Soil Science Commons^™

Random Forests Applied As A Soil Spatial Predictive Model In Arid Utah, Alexander Knell Stum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Initial soil surveys are incomplete for large tracts of public land in the western USA. Digital soil mapping offers a quantitative approach as an alternative to traditional soil mapping. I sought to predict soil classes across an arid to semiarid watershed of western Utah by applying random forests (RF) and using environmental covariates derived from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and digital elevation models (DEM). Random forests are similar to classification and regression trees (CART). However, RF is doubly random. Many (e.g., 500) weak trees are grown (trained) independently because each tree is trained with a new randomly …

Salinity Inventory And Tolerance Screening In Utah Agriculture, Austin Mccoy Hawks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil salinity, a yield-limiting condition, has plagued crop production for centuries by reducing crop productivity. Research has introduced methods for successfully managing soil salinity. This research discusses the adaptation of established management methods to create new soil salinity management techniques.

One adapted technique is an automated crop screening apparatus. A new design was created and successfully used in rapidly screening two strawberry cultivars to determine their tolerance to salinity. Screening crops and determining their tolerance to yield-limiting conditions are essential in managing soil salinity.

Another salinity management tool used in this research was electromagnetic induction (EMI). EMI was used to …

Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Intermountain West, aspen (Populus tremuloides) has declined mainly due to a combination of successional processes, fire suppression and long-term use of ungulates which has led to replacement by conifers, sagebrush or other shrub communities. Conifer encroachment is believed to cause critical changes in the ecosystem properties. In order to understand the impacts of conifer encroachment on soil properties such as soil organic carbon (SOC) storage, soil morphology, and soil chemical properties, and the implications of such changes, it is very important to assess the soil properties under the two vegetation types. The objectives of this study …

Effects Of Olfactory And Visual Predators On Nest Success And Nest-Site Selection Of Waterfowl In North Dakota, Jennifer Borgo

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Identification Of Subsoil Compaction Using Electrical Conductivity And Spectral Data Across Varying Soil Moisture Regimes In Utah, Jay Murray Payne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Subsoil compaction is a major yield limiting factor for most agricultural crops. Tillage is the most efficient method to quickly treat compacted subsoil, but it is also expensive, increases erosion, and accelerates nutrient cycling.

The use of real-time electrical conductivity (EC) and near-infrared (NIR) reflectance values to differentiate compacted areas from uncompacted areas was studied. This method has potential to reduce monetary and time investments inherent in traditional grid sampling and the resultant deep tillage of an entire field. EC and NIR reflectance are both very sensitive to spatial variability of soil attributes.

The objective of this research was to …

Measurement Of Fine Spatial Scale Ecohydrologic Gradients In A Pinyon-Juniper Ecosystem, Matthew David Madsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, …

Optimal Irrigation Management For Sloping, Blocked-End Borders, Jorge Jose Escurra

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m³/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m).

To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase …

Extending The Season For Sustainability In Utah, Britney Hunter

Undergraduate Honors Capstone Projects

The importance of providing fresh produce on a local level is becoming a widespread consideration among people concerned with the character of their food. For regions without an opportune growing climate, extending the growing season can drastically advance productivity. High tunnels are one way to effectively and profitably extend the growing season in cold climates. The benefits of growing in a high tunnel go beyond raising the temperature. High tunnels contribute to higher quality small fruits and vegetables. The benefits of growing in high tunnels have been explored in other states and could be exploited by Utah growers. Utah's climate …

Terpenes And Carbohydrate Source Influence Rumen Fermentation, Digestibility, Intake, And Preference In Sheep, J. J. Villalba, F. D. Provenza, K. C. Olson

Green Canyon Environmental Research Area, Logan Utah

We hypothesized that toxins and nutrients in foods interact to influence foraging behavior by herbivores. Based on this hypothesis we predicted that 1) terpenes in big sagebrush (Artemisia tridentata) influence intake and preference in sheep for diets varying in sources of nonstructural (barley grain) and structural (sugar beet pulp) carbohydrates, and 2) these effects are due to the differential effects of terpenes on fermentation products and apparent digestibility of each class of carbohydrates. Lambs were fed 2 isoenergetic and isonitrogenous diets with varying proportions of the same ingredients (beet pulp- and barley grain-based diet) or offered a choice between the …

Soil Survey Of Grand Staircase- Escalante National Monument Area, Parts Of Kane And Garfield Counties, Utah, United States Department Of Agriculture, Natural Resources Conservation Service

All U.S. Government Documents (Utah Regional Depository)

This soil survey contains information that affects land use planning in this survey area. It contains predictions of soil behavior for selected land uses. The survey also highlights soil limitations, improvements needed to overcome the limitations and the impact of selected land uses on the environment. This soil survey is designed for many different users. Farmers, ranchers, foresters and agronomists can use it to evaluate the potential of the soil and the management needed for maximum food and fiber production. Planners, community officials, engineers, developers, builders and home buyers can use the survey to plan land use, select sites for …

Bioavailability/Toxicity Of Iron From Aerobically Processed Organic Fertilizer, Stacey Marie Wilson

Undergraduate Honors Capstone Projects

For an undergraduate Honor's project, I worked under the direction of Dr. Jeffery Hall to determine the bioavailability and toxicity of iron from Milorganite® fertilizer, an aerobically processed organic fertilizer. The Milorganite® Company is a subsidiary of the Milwaukee Municipal Sewage District and produces a fertilizer of high iron content (approximately 5-7%). The high iron content has resulted in concern about the toxic potential, which until now was unknown. This thesis paper will explain iron chemistry, bioavailability, requirements, absorption, toxicity, and treatments, followed by a description of fertilizer types and contents. This will be followed by a description and reasoning …

Post-Tillage Dynamics Of Soil Structural And Hydraulic Properties Induced By Capillary Forces And External Loading, Teamrat Afewerki Ghezzehei

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tillage modifies the soil structure to create conditions favorable for plant growth. However, the resulting loose structure is susceptible to collapse by internal capillary forces and external compactive stresses with concurrent changes in soil hydraulic properties. Presently, limited understanding of these complex processes often leads to consideration of the soil plow-layer as a static porous medium. The objective of this dissertation was to develop physically based modeling of soil structural dynamics at the pore scale, based on soil mechanical and rheological properties. The basic geometrical framework of the models was based on regular packing of monosized spherical aggregates forming unit-cells. …

Molecular Characterization Of Soil Ammonia-Oxidizing Bacteria Based On The Genes Encoding Ammonia Monooxygenase, Jose Javier Alzerreca

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ammonia-oxidizing bacteria (AOB) are chemolithotrophs that oxidize ammonia/ammonium to nitrite in a two-step process to obtain energy for survival. AOB are difficult to isolate from the environment and iso lated strains may not represent the diversity in soil. A genetic database and molecular tools were developed based on the ammonia monooxygenase (AMO) encoding genes that can be used to assess the diversity of AOB that exist in soil and aquatic environments without the isolation of pure cultures. The amo genes have excellent potential as molecular markers; since AMO is only found in the AOB and is essential for their metabolism, …

Highline Breaks Watershed [Microform] : Otero County, Colorado, Pueblo County, Colorado : Watershed Plan And Environmental Assessment, United States Natural Resources Conservation Service, Colorado State Soil Conservation Board

Environmental Assessments (NV)

No abstract provided.

Characterization Of Dielectric Properties Of Earth Materials At Low Frequencies, Tarrah Dawn Henrie

Undergraduate Honors Capstone Projects

Sharma and de Lima (1992) have proposed a model based on Fixman's theoretical development of charged macromolecules in external fields (1980). There are three types of charges considered: the fixed surface charges that are covalently bonded, the layer of bound counterions, and the diffuse layer (Fixman, 1980, Lyklema, 1983 ). Figure (1) shows these different layers. Other common theories, such as Schurr's only consider the bound counterions and the diffuse layer. Schurr assumes that the diffuse layer ions can exchange with the electrolyte. A consequence of this assumption is the lack of polarization of the diffuse layer. This leads to …

Utilization Of Spatially Distributed Soil Resources By Several Species Common To The Great Basin, Sarah Duke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heterogeneous spatial and temporal distributions of soil resources important to plant growth have been documented in the sagebrush steppe ecosystem. There can exist as much variability in soil resources within the root zone of individual plants as exists across an entire field. The objective of this dissertation research was to evaluate how plants respond to, utilize and influence the spatial heterogeneity of soil resources. The three specific sets of questions addressed are outlined in the three main chapters of this dissertation.

My first study addressed how the number and concentration of phosphorus (P) patches in the root zone of an …

A Slow-Release Nitrogen Fertilizer: Ammonium-Loaded Clinoptilolite, T. Scott Perrin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crops grown in sandy soils require frequent irrigation. As a result, nitrogen (N) fertilizers. such as ammonium sulfate((NH₄)₂SO₄), are leached from the rooting zone of crops. This loss of N increases N fertilizer use and the potential for nitrate (NO₃^-) contamination of water. Ammonium-loaded clinoptilolite (NH₄⁺-Cp) may reduce this N leaching, increase N fertilizer use-efficiency, and prevent NO₃- contamination of water while sustaining normal crop growth.

The potential of NH₄⁺-Cp as a N fertilizer was assessed in three leaching experiments without plants and …

Identification Of Belowground Woody Structures Using Molecular Biomarkers, Benny R. Bobowski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Within the last two decades substantial progress has been made in understanding seed bank dynamics and the contribution of the soil seed bank to a post-disturbance plant community. There has been relatively little progress, however, in understanding perennial bud bank dynamics and the contribution of the soil bud bank to secondary succession. This lack of information is due primarily to the inability to reliably identify roots, rhizomes, and lignotubers that lie dormant beneath the soil surface. This scientific investigation, therefore, addressed the issue of identification of belowground woody structures.

The first objective was to develop a methodology that utilizes molecular …

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 …

Discussion And Measurement Of Soil Erosion In Iceland, Kimberly Jane Richardson

Undergraduate Honors Capstone Projects

Soil erosion has occurred since the beginning of time. It is a natural process, but one that has been increasing at an alarming rate. Once soil is eroded--whether it is blown out to sea or washed down a river to sedimentize a lake--it is lost. It is almost impossible to reestablish similar soil components and characteristics in a given system. Since soil and vegetation reestablishment is expensive, the prevention of soil erosion by controlling its causes has become the most cost-effective reclamation effort.

After spending six months in Iceland, I wrote this paper on the unique erosion problems facing that …

Final Oil And Gas Leasing Environmental Impact Statement [Microform] : Grand Mesa, Uncompahgre And Gunnison National Forests V1, United States Forest Service

Environmental Assessments (NV)

No abstract provided.

Final Oil And Gas Leasing Environmental Impact Statement [Microform] : Grand Mesa, Uncompahgre And Gunnison National Forests V2, United States Forest Service

Environmental Assessments (NV)

No abstract provided.

Effects Of Polyacrylamide On Rangeland Soils And Plants, Saud Leily R. Al-Rowaily

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this study were to determine the effects of two forms of polyacrylamide (PAM) conditioners (Cross-linked and Non-cross-linked PAM) on evaporation, saturated hydraulic conductivity, water retention, crust and crack formation of soils, seed germination, and seedling and tubeling growth.

The two PAM conditioners, 0.2% concentration by weight, were mixed with seven soils of different textures (sandy loam, silt, silty clay loam, silt loam, fine sand, medium sand, and coarse sand) to investigate the effects on evaporation, saturated hydraulic conductivity, and water retention. Soil samples of different textures were brought to field capacity and placed in a growth chamber …

Soil Heterogeneity And Its Exploitation By Plants, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this dissertation I first examine the ability of individual plants in the field to garner localized soil nutrients. I then measure actual soil variability around perennial plants and use various statistics to quantify the scale and degree of that variability.

Soil patches on opposite sides of Pseudoroegneria spicata tussocks were treated with distilled water or a nutrient solution containing N, P, or K in three field experiments. When P was augmented in the enriched soil patches, rates of P uptake increased significantly for roots from enriched patches compared with roots in control patches. Rates of ammonium and potassium uptake …

Root Exploitation Of Fertile Soil Microsites, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Root exploitation of enriched soil microsites was examined for the tussock grasses Agropyron desertorum and Agropyron spicatum and the shrub Artemisia tridentata. Two mechanisms of exploitation of the microsites were examined: root proliferation and changes in nutrient uptake capacity. One day after nutrient solution was applied to small soil patches, the mean relative growth rate of Agropyron desertorum roots in enriched patches was two to four times greater than for roots of the same plants in soil patches treated with distilled water. This rapid and striking root proliferation occurred in response to N-P-K enrichment as well as to P or …

Soil Temperature Influence On Water Use And Yield Under Variable Irrigation, Jon M. Wraith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The need for efficient use of water resources has increased the importance of optimum soil water usage in agricultural systems. Soil temperature has been shown to be important in influencing the early development of many plant species. Many agricultural regions have suboptimal soil temperature regimes for plant growth, and some cultural practices have been shown to reduce near-surface soil temperatures. The seasonal influence of soil temperature on soil water extraction and aboveground and belowground plant growth under variable irrigation was investigated at the USU Greenville Farm in Logan, UT. Soil surface mulches and buried heat cables were used to modify …

Classification And Interpretation Of Selected Soil Data From A Tropical Region Of Bolivia, Noemi Sabillon

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

"Half of the uncultivated land of the world, or some 80 million hectars (ha), lies in the humid tropics, where the climatic environment offers a high potential for crop production. If only 2 per-cent of this area were put into cultivation with good management practices, enough food could be produced to feed the present population of Latin America" (Committee on Tropical Soils, National Academy of Sciences, 1972).

Boron Composition Of Alfalfa In Utah As Related To Soils And Irrigation Waters, Robert N. Radtke Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Eighteen field plots at 15 locations were selected throughout the state to evaluate the status of the boron content in irrigation waters, soils, and alfalfa (Medicago sativa) plant tissue under irrigated conditions.

No boron deficiency symptoms were observed in any of the alfalfa plants at any of these locations, nor were any of the plant tissue boron levels inadequate. Only two locations were found in which the alfalfa plants exibited toxicity symptoms. These locations were along the Indian and Antelope Creeks in Duchesne County which contain high boron levels in the water. All the alfalfa and soil tested …

Proceedings -- National Wilderness Research Conference: Current Research, United States Department Of Agriculture, Forest Service

Forestry

Includes more than 70 reports of current wilderness research. Papers are organized around nine topics: wilderness resource research, including natural fire, air quality, impacts to soil and vegetation, fish and wildlife, and water; and wilderness user research related to recreational use and user characteristics, attitudes and behavior, benefits, and management concepts and tools.

The Guy Smith Interviews: Rationale For Concepts In Soil Taxonomy, U.S. Soil Conservation Service

Natural Resources-Planning, Management, and Conservation

Interviews with Guy D. Smith, former director of the Soil Survey Investigations Division of the Soil Conservation Service and distinguished international soil scientist.