Digital Commons Network^™

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 …

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 …

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 …

Selection And Propagation Of Pinyon Pine, Kylie M. Lawson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Single-leaf pinyon pines are drought tolerant trees native to the Great Basin. This species is a source of wild-collected, edible pine nuts that are in great demand. With no previous research apparent, this thesis aimed to identify wild trees with high cone production as sources for evaluating grafting onto immature and mature trees. Wild sources of scions were identified from four wild stands and six trees per stand. Counting and analyzing the number of scars left by mature cones along the leader branch provided an estimate for each tree‚Äôs productivity and identified trees with greater productivity within a stand. The …

Fruit Tree Responses To Water Stress: Automated Physiological Measurements And Rootstock Responses, William D. Wheeler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

New orchard plantings utilize trees grafted to dwarfing rootstocks planted close together to facilitate larger harvests. These dwarfing rootstocks have not been comprehensively studied for their ability to withstand drought. This is of special importance in the Intermountain West which has limited rainfall. Additionally, orchard growers face competition for water from a growing population and increased uncertainty in rainfall from climate change. My research examined the use of dendrometers, which measure changes in trunk diameter, and sap flow sensors, which measure how quickly sap moves, as methods to inform growers about tree water status. I also used a weighing lysimeter …

Propagation Of Two Utah Native Plants: Ceanothus Velutinus And Cercocarpus Montanus, Asmita Paudel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Among various water conservative approaches, the use of native plants in landscape, such as Ceanothus velutinus (snowbrush ceanothus) and Cercocarpus montanus (alder-leaf mountain mahogany), is attractive. Efficient propagation methods are required to allow these native species to use in water-efficient landscaping. Sexual (seed) and asexual/vegetative (cuttings and micropropagation) propagation methods were evaluated.

Seeds of both C. velutinus and C. montanus were scarified and/or stratified and treated with gibberellic acid (GA₃) to break dormancy. The results showed hot water scarification and 2-3 months of stratification effectively broke the dormancy of C. velutinus seeds, and stratification for 2-3 months was …

Effects Of Wi-Fi-Enabled Smart Irrigation Controllers On Water Use And Plant Health Of Residential Landscapes In The Intermountain West, Shane R. Evans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Residential and commercial landscapes provide home and business owners with several benefits. These benefits range from improved air quality and flood control to the reduction of noise and breakdown of organic chemicals. However, these landscapes are routinely overwatered which can lead to plant disease, nutrient pollution, and large amounts of water being wasted. Utah State University, in conjunction with the Center for Water Efficient Landscaping (CWEL), the Utah Division of Natural Resources and Weber Basin Water Conservancy District, conducted an experiment to determine if Wi-Fi-enabled smart irrigation controllers conserve water as compared to average residential irrigation amounts and manually programmed …

Water Use In Jujube (Ziziphus Jujuba) With Applications In Irrigation Timing And Quantity, Preston S. Colver

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Jujube (Ziziphus jujuba) is a major fruit crop in China where it has been a favored cash crop and successfully used to address erosion problems in the Loess Plateau region of western China. Further use of jujube in forestry projects and improved agricultural efficiency are very promising. This study sought to repeat a water-use study in two climates: a hot, semi-arid climate in Yangling, Shaanxi, China and a dry-summer, continental climate in Logan, Utah, USA. The study took physiological measurements on the trees with the aim of characterizing the way that jujube uses water. This would help to …

Nodulation And Growth Of Shepherdia × Utahensis ‘Torrey’, Ji-Jhong Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Shepherdia ×utahensis ‘Torrey’ (Elaeagnaceae) is a hybrid of two native actinorhizal plants in the Intermountain West, S. argentea (silver buffaloberry) and S. rotundifolia (roundleaf buffaloberry). Due to actinorhizal symbiosis, atmospheric nitrogen (N₂) can be converted to ammonium, a bioavailable form. Actinorhizal plants have great value in sustainable nursery production and urban landscape use. However, nitrogen fertilizer negatively affects the nodulation of actinorhizal plants. As a newly developed hybrid, both the symbiont identity and nodule formation of S. ×utahensis ‘Torrey’ remain largely unknown. Therefore, experiments were conducted to investigate the nodule formation of S. ×utahensis ‘Torrey’ inoculated with field …

Assessment Of Compost On Dryland Wheat Yield And Quality, Soil Fertility And Water Availability In Utah, Kareem A. Adeleke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 2014-2016 Kareem Adeleke undertook a graduate project under the supervision of Utah State University (USU) Plants, Soils and Climate professors, Drs. Jennifer Reeve, Astrid Jacobson, and Earl Creech. Organic wheat producers face numerous challenges, such as low soil moisture, soil erosion, and low soil fertility. Organic wheat growers generally do not apply fertilizer due to inability to recoup the costs in the short-term. Compost enhances long-term improvement in soil quality, soil fertility and increase yield in low input environments. Understanding of compost carryover effects in dryland wheat systems is necessary for increased yield that will allow adequate supply of …

Soil Health, Phosphorus And Carbon Dynamics In Response To A One-Time Compost Application And Cover Crops In Organic Dryland Winter Wheat, Idowu Ademola Atoloye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Organic dryland winter wheat (Triticum aestivum) growers in the U.S. are faced with high interannual variability in yields. This is related to the low annual precipitation and low soil fertility on the cultivated soils. Improving soil health is the key to increasing and maintaining crop yields. In this study, we compared the effects of different rates (0, 12.5, 25 and 50 Mg DW ha^-1 compost and 2 Mg ha manure^-1) of large quantities of steer manure compost and the inclusion of cover crops versus fallow on soil health and on carbon and phosphorus dynamics in …

Examination And Empirical Forecast Of Wheat Yield In Northwest India Based On Climate And Socio-Economic Factors, Avik Mukherjee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study summarizes the findings of research organized in two parts. The first part includes the impact of climate and socio-economic factors that affected wheat yield in northwest India during the 2000s. The second part focused on the forecast of average wheat yield for the two highest wheat producing states Punjab and Haryana.

Initial study focused on the impact of climate factors on wheat yield in northwest India. It has been found that above normal temperature coupled with water shortage i.e. irregular irrigation and low soil moisture contributed to the prolonged yield reduction during 2002-2010.

Next, we reviewed the socio-economic …

Response Of Glyphosate-Resistant Alfalfa To Glyphosate Application In The Intermountain West, Logan Chet Loveland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Glyphosate-resistant (GR) alfalfa (Medicago sativa L.) has been widely adopted in the Intermountain West United States, where alfalfa plays an important role in agriculture. Exceptional tolerance to glyphosate application has been a reported strength of this technology; however, growers have recently reported potential crop injury under certain environmental conditions. The purpose of this study was to document and characterize the injury, identify local conditions that may have contributed to crop injury, and determine best management practices for avoiding injury to GR alfalfa in the Intermountain West. The effects of glyphosate rate and application timing were investigated at 24 sites …

Enhancing The Production And Sustainability Of Pasture-Fed Beef Using Non-Traditional Legume Forages, Andrea I. Bolletta

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Despite the increasing worldwide demand for beef as a protein source, consumers are concerned about the sustainability of ruminant production systems. Their main concerns are animal welfare for feedlot-fed animals, greenhouse gas (GHG) emissions, global warming and worker safety. Traditional feedlot-based beef production systems have been associated with locally greater levels of soil, water and air contamination, as well as the overuse of antibiotics and growth hormones. The use of legume pastures such as cicer milkvetch (CMV) and birdsfoot trefoil (BFT), which fix their own nitrogen (N) and often contain beneficial secondary compounds such as tannins and provide for rapid …

Salinity Tolerance In Kentucky Bluegrass Hybrids, Paul G. Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Diminishing water sources in the Intermountain West have led to increased use of alternative sources of water. These sources, such as reclaimed water, generally have elevated salinity levels that may slow growth, and cause a decline in turfgrass quality. Kentucky bluegrass (Poa pratensis L.) is sensitive to salt stress, but is otherwise very well adapted to many turfgrass areas because of its dark color, durability, ability to recover from wear, and soft texture. Because of these positive traits, it has been the subject of selection for salt tolerance. This study was designed to evaluate the salt tolerance of hybrids …

The Influence Of Adjacent Weed Populations On Thrips And Iysv In Onion, S. Andrew Swain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Onion thrips (Thrips tabaci) and Iris Yellow Spot Virus (IYSV) constitute a pest complex of global concern for allium growers. Yield losses due to onion thrips alone can be heavy, and in tandem with IYSV, these losses can be complete.

This study was one phase of a multi-phase research project intent on exploring the potential drivers of thrips and virus infestation in onion. Preliminary observations in participating growers’ fields in northern Utah pointed towards a potential link between weedy field borders and thrips/IYSV infestation in onion. Field work was carried out at the Kaysville experiment station examining the …

Herbage Characteristics Affecting Intake By Dairy Heifers Grazing Grass-Monoculture And Grass-Birdsfoot Trefoil Pastures, Marcus F. Rose

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pasture-based dairies have become more prevalent in recent years due to a higher proportion of organic milk demand and production. Organic certification requires that animals must graze at least 120 days in each growing season. However, dry matter intake is often limited when dairy animals receive most of their herbage from pasture, resulting in lower animal performance and milk production. The purpose of this study was to analyze the complimentary effect of high energy grasses with birdsfoot trefoil (BFT) tannins to improve intake of dairy heifers. Jersey heifers were rotationally grazed for 105 days in 2017 and 2018 on eight …

Linkage Of Climate Diagnostics In Predictions For Crop Production: Cold Impacts In Taiwan And Thailand, Parichart Promchote

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research presents three case studies of low temperature anomalies that occurred during the winter–spring seasons and their influence on extreme events and crop production. We investigate causes and effects of each climate event and developed prediction methods for crops based on the climate diagnostic information. The first study diagnosed the driven environmental-factors, including climate pattern, climate change, soils moisture, and sea level height, associated with the 2011 great flood in Thailand and resulting total crop loss. The second study investigated climate circulation and indices that contributed to wet-and-cold (WC) events leading to significant crop damage in Taiwan. We developed …

Genetic Mapping Of Grass Monoculture And Grass-Legume Mixture Compatibility Qtls In Intermediate Wheatgrass, John Mortenson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to increased environmental stewardship and fertilizer prices, there is increased interest in using legume mixes in perennial croplands. The objective of this study was to compare quantitative genetic parameters and quantitative trait loci (QTLs) associated with intermediate wheatgrass (Thinopyrum intermedium) when grown in 1) a non-competitive spaced environment, 2) a polyculture with alfalfa (Medicago sativa), and 3) a monoculture with crested wheatgrass (Agropyron desertorum). Traits evaluated include plant growth characteristics (Zadok’s maturity, height, and tiller count), biomass, and forage nutritive value (CP, NDF, ADF, ADL, IVTD, NDFD, NFC, ME, RFQ). A linkage map …

Explorations And Collaborations On Two Under-Recognized Native American Food Crops: Southwest Peach (Prunus Persica) And Navajo Spinach (Cleome Serrulata), Reagan C. Wytsalucy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agricultural production among the Native American populations of the Southwest declined significantly during the twentieth century. Corn, beans and squash, the three most recognized traditional food crops, remains widespread, but knowledge regarding the traditional management of these crops was lost. The loss of traditional knowledge for Southwest Indigenous Nations was more pronounced for the Southwest peach (Prunus persica) and Navajo spinach (Cleome serrulata Pursh). The Navajo, Hopi, and Zuni Nations are all seeking to increase the availability of traditional crops for their original uses, such as for food and wool dye. In order to revitalize traditional agriculture …

Phosphorus Rate Effects With And Without Avail® On Dryland Winter Wheat In An Eroded Calcareous Soil, Ryan C. Hodges

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soluble phosphorus fertilizer is bound in the soil rapidly after application in soils high in calcium. A fertilizer additive known as AVAIL® (J.R. Simplot Company) is purported to keep applied phosphorus fertilizer more available to plants by binding to soil minerals such as calcium, magnesium, and iron, thereby reducing phosphorus binding. This could prove useful due to the attraction of AVAIL® with cations such as Ca²⁺, but is fairly unstudied for dryland wheat production on alkaline, calcium-rich soils. The objective of this study is to evaluate the effect of low-rate fertilizer treatments with AVAIL® on dryland small grain …

Untangling The Economic And Social Impediments To Producer Adoption Of Organic Wheat, Donya L. Ralph-Quarnstrom

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumer demand for organic products has shown double-digit growth in recent years encouraging the development of a wider range of goods (Greene, 2017). Americans with an annual household income under $30,000 actively purchase organic foods at nearly the same rate as households with over $75,000 in annual incomes, 42% versus 49% (Greene et al., 2017). Previous research observed the adoption of organic farming practices on a combination of different grains, fruits and vegetables, meat, and dairy products from across the globe. However, this is the first study to examine the adoption of organic wheat in the Western U.S. By addressing …

Interactions Between Biochar And Compost In Organic Winter Wheat Production And Soil Quality Under Dryland Conditions, Phearen Kit Miller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Organic wheat grown under dryland conditions encounters challenges such as limited nutrients and water. Maintaining organic wheat production requires solutions to these problems in order to retain economic sustainability for the farmers.

Research on biochar and compost have been conducted globally. Despite well known benefits of compost on soil and crop production, few organic farmers apply compost to their fields. Research on biochar is still new. Biochar is charcoal created from pyrolyzing agricultural material under conditions of low oxygen and high heat. Many studies claim that biochar is a valuable soil amendment for improving organic production and reducing environmental pollution …

A Simple Metabolic Switch May Activate Apomixis In Arabidopsis Thaliana, David Alan Sherwood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Apomixis, asexual or clonal seed production in plants, can decrease the cost of producing hybrid seed and enable currently open pollinated crops to be converted to more vigorous and higher yielding hybrids that can reproduce themselves through their own seed. Sexual reproduction may be triggered by a programmed stress signaling event that occurs in both the meiocyte, just prior to meiosis, and later in the egg just prior to embryo sac maturation. The prevention of stress signaling and the activation of a pro-growth signal prior to meiosis triggered apomeiosis, the first half of apomixis. The same approach was used prior …

Silage Corn Hybrid Response To Row Width And Plant Density In The Intermountain West, Mark A. Pieper

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Corn (Zea mays L.) hectarage has increased rapidly in Utah and Idaho in recent years due to expansion of the dairy industry, but little is known about corn production practices that optimize yield and quality of silage corn in semi-arid irrigated cropping systems. The objective of this study was to determine the dry matter yield and quality effects of corn hybrids grown in different plant densities and row widths in the Intermountain West. Field experiments were conducted under irrigation in 2015 and 2016 at locations near North Logan, Utah and Jerome, Idaho. The experimental design was a randomized complete …

Utilizing Legumes To Improve Production And Nutritive Value Of Intermountain West Pastures, Jacob T. Briscoe

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pastures in the Intermountain Western United States mainly consist of cool-season grasses which lack production without supplemental nitrogen. Legumes provide nitrogen at reduced cost compared to nitrogen fertilizer. There is a need for proven methods of inter-seeding legumes into existing cool-season grass pastures as well as knowledge of how animals prefer legumes to grasses and how the nutritive value of forages change throughout the growing season. This research provides a resource for effective integration of legumes into pastures of the Intermountain West. Alfalfa, birdsfoot trefoil, and cicer milkvetch were inter-seeded into existing cool-season grass pastures following pretreatments of light tillage, …

Pharmacologically Induced Meiosis Apomeiosis Interconversions In Boechera, Arabidopsis And Vigna, Lei Gao

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Apomixis is a clonal propagation method that produces offspring identical to the mother plant. With this feature, superior traits could be maintained over generations. However, our knowledge about apomixis is limited. In this study, we analyzed several apomictic Boechera embryologically to learn the details of apomixis. Meanwhile, we designed chemical treatments to successfully induce sex in apomictic plants and apomixis in sexual plants. Our experiments suggest that sex and apomixis coexist in plants and that sexual and apomictic reproduction are switchable by treating with specific chemicals.

Pruning Strategies For High Density ‘Montmorency' Tart Cherry, Sheriden M. Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The tart cherry (Prunus cerasus) is the most significant fruit tree crop in Utah, accounting for roughly 51% of the total statewide commercial fruit acreage. In order to accommodate harvesting equipment, tart cherries are grown in conventional orchards with large trees spaced up to 5.5 meters apart. New methods of harvest are adapted to smaller trees in tighter spaced high density (HD) orchards. HD orchards bear fruit earlier in the orchard life than conventional orchards, but likely require different pruning and management strategies, which have not yet been determined for tart cherry. Experimental HD orchards were used to …