Agronomy and Crop Sciences Commons^™

Terrarium- An Ecosystem In A Jar, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

STEM education is supported through hand's-on activities in the classroom. Content understanding and reaffirmation of knowledge is supported through this informative STEM-Quick card that teachers or extension educators can distribute to participants for reference. Terrariums provide an example of a closed ecosystem where water and carbon cycling is demonstrated and plant growth can be observed. This card presents the steps to building and caring for an easy to create terrarium.

Scalable Machine Learning Framework For Adaptive Irrigation Management Of Maize And Soybean In The U.S. Midwest, Precious N. Amori, Derek M. Heeren, Yeyin Shi, Eric Wilkening, Ivo Z. Goncalves, Guillermo R. Balboa, Daran R. Rudnick, Abia Katimbo, Randall S. Ritzema

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Conventional soil water balance (SWB) irrigation scheduling tools, such as FAO-56-based Spreadsheets and the Spatial Evapotranspiration Modeling Interface (SETMI), rely heavily on manual inputs and periodic field measurements, leading to delayed recommendations and missed opportunities to prevent crop stress. More critically, these tools lack the computational scalability and adaptability to leverage the high-frequency, high-volume datasets now available through modern sensing technologies. As precision irrigation increasingly depends on integrating spatially and temporally nuanced field information, there is a pressing need for decision-support systems that can process Big Data efficiently and respond in real-time. To overcome these limitations, we developed and validated …

Soybean Seed Yield Distribution Within The Canopy As Affected By Nitrogen Supply, Lucia Bonfanti

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

Soybean [Glycine max (L.) Merr.] seed yield is influenced by the seasonal availability of resources (i.e., nutrients, light, and water). While nitrogen (N) supply is becoming a soybean yield-limiting factor, the N-induced effect in seed yield components is still unclear. The objective of this research was to assess the effect of N supply on soybean yield components distribution within the canopy. A Full-N treatment, which provided the crop with ample N supply, was compared against a Zero-N treatment in which the crop relied on soil N and biological N fixation at nine high-yielding irrigated soybean environments in Nebraska, with …

Nitrogen Limitation In Soybean: Physiology And Diagnosis, Luzviminda Ann Ramos Sazon

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

In high-yield soybean environments, the seed yield is limited by nitrogen (N) supply. However, the response of soybean to N fertilizer application is inconsistent. Understanding the seasonal N uptake dynamics in soybean can provide insights on diagnosing N limitation if soybean. To understand soybean N dynamics, we assessed seasonal trends on dry matter and N accumulation in vegetative organs (leaves, stems, and petioles) from 42 field experiments. Each experiment included a ‘zero-N’ treatment, where crops relied on N supply from soil and biological N fixation (BNF), and a ‘full-N’ that received ample N via N fertilizer addition. Vegetative storage proteins …

Exploring The Physiological, Biochemical, And Enzymatic Responses Of Vigna Mungo Varieties To Mungbean Yellow Mosaic India Virus (Mymiv) Infection, Subham Dutta, Poly Saha, Mritunjoy Barman, R. Poorvasandhya, Moumita Panda, Tarique Ahmed, Thomas Wilbur Davis, Bulbul Ahmed, Mudagadde G. Deeksha, Jayanta Tarafdar

Department of Entomology: Faculty Publications

This study aims to enhance sustainable disease management in black gram by identifying varieties resistant to Mungbean Yellow Mosaic India Virus (MYMIV). We screened sixteen black gram genotypes, assessing physiological, biochemical and enzymatic basis. Results revealed a range of resistance levels, with PANT URD-19 showing the highest resistance (PDI 0.47%) and Pejua the lowest (PDI 37.24%). Seven genotypes demonstrated strong resistance, highlighting the necessity for targeted breeding. Variations in leaf thickness, trichome density, stomatal frequency, and epicuticular wax content were significant, with resistant varieties like LBG-888 and PANT URD-19 exhibiting thicker leaves, higher trichome density, and more wax, correlating with …

Broad-Spectrum Resistance To Fungal Foliar Diseases In Wheat: Recent Efforts And Achievements, Amira M.I. Mourad, Asmaa A.M. Ahmed, P. Stephen Baenziger, Andreas Börner, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Wheat (Triticum spp.) is one of the most important cereal crops in the world. Several diseases affect wheat production and can cause 20-80% yield loss annually. Out of these diseases, stripe rust, also known as yellow rust (Puccinia striiformis f. sp. tritici), stem rust (Puccinia graminis f. sp. tritici), leaf rust (Puccinia recondita), and powdery mildew (Blumeria graminis f. sp. tritici) are the most important fungal diseases that infect the foliar part of the plant. Many efforts were made to improve wheat resistance to these diseases. Due to the continuous advancement in …

Disentangling Genotype And Environment Specific Latent Features For Improved Trait Prediction Using A Compositional Autoencoder, Anirudha Powadi, Talukder Zaki Jubery, Michael C. Tross, James C. Schnable, Baskar Ganapathysubramanian

Department of Agronomy and Horticulture: Faculty Publications

In plant breeding and genetics, predictive models traditionally rely on compact representations of high-dimensional data, often using methods like Principal Component Analysis (PCA) and, more recently, Autoencoders (AE). However, these methods do not separate genotype-specific and environment-specific features, limiting their ability to accurately predict traits influenced by both genetic and environmental factors. We hypothesize that disentangling these representations into genotype-specific and environment-specific components can enhance predictive models. To test this, we developed a compositional autoencoder (CAE) that decomposes high-dimensional data into distinct genotype-specific and environment-specific latent features. Our CAE framework employed a hierarchical architecture within an autoencoder to effectively separate …

Industrial Hemp Biomass Negatively Affected By Herbicide Drift From Corn And Soybean Herbicides, Milos Zaric, Bruno Canella Vieira, Barbara Houston, Guilherme Sousa Alves, Samuel E. Wortman, Julie A. Peterson, Greg R. Kruger

Department of Agronomy and Horticulture: Faculty Publications

The establishment of industrial hemp (Cannabis sativa L.) fields near row crops has raised concerns about the potential adverse effects of herbicide drift on hemp production. This study examined hemp susceptibility to drift of herbicides registered for use in corn and/or soybeans. Herbicide solutions (2,4-D, dicamba, glufosinate, glyphosate, imazethapyr, lactofen, mesotrione) were applied separately in the wind tunnel (3.6 m s⁻¹ airspeed), simulating drift scenarios, with conventional TP95015EVS (TP) and air inclusion AI95015EVS (AI) flat fan nozzles calibrated to deliver 140 L ha⁻¹ carrier volume at 230 kPa. Mylar cards and hemp plants (20–25 cm tall) were placed …

Designing A Decision-Support Tool For Fertilizer Recommendations In Oil Palm Smallholders, Rana Farrasati

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

Oil palm (Elaeis guineensis Jacq.), originally from West Africa, now accounts for 42% of global vegetable oil production and mainly includes key regions cultivated in tropical regions of Southeast Asia, West Africa, South America, and Central America. Despite its economic significance, the oil palm industry faces challenges of stagnant yields and large yield gaps, particularly among independent smallholders. These issues often stem from inadequate nutrient management practices and limited agronomic knowledge. Our objective was to quantify nutrient requirements for mature oil palm plantations as a basis to design a decision support tool (DST) for fertilizer recommendations. To do so, …

Bio-Based Sprayable Mulch For Weed Control In Row Crop Systems, Camila Chiaranda Rodrigues

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

Improving current crop productivity levels requires transformative advancements in management, engineering, and science. One of the main challenges is the increasing difficulty of weed management due to herbicide-resistant weeds. There is a growing need for alternative weed management methods to reduce pesticide use and improve environmental safety. An emerging technology that is being developed is spray-on films which could help address these challenges. Spray-on films are liquid solutions that after spraying on the soil will dry and form a physical barrier. The overall objective of this research was to evaluate the effectiveness of a chicken feather bio-based sprayable mulch film …

Assessing The Above- And Belowground Productivity Of Fall-Planted Cover Crop Cultivars In Nebraska's Diverse Ecoregions, Bridget Mckinley

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

Cover crops (CC) provide essential ecosystem services including soil conservation, nutrient cycling, and weed suppression, through the accumulation of aboveground (AGB) and belowground (BGB) biomass. While AGB has been widely studied, BGB contributions, particularly root development and distribution, remain less understood. This study evaluated fall-planted CC across three Nebraska ecoregions, assessing AGB productivity, BGB biomass, and correlations between ground cover, plant height, and AGB.

Thirty treatments, including grasses, legumes, brassicas, and mixtures, were evaluated over two fall growing seasons (2022–2023 and 2023–2024) at three UNL research centers in northeast, west central, and west Nebraska. AGB was highest at west site …

Understanding Limitations In Photosynthesis And Cold Tolerance In Panicoid Grasses: Maize And Sorghum, Fangyi Li

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

Sorghum and maize, both key crops within the Poaceae family (commonly known as the grass family), are staple foods in various regions and play a vital role in global food systems and economic development. These crops thrive in similar climates, particularly in warm, arid, and semi-arid regions. As subjects of extensive agricultural research, both maize and sorghum are being studied to enhance stress resistance and improve yield. Due to their botanical similarities, advances in one crop often inform practices in the other. The goal of this dissertation is to deepen our understanding of the photosynthesis process and cold tolerance in …

Trucks, Trains, And Barges: For Brazilian Soybeans, It’S Not Your Grandpa’S Infrastructure Anymore, Fabio Mattos

Cornhusker Economics

In the popular movie “Planes, Trains & Automobiles”, the tagline said, “Steve Martin had no reason to panic… until John Candy came along”. In the soybean market, we could say, “We had no reason to panic… until Brazil came along”. Brazil has been rapidly growing its soybean production for the last 30 years and has recently become the largest exporter in the world. In 2024/25, USDA estimates that Brazil will account for 58% of soybean exports worldwide, followed by the United States with 28%. These are roughly the numbers for 2023/24 and 2022/23 as well.

Still, despite the massive growth …

Your Sco/Eco Policy Under The Hood: What County Yield Is The Rma Using?, Cory Walters, Ken Harrison, Connor Whalen

Cornhusker Economics

Over the past decade, crop insurance has continued to expand contract offerings through new area-based policies. Supplemental Coverage Option (SCO) was introduced in the mid-2010s. Enhanced Coverage Option (ECO) was introduced in the early 2020s, and Margin Protection (MP) was introduced in the mid-to-late 2010s. The ECO premium subsidy was recently increased for the 2025 crop year to further encourage producer participation. Both the SCO and ECO programs have experienced increased participation for a variety of reasons.

Twas Facilitates Gene-Scale Trait Genetic Dissection Through Gene Expression, Structural Variations, And Alternative Splicing In Soybean, Delin Li, Qi Wang, Yu Tian, Xiangguang Lyv, Hao Zhang, Huilong Hong, Huawei Gao, Yan-Fei Li, Chaosen Zhao, Jiajun Wang, Ruizhen Wang, Jinliang Yang, Bin Liu, Patrick S. Schnable, James C. Schnable, Ying-Hui Li, Li-Juan Qiu

Department of Agronomy and Horticulture: Faculty Publications

A genome-wide association study (GWAS) identifies trait-associated loci, but identifying the causal genes can be a bottleneck, due in part to slow decay of linkage disequilibrium (LD). A transcriptome-wide association study (TWAS) addresses this issue by identifying gene expression–phenotype associations or integrating gene expression quantitative trait loci with GWAS results. Here, we used self-pollinated soybean (Glycine max [L.] Merr.) as a model to evaluate the application of TWAS to the genetic dissection of traits in plant species with slow LD decay. We generated RNA sequencing data for a soybean diversity panel and identified the genetic expression regulation of 29 …

Understanding Session Disparities And Advancing Experiential Learning In Turfgrass Management, Luqi Li

UNL Faculty Course Portfolios

PLAS 229: Introductory Turfgrass Management Laboratory is a sophomore-level course focusing on the practical skills required in turfgrass management. This portfolio documents the teaching methods, course materials, and an analysis of student learning outcomes with a focus on understanding disparities in student performance across sessions and enhancing practical skills through applied activities. Statistical analysis revealed that Session A outperformed Session B on two key field quizzes. This disparity is attributed to logistical differences: students in Session A attended the hands-on, field-based learning opportunities, while Session B faced scheduling conflicts that limited engagement with critical content. These findings underscore the importance …

Summer- And Fall-Planted Cover Crops Across Nebraska: Assessing Performance Using Aerial Imagery And Evaluating Short-Term Soil Impacts, Grace Emperatriz Pacheco Jiron

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

Cover crops are widely recognized for improving soil health and promoting sustainability in agricultural systems. Despite the increasing use of monitoring tools like aerial imagery, their application in evaluating summer-planted cover crops in the Great Plains remains limited, hindering effective management strategies. Fall-planted cover crops provide long-term environmental benefits, including enhanced soil quality and erosion control; however, understanding their short-term effects on soil properties is crucial for encouraging adoption. This study assessed summer- and fall-planted cover crops across Nebraska, integrating aerial imagery and soil health analyses.

Over two years, fifteen summer-planted monocultures and five mixtures were evaluated for establishment, biomass …

Climate Smart Agriculture, J. David Aiken

Cornhusker Economics

There are several programs encouraging producers to reduce their carbon intensity, including United States Department of Agriculture climate-smart agriculture programs, the 2024 Nebraska Climate Action Plan, and the 2024 Nitrogen Reduction Incentive Act. The hope is that producers with lower carbon intensity (CI) scores will receive a premium for their products. Producers would be well advised to learn more about these programs, as reducing carbon intensity in agriculture seems to be an emerging agricultural policy trend that will be with us for some time to come.

Dissecting The Genetic Architecture Of Sunflower Disc Diameter Using Genome-Wide Association Study, Yavuz Delen, Ravi V. Mural, Semra Palali-Delen, Gen Xu, James C. Schnable, Ismail M. Dweikat, Jinliang Yang

Department of Agronomy and Horticulture: Faculty Publications

Sunflower (Helianthus annuus L.) plays an essential role in meeting the demand for edible oil worldwide. The yield of sunflower seeds encompasses several component traits, including the disc diameter. Over three consecutive years, 2019, 2020, and 2022, we assessed phenotypic variation in disc diameter across a diverse set of sunflower accessions (N = 342) in replicated field trials. Upon aggregating the phenotypic data from multiple years, we estimated the broad sense heritability (H²) of the disc diameter trait to be 0.88. A subset of N = 274 accessions was genotyped by using the tunable genotyping-by-sequencing (tGBS) method, …

Willingness To Pay And Market Potential For Biowrap: An Economic Study Of A New Biodegradable Mulch Product In Home Gardening, Gengchen Cai

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

This study explores the market potential of BioWRAP, a biodegradable sprayable weed suppression product, by assessing the willingness to pay (WTP) among American home gardeners. Traditional plastic mulch offers significant agronomic benefits but poses considerable environmental challenges, making BioWRAP a promising alternative due to its similar benefits and reduced environmental impact. Using a double-bounded contingent valuation method, we analyze the WTP for BioWRAP among different demographic groups and gardening practices. Our findings indicate that the highest WTP for BioWRAP is among home gardeners who currently use chemical sprays for weed suppression, followed by those using physical barriers, with the lowest …

Cover Crop Utilization Across Nebraska And Implications For Cropland Lease Arrangements In 2024, Jim Jansen, Jeffrey Stokes

Cornhusker Economics

The Nebraska Farm Real Estate Market Survey and Report 2023-2024 provides insight on recent trends in the market value of land and cash rental across the state. Each year, the special feature section covers topics on new or emerging issues related to the agricultural land industry in Nebraska. These topics reflect the interest expressed by panel members and readership of the Nebraska Farm Real Estate Market Highlights Reports. The special feature section in 2024 focuses on trends and considerations for cover crops across Nebraska and implications on lease arrangements.

Findings from the 2022 Census of Agriculture in Table 1 provide …

Association Mapping Of Important Agronomic Traits In Mucuna Pruriens (L.) Dc., Patrush Lepcha, Mahesh Shekhar, Leelambika Murugesan, Mahammad Jaheer, Ratan Chopra, Vikas Belamkar, Narayana Sathyanarayana

Department of Agronomy and Horticulture: Faculty Publications

Background The tropical legume Mucuna pruriens (L.) DC. can meet three agricultural needs: low-cost protein, highvalue medicines, and green manure or cover crops. But like other underutilized crops, it needs more modern breeding resources. Identifying marker-trait associations (MTAs) can facilitate marker-assisted breeding and crop improvement. Recent studies have demonstrated the feasibility of identifying MTAs using a small number of accessions (< 100). We have characterized a panel of 70 M. pruriens accessions across two consecutive years and performed association analysis for 16 phenotypic traits related to seed (seed length, seed width, seed thickness, seed yield per plant, hundred seed weight); pod (pod length, pod width, number of pods …

Assessing Soil Properties & Suitability For Optimized Irrigation Development In Sudan, Northern Africa, Suhib O. Hamid

Department of Agricultural and Biological Systems Engineering: Masters Project Reports

In Chapter 1, soil properties essential for efficient irrigation are thoroughly assessed. Factors such as soil texture, infiltration rates, and nutrient content are analyzed to provide insights into the selection of modern irrigation systems. Utilizing data collected from 3,192 locations through GPS and laboratory analyses, alongside sophisticated ranking systems, the research determines the most suitable irrigation methods for specific soil series. Findings highlight the remarkable efficiency of drip irrigation across various soil types, contrasting with the consistently lower performance of surface irrigation. The chapter emphasizes the significance of considering soil variability, evapotranspiration, and investment factors in selecting irrigation methods for …

Assessing Even Flat-Fan Nozzles For Spot Spray Herbicide Applications, Thiago H. Vitti

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

Herbicide efficiency in row-crop agriculture can be improved using precision technologies for controlling weeds and minimize agronomic, economic, and environmental impacts. Site-specific weed management technologies, such as spot-sprayers, allow herbicides to be sprayed only where weeds are present in the field. Understanding application parameters and their influence on weed control for site-specific spot-spray applications is essential. This research involved laboratory and greenhouse studies to investigate the coverage and coefficient of variation (CV) of even flat-fan spray nozzles under different spot-spray application scenarios, as well as the effect of weed size and application method on the control of various weed species …

Identifying Genes Linked To Variation In Metabolic And Whole Plant Phenotypes Using Data From Genome Resequencing, Transcriptomics, And Metabolic Profiling Of A Field-Grown Maize Diversity Panel, Ramesh Kanna Mathivanan

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

Maize metabolism is highly complex and influenced by genetic variation, yet the specific genes contributing to this variation and their links to non-metabolic traits remain less understood. To address this knowledge gap, we identified genes involved in maize metabolic variation and linked them to non-metabolic traits. We utilized a quadruplicate dataset of whole genome resequencing, transcriptomic, metabolic, and whole plant phenotype data from a single common field experiment of 660 diverse maize inbred lines. Leaf samples were collected shortly before flowering and analyzed using GC-MS for 26 metabolites. A Resampling Model Inclusion Probability Genome-Wide Association Study (RMIPGWAS) of approximately 2.6 …

Integrating Water And Nitrogen Management For Sustainable Agriculture: Optimizing Resource Use Efficiency And Maximizing Crop Productivity, Jiaming Duan

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

Advisors: Derek Heeren and Daran Rudnick Maize, accounting for over 95% of national grain production in the United States, is highly sensitive to water and nitrogen (N) inputs. Conventional agricultural practices often lead to excessive application, causing groundwater contamination through nitrate leaching. Therefore, there is a demand for integrating water and nitrogen management with innovative scheduling methods for sustainable agricultural development.

This dissertation first reviewed two decades of U.S.-based research, highlighting the optimal management of water and N to enhance yield, water use efficiency (WUE), and nitrogen use efficiency (NUE). Findings indicate that maintaining optimal levels of N and water …

Dynamics Of Soybean Seed Protein And Oil Content With Depth In The Canopy, Hafith Furqoni

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

Understanding the physiological basis of variation in seed composition is critical for optimizing soybean seed composition. Also, studying dry matter accumulation and nitrogen uptake, partitioning, and redistribution in soybeans is crucial due to its direct impact on seed yield levels and overall plant productivity. This study aimed to test the primary proxy influencing seed protein and oil content, which is their accumulation rate determined by the assimilate supply per seed. The second objective was to comprehensively understand soybean dry matter (DM) accumulation and nitrogen (N) uptake, partitioning, and removal patterns within the canopy. Field experiments were conducted using two soybean …

Integration Of Matlab And Machine Learning To Accelerate Evaluation Of Biological Activity In Agricultural Soils And Promote Soil Health Improvement Goals, Andrew Stiven Ortiz Balsero

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

Traditionally, assessments of soil biological activity have been confined to laboratory settings, creating a disconnect with practical in-field methods. To bridge this gap, cotton fabric degradation has been used to illustrate soil microbial activity under different management practices. While effective, these demonstrations are subjective and labor-intensive.

Researchers have explored using image processing software like ImageJ and Adobe Photoshop to streamline this process. Although these tools accurately quantified fabric degradation under varying soil conditions, the methods remained labor-intensive and complex. Consequently, these methods were still not ideal for on-farm use by agricultural practitioners.

To further address labor and complexity limitations, the …

Greater Aperture Counteracts Effects Of Reduced Stomatal Density On Water Use Efficiency: A Case Study On Sugarcane And Meta-Analysis, Daniel Lunn, Baskaran Kannan, Amandine Germon, Alistair Leverett, Thomas E. Clemente, Fredy Altpeter, Andrew D.B. Leakey

Department of Agronomy and Horticulture: Faculty Publications

Stomata regulate CO₂ and water vapor exchange between leaves and the atmosphere. Stomata are a target for engineering to improve crop intrinsic water use efficiency (iWUE). One example is by expressing genes that lower stomatal density (SD) and reduce stomatal conductance (g_sw). However, the quantitative relationship between reduced SD, g_sw, and the mechanisms underlying it is poorly understood. We addressed this knowledge gap using low-SD sugarcane (Saccharum spp. hybrid) as a case study alongside a meta-analysis of data from 10 species. Transgenic expression of EPIDERMAL PATTERNING FACTOR 2 from Sorghum bicolor (SbEPF2) in sugarcane …

Revisiting Fr13a For Submergence Tolerance: Beyond The Sub1a Gene, Waseem Hussain, Mahender Anumalla, Abdelbagi M. Ismail, Harkamal Walia, Vistas Kumar Singh, Ajay Kohli, Sankalp Bhosale, Hans Bhardwaj

Department of Agronomy and Horticulture: Faculty Publications

Rice landrace FR13A is the original donor of the SUB1A gene. FR13A harbors hidden genetic variation that surpasses the submergence tolerance level of SUB1A. Here, we provide an overview of the unique features of FR13A associated with exceptional recovery ability that have been overlooked since the significant discovery of the SUB1 locus. We present a detailed overview of how to underpin the new genes associated with the recovery ability seen in FR13A. Finally, we propose a unique approach to develop rice cultivars that surpass submergence tolerance beyond the SUB1 locus from FR13A.