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 …

Aspen And Spruce Densities Affect Tree Size, Future Stand Volume, And Aboveground Carbon Following Precommercial Thinning, Philip G. Comeau, Mike Bokalo

Aspen Bibliography

Data collected over a 30-year period from an experiment replicated across 21 locations in western Canada are used to explore the effects of precommercial thinning of trembling aspen to a range of densities in combination with three initial white spruce densities on tree growth and stand dynamics. Increasing differentiation amongst the 15 treatments was observed with age after thinning for both spruce and aspen responses. Spruce height and diameter declined with increasing aspen density. At age 10 spruce diameter with no aspen was 1.5× that of spruce in unthinned while it was 2.6× that of spruce in unthinned at age …

Irrigation Zone Delineation And Management With A Field-Scale Variable Rate Irrigation System In Winter Wheat, Elisa A. Flint, Bryan G. Hopkins, Jeffery D. Svedin, Ruth Kerry, Matthew J. Heaton, Ryan R. Jensen, Colin S. Campbell, Matt Yost, Neil C. Hansen

Plants, Soils, and Climate Faculty Publications

Understanding spatial and temporal dynamics of soil water within fields is critical for effective variable rate irrigation (VRI) management. The objectives of this study were to develop VRI zones, manage irrigation rates within VRI zones, and examine temporal differences in soil volumetric water content (VWC) from irrigation events via soil sensors across zones. Five irrigation zones were delineated after two years (2016 and 2017) of yield and evapotranspiration (ET) data collection. Soil sensors were placed within each zone to give real time data of VWC values and assist in irrigation decisions within a 23 ha field of winter wheat ( …

Asparagus Breeding: Future Research Needs For Sustainable Production, Daniel Drost

Plants, Soils, and Climate Faculty Publications

Productivity in asparagus (Asparagus officinalis L.) is determined in part by (1) the selection of superior, adaptive genetics, (2) matching the selected genetics to the production environment, and (3) managing the crop production system in ways to maximize harvest potential that are sustainable, profitable, and efficient. Over the last 100 years, a considerable effort by asparagus researchers has gone into breeding superior genetic lines, testing those in numerous locations, and studying how asparagus responds to a multitude of inputs (fertilizers, irrigation, fungicides, herbicides, insecticides). Farmers worldwide have benefited from all of these improvements. However, as we look to the …

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, …

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. …

Trends In Us Crop Yields & Water Use, Britta L. Schumacher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Over half the land in the US is dedicated to agriculture, with the vast majority of all cropland cultivated in corn, wheat, or soybean. Despite continuing advances in agricultural technologies, and consistent yield growth over the twentieth century, research suggests that environmental change is already impacting agricultural yield and future changes are sure to exacerbate challenges to agricultural production. It follows that the future of US agriculture depends on the evolution of the changing climate, the relationship between crop yields and the environment, on-farm management and adaptations, the ecosystems that support agriculture, the political and economic incentives that shape what …

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 …

Ecology And Economic Impact Of The Invasive Brown Marmorated Stink Bug (Hemiptera: Pentatomidae; Halyomorpha Halys) In The Utah Agricultural Landscape, Zachary R. Schumm

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The brown marmorated stink bug (BMSB) is a major insect pest that causes economic loss to a diversity of U.S. fruit and vegetable crops, and invades homes and human structures, causing nuisance issues for homeowners. This destructive insect causes millions of dollars of crop damage annually, and is difficult to manage due to its resistance to some common insecticides. BMSB is a relatively new pest to Utah, and its biology and ecology is not well known in the high elevation, arid Intermountain West region. In Chapter II, I explored the potential impact of BMSB to tart cherry, an unstudied crop …

Secondary Electron Yield Analysis Of Contamination Found On Long Duration Exposure Facility Panels, Trace Taylor

Student Research Symposium

The Long Duration Exposure Facility (LDEF) was a NASA mission designed to view the long-term effects of space exposure which flew in the Low Earth Orbit (LEO) environment from 1984 to 1990. The mission was originally planned to last 9 months but, after a series of delays resulting from the Challenger explosion, remained in space for 69 months before it was recovered. LDEF results are very noteworthy as the number of long exposure materials available for study is limited by the expense required to launch and retrieve them. USU received a plate that flew on the LDEF mission and has …

The Impacts Of Crop, Soil, And Water Management On Corn Silage Yield, Tina Sullivan

Student Research Symposium

A resource on the minds of nearly all in the Intermountain West is water. Increases in urban growth, less winter snowpack, watershed depletions, and persistence in drought continue to point towards the need to optimize water in agriculture. Numerous management practices today have water-saving capabilities or allow water to be used during more efficient times of the growing season. Some include advanced pivot technologies, drought tolerant crop genetics, and soil wetting agents. Many studies show these individual practices usually help optimize water use, yet few, have evaluated how these various combinations might combine or 'stack' to optimize water use. An …

Uintah Basin’S Wastewater Evaporation Ponds Could Yield Bioenergy | Biological Engineering, Usu College Of Engineering

College of Engineering News

LOGAN, Utah, Sept. 15, 2015 – The wastewater evaporation ponds that support the oil and natural gas extraction industries in the Uintah Basin may soon help spur the development of alternative bio-based fuels.

Irrigated Birdsfoot Trefoil Variety Trial: Forage Yield, Jennifer W. Macadam, Thomas C. Griggs

All Current Publications

Like alfalfa, birdsfoot trefoil is a deep-rooted legume that fixes its own nitrogen. However, it contains a small amount of tannin which means that cattle and sheep will not bloat, even when grazing birdsfoot trefoil in pure stands. In this bulletin, we report on the dry matter production of a number of cultivars of birdsfoot trefoil and find that it yielded about two-thirds as much as alfalfa in pure stands.

Herbicide Strategies To Maximize Yield In Glyphosate-Resistant Corn, Earl Creech, Clark Israelsen, Mike Pace, Ralph Whitesides

All Current Publications

Water, nutrients, space, and sunlight are critical resources for the growth and development of all crops. Over the years, recommendations for inputs such as fertilizer, irrigation, and seeding rate have been fine-tuned to maximize yields while minimizing cost. Weeds compete with crops for this limited pool of resources. As resource availability shrinks, crop yields almost immediately begin to decline

Electron-Induced Electron Yields Of Uncharged Insulating Materials, Ryan Carl Hoffmann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Presented here are electron-induced electron yield measurements from high-resistivity, high-yield materials to support a model for the yield of uncharged insulators. These measurements are made using a low-fluence, pulsed electron beam and charge neutralization to minimize charge accumulation. They show charging induced changes in the total yield, as much as 75%, even for incident electron fluences of <3 fC/mm², when compared to an uncharged yield. The evolution of the yield as charge accumulates in the material is described in terms of electron recapture, based on the extended Chung and Everhart model of the electron emission spectrum and the dual dynamic …

Measurement Methods Of Electron Emission Over A Full Range Of Sample Charging, R. C. Hoffman, John R. Dennison

All Physics Faculty Publications

The electron emission properties of a material subject to incident radiation flux are key parameters in determining to what equilibrium charge a spacecraft will established under given environmental conditions. However, there is a complex relation between these emission properties and the charge built up in spacecraft insulators. Complex modeling codes have been developed to predict the potential a spacecraft will adopt as a consequence of its interaction with the space plasma. These require correct models of the electron yields as a function of charge to accurately predict the both the charge build up and the equilibrium potential of spacecraft components. …

Beef Quality And Yield Grading, Dale Zobell, Lyle Holmgren, Dick Whittier

All Current Publications

No abstract provided.

Optimizing Conjunctive Use And Groundwater Yield, Richard C. Peralta, Rahman Rahimzadegen, Narendra K. Tyagi

Civil and Environmental Engineering Faculty Publications

Advances in computer power and mathematical optimization procedures can improve planning and developing sustainable irrigation systems. Simulation and optimization models can help plm1 groundwater and conjunctive use strategies to best achieve management goals while satisfying mm1agement a11d physical constraints. Simulation/optimization models that couple calibrated flow and transport simulation models with optimization algorithms can help design the best water management strategies. Mm1agers can be relatively sure that the groundwater system will respond acceptably when appropriate procedures are employed to develop the water management strategies. Presented case studies illustrate situations in which developed strategies simultaneously address conflicting management goals such as: maximizing …

The Effect Of Salinity Level Upon The Yield, Root Growth, And Water Extraction Of Contrasting Rooting Subpopulations Of Alfalfa (Medicago Sativa) Under Conditions Of Zero Leaching, Laura A. Vincent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major problem in irrigated agriculture in the Western U.S. is the gradual accumulation of salinity in the plant root zone. These nonuniformly saline soils contain increasing amounts of salinity with depth, and salt accumulation is accelerated in situations where leaching is minimized. Root growth and thus plant yield is limited in these soils due to decreased water uptake. We studied the root growth of two subpopulations of alfalfa differing in their ability to produce fibrous roots to determine if altering root morphology would increase plant yield and water extraction, in an irrigated saline soil.

Soil profiles for a control …

Global Climate Change Response Program, Water Yield In Semiarid Environment Under Projected Climate Change, United States Department Of The Interior

Water

This paper presents the practical application of a distributed parameter climate vegetation hydrologic model (CVHM) and its ability to simulate hydrologic response under existing conditions and under assumed CO₂-induced climate and vegetation change. Applying the model to the Weber River basin provided a basis for determining the impacts of climate change on the hydrologic response. By using a "what if" scenario this model included the changes in plant transpiration rates and in vegetation cover under a CO₂-altered climate change and the effects of these changes on water yield.

The Role Of Defects In Semiconductor Materials And Devices, D. B. Holt

Scanning Microscopy

This literature review leads to the conclusion that recently the basis for an understanding of the electrical and optical properties of structural defects in semiconductors, especially in silicon, has begun to emerge. This is due largely to the ability of scanning electron microscopy (SEM) electron beam induced current (EBIC) and cathodoluminescence (CL) to determine the properties of single, well-defined defects in "state of the art" material. However, there are still major differences concerning the physical models to be used to explain different forms of dislocation EBIC contrast variation with temperature and beam current. Basic ideas in this field are emphasized. …

Considering Ecological Constraints While Optimizing Sustained Groundwater Yield, Pahvant Valley, Utah, Getachew Belaineh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Concern for groundwater quality and availability is increasing in Pahvant Valley. Ground-water levels are declining due to intense groundwater extraction for irrigation; water having high total dissolved solids concentration is flowing from the southwest toward the pumping sites; and discharge from natural springs in a wildlife refuge is declining. Transient simulation of aquifer response to 20 years of the 1985 pumping rates (beginning with 1985 groundwater level) predicted that spring discharge would decrease by as much as 87% from 1985 rates. Presented are preliminary pumping strategies that maximize sustainable, steady-state groundwater extraction without unacceptably reducing discharge from the springs. A …

Swift Heavy Ion Induced Electron Emission From Solids, Hermann Rothard

Scanning Microscopy

Quite a number of experiments have been performed on electron emission from solids induced by slow (projectile velocity Vp < 1 atomic unit) or medium velocity heavy ions (projectile energy Ep < 1 MeV/u). Only a few experiments have been made with fast heavy ions (projectile atomic number Zp > 8, Ep > 2 MeV/u) concerning either electron emission yields -y, or double differential electron energy spectra d2n(0)/dEd0 as a function of the observation angle 0. We present the results obtained so far on electron emission induced by fast (Ep > 2 MeV/u) heavy ions (Zp ~ 6). Topics discussed include experimental results for electron yields, -energy and -angular distributions and channelling phenomena as well as the theoretical approaches. We also present new results from recent studies on the evolution of electron yields …

Managing Lodgepole Pine To Yield Merchantable Thinning Products And Attain Sawtimber Rotations, United States Department Of Agriculture, Forest Service

Forestry

This paper suggests solutions for a longstanding problem in managing lodgepole pine forests -- that of managing individual stands to reach their planned rotation age, despite serious hazard from bark beetles and wildfire. The management regimes presented yield merchantable thinning products. The 80-year sawtimber rotation can be achieved using these management recommendations. Thinning at 30 years of age is central to achieving the recommended alternative management regimes. The authors suggest that agencies give roundwood operators a portion of the thinning stemwood as payment. Management regimes that provide attainable rotations are presented in summary tables, by three site index classes and …

Optimal Perennial Groundwater Yield Planning For Complex Nonlinear Aquifers: Methods And Examples, Shu Takahashi, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Optimal perennial groundwater yield pumping strategies were computed for a complex multilayer aquifer with: (i) confined and unconfined flow, and (ii) many flows typically described by piecewise-linear (nonsmooth) equations. The latter flows account for over 50% of the aquifer discharge from the test area, the eastern shore of the Great Salt Lake in Utah. Normally utilized response matrix (RM) and embedding (EM) simulation/optimization modelling procedures did not converge to optimal solutions for this area; they diverged or oscillated. However, the newly presented linear RM and EM approaches satisfactorily addressed the nonlinearities posed by over 2000 piecewise-linear constraints for evapotranspiration, discharge …

Influences Of Nitrogen Supply And Elevated Co2 On Nitrogen Consumption, Nitrogen Loss, Tissue Nitrogen Concentration, And Yield Of Hydroponic Wheat, Karl B. Ritchie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wheat was grown hydroponically for 23 days (early boot stage) in a controlled environment at NO₃^- concentrations of 100 and 1000 μmol and CO₂ levels of 360 and 1200 μmol mo1^-1. Nitrogen consumption and transpiration were measured daily. Tissue nitrogen concentration, total biomass, and percent root mass were measured at harvest. Nitrogen recovery and nitrogen use efficiency were calculated. Elevated CO₂ increased nitrogen consumption of the 100 μmol NO₃^- treatment by 13.6% and the 1000 μmol NO₃^- treatment by 21.3%. These increases were particularly evident during …

Optimizing Perennial Groundwater Yield Planning For Nonlinear Systems: Approach Comparison, Shu Takahashi, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Four alternative simulation/optimization models useful for computing optimal sustained-yield (steady-state) groundwater pumping strategies are compared in terms of formulation, solution procedure, accuracy, and computational efficiency. The different models require different computer processing time and memory. For the aquifer tested system, if more than 10% of the cells have pumping as a decision variable, a fully linearized embedding model will require less computer memory than any other model. All the models address linear and nonlinear steady-state flow in multilayer, unconfined/confined aquifers. They also address several types of nonsmooth external flows. Newly presented are a response matrix model solving external flows described …

Sectar: Model For Economically Optimal Sustained Groundwater Yield Planning, Richard C. Peralta, K. Asghari, R. N. Shulstad

Civil and Environmental Engineering Faculty Publications

This paper presents an approach for computing economically optimal sustained yield ground-water extract ion strategies and supportable irrigated crop acreages. Computed regional strategies maximize the present value of net economic return_ They are useful for long-term agricultural planning because they are sustainable even beyond the planning period considered within the economic optimization. The hybrid approach uses only steady-state flow equations and iterative simulation/optimization to reduce optimization memory requirements below that required by conventional models utilizing both steady and unsteady equations. SECTAR, a quadratic optimization planning model assumes heads will evolve toward optimal steady-state but does initially not know the nonlinear …

Optimal Conjunctive Use-Sustained Yield Pumping Analysis For Eastern Arkansas, Rosalinda R.A. Cantiller, Richard C. Peralta, Hossein Azarmnia

Civil and Environmental Engineering Faculty Publications

The likelihood that irrigated agricultural acreages will increase in eastern Arkansas is high. This results from favorable agricultural soils, climate, and the availability of significant water resources.

Conjunctive Use/Sustained Groundwater Yield Design, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Assuring the sustained availability of groundwater from all parts of an aquifer system is analogous to assuring that the potentiometric surface does not change over the long term. Such a steady-state surface is maintained by a specific spatially distributed pattern of groundwater withdrawal. The finite difference form of the linearized Boussinesq equation for steady two-dimensional flow through porous media is used in models that design optimal regional potentiometric surfaces and the conjunctive water use/sustained yield strategies that maintain them. Presented objectives of such models include minimization of unmet water needs. minimization of the regional cost of attempting to satisfy water …