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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 …

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 …

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. …

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 …

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 …

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 …

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 …

Mechanisms Of Overyielding And Coexistence In Diverse Tallgrass Prairie Communities, Leslie E. Forero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants compete for the same basic nutrient and water resources. According to the competitive exclusion principle, when a substantial overlap in resource pools exists, the best competitor for resources should drive all other species to extinction. The ability for plants to coexist in violation of the competitive exclusion principle is the “biodiversity paradox”. Coexistence is actually beneficial for plants: as species diversity increases, you typically see increases in plant biomass production (known as the biodiversity-productivity relationship). The mechanisms behind coexistence and the biodiversity-productivity relationship remain an ecological mystery. One hypothesis is that plants obtain water and nutrients from different places …

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 …

Compost And Cover Crop Effects In Dryland Organic Wheat, Michael D. Deakin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Producers of dryland organic wheat (Triticum aestivum L.) in the western USA struggle to maintain adequate soil fertility due to the high cost of organic fertilizers and concerns over moisture use of cover crops. Low soil fertility results in decreased wheat yield and quality, and increased year-to-year variability in yield and quality based on weather. This study was conducted to measure the effects of, and interactions between, cover crop mixes and a one-time compost application on soil health and winter wheat yield and quality. The study was located on three adjacent certified organic wheat farms near Snowville, UT, each …