Index Catalog // ScholarsArchive@OSU

Water content and electrical conductivity profile measurements for dispersive media using enhanced time domain and frequency domain models

Creator:: Flugstad, Benjamin A.
Abstract:: Water conservation and water quality are rapidly increasing in importance in all areas of the world. The ability to accurately measure soil water content and salinity, over a wide variety of conditions, is key to meeting this need. A set of forward prediction models and waveform interpretation algorithms to extract...
Resource Type:: Dissertation
Full Text:: Irrigation) . 240 Figure 4.3a: Soil Moisture Content Measurement Cell w/PCBA at Bottom and Parallel Wire

Addressing Data Resolution in Precision Agriculture

Creator:: Kelley, Jason
Abstract:: Irrigated agriculture constitutes the greatest consumptive water use globally, so that irrigation efficiency measures are an important part of global efforts to best utilize this limited resource. However, greater irrigation efficiency must be achieved while simultaneously maintaining or increasing crop yields and farming profitability. Incremental water use decisions are made...
Resource Type:: Dissertation
Full Text:: irrigation demand. Soil moisture measurement helps determine how much water that is available to crops

Improving soil water determination in spatially variable field using fiber optic technology and Bayesian decision theory

Creator:: Sayde, Chadi
Abstract:: Achieving and maintaining sustainability in irrigated agriculture production in the era of rapidly increasing stress on our natural resources require, among other essential actions, optimum control and management of the applied water. Thus, a significant upgrade of the currently available soil water monitoring technologies is needed. The primary goal of...
Resource Type:: Dissertation
Full Text:: limited the problem of measurement uncertainty is often circumvented by maintaining soil moisture at

Towards autonomous irrigation : comparison of two moisture sensing technologies, irrigation distribution analysis, and wireless network performance at an ornamental container nursery

Creator:: Bailey, Daniel R.
Abstract:: As ornamental container nurseries face diminishing water allocations, many are looking to automated irrigation solutions to increase their water application efficiency. This thesis presents the findings of a study conducted at a commercial container nursery to determine 1) whether a capacitance or load cell sensor was better suited for monitoring...
Resource Type:: Masters Thesis
Full Text:: ................................ 25 1.12 Ideal soil moisture retention curve

Evaluation of six tools for estimating woody biomass moisture content

Creator:: Becerra Ochoa, Fernando Amador
Abstract:: Woody biomass transportation costs and market values/costs are strongly correlated with the woody biomass moisture content. Properly managing moisture content can potentially lead to economic and environmental advantages in biomass energy markets. Good management requires accurate moisture content measurements. Therefore, availability of accurate, precise, reliable, and efficient tools to assess...
Resource Type:: Masters Thesis
Full Text:: Moisture Content AN ABSTRACT OF THE THESIS OF Fernando Amador Becerra Ochoa for the

Effects of Initial Moisture and Surface Properties on Sorptivity of Coarse Soil and Sand

Creator:: Ambrowiak, Gloria M.
Abstract:: Many different models and mechanisms of water imbibition into soil have been described in the literature. Theoretical equations based on those models exist to predict how water will flow in porous media. These models can be useful, but have their weaknesses. Research on imbibition and infiltration into soils has mostly...
Resource Type:: Masters Thesis

Exploring mechanisms that drive the development of reversible soil hydrophobicity

Creator:: Woolverton, Priscilla B.
Abstract:: This study focuses on one widespread characteristic of poor soil quality: hydrophobic soil. Previous research has produced conclusive evidence to show that soil hydrophobicity is affected by soil organic matter (SOM) and soil water content (WC). Hydrophobicity that responds to changes in WC is a unique form of surface hydrophobicity...
Resource Type:: Masters Thesis
Full Text:: measurement of wettability and soil organic matter characterization...................................... 24

Characterization of hydrologic parameters and processes in shrink-swell clay soils

Creator:: Stewart, Ryan D.
Abstract:: Vertisols and other vertic-intergrade soils are found all over the globe, including many agricultural and urban areas. These soils are characterized by their cyclical shrinking and swelling behaviors, where bulk density and porosity distribution both vary as functions of time and/or soil moisture. In turn, alterations in physical soil parameters...
Resource Type:: Dissertation
Full Text:: soil moisture. In turn, alterations in physical soil parameters become manifest as crack networks

Distinguishing biological and physical controls on soil respiration

Creator:: Phillips, Claire L.
Abstract:: Soil respiration, or the combined CO₂ emissions from roots and soil microorganisms, constitutes one of the largest losses of carbon (C) from terrestrial ecosystems. The major drivers of soil respiration, which include soil moisture, temperature, and substrate quality, have been known for some time. Nevertheless, correlations between these drivers and...
Resource Type:: Dissertation
Full Text:: ecosystems. The major drivers of soil respiration, which include soil moisture, temperature, and substrate

Unsaturated Soils and Foundation Design : Theoretical Considerations for an Effective Stress Framework

Creator:: Baker, Josiah D.
Abstract:: This study presents the theoretical background necessary to model the bearing capacity of shallow and deep foundations in partially saturated soils. The conventional bearing capacity equations for shallow and deep foundations and the 𝛽-method for deep foundation side resistance have been modified to include the effects of matric suction and...
Resource Type:: Masters Thesis
Full Text:: ....................................................................19 2.3.1. Soil Water Characteristic Curve

The methodology, implementation, and analysis of the isotopic composition of soil respired CO₂ in forest ecological research

Creator:: Kayler, Zachary Eric
Abstract:: Soils are the largest terrestrial pool of carbon, therefore it is critical to understand what controls soil carbon efflux to the atmosphere in light of current climate uncertainty. The primary efflux of carbon from soil is soil respiration which is typically categorized into autotrophic and heterotrophic respiration. These two components...
Resource Type:: Dissertation
Full Text:: and the carbon isotopic signature; soil moisture primarily influenced tree processes related to

Ecohydrological mediation of water budget partitioning and time scales of subsurface flow in a seasonally semi-arid grassland

Creator:: Pangle, Luke A.
Abstract:: Understanding how the interactions and feedbacks between plant function, climate, and soils ultimately affects the terrestrial water balance and subsurface flow processes is major challenge in scientific hydrology. This dissertation summarizes the findings of a manipulative climate warming experiment, an observational field study that utilized stable-isotope tracers, and associated modeling...
Resource Type:: Dissertation
Full Text:: of evapotranspiration, soil moisture, and potential groundwater recharge to a 3.5˚C temperature

Response of Roughstalk Bluegrass (Poa trivialis L.) to Waterlogging Stress

Creator:: Liu, Mingyang
Abstract:: Roughstalk bluegrass (Poa trivialis L.) (RB) is a weed species that increased very quickly in grass seed production fields of the Willamette Valley. The invasion of RB in grass seed crops often occurs in waterlogged soils. In waterlogged areas, RB exhibited better competitiveness and had greater population densities than other...
Resource Type:: Dissertation
Full Text:: Crop Science Head of the Department of Crop and Soil Science Dean of the Graduate

Radiologic sampling of surface soils near a USEPA superfund site

Creator:: Blakeman, Christopher John
Abstract:: The human health effects of acute exposure to high levels of ionizing radiation are well understood; however, when these irradiations occur at low levels, there is controversy as to their potential health threat (BEIR V, 1990). For individuals living in areas where the level of naturally occurring background radiation is...
Resource Type:: Masters Thesis
Full Text:: uppermost soil layers. Soil samples were collected from seven sites located between 1.3 and 6.7 km along a

Quantification of state-and-transition model components utilizing long-term ecological response data following one-seed juniper treatment on a deep sand savannah ecological site

Creator:: Shaver, Patrick L.
Abstract:: A proposed state-and-transition model (STM) for the Deep Sand Savannah ecological site in central New Mexico was developed using historical data and expert knowledge. This STM was tested utilizing data from short and long term one-seed juniper (Juniperus monosperma (Engelm.) Sarg.) control experiments initiated in 1981 and 1985. Utilizing data...
Resource Type:: Dissertation
Full Text:: 2003. Soil moisture data indicated the treated plots contained significantly (α=0.05) more available

Response of Soil Temperature, Moisture, and Respiration Two Years Following Intensive Organic Matter and Compaction Manipulations in Oregon Cascade Forests

Creator:: Gallo, Adrian Carlos
Abstract:: Forest soils contain a substantial portion of global terrestrial carbon stores. Forest management can influence the soil carbon pool and how soil organic matter functions. The long-term productivity of forests is an ongoing goal where land managers utilize biomass and timber. A site-specific understanding of intensively managed forests can ensure...
Resource Type:: Masters Thesis
Full Text:: presented on September 20, 2016. Title: Response of Soil Temperature, Moisture, and Respiration Two

Soil Water Tension Irrigation Criteria Affects Both Stevia Rebaudiana Leaf Yield and Leaf Steviol Glycoside Composition

Creator:: Parris, Cheryl A.
Abstract:: Stevia (Stevia rebaudiana) is a perennial herbaceous plant native to Paraguay and used traditionally by the native Guarani peoples for centuries to sweeten medicinal teas. Stevia has only been commercially cultivated over the past 50 years and cultural practice information suitable for implementation by growers is limited. Currently stevia’s commercial...
Resource Type:: Masters Thesis
Full Text:: compounds change under different soil moisture criteria, and to what extent can correlations be found with

Forest Soils and Topography : Decoding the Influence of Physical Site Characteristics on Soil Water and Forest Productivity in Oregon's Coast Ranges

Creator:: Rodman, Henry
Abstract:: Forest soils and topography have long been known to influence forest productivity in complex terrain such as Oregon’s Coast Ranges. Incorporating physical site characteristics into predictions of forest growth and yield, however, has been problematic because of the high spatial variability of soil properties and the challenges associated with representing...
Resource Type:: Masters Thesis
Full Text:: provide an index of deeper-soil water holding capacity. Analysis of a time series of soil moisture

Using soil data to enhance modeling of forest responses to climate change

Creator:: Peterman, Wendy L.
Abstract:: The over-arching theme of this work is that soil data affect the performance and realism of vegetation models with particular focus on their ability to predict or explain disturbances such as fire or disease. We tested the sensitivity of the Excel version of the 3-PG model to soil properties and...
Resource Type:: Dissertation
Full Text:: on diseases and insect attacks, I noticed that soil moisture and soil temperature were often

Long-term Ecohydrologic Response to Western Juniper (Juniperus occidentalis) Control in Semiarid Watersheds of Central Oregon : A Paired Watershed Study

Creator:: Ray, Grace L.
Abstract:: Rangelands span over 50% of the globe and approximately 70% of the United States. Although livestock production is an important use of rangelands, the benefits of rangelands are highly diverse. Humans find intrinsic value in protecting these unique and variable landscapes for wildlife, vegetation, and recreation enthusiasts. Woodland plant encroachment...
Resource Type:: Masters Thesis
Full Text:: < 0.05) mean value of soil water content for three (July, January, and May) out of five measurement

The expression of functional traits during seedling establishment in two populations of Pinus ponderosa from contrasting climates

Creator:: Kerr, Kelly L.
Abstract:: Vegetation patterns and species distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting climatic regimes could exhibit differences in the degree to which certain functional traits related to establishment are expressed. Tree seedling survival is crucial for forest regeneration, and thus may be a...
Resource Type:: Masters Thesis
Full Text:: distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting

Context matters : A multi-scale assessment of riparian tree response to upslope density reduction

Creator:: Ruzicka, Kenneth J., 1982-
Abstract:: Forest management is rapidly undergoing a transformation from a discipline based on efficient commodity production to one for multiple uses, especially on federally managed land in the United States. This new management paradigm has challenged silviculturists to develop and adapt forest management techniques that can deal with increased demands. Using...
Resource Type:: Dissertation

Influence of cover crop residue management on soil moisture, vine growth, and productivity in a pre-production vineyard in the Willamette Valley

Creator:: Curtis, Morgan A.
Abstract:: The use of cover crops in young vineyards is not widely accepted in the Pacific Northwest due to concerns of water and nutrient competition between the cover crop and vines. The last 2 years of a 4-year study started in 2009 are reported here. The study evaluated the use of...
Resource Type:: Masters Thesis
Full Text:: on May 24, 2013 Title: Influence of Cover Crop Residue Management on Soil Moisture, Vine Growth

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