Bioresource and Agricultural Engineering Commons^™

Co-Encapsulation Of Microalgae Haematococcus Pluvialis And Lactic Acid Bacteria Lacticaseibacillus Casei Via Filamentous Fungi Scaffolds Improved Probiotic Viability In Simulated Gastro-Intestinal Conditions, Suvro Talukdar, Tyler J. Barzee

Biosystems and Agricultural Engineering Faculty Publications

Fungal-assisted cell immobilization has emerged as a promising approach for food, energy and environmental applications, utilizing the hyphal network of filamentous fungi to encapsulate microorganisms. Co-encapsulation of multiple microorganisms within fungal pellets enables the development of food delivery systems that combine complementary functional and nutritional properties, including enhanced probiotic protection and delivery of bioactive compounds. This study used edible filamentous fungus Aspergillus awamori to encapsulate Haematococcus pluvialis microalgae and Lacticaseibacillus casei lactic acid bacteria (LAB) for probiotic delivery. Both active and heat-deactivated pellets successfully co-encapsulated microalgae and LAB, although low shear conditions were required for inactive fungal states. Under in-vitro …

Exploring Relational Farming Futures For Responsible Innovation In Precision Agriculture Through Q-Method And Speculative Design, Bhavna Joshi, Maaz Gardezi, Edward Prutzer, Awais Hameed Khan, Asim Zia, Benjamin E. K. Ryan, Ali Dadkhah, Donna M. Rizzo, John T. Mcmaine, David Clay

Biosystems and Agricultural Engineering Faculty Publications

This article draws on concepts of speculative design and responsible innovation to examine the possible impacts of data-driven precision agriculture on farmers and farm work. We use an innovative mixed-method approach to research design. Using artistic depiction of futures of precision agriculture in design workshop and in-depth semistructured interviews conducted with the farmers in Vermont and South Dakota, we explain how farmers perceive different futures of precision agriculture. Specifically, in our design workshop, we combined visual arts and social science methods, namely Q-method, to explore existing and new relationships between humans, technologies, and environment in the design, deployment, and use …

Deep Learning Framework For Sow Posture Classification From Depth Images: Comparison With Data Transformation Techniques, Models, And Cross-Validation, Md Towfiqur Rahman, Tami M. Brown-Brandl, Gary A. Rohrer, Sudhendu R. Sharma, Suzanne M. Leonard, Yeyin Shi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Piglet preweaning mortality (PWM) in the United States averages ≈14–15%, with sow overlaying causing about one third proportion of these losses. This research aimed to develop and evaluate deep learning models to classify six sow postures using depth images to monitor behaviors linked to overlaying risk. Top-down depth images were captured with Kinect V2^® cameras at 10 frames min^-1 for five consecutive days (2 days before to 2 days after farrowing), yielding 26,506 training images from 18 sows, 17,901 testing images from 12 sows, and 4,697 additional images from three sows in diagonal stalls for external validation. Three …

Assessment Of Soybean Response To Irrigation Variability In Eastern Nebraska Using The Aquacrop Model, Anmol Singh, Saleh Taghvaeian, Yufeng Ge, Derek M. Heeren, Frank Bai

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Soybean [Glycine max (L.) Merr.] is a major irrigated crop in eastern Nebraska, where recent expansions in irrigated agriculture and projected trends in irrigation demand necessitate thorough investigations of approaches that can optimize its irrigation management. In this study, the AquaCrop model was calibrated and validated using 19 variable irrigation treatments from a five-year field experiment. The model accurately simulated canopy cover, soil water content, and grain yield, with validation normalized root mean square error (nRMSE) of 12%, 7%, and 7%, respectively. The model was subsequently applied to estimate soybean yield and water requirement during a 15-year period (2010–2024) …

Mechanical Fractionation Of Wheat Middlings For Application In Pyrolysis And Animal Feed, Okwudili I. Obiakor

Dissertations, Master's Theses and Master's Reports

Wheat middlings are grain byproducts that are underused for bioenergy production despite having a high lignocellulose content. Its use as a feedstock for catalytic pyrolysis depends on effective and sustainable fractionation to enhance efficiency and product yield. This study tested mechanical pre-fractionation (sieving and air classification) to reduce ash content of certain fractions to < 1% for catalytic pyrolysis and enrich nutrient levels of other fractions for feed applications. Wheat middlings were separated into 11 fractions using screen sizes from 106 µm to 1651 µm, and the composition of each fraction was characterized (ash, protein, structural carbohydrates, lignin, starch, and simple sugars). For cyclone separation, a full factorial design was used to study the effect of air velocity (15,18, 20 m/s) and feed rate (33, 35, 38 kg/h) on the amount of material collected in the underflow and overflow, and the composition of these fractions was characterized. Sieving showed a pronounced segregation of ash content, from 4.5% to 6.5% in wheat middlings fractions, with 5.7% being the lowest for coarse fractions which has higher lignocellulose content, and 4.5% in the fine fraction (150-212 µm). The same defined enrichment was observed in all nutrients except for protein. Starch enrichment zone were defined in the fine fractions (212 µm and below), for structural carbohydrates and lignin in the coarse fractions (600 µm and above), and for ash in coarse fractions (1180-1651 µm). In contrast, protein content was not significantly different between various fractions (p value=0.787). The fiber rich fraction (> 600 µm), suitable for pyrolysis, which have a composite ash value of 6.0% can be sorted and mixed with intermediate fractions to reduce ash to 5.3% and the remaining fractions rich in digestible nutrients used for animal feed formulation. Compared to sieving, cyclone separations did not …

An Integrated Pull System Framework For Disassembly Industries: Bridging The Supply-Demand Mismatch In Duck Meat Processing, Hongchao Yu

Graduate Research Theses & Dissertations

Disassembly-based production systems, such as duck meat processing, face inherent operational challenges due to one-to-many production structures, short product shelf life, and volatile customer demand. A single carcass must be processed into multiple products at largely fixed biological ratios, while demand varies across products and over time. This supply-demand mismatch frequently leads to simultaneous surplus and shortage, resulting in unstable shipment schedules, excess inventory, and unavoidable waste. Traditional order-driven pull systems typically respond to orders independently and are limited in their ability to coordinate these interrelated effects.

This dissertation develops an integrated pull system framework for perishable disassembly processes, using …

Feasibility Of Corn Stover For Biogas Production In Northwestern Illinois: A Case Study Of Jo Daviess And Carroll Counties, Anthony Amotoe-Bondzie

Masters Theses

The growing demand for renewable energy and sustainable waste management has intensified interest in agricultural residues such as bioenergy feedstocks. This study evaluated the feasibility of converting corn stover into biogas through anaerobic digestion (AD) in Jo Daviess and Carroll Counties, Illinois, with consideration of the Savanna Industrial Park as a potential centralized processing hub. Although corn stover represents one of the largest biomass resources in the United States, this research identifies a critical gap between theoretical availability and practically recoverable feedstock. Using a mixed-methods framework, the study integrates biomass quantification, methane yield modeling, economic analysis, and policy assessment. Results …

Mechanical Quality Of Hemp Fiber As Influenced By Tillage, Cover Crop, And Nitrogen Management In Regenerative Organic Systems, Parinaz Heydar, Alyssa Pierce, Gabriella Fioravanti, Ronald Kander

School of Design and Engineering Papers

Industrial hemp (Cannabis sativa L.) is an emerging crop for renewable fiber materials. For farmers, finding a balance between agronomic performance and economic return is crucial, especially when targeting specific markets like the textile industry, which values not just fiber quantity, but overall quality. This field study, conducted at the Rodale Institute in Kutztown, Pennsylvania, assessed the effects of tillage (till vs. no till), cover crop (with cover vs. no cover), and nitrogen (N) rate (0, 50, 100, 150 kg ha⁻¹) on hemp fiber yield, N concentrations in leaf and stalk, and mechanical performance under regenerative organic conditions. Fiber mechanical …

Deep-Learning-Enhanced Automated Coherent-Light Diffraction System For High-Speed, Highly Accurate Strain-Specific Foodborne Bacterial Recognition, Yang Tian, Ziyu Liu, Yinuo Huang, Ramesh Bahadur Bist, Yiting Xiao, Samantha Marrianne Howe, Tsung Cheng Tsai, Terry Howell, Jeyam Subbiah, Michael L. Looper, Dongyi Wang

Biological and Agricultural Engineering Faculty Publications and Presentations

Rapid, accurate differentiation of bacterial pathogens at both species and strain levels is critical for clinical diagnostics, food safety, and epidemiological surveillance. We report a fully automated laser-diffraction platform that achieves rapid, label-free identification of bacterial pathogens at both species and strain levels. The system integrates dual cameras, an automated X-Y stage, and deep-learning classifiers to deliver sub-second, nondestructive diagnostics without reagents or culture. Using diffraction patterns from eight strains, including Escherichia coli O157:H7, K12, ATCC 25922, F18, Salmonella enterica, Listeria monocytogenes, Listeria innocua, and Staphylococcus aureus, a custom YOLO11x model attained 100 % Top-1 accuracy under five-fold stratified cross-validation …

In-Field Tractor Operational Load Profile Generation In Support Of Advanced Tractor Testing In Mixedmode Power, Andrew Donesky

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

This dissertation addresses the need to better characterize real-world tractor power requirements across drawbar, power take-off (PTO), and hydraulic modes to support more representative tractor testing. Conventional testing protocols, such as OECD Code 2, emphasize steady-state performance under controlled high-load conditions, which do not reflect the mixed and dynamic demands of modern field operations. To address this gap, a Tractor Instrumentation System (TIS) was developed, validated, and deployed to collect high-resolution, mixed-mode power data during planting, anhydrous ammonia application, and grain cart operations. The TIS integrates physical sensors, including custom load pins, hydraulic pressure/flow sensors, and a redesigned PTO torque …

An Integrated Modeling Framework To Evaluate Circularity Of The Corn–Water–Ethanol–Beef Nexus, Heydi Han

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

This dissertation examines the transition from conventional linear agricultural and food bioenergy systems toward more circular, resilient, and resource-efficient configurations. Prior research indicates that spatial and temporal variability in soil, weather, animal biological responses, and management decisions strongly influences productivity, nutrient-use efficiency, and profitability. Studies have also shown that a diversified circular system can buffer these sources of variability, improving stability and adaptive capacity. Building on these insights, the central focus of this work is to develop an integrated modeling framework to evaluate circularity within the Corn-Water-Ethanol-Beef (CWEB) nexus and explore how climate variability and management choices shape system-wide performance. …

Applied Research In Field Crop Pathology For Indiana, 2024, Darcy E. P. Telenko, Sujoung Shim

Purdue University Press Books

Applied Research in Field Crop Pathology for Indiana, 2024 serves as a summary of the applied field crop pathology research trials conducted in 2024 under the direction of the Purdue Field Crop Pathology program in the Department of Botany and Plant Pathology at Purdue University. In Indiana, there are more than 57,600 farms, 16,000 crop producers, and 900 certified crop advisers, Extension educators, and crop-protection industry representatives who manage more than 11.4 million crop-production acres with a total value of $6.3 billion annually. There are more than twenty diseases affecting corn, soybeans, and wheat that may decrease crop production and …

Spatially Mapped Statewide Estimated Potential Evapotranspiration Using An Efficient Surface Interpolation Method: A Case Study Of South Carolina, Sudhanshu S. Panda, Devendra M. Amatya, Ka Kit Liu, Augustine Muwamba, Timothy J. Callahan

Journal of South Carolina Water Resources

Potential evapotranspiration (PET) exhibits substantial spatial and temporal variability across large landscapes, necessitating site-specific estimation for accurate environmental and water resource assessments. However, obtaining PET or ET data for specific locations across an entire state remains challenging due to the limited number of weather stations and associated environmental datasets. This study aimed to develop an automated geospatial modeling framework to map PET distribution across South Carolina, USA, using PET estimated by the temperature-based Hargreaves–Samani (H–S) method with daily weather data from 59 NOAA stations. Because the accuracy of spatial interpolation depends on both the target variable and the desired spatial …

Locations Of Outfalls In The Indian River Lagoon And Lake Worth Lagoon, Florida, Kelly M. Kibler, Melinda J. Donnelly, Vincent Encomio, Madison Giuntoli, Manisha Thenuwara, Brice Bennett, Laura Andrade Barron, Mariam Sonbol, Wynter Raine Seppala, Namritha Ramakrishnan, Jennifer Jordan Báez, Beth Orlando, Irene Arpayoglou, Melissa Meisenburg

Indian River Lagoon Shorelines

The spatial dataset: UCF_Outfalls_IRL_LWL.shp was created under grants from the Indian River Lagoon National Estuaries Program and Florida Sea Grant. These projects cumulatively led to creation of a living shoreline restoration prioritization model and hydrodynamic habitat suitability models for 1,550 km (963 miles) of estuarine shorelines in Indian River Lagoon (IRL) and Lake Worth Lagoon (LWL).

The dataset presented here includes the location of outfalls identified throughout the study region and general characteristics of the shoreline where they were identified.

Seagrass Persistence In The Indian River Lagoon And Lake Worth Lagoon, Florida, Kelly Kibler, Melinda Donnelly, Vincent Encomio, Madison Giuntoli, Manisha Thenuwara, Brice Bennett, Laura Andrade Barron, Mariam Sonbol, Wynter Raine Seppala, Namritha Ramakrishnan, Jennifer Jordan Báez, Beth Orlando, Irene Arpayoglou, Melissa Meisenburg

Indian River Lagoon Shorelines

The spatial dataset: UCF_seagrasspersistence_IRL_LWL.shp was created with support from the Indian River Lagoon National Estuaries Program and Florida Sea Grant. These projects cumulatively led to creation of a living shoreline restoration prioritization model and hydrodynamic habitat suitability models for 1,550 km (963 miles) of estuarine shorelines in Indian River Lagoon (IRL) and Lake Worth Lagoon (LWL). The dataset presented herein represents persistence of seagrass throughout waters of the IRL and LWL.

Living Shoreline Prioritization And Hydrodynamic Habitat Suitability Models For Restoration In The Indian River Lagoon And Lake Worth Lagoon, Florida, Kelly M. Kibler, Melinda J. Donnelly, Vincent Encomio, Madison Giuntoli, Manisha Thenuwara, Brice Bennett, Laura Andrade Barron, Mariam Sonbol, Wynter Raine Seppala, Namritha Ramakrishnan, Jennifer Jordan Báez, Beth Orlando, Irene Arpayoglou, Melissa Meisenburg

Indian River Lagoon Shorelines

The spatial dataset: UCF_shorelinemodel_IRL_LWL.shp, was created with support from the Indian River Lagoon National Estuaries Program and Florida Sea Grant. These projects cumulatively led to creation of a living shoreline restoration prioritization model and hydrodynamic habitat suitability models for 1,550 km (963 miles) of estuarine shorelines in Indian River Lagoon and Lake Worth Lagoon.

The dataset presented herein includes:

1. shoreline data from >15,000 transects collected in the field,
2. shoreline wave climate data created through hydrodynamic modeling and frequency analysis of historic data,
3. categorization of potential risk for shoreline boat wake impact,
4. persistence of seagrass within 210 m of the shoreline, …

Reengineering Resilience: Bio-Resilience Bonds For Financing Microbial Infrastructure And Climate Equity, Reece Buckley

COP30

This policy proposal introduces Bio-Resilience Bonds (BRBs), a performance-based financial instrument designed to monetise microbial ecosystem services as measurable climate infrastructure. Microbial ecosystems are crucial for climate resilience, yet they are often overlooked in mainstream adaptation f inance frameworks. Their ability to regulate carbon and nitrogen cycles, reduce methane emissions and enhance soil and water stability (Delgado-Baquerizo et al., 2016) makes them essential assets for climate mitigation and adaptation. With global adaptation needs exceeding £2.7 trillion (UNEP, 2024), this oversight indicates a systemic failure to recognise biology as a form of infrastructure. BRBs transform microbial outputs into localised key performance …

Using Drone And Ai To Map Leaf Water Potential And Stem Water Potential For Water Stress Management In Commercial Vineyards, Alfonso F. Torres-Rua

Funded Research Records

No abstract provided.

Evaluation Of Robotic Swabbing And Fluorescent Sensing To Monitor The Hygiene Of Food Contact Surfaces, Siavash Mahmoudi, Clark Griscom, Pouya Sohrabipour, Yang Tian, Chaitanya Palleria, Philip G. Crandall, Dongyi Wang

Biological and Agricultural Engineering Faculty Publications and Presentations

Effective environmental monitoring is critical for preventing microbial and allergenic cross-contamination. However, manual swabbing methods, commonly used to verify hygienic conditions, are prone to inconsistent results because of variability in pressure, coverage, and techniques. Two novel solutions will be explored to address these challenges: a robotic swabbing system with tactile sensing control, and a fluorescence/absorbance spectrometer for non-contact, protein-based residue detection. The robotic system was evaluated against trained and untrained humans, measuring water pickup, surface coverage, and pressure consistency. Concurrently, the fluorescence system analyzed model poultry protein soil to correlate spectral patterns with contamination levels. The robotic system demonstrated statistically …

Irrigation Scheduling Methods: Checkbook Vs Fao-56, Adarsha Neupane, Vidya Samadi

Forestry and Natural Resources

Irrigation scheduling addresses two critical questions: when to irrigate and how much water to apply. Providing the optimal amount of water at the right time enhances water use efficiency, leading to improved crop production, while minimizing water losses and ensuring sustainable water management. This article compares two widely used soil water balance-based irrigation scheduling methods—Checkbook and FAO-56—by evaluating their principles, advantages, and limitations, with a focus on how each method tracks and manages soil moisture. To illustrate their differences, we present example calculations demonstrating how each method estimates irrigation timing and amount. The Checkbook method, widely adopted for its simplicity, …

Cultivation Of Botryococcus Braunii For The Production Of Hydrocarbons Suitable For Fuel Use, Bryan C. Carroll

All Theses

Energy security, rural poverty, and climate change are pressing issues of our time. Biofuels provide a solution to these issues, with a focus on sustainable aviation fuel, SAF, due to compatibility with aircraft infrastructure and energy density. This research aims to review and produce knowledge about a specific microalga, Botryococcus braunii, for its potential for SAF. First a literature review on the process was conducted followed by an experimental study on the impact of aqueous media and inorganic carbon its growth and hydrocarbon content. The literature review found the process consists of cultivation followed by lipid extraction or hydrothermal …

Evaluation Of Performance Characteristics And Groundwater Contamination Risks Associated With On-Farm Swine Carcass Disposal Via Composting And Shallow Burial With Carbon, Gustavo Castro Garcia

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

This dissertation evaluates the performance of three on-farm swine carcass disposal methods: whole carcass composting (WCC), ground carcass composting (GCC), and shallow burial with carbon (SBC), focusing on biosecurity factors and groundwater contamination risks. Foreign animal diseases (FADs), such as African swine fever and classical swine fever, pose severe economic and animal well-being risks if introduced to the United States. With confirmation of an FAD, swine movement will be halted, creating an urgent need for practical, biosecure, and environmentally responsible on-farm disposal strategies for swine carcasses. Nebraska, as a leading swine-producing state, exemplifies the vulnerability of high-density livestock regions to …

Biological Hydrogen Process Improvements By High Temperature Simultaneous Saccharification And Fermentation, Frank W. Jeffries V

All Theses

The hyperthermophilic bacterium Thermotoga neapolitana is established as a versatile organism for fermentative hydrogen (H₂) production. Batch experiments were carried out to investigate the cell yield, product yield, and kinetic parameter values for individual media containing five carbohydrates. The highest H₂ yield of 15.56±0.31 mmol-H₂/g-carbohydrate was reported for glucose medium. H₂ yield was measured to be 14.51±0.38, 14.44±1.15, 11.88±0.84, and 11.53±0.73 mmol/g for media containing xylose, cellobiose, arabinose and xylan respectively. Acetic acid yield followed a similar trend, where the obtained values were 0.470±0.01, 0.462±0.04, 0.431±0.01, 0.409±0.03, and 0.406±0.01 g-acid/g-carbohydrate for glucose, cellobiose, xylose, …

Development Of A Machine Learning Framework For An Irrigation Decision Support System, Eric Wilkening, Derek M. Heeren, Yeyin Shi, Laila A. Puntel, Guillermo R. Balboa, Abia Katimbo, Kuan Zhang, Precious Nneka Amori, Bruno Lena

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Currently used irrigation scheduling techniques often require significant human intervention and are time consuming, particularly for variable rate irrigation. This research aimed to develop a conceptual framework that incorporates disparate data sources leveraging both mechanistic and machine learning (ML) approaches. The overarching objective is to utilize the growing availability of data and technology to manage irrigation more precisely, which will minimize negative impacts of irrigation on our water resources. An initial irrigation machine learning model was proposed and tested in this study as a key component of an edge-cloud computing and federated learning decision-making framework. The specific objectives were (1) …

Traditional Energy And Renewable Energy And Their Implications On Sustainable Development (Examples From Lebanon And The World), Radwan Ejel

Al Jinan الجنان

This study aims to introduce the types of fossil and renewable energies by presenting the various associated concepts. It shows their characteristics, in addition to the concept of sustainable development, to show the extent of traditional energy's repercussions on sustainable development and the role of renewable energies in promoting its concept through its three economic, social, and environmental dimensions. It also presents some statistical models on renewable energy, especially solar energy in Lebanon, the Arab world, and the world.

Previously, man used to invest in traditional fossil energy, such as oil, gas, and coal, to meet his economic and technological …

Groundwater Flooding On Highways In The Nebraska Sandhills: Applying Remote Sensing, Precipitation And Groundwater Modeling To Determine Depth, Cause And Frequency, Aaron R. Mittelstet

Nebraska Department of Transportation: Research Reports

Climate change significantly impacts infrastructure sustainability, particularly through shifts in precipitation patterns, intensity, and duration. These precipitation dynamics may increase the occurrence of surface water and groundwater flooding. Groundwater in the Nebraska Sand Hills (NSH), including the thickest portions of the High Plains Aquifer, extends close to the land surface in interdunal areas, making the NSH vulnerable to groundwater flooding. Recent events involving heavy precipitation, snow melt, and rising groundwater levels have caused prolonged highway flooding, disrupting transportation networks. This study estimates groundwater flood inundation depth, duration and frequency in the highways of NSH using remote sensing techniques and groundwater …

Geophysical Tools For Agricultural Management: Trends, Challenges, And Opportunities, Sophia Becker, Trenton Franz, Yufeng Ge, Joe Luck, Derek M. Heeren

School of Natural Resources: Faculty Publications

Agrogeophysics is a convergence of proximal soil sensing and hydrogeophysics in which geophysical methods are used to describe soil patterns and dynamics that shape agronomic management (including precision agriculture). To fully realize its potential for optimizing agricultural production, current barriers and targets for future agrogeophysics research must be identified. In this review, we compare the trajectory of agrogeophysics within peer-reviewed literature, patents, and the US university extension literature and examine the current challenges and opportunities for supporting agricultural production and sustainability with agrogeophysical tools. We conducted a repeatable search of Web of Science and Scopus for seven geophysical methods (electromagnetic …

Ai Tools In Natural Resources And Environmental Systems For The Classroom, Research, Extension And Industry, Derek M. Heeren, C. T. Agouridis, Debabrata Sahoo, Isaya Kisekka, Trisha L. Moore

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This white paper synthesizes a series of panel insights on AI adoption across education, Extension, research and industry contexts within natural resources and environmental systems. It emphasizes that while advanced machine learning and generative AI introduce structural shifts in autonomy, scale, and cognitive augmentation, their value lies in augmenting, not replacing, human expertise. Applied tool examples include decision‑support systems for rural water operators, HAB‑diagnosis apps integrating image classification and natural‑language guidance, an irrigation educational chatbot tailored to user background, and sensor‑driven orchard AI for light interception estimation and data gap filling. A recurring design imperative involves co‑development with end users, …

Response Of Soybean To Variable Irrigation Levels In Eastern Nebraska Using The Aquacrop Model, Anmol Singh

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

AquaCrop was calibrated and validated for soybean [Glycine max (L.) Merr.] using 19 irrigation treatments from five years using data from field experiments. The model accurately simulated canopy cover (CC), soil water content (SWC), and grain yield, with overall validation nRMSE values of 12%, 7%, and 7%, respectively. The overall validation nRMSE for SWC in individual 30-cm soil layers was comparatively higher, at 19%. The model was subsequently applied for long-term simulations (2010–2024) to estimate soybean yield and water requirements for two dominant soil types, Yutan silty clay loam and Tomek silt loam under three irrigation levels - rainfed, …

Legacy Nutrient Transport By Overland Sheet Flow, John E. Gilley, Ryan P. Mcgehee, Kenneth M. Wacha

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The transport of phosphorus (P) and nitrogen (N) from sites containing varying quantities of legacy nutrients was evaluated in this investigation. The data that were examined were collected during four previously reported field hydrologic studies performed in eastern Nebraska. Additional flow was introduced to the top of the rainfall simulation plots to replicate runoff conditions occurring along a hillslope. It was observed that both P and N delivery were influenced by runoff rate on sites where beef cattle manure or inorganic fertilizer had been applied. Legacy nutrient delivery appeared to have been influenced by the quantity of nutrients released at …