Agronomy and Crop Sciences Commons^™

Plas 439: Organic Farming And Food Systems Faculty-Led Inquiry Into Reflective Scholarly Teaching Benchmark Portfolio, Christian Stephenson

UNL Faculty Course Portfolios

Organic Farming and Food Systems is a senior and graduate level course for students in the Department of Agronomy and Horticulture. This course was previously offered but has been significantly modified as I have taken on responsibility for the course. Goals for the course include student comprehension of the methods of organic and regenerative farming and the impacts of those methods on economic, environmental, and social sustainability. An additional goal is to build student competency in the evaluation of primary, secondary, and tertiary information resources and critical thinking surrounding issues in food production. Assessment for the course was through diverse …

Hymenopteran Parasitoids Of Fall Armyworm (Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)) In Australia, With The Description Of Five New Species In The Families Braconidae And Eulophidae, Erinn P. Fagan-Jeffries, Melina M. Miles, Tareva-Chine C. Atkin-Zaldivar, Andy G. Howe, Siva Subramaniam, Donna M. Chambers, Frezzel Praise J Tadle, Saleh Adnan, Verni Sivasubramaniam, Alice Woodward, Helen Spafford, Brian Thistleton

Biosecurity Research Articles

Fall armyworm, Spodoptera frugiperda (J.E. Smith) is an invasive pest of agricultural crops including sweet corn and maize. The moth was first recorded in Australia in January 2020 and is now considered established in most states and territories, and research is underway to develop management strategies. Extensive rearing of S. frugiperda larvae and eggs occurred from March 2020 to April 2023 to understand the parasitoid complex present in Australia and identify potential biological control agents. We report here on the hymenopteran parasitoids reared during this period, which were identified using a combination of morphology and COI DNA barcoding, and provide …

Rain And Potential Evapotranspiration Are The Main Drivers Of Yield For Wheat And Barley In Southern Australia: Insights From 12 Years Of National Variety Trials, Edward G. Barrett-Lennard, Nicholas George, Mario D'Antuono, Karen W. Holmes, Phillip R. Ward

Grain and Other Field Crops Research Articles

Context
Water is widely assumed to be the factor most limiting the growth of annual crops in rainfed environments, but this is rarely tested at sub-continental scale. Aims
Our study aimed to determine the key environmental and management variables influencing the yield of wheat and barley in the grain-production regions of southern Australia, using data from National Variety Trials. Methods
We used generalised additive models to determine the importance of climatic and management variables on wheat and barley grain yield. We determined the effects of the best one, two or three variables and their interactions. Key results
The aridity index, …

Investigating The Impact Of Climate Change On Evapotranspiration Using Modeling, Faten Waheed

Theses and Dissertations

The available water resources are at risk due to climate change and the increasing water demand. Evapotranspiration is a very important element in water cycle. Evapotranspiration is perceived as a linking mechanism between the surface of the land and the atmosphere. Therefore, investing appropriate approaches to estimate evapotranspiration and the implication of climate change on evapotranspiration and available water resources are of great importance for better water management and food security. Penman-Monteith (PM) equation is considered as one of the most widely used equation for estimating ETo. It is also one of the most complex energy balance equations requiring detailed …

Assessing The Use Of Regenerative Agriculture In California Almonds As Climate Change Resilience, Skyler M. Seamons

Master's Projects and Capstones

The agriculture sector is responsible for 10% of the United States’ greenhouse gas emissions. In turn, anthropogenic climate change threatens crops. With its Mediterranean climate, California is the country’s largest agricultural-producing state. Many California crops are at risk due to increasing temperatures and changed precipitation patterns. This paper investigates regenerative farming techniques as a tool to protect California crops from a changing climate. Almonds are used as a case study to analyze the soil management practices, finances, and policies underlying regenerative agriculture in California. A literature review and comparative analysis are used to compare regenerative and conventional soil management practices …

Cereal Rye Cover Crop Termination At Or Before Soybean Planting Has Minimal Effect On Soybean Yield Across The Midwestern Us, Tatiane Severo Silva, Spyridon Mourtzinis, Anthony Justin Mcmechan, Gabriela Inveninato Carmona, Bruce D. Potter, Kelley J. Tilmon, Louis S. Hesler, Nicholas J. Seiter, Robert Wright, Shannon L. Osborne, Thomas E. Hunt, Shawn P. Conley

Department of Entomology: Faculty Publications

Context: Interest is growing among farmers in the Midwestern US region in the potential benefits of establishing cereal rye (Secale cereale L.) as a cover crop. However, they are concerned about the implications and potential trade-offs due to this practice. Objective: We aimed to evaluate the effects of cereal rye cover crop termination at or before soybean planting on soybean (Glycine max [L.] Merr.) seed yield. Methods: Field experiments were conducted from 2019 to 2021 across 28 location-years in the Midwestern US. Treatments consisted of no cereal rye, cereal rye termination before soybean planting, and termination at planting. …

Adopting Yield-Improving Practices To Meet Maize Demand In Sub-Saharan Africa Without Cropland Expansion, Fernando Aramburu-Merlos, Fatima A. M. Tenorio, Nester Mashingaidze, Alex Sananka, Stephen Aston, Jonathan J. Ojeda, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Maize demand in Sub-Saharan Africa is expected to increase 2.3 times during the next 30 years driven by demographic and dietary changes. Over the past two decades, the area croppedwithmaize has expanded by 17million hectares in the region, with limited yield increase. Following this trend could potentially result in further maize cropland expansion and the need for imports to satisfy domestic demand. Here, we use data collected from 14,773 smallholder fields in the region to identify agronomic practices that can improve farm yield gains. We find that agronomic practices related to cultivar selection, and nutrient, pest, and crop management can …

The De-Domestication Of Ornithopus Sativus Brot. To Develop Cultivars With Physical Dormancy (Hardseed), Robert J. Harrison, Bradley J. Nutt, Ronald J. Yates, Belinda F. Hackney, John G. Howieson

Grain and Other Field Crops Research Articles

Ornithopus sativus Brot. (French serradella) is a forage legume that is well adapted to acidic coarse textured soils (sands) which are characterized by poor nutrition and an inability to retain water. During the process of domestication of O. sativus, there was an unintentional loss of seed physical dormancy (PY) thus compromising its self-regeneration after a cropping interval. Through mass screening of seed, we identified for the first time that heritable sources of PY exist in three populations of O. sativus. This rare genetic material was then incorporated into suitable genetic backgrounds of differing maturity through targeted hybridization. We demonstrated …

Evaluating The Yield Of Surviving Plants From Early-Season Hail Damage In Corn: A Field Survey, I. P. Lisboa, Christopher A. Proctor, R W. Elmore, A. J. Mcmechan, N. D. Mueller, J. Wilson, G. Zobeck, Aaron Nygren, A. Bastidas, Osler Ortez

Department of Agronomy and Horticulture: Faculty Publications

Economic losses due to hailstorms acrossUS corn fields occur every year.Hailstorms result in leaf defoliation, decreasing photosynthetic area and impairing carbon assimilation and crop yield for all corn (Zea mays L.) development stages. However, more attention is often given to stand reductions rather than damage to stems or leaf defoliation. During the 2014 growing season, a natural hail event affected many areas of eastern Nebraska. Twelve affected corn fields were surveyed and included in this study. An injury score scale (1–5) was developed based on various injury and severity levels before the V6 (6-leaf corn growth stage) (six-collared leaves). …

Agroecology And Soil Stewardship: Values And Techniques Of Smallholder Farmers In Bernalillo County, Stephanie Olivas

Geography ETDs

Agrarian movements around the world use agroecology to build sovereignty and steward dynamic ecosystems. Research has shown that agroecological farmers steward more resilient crops, more resilient soil biomes, and greater biodiversity than conventional agriculture. GIS and remote sensing offer many tools to detect the impacts of these farmers on the environment, but it is less clear how such technologies fit into agroecological goals. This study asks: what values, experiences and knowledge do smallholder producers in Bernalillo County embody in their soil stewardship practices? Also, what experience or knowledge do smallholder producers in Bernalillo County have about remote sensing, and would …

Characterization Of Zmsnrk1 Genes And Their Response To Aphid Feeding, Drought And Cold Stress, M. Aydin Akbudak, Kubra Yildiz, Durmus Cetin, Utka Yukselbaba, Vibha Srivastava

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The SnRK1 complex in plants regulates metabolism in response to environmental stresses and glucose depletion, for stress adaptation and energy homeostasis. Through phosphorylation of various targets, SnRK1 orchestrates intricate regulatory mechanisms involved in autophagy, nutrient remobilization, and TOR activity inhibition, showcasing its pivotal role in coordinating plant metabolism and stress responses. The present study aimed to identify members of the SnRK1 gene family in the maize genome and characterize them using bioinformatics and expression analyses under aphid feeding, drought, and cold stress. The focus of the study was to conduct a comprehensive analysis towards determining gene diversity of ZmSnRK1 genes, …

And Food Justice For All: Advancing Access To Just And Sustainable Food Systems, Makenna Grace Landry

Graduate Student Portfolios, Professional Papers, and Capstone Projects

A collection of work exploring food justice and food access programming in Western Montana, as well as a critique of the Bayer-Monsanto merger.

Natural Variation In Lonely Guy-Like 1 Regulates Rice Grain Weight Under Warmer Night Conditions, Jaspreet Sandhu, Larissa Irvin, Anil Kumar Chandaran, Shohei Oguro, Puneet Paul, Balpreet Dhatt, Waseem Hussain, Shannon S. Cunningham, Cherryl O. Quinones, Argelia Lorence, Maria Arlene Adviento-Borbe, Paul E. Staswick, Gota Morota, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Global nighttime temperatures are rising at twice the rate of daytime temperatures and pose a challenge for rice (Oryza sativa) production. High nighttime temperature (HNT) stress affects rice yield by reducing grain weight, size, and fertility. Although the genes associated with these yield parameters have been identified and characterized under normal temperatures, the genetic basis of grain weight regulation under HNT stress remains less explored. We examined the natural variation for rice single grain weight (SGW) under HNT stress imposed during grain development. A genome-wide association analysis identified several loci associated with grain weight under HNT stress. A …

Quemando Leña En Guatemala: Salud, Sostenibilidad Y Costumbres, Sydney Underhill

World Languages and Cultures Senior Capstones

In the Central American country of Guatemala, firewood is an important fuel source. Eighty-eight percent of households in rural areas use wood stoves and open fires to cook and heat their homes. This tradition has fundamental roots in the culture and customs of Guatemala. Unfortunately, these methods contribute to air pollution. Consequently, it also results in smoke inhalation, which causes health problems. Additionally, the massive agriculture of other crops decreases the amount of firewood available to these households, affecting the sustainability of the resource. Some communities resist changing their use of firewood due to the profound nature that firewood holds …

First Record Of The Invasive Chenopodium Aphid, Hayhurstia Atriplicis (Linnaeus, 1761) (Hemiptera: Aphididae), In Colombia, Takumasa Kondo, Roberto Rosero, Jackeline Gaviria

Insecta Mundi

The chenopodium aphid, Hayhurstia atriplicis (Linnaeus, 1761) (Hemiptera: Aphididae), is reported for the first time in Colombia. The aphid was found on the aerial parts of the quinoa plant, Chenopodium quinoa Willd. (Amaranthaceae), especially on the leaves, in five municipalities in the department of Cauca, Colombia. Brief information on its natural enemies, distribution and biology is provided. This is the only aphid in Colombia known to cause malformations on the leaves of quinoa plants. In South America, this aphid has been found previously only in Ecuador, where it was reported for the first time in 2023 based on specimens collected …

Identifying High-Value Tactical Livestock Decisions On A Mixed Enterprise Farm In A Variable Environment, Michael Young, John Young, Ross S. Kingwell, Philip E. Vercoe

Animal production and livestock research articles

Context

Australia is renowned for its climate variation, featuring years with drought and years with floods, which result in significant production and profit variability. Accordingly, to maximise profitability, dryland farming systems need to be dynamically managed in response to unfolding weather conditions.

Aims

The aim of this study is to identify and quantify optimal tactical livestock management for different weather-years.

Methods

This study employed a whole-farm optimisation model to analyse a representative mixed enterprise farm located in the Great Southern region of Western Australia. Using this model, we investigated the economic significance of five key livestock management tactics. These included …

Annual Pasture Quantity And Quality In South West Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

The productivity of sheep is largely governed by the amount of pasture they eat and this is influenced by the quantity of the pasture on offer and its quality. Assessing pasture quantity and quality throughout the growing season gives managers the information they need to manage animal performance and pasture condition.

The Department of Primary Industries and Regional Development provides this information for farmers to help improve the productivity and profitability of the livestock industry in Western Australia.

Managing Barley Powdery Mildew In The Face Of Fungicide Resistance, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Barley powdery mildew populations resistant to some fungicide active ingredients are present in the WA grainbelt. Integrated disease management strategies to manage the disease include growing varieties with improved resistance and strategic use of fungicides.

Barley Production: Effects Of Weather Damage And Varietal Purity On Quality, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Australian barley is regarded for its quality and suitability for both malting and animal feed, although varietal differences and environmental conditions during production can influence its quality.

Evaluation Of Late Season Potassium Applications To Arkansas Soybean, Carrie Ortel

Graduate Theses and Dissertations

Potassium (K) deficiency is one of the most important yield limiting factors in Arkansas soybean (Glycine max (L.) Merr.) production, although there are recently improved diagnostic and management opportunities available. However, several questions regarding the successful implementation of in-season K management in soybean production remain. Therefore, the research objectives were to (a) delineate the relationship between drought stress and K deficiency on soybean vigor, (b) identify the spatial dependencies of leaf-K concentrations at the production scale, (c) develop a leaf sampling protocol, (d) calibrate the fertilizer-K rate needed to correct varying levels of K deficiency at 15, 30, and …

On-Farm Nitrogen And Irrigation Management Strategies To Protect Groundwater Quality In The Bazile Groundwater Management Area, Arshdeep Singh

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

Increasing groundwater nitrate (NO₃-N) contamination has raised significant environmental and health concerns in the irrigated sandy soils of Nebraska. Four studies were conducted to evaluate the impact the impact of 1) static (NE Yield Goal) vs. dynamic nitrogen (N) recommendations tools (Maize-N, Canopy Reflectance Sensing, Granular, and Adapt-N), 2) three N (optimum, suboptimum, and low) and irrigation rates (farmer’s full irrigation (FIT), 80% FIT, and 60% FIT), 3) conventional N sources vs. enhanced efficiency fertilizers (EEFs), and 4) multiple N splits (2, 3, 4, and 5-N splits) on agronomic (maize yield), environmental (NO3-N leaching), and economic returns (return …

In-Field Optimization Of Soil Water Parameters For Irrigation Scheduling, Ishani Lal

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

Several precision technologies are being developed to assist farmers in informed irrigation decision-making. These technologies aim to enhance irrigation water efficiency, check overirrigation, boost crop water productivity, and promote the sustainable utilization of water resources. We hypothesize that soil moisture parameters used in irrigation decision tools need to be validated to best represent the correct state of soil moisture in the field. This is an important factor that affects the accuracy of the irrigation recommendations forecasted by the decision support tools. In this research, we evaluated different methods of estimating field capacity (FC) and wilting point (WP) to optimize soil …

Establishment Of Wildflower Islands To Enhance Roadside Health, Ecological Value, And Aesthetics, Jackson Ebbers

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

Roadsides provide an abundant opportunity to increase connectivity of fragmented landscapes with diminishing floral resources for pollinating insects. The ecological value of these sites is often overlooked as quality habitat for pollinators, particularly monarch butterflies, which have been experiencing severe declines due to loss of habitat and loss of milkweeds that provide food for their larvae. Land managers across the nation are realizing the potential of roadsides to provide high quality floral resources for the benefit of insects and other wildlife. Current wildflower seed mixes used by state transportation departments are often low diversity and may only be implemented following …

Using Annual Forages To Replace Declining Cool-Season Grass Pasture Availability, Jonathon Matthew Jenkins

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

As land area in grain crop production increases in the US Midwest, perennial pasture availability decreases but the demand increases. Matching the seasonal growth patterns of C₃ and C₄ plant species to grow forages that are complementary allows producers to fill production gaps in otherwise monoculture systems and possibly increase overall productivity. One way to fill the forage production gap of C₃ grass dominated pastures is by producing a warm-season, annual forage in a separate field. However, with continual reductions in land availability, this may not be an option. Using two studies, our objectives were to improve …

Impact Of Early-Season Postemergence Co-Applications Of Foliar And Residual Herbicides On Crop Injury, Growth, And Yield In 2,4-D- And Dicamba-Tolerant Cotton (Gossypium Hirsutum L.), Logan N. Vallee

LSU Master's Theses

Studies were conducted in 2021 through 2023 at the LSU AgCenter Dean Lee Research and Extension Center near Alexandria, LA to determine the sensitivity of 2,4-D- or dicamba- tolerant cotton (Gossypium hirsutum L.) to an early season application of a Group 15 and foliar-only herbicides. Both studies were randomized complete block designs with a two-factorial arrangement of treatments with four replications. In the dicamba-tolerant cotton study, Factor A consisted of no foliar-herbicide, dicamba alone, glyphosate alone, or dicamba plus glyphosate. Factor B consisted of either no Group 15 residual herbicide, acetochlor, or S-metolachlor. In the 2,4-D- tolerant cotton …

Evaluation Of Essential Oils And Their Major Components For Disease Resistance, Serkan Tokgöz

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

Essential oils (EOs) are natural hydrophobic compounds, which are highly complex, typically comprising 20 to 60 constituents, with two or three main components making up 20% to 95% of their composition, alongside other minor constituents. Research has firmly established the potent antibacterial and antifungal properties of EOs and their primary components. To assess their efficacy, one EO, nutmeg oil, and seven main components, including safrole, toscanol, safraleine, cinnamaldehyde, carvacrol, carvone, and thymol, were tested against four economically significant fungal pathogens (Alternaria solani, Fusarium graminearum, Rhizoctonia solani, and Sclerotiorum sclerotiorum), one oomycete pathogen (Phytium ultimum …

Irt-Based Irrigation Scheduling And Dry Bean Crop Water Productivity Under Different Irrigation Scenarios In The Nebraska High Plains, Angie Gradiz

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

Irrigation plays a critical role for crop production in western Nebraska of the United States, where crop evapotranspiration often exceeds in-season precipitation. This study investigated the impacts of different irrigation treatments on yield and key physiological parameters of dry edible beans grown in semi-arid western Nebraska during the 2022-2023 growing seasons. Seven irrigation levels (0%, 25%, 50%, 75%, 100%, 125%, 150%) of the fully irrigated treatment (FIT), were applied using a Variable Rate Irrigation (VRI) Linear-Move Sprinkler System. Additionally, an eighth treatment was scheduled based on measurement from infrared radiometry thermometers (IRT) to evaluate the performance of the two-source energy …

Impact Of Plant Defenses And Aphid-Associated Microbes In Modulating Sorghum–Sugarcane Aphid Interactions, Edith Ikuze

Department of Entomology: Dissertations, Theses, and Student Research

Sorghum (Sorghum bicolor) is a vital cereal crop globally, facing challenges from invasive pests such as the sugarcane aphid (SCA; Melanaphis sacchari). To elucidate mechanisms of sorghum resistance to SCA, we examined the role of plant defenses and the influence of aphid-associated microbes in modulating sorghum defenses. Lignin is a complex heterogenous polymer present in nearly all plant cell walls that plays a critical role in protecting plants from various stresses. In this study, we investigated the role of the caffeoyl coenzyme-A O-methyltransferase (CCoAOMT), one of the core enzymes in monolignol biosynthesis pathway that leads to lignin …

Next-Generation Crop Monitoring Technologies: Case Studies About Edge Image Processing For Crop Monitoring And Soil Water Property Modeling Via Above-Ground Sensors, Nipuna Chamara

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

Artificial Intelligence (AI) has advanced rapidly in the past two decades. Internet of Things (IoT) technology has advanced rapidly during the last decade. Merging these two technologies has immense potential in several industries, including agriculture.

We have identified several research gaps in utilizing IoT technology in agriculture. One problem was the digital divide between rural, unconnected, or limited connected areas and urban areas for utilizing images for decision-making, which has advanced with the growth of AI. Another area for improvement was the farmers' demotivation to use in-situ soil moisture sensors for irrigation decision-making due to inherited installation difficulties. As Nebraska …

Malt Quality Parameters For Malting Barley, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Have you ever wondered how beer is made and what makes barley varieties different from each other in the eyes of the brewer? The barley malting process and main barley malt quality characteristics are briefly described on this page.