importance, a comprehensive and spatially consistent national database of these facilities remains limited. This dataset provides labeled training data, trained deep learning models, and geospatial detection outputs developed to support automated identification of open cattle feedlots from aerial imagery. The dataset includes a manually curated shapefile of 11,746 open cattle feedlot facilities identified through visual interpretation of high-resolution aerial imagery in highly productive counties of Nebraska, Kansas, and Texas. These labels …

De Novo Annotation Reveals Transcriptomic Complexity Across The Hexaploid Wheat Pan-Genome, Benjamen White, Thomas Lux, Rachel Rusholme-Pilcher, Angéla Juhász, Gemy Kaithakottil, Susan Duncan, James Simmonds, Hannah Rees, Jonathan Wright, Joshua Colmer, Sabrina Ward, Ryan Joynson, Benedict Coombes, Naomi Irish, Suzanne Henderson, Tom Barker, Helen Chapman, Leah Catchpole, Karim Gharbi, Utpal Bose, Moeko Okada, Hirokazu Handa, Shuhei Nasuda, Kentaro K. Shimizu, Heidrun Gundlach, Michelle L. Colgrave

Research outputs 2022 to 2026

Wheat is the most widely cultivated crop in the world, with over 215 million hectares grown annually. The 10+ Wheat Genomes Project recently sequenced and assembled to chromosome-level the genomes of nine wheat cultivars, uncovering genetic diversity and selection within the pan-genome of wheat. Here, we provide a wheat pan-transcriptome with de novo annotation and differential expression analysis for these wheat cultivars across multiple tissues. Using the de novo annotations we identify cultivar-specific genes and define the core and dispensable genomes. Expression analysis across cultivars and tissues reveals conservation in expression between a large core set of homeologous genes, in …

An Investigation Of The Characteristics And Uses Of School Farms In California Ffa’S Superior Region, Emily R. Fuller, Jessica M. Toombs

Journal of Research in Technical Careers

This study investigates the characteristics and uses of school farms within Northern California, focusing on their role in school-based agricultural education (SBAE). The research aims to determine the structural and operational attributes of these facilities and to identify their primary uses as experiential learning tools. Utilizing a descriptive survey design, data were collected from 74 agricultural educators. Findings reveal that school farms, averaging 21.27 acres, are predominantly managed by agriculture teachers and are primarily used for housing market animals, supporting Supervised Agricultural Experience (SAE) projects. The study highlights the need for diversified school farm facilities to enhance experiential learning across …

Mountain Communities During A Time Of War: A Case Study Of The Hutsul Region In The Carpathian Mountains Of Ukraine, Pavlo Rybaruk

Electronic Theses and Dissertations

This thesis investigates the ethno-ecological technologies employed by the Hutsul people within the highland agrarian economy of the Carpathian Mountains. Over centuries, the Hutsuls have developed ethno-ecological technologies that maintain ecological integrity while supporting community livelihoods.

The study addresses three primary research questions: What are the most important ethno-ecological technologies of the Hutsul highland economy? How might these traditional ethno-ecological practices be applied to economic, agricultural, and tourism development in the Hutsul region? How might these traditional ethno-ecological practices be combined with contemporary approaches to encourage sustainable development in the region?

The research explores the devastating impact of the Russian …

Evaluation Of Ramp Instead Of Forage During Grain Adaptation And Different Sorghum Varieties On Enteric Methane Production From Cattle, Jack T. Fort

Department of Animal Science: Dissertations, Theses, and Student Research

Two experiments were conducted to evaluate the use of RAMP (Cargill Corn Milling, Blair, Nebraska) compared with traditional forage-based adaptations on methane (CH₄) and carbon dioxide (CO₂) emissions, performance, and carcass characteristics. Experiment 1, 64 yearling British × Continental steers (initial BW = 423 ± 6 kg) were adapted using 100% RAMP (RAMP) or a traditional forage diet (CON; 43% forage) before transitioning 22 d to a common finishing diet containing 65.6% steam-flaked corn. Emissions were measured in paired replications using a two-chamber indirect calorimetry barn. During adaptation RAMP did not affect CH₄ production (g/d; …

Impact Of Constant Versus Variable Inclusions Of Modified Distillers Grains Plus Solubles On Feedlot Cattle Performance And Carcass Characteristics And Impact Of The Frequency Of Varying Modified Distillers Grains Plus Solubles Inclusions In Feedlot Diets On Performance, Carcass Characteristics, Feeding Behavior, And Ruminal Ph Of Finishing Steers, Paige M. Madison

Department of Animal Science: Dissertations, Theses, and Student Research

Inconsistent availability or supply of distillers grains (DGS) can cause more variation in DGS inclusions throughout the feeding period. Two feedlot experiments evaluated the effects of varying inclusions of modified distillers grains plus solubles (MDGS) in feedlot diets. Beef steers (n = 400; initial BW = 287) were used in a 2 × 2 + 1 factorial experiment with treatments including: control with no MDGS compared to 2 inclusions (10% and 25%) of MDGS diet inclusions fed consistently or variably. No interactions were observed between MDGS consistency and inclusion for any performance or carcass characteristics (P > 0.10), so …

Integrating Innovative Sensing And Ground Measurements For Forage Mass Estimation In Rye Pasture, Pedro Henrique Jota Fernandes

Department of Animal Science: Dissertations, Theses, and Student Research

The United States beef industry relies on forages to provide up to 80% of total lifetime dry matter intake, making accurate forage mass estimation essential for determining stocking rates, improving grazing efficiency, and supporting economic sustainability. Traditional methods to quantify forage mass, however, are time-consuming and labor-intensive. This thesis presents research efforts to achieve accurate forage mass estimation in cereal rye pasture by integrating novel sensing technologies.

Chapter 1 reviews the importance and evolution of forage mass estimation methods, from destructive clipping to indirect approaches based on canopy measurements. It then introduces remote sensing, from proximal tools to drone- and …

Investigation Of Changes In Exotic Bird Serum Vitamin D Levels Between Indoor And Outdoor Housing, Alexander J. Marley

Department of Animal Science: Dissertations, Theses, and Student Research

Vitamin D is a fat-soluble vitamin that is directly related to sunlight and is involved in multiple physiological processes including calcium metabolism, feather quality, and chick development. Most vertebrate species are capable of both absorption of exogenous vitamin D and internal synthesis of vitamin D, with vitamin D3 (cholecalciferol), being more accessible and bioactive in bird species. In exotic bird species, dietary requirements for vitamin D3 are largely unknown, and the ability to maintain adequate serum concentrations of vitamin D3 metabolites without direct sunlight exposure also requires evaluation. Concerns arise in situations where individuals may be housed indoors for extended …

A Mixed Methods Study Of The Weather And Climate Science Curriculum Pilot In South Carolina K-12 Schools, 4-H, And Agricultural Education Programs, Emily B. Hood

All Dissertations

Weather and climate science topics in K-12 education are more important now than ever due to extreme weather and climate events happening worldwide. Most U.S. science teachers included climate science in their courses, but they may not have a sufficient background in the topic which can hinder their efforts, or there is no explicit curriculum for the teacher to utilize. Research indicates that there is a need for innovation in the curriculum to help prepare children to become the next generation of leaders and address complex problems, such as issues related to weather and climate science. There are a few …

Novel Approaches To Disinfecting Poultry Processing Wastewater For Reuse, Seth Olorunmijuwonlo Adesope

Graduate Theses and Dissertations

Water is an essential resource used in poultry processing, generating large volumes of foodborne pathogen-rich wastewater posing treats to public health. Treating poultry processing wastewater (PPW) is crucial for safe water reuse and sustainable development. Conventional disinfection methods like aerobic digestion and chlorination, although effective, impose considerable operational cost and generate harmful by-products. Integrated recycling systems such as advanced oxidation processes (AOPs) which destroy micro-organisms through the generation of reactive oxygen species (ROS) present a promising opportunity for enhancing resources and sustainability. This study investigated the use of photo-electrochemical (PEC), specifically by combining electrochemical (EC) and photochemical (PC; Photosensitizer and …