Digital Commons Network^™

Comparison Of Private And Public Lab Fertilizer Recommendation Impacts On Field Crop Production And Soil Test Results, Megan Baker

All Graduate Theses and Dissertations, Fall 2023 to Present

There are many sources that farmers utilize to determine fertilizer needs for crops such as private and public labs, crop advisors, and fertilizer dealers. In many cases, these sources provide recommendations for a specific crop that can vary greatly, which can lead to large differences in cost. An experiment was established in 2021 with 12 sites across the state of Utah in alfalfa, small grains, and corn to test and compare fertilizer recommendations from five labs. The recommendations tested were from two public labs (Utah State University and the University of Idaho) and three commercial labs located in the Western …

Contrasting Nitrogen Sources Impact Nitrogen Use Efficiency And Soil Health Under Silage Corn Production In A Semi-Arid Environment, Phearen Kit Miller

All Graduate Theses and Dissertations, Fall 2023 to Present

Silage corn production challenges sustainable intensification and soil health in semi-arid environments because the entire aboveground biomass is harvested and removed from the field. An irrigated silage corn field study was conducted over a decade comparing nitrogen fertility sources using a complete randomized block design with four treatments: control with no nitrogen fertilizer (control), low ammonium sulfate at 112 kg N ha⁻¹ (AS100), high ammonium sulfate at 224 kg N ha⁻¹ (AS200), and steer manure compost at 224 kg total N ha⁻¹ (compost). Research focused on the impact of these contrasting nitrogen sources on silage corn production, …

Furthering Indaziflam-Based Management Strategies Of Three Invasive Annual Grasses In Northern Utah, Peter Weston Maughan

All Graduate Theses and Dissertations, Fall 2023 to Present

Indaziflam is an herbicide highly recognized for its potential to effectively control weedy, winter germinating grasses, such as downy brome, as the herbicides prevents seed germination for several years. Unfortunately, most of these studies only capture the first 2-3 years of indaziflam’s 3-5 years soil activity. This thesis sought to better understand indaziflam’s long-term effects by monitoring both a healthy ecosystem and a degraded ecosystem for up to 5 years after indaziflam application. A secondary study was also conducted to better understand the potential of revegetation via reseeding in indaziflam treated soils. The study concluded that indaziflam very little long-term …

Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Dyer’s woad (Isatis tinctoria L.) is a non-native forb that continues to threaten natural areas throughout Northern Utah and much of the Intermountain West. Once introduced, dyer’s woad can become extremely invasive, decreasing forage quality, and displacing native species. While dyer’s woad is found throughout much of Northern Utah, its range in other states remains limited. If promptly managed, control success in these areas will be much higher and populations may be kept at bay before ecological damage becomes severe.

This project tested the ability of dyer’s woad seedlings to compete with common rangeland grasslands at varied densities as …

Reducing Inputs And Adding Value To Turfgrass Systems Through Clover Inclusion And Plant Growth-Promoting Rhizobacteria Applications, Paige E. Boyle

All Graduate Theses and Dissertations, Fall 2023 to Present

Recently, the US has seen an expansion in the amount of turfgrass land cover (lawns, parks, roadsides, sports fields, and golf courses), as well as an interest in reducing fertilizer, water, and pesticide use in these grass systems. To help maintain quality and function while reducing resource inputs, two promising approaches have emerged: planting clover into lawns and applying plant growth-promoting rhizobacteria.

White clover and grass mixtures have been studied for their ability to cut down on fertilizer usage and provide a uniform, dark green lawn, but other clover types have not been as widely studied and may provide similar …

Water Conservation Through Drought-Resilient Landscape Plants And Deficit Irrigation, Ji-Jhong Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increases in urban population and inadequate rainfall result in imbalanced water budgets in urban and sub-urban regions. Water conservation becomes important in urban landscapes because of increased water demands. Modern landscape designs require drought-resistant plants to maintain urban landscape greenness during water scarcity. Irrigating plants at their irrigation requirements, which is the minimum irrigation rate that can achieve acceptable aesthetic quality, can also conserve water. However, the drought tolerance and irrigation requrements of most landscape plants have not been widely evaluated. Shepherdia ×utahensis ‘Torrey’ (‘Torrey’ buffaloberry) and Penstemon species (beardtongues) are low-water-use landscape plants, but their drought resistance mechanisms are …

Evapotranspiration And Energy Balance Of Irrigated Urban Turfgrass, Matthew D. Miksch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water usage for irrigation is a big consumer of water resources in urban areas in Utah and other parts of the Intermountain Region of the Western United States. As populations continue to increase in these states, it is important to understand how much water is being used by urban landscapes in order to plan and manage future water resources. Evapotranspiration (ET), or the amount of water leaving a surface over a certain timeframe due to both transpiration from plants and evaporation from the soil, is a key variable in understanding how much water urban landscapes are really using to grow …

Practical Improvements For Pivot And Surface Irrigation, Jonathan A. Holt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Irrigation is critical to meeting global food and fiber demands. Optimizing agricultural irrigation may help sustain production levels, while reducing its demand for water. This research evaluated precision sprinklers and drip irrigation for pivots, five pivot track mitigation tools, three scientific irrigation scheduling (SIS) methods, sensors for surface irrigation cutoff, and automating surface systems to implement surge irrigation. With pivots and surface irrigation being the most common methods for irrigation in the West, small improvements from these tools could result in significant water savings.

Low energy precision application (LEPA) sprinklers and mobile drip irrigation (MDI) were tested on two pivots. …

Evaluating Quaking Aspen's Influence On Fire Behavior, Kristin A. Nesbit

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In western North America, quaking aspen (Populus tremuloides Michx.) forests have long been described as low flammability, “fireproof” forest types that are less likely to burn or burn less intensely than coniferous forests. While this assumption has been based on limited scientific research and is largely anecdotal, there is growing interest in the western U.S. to promote aspen near human developments to reduce fire risk. I investigated the available evidence for aspen forests reducing fire occurrence, behavior, and severity, and assessed possible factors that affect flammability in aspen forests to better understand when and where aspen burn, and when …

Dust Deposition Changes Production, Chlorophyll-A And Community Composition In Mountain Lakes, Jiahao Wen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increasing quantities of dust emitted from semi-arid soils, agricultural soils, and urban regions are blown to remote mountain lakes in the American West. Remote mountain lakes lacking local nutrient inputs and presenting simple food webs that are easily affected by climate changes. Dust can carry nutrients (e.g., nitrogen and phosphorus) to mountain lakes and potentially enhance algae growth and change algal communities. However, experimental tests of this hypothesis are lacking. Using in situ experiments, we investigated the effects of dust enrichment on the production, biomass, and primary algal species in three mountain lakes in the American West. We found that …

Approaches To Supplementing Silicon In Soilless Media And The Value Of Silicon In The Mitigation Of Drought Stress, Mackenzie Grace Dey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Silicon (Si) is not considered an essential element for plants to complete their lifecycle, but is known to be beneficial for plants under environmental stress such as drought. Unlike natural soils, Si is minimally bioavailable in soilless media. With indoor agriculture and greenhouse production increasing, the benefits of Si have been seen and Si should be supplemented. This work aimed to characterize and quantify the dissolution of Si from media substrates and additives to achieve a steady-state release of Si in soilless media. Typical media components such as coconut coir, peat moss, perlite, rock wool, sand, and vermiculite minimally released …

Evaluating Strategies For Anemone And Ranunculus Cut Flower Production In The Us Intermountain West, Shannon Rauter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

National growth in small-scale, specialty cut flower farms is reflected in Utah, where 145 members have joined the Utah Cut Flower Farm Association since its 2019 founding. Cool season cut flower production is limited in Utah and the Intermountain West by a narrow harvest window and elevated soil salinity. The objective of this research was to optimize production systems for anemone (Anemone coronaria L.) and ranunculus (Ranunculus asiaticus L.) in the Intermountain West by evaluating season advancement methods within a high tunnel and field production system, as well as the salinity sensitivity of each species. Fall planting dates, …

Management Of Garlic Mustard (Alliaria Petiolata), Sahara Mustard (Brassica Tournefortii), And Elongated Mustard (Brassica Elongata) In Utah, Natalie Layne Fronk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The invasive mustard species Sahara mustard (Brassica tournefortii), garlic mustard (Alliaria petiolata) and elongated mustard (Brassica elongata) negatively impact a variety of ecological systems across the state of Utah. The distribution of these species in Utah is relatively limited at the current time. If prompt action is taken, it may be possible to contain and manage these species before irreparable ecological and agricultural damage occurs. For this reason, all three mustards are listed by the State of Utah as weeds of high priority for management.

This project tested multiple strategies to determine effective species-specific …

Dairy Breed, Grass-Birdsfoot Trefoil Mixture, And Pasture Nutrition Effects On Intake, Feed Efficiency, And Grazing Adaptation, Michael Greenland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dairy cattle have lower dry matter intake (DMI) on pastures thus leading to less weight gain and milk production than feedlot cows. This study was conducted to determine whether different dairy breeds are better adapted to lower or higher quality pastures as measured in DMI and feed efficiency. The eight treatments consisted of Jersey, Holstein, Holstein-Jersey crossbreds, and 3-breed crossbreds (Montbéliarde-Swedish Red-Holstein) heifers on grass monocultures and grass-BFT mixtures. We observed greater DMI on grass-BFT mixtures. Among breeds, Holstein had the greatest DMI, then the two crossbreds, and Jersey had the least. Feed efficiency was most favorable for Jersey, less …

Soil Genesis Across A Climo-Lithosequence Of Western Haleakalā, Maui, Ryan C. Hodges

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The soils of western Haleakalā are incredibly diverse due to two primary reasons: 1) they receive varying levels of rainfall based on location relative to Haleakalā, and 2) volcanic vents upwind of the area indicate that volcanic ash has blanketed much of western Haleakalā in the past. Ash can weather to form short-range-order materials, which contribute to the classification of andic soil properties. Due to their structure, short-range-order materials impart soil behavior that creates benefits and challenges in land management. Therefore, an understanding of how these soils formed and differ, and where andic soils occur is crucial.

The objectives of …

Development Of Late-Heading Orchardgrass Germplasm, Megan Marie Getz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dactylis glomerata L., orchardgrass, is commonly grown with perennial forages such as alfalfa (Medicago sativa L.). However, commercial orchardgrass cultivars currently grown in the Intermountain West generally flower earlier than alfalfa. This results in a reduction in grass nutritional value if harvested to maximize the alfalfa yield, because the two species mature at different rates. Thus, there is a need to better understand the genetic basis of flowering time in orchardgrass and develop late-flowering populations. The objectives of this research were to evaluate the ability to identify and use molecular markers to identify and select late-heading orchardgrass; and to …

Antimicrobial Assay Of Sagebrush Roots, Lauren Rachel (Moody) Mcfadden

Undergraduate Honors Capstone Projects

Plants produce secondary metabolites for various functions, one of which is antibacterial activities. Sagebrush has historically been used by Native Americans for different medicinal purposes, suggesting that it may have secondary metabolites that would have medicinal values, including antimicrobial activities, and can be a natural source for antibiotics. This study aims to carry out the antimicrobial activity of Sagebrush root extract against a handful of bacteria. We tested the antimicrobial activity of root extract of Sagebrush against six bacteria such as Bacillus subtilis, Bacillus cereus, E. coli DHSα (Lab cloning strain), Agrobacterium tumefaciens GV3101 (Lab cloning strain), Pseudomonas …

4r Nitrogen And Water Optimization Combinations For Intermountain West Field Crops, Tina Sullivan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The concept of 4R (right source, rate, placement, and timing) management needs little introduction due to the surplus of nutrient studies in the literature for most cultivated crops. However, few studies have looked at these practices in the Intermountain West with nitrogen use, and fewer looked at 4R irrigation management. A survey was conducted to explore the interactions of nitrogen and irrigation management, test sensitivity to supply and price changes of nitrogen and irrigation for Utah and Idaho growers of small grains, corn, and potatoes, and determine the current adoption of precision agriculture options and identify the opportunities to improve. …

Opportunities For Optimal Apple Production Management In Arid Conditions, Sam Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Apple trees are susceptible to biotic and abiotic stresses in the Intermountain West. The arid climate along with non-ideal soils make apple production challenging. Also, as high-quality agricultural land is developed, crop production gets pushed to land that often is saline. Apple trees grow poorly in saline soils. If apples are going to be grown in Utah, rootstocks must be identified that will tolerate saline soils. The USDA rootstock breeding program produced some rootstocks that may show salt tolerance. This project assessed the salt tolerance of these apple rootstocks in the greenhouse and in the field. Test rootstocks were compared …

Control Of Three Invasive Annual Grasses In Utah Using Herbicides Including Indaziflam, Hailey L. Buell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasive grasses pose a threat to rangeland ecosystems in Utah. Three grasses in particular: downy brome, medusahead, and ventenata can push out native plants and prevent other vegetation from germinating. These grasses can also degrade grazing lands for cattle and act as kindling for wildfires. The use of herbicides is the most common way to rid a site of invasive plants. Herbicides that prevent germination for many years work well to keep annual grasses at bay while not harming the many long-living native plants that are already growing.

A study was designed on a site infested with downy brome to …

Soil Health Monitoring And Management In Corn And Soybean Agroecosystems Of The Midwestern U.S., Bradley S. Crookston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil health is a concept and condition of the soil where measurable soil properties represent the capacity of a soil fulfilling its intended use, such as producing crops, without constraint to its agro-ecological quality. Soil health assessments are used to estimate the health of a soil by assessing soil biological, chemical, and physical attributes, called soil health indicators, and scoring them on a scale, usually 0 to 100, to guide soil and crop management. However, there are few large-scale analyses of soil health assessment scores and their relationships with crop yield. Understanding how soil health assessments relate to crop yield …

The Plant Growth Promoting Ability Of The Microbiome Of Ceanothus Velutinus From The Intermountain West Region, Jyothsna Ganesh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to the ever-changing climate and deterioration of the earth’s ecosystem, environmental stresses like abiotic (drought, salinity) and biotic stresses (pathogen infection) gravely affected plant growth. Native plants are a great way of improving these effects on the urban landscape. They can be used as ornamental plants in landscaping as they are accustomed to their natural environment. The Center for Water-Efficient Landscaping at Utah State University has released a list of plants to be used for low water use landscaping. One such native plant is Ceanothus velutinus (snowbrush ceanothus). They are evergreen plants that can grow in dry and harsh …

Phytochrome Physiology And Plant Perception Of Far-Red Photons, Paul Kusuma

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Photons are the primary energy source for most life on Earth, as they drive photosynthesis, a process that turns the CO₂ in air into food. One crucial parameters for the optimization of growth is leaf area, which determines the ability of a plant to capture photons for photosynthesis. In order to gain access to photons in shaded environments, plants have evolved unique sensors, called photoreceptors, which respond to changes in the color and intensity of light.

Far-red photons (photons at the edge of human vision that appear as dim red light) hold particular promise in regulating plant shape and …

Season Advancement Of Cool Season Cut Flower Crops Snapdragon And Peony, Maegen A. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Demand and production of specialty cut flowers is growing across the U.S., but research is lacking in the U.S. Intermountain West, where the semi-arid and high elevation climate offers unique challenges for growers. The goal of this study was to evaluate the stem quality, harvest timing, and yield of snapdragon (Antirrhinum majus) ‘Chantilly’, ‘Potomac’, and ‘Rocket’ and peony (Paeonia lactiflora) ‘Coral Charm’ as cool-season cut flower crops under high tunnel and field production in North Logan, Utah. Snapdragons were transplanted at three-week intervals beginning in early-February in high tunnels and ending in late-May in the field. …

Seeding Rate, Nitrogen Fertilzer, And Cutting Timing Effects On Teff Forage Yield And Nutritive Value, Michael C. Laca

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Teff [Eragostis tef (Zucc.) Trotter] is a relatively new forage gaining popularity in the United States; however, information regarding agronomic production practices is lacking. This study was conducted to determine the combination of seeding rate, fertilization, and harvest timing to optimize teff dry-matter yield (DMY) and nutritive value. Four seeding rates (2, 5, 8, and 11 lb/acre), four nitrogen (N) fertilizer rates (0, 25, 50, and 100 lb/acre), and two harvest strategies [boot stage (2-cut) and full seed-head stage (1-cut; stockpiled)] were evaluated in 2010 and 2011 in Kaysville, UT and Yerington, NV. The effects of harvest (1- vs …

Interactive Effects Of Soil And Browsing On Big Sagebrush: Implications For Restoration Success, Kyle Nehring

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Heterogeneity in landscape conditions (e.g., soil types) precludes a “one size fits all” management strategy across large landscapes. New management approaches that explicitly account for heterogeneous landscapes (and the variable conditions therein) will be required to maintain habitat quality. In particular, we require an improved mechanistic understanding of how the outcomes of conservation and restoration actions are contingent upon a) contextual abiotic factors (e.g., moisture availability mediated by soils and precipitation) and b) their interactions with biotic factors (e.g., browsing wildlife).

We propose to answer fundamental questions about how big sagebrush (Artemisia tridentata), the foundational species for sagebrush …

Conserving Water Through Modular Planting Design: Water-Wise Templates For Ogden's Residential Front Yard Landscapes, Jessica Clements

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Due to the arid climate of the Wasatch front and the projected population growth in the next thirty years, water conservation is essential. Consequently, because the landscape consumes 60% of Utah residences’ purified drinking water, water-wise landscaping needs to be a priority. This thesis creates water-wise landscape templates that can be applied to the front yards of Ogden rental properties using a modular planting method. This study determines best practices by researching topics such as water-wise plants for Northern Utah, templates utilized in other areas, modular planting, and existing organizations with similar goals. This results in a user-friendly guide that …

Fatty Acid Composition Of Forages And Their Effect On The Fatty Acid Composition In Beef Cattle, Britney G. Allen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study focused on how diet changes the rumen microbiome in the cattle and the effects of that on the long chain fatty acids (LCFA) by microbes in the rumen, and on the short chain fatty acids (SCFA) these microbes produce from feed carbohydrates like fiber and starch. The abundance of bacteria belonging to the phyla Tenericutes and Proteobacteria increased in response to high-fiber or high-starch diets, respectively. The production of two SCFA was positively correlated with the presence of increased Tenericutes (acetate) and Proteobacteria (propionate). A greater acetate to propionate ratio is associated with elevated production of enteric methane …

Seeding Rate, Herbicide, And Irrigation Effects On Spring-Seeded Oat-Alfalfa Companion Crops, Carson D. Roberts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Small grain companion crop seeding rate recommendations for alfalfa (Medicago sativa L.) establishment are dated and inconsistent, and how a small grain companion crop seeding rates should be adjusted at different moisture levels is unknown. A study was conducted to provide clarity about oat (Avena sativa L.) companion crop seeding rates that maximize weed suppression and forage yield and minimize the effect on alfalfa stand establishment. This experiment considered oat companion crop seeding rates at various irrigation levels. Companion crop treatments consisted of oats sown at 89, 45, 22, 10, and 0 (with and without herbicide) kg ha …

Innovative Water Management Using Advanced Irrigation Systems And Biochar, Jonathan A. Holt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two approaches to water optimization in agriculture are to increase soil water retention and improve the efficiency of irrigation. A soil amendment that has received attention for its ability to increase soil water retention is biochar, the remaining biomass after high C materials have been pyrolyzed (burned with limited oxygen and heat). Two studies were conducted at a total of 10 site-years in Utah from 2018 to 2020 to evaluate how wood biochar influences the productivity and crop quality of irrigated alfalfa (Medicago Sativa L.), corn (Zea mays L.), and wheat (Triticum L.), along with soil water tension. One study …