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Filtering by: Creator Downing, Dave G. Remove constraint Creator: Downing, Dave G. Advisor Myrold, David D. Remove constraint Advisor: Myrold, David D. Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.)

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  • Impact of Dairy Manure Digestate on Microbial Activities in Soil

    Creator:
    Waggoner, Ashley L
    Abstract:
    Amendments and fertilizers applied to optimize crop production and improve soil health also supply inputs of soil organic matter (SOM) and nutrients that affect soil microorganisms. In the dairy-intensive Pacific Northwest, dairy manure is stored as slurry mixtures until conditions are appropriate for soil application. During storage, the manure begins...
    Resource Type:
    Dissertation
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    total N g-1 dry soil of a local stored dairy manure and digestate and a mineral N source. The manure

  • Community composition and activities of denitrifying bacteria in soils

    Creator:
    Rich, Jeremy J.
    Abstract:
    Few studies have directly compared denitrifying community composition and activities in soils by coupling molecular-genetic techniques and traditional measures of denitnfication. I investigated communities of denitrifying bacteria from adjacent meadow and forest soils in the Cascade Mountains, Oregon. A key gene in the denitrification pathway, N₂O reductase (nosZ), served as...
    Resource Type:
    Dissertation
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    et al. 1997, Naeem et al. 1994, Tilman and Downing 1994). However, despite tremendous advances in

  • Using Algal Biomass as a Fertilizer

    Creator:
    Cappellazzi, Shannon B.
    Abstract:
    Algae can be used in a variety of wastewater systems to capture nutrients while fixing carbon dioxide from the atmosphere. I conducted field trials at three locations in Oregon with both corn and potato crops to assess the agronomic value and environmental impact of using the resulting algal biomass as...
    Resource Type:
    Dissertation
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    C ro p p H Sa n d Si lt C la y To ta l C T ot al N P* K* * S* * C a* * M g ** B

  • Effects of vegetation and disturbance on fungal communities in the western Cascades of Oregon

    Creator:
    Kageyama, Stacie Ann, 1967-
    Abstract:
    The use of high throughput molecular methods that allow for the study of bacterial communities in environmental samples is commonplace in microbial ecology. Until recently, fungal community ecology has focused on isolation, collection of sporocarps, or collection of ectomycorrhizal roots. The techniques used to extract and amplify DNA from environmental...
    Resource Type:
    Dissertation
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    my co-major professors, Dave Myrold and Randy Molina, for their guidance and encouragement, and for

  • An Examination of Factors Controlling the Activity of Ammonia- and Nitrite-oxidizers in Diverse Soils

    Creator:
    Giguere, Andrew T.
    Abstract:
    Nitrification is a critical step in the global nitrogen cycle involving the biological oxidation of ammonia (NH₃) to nitrite (NO₂⁻ ) and then to nitrate (NO₃⁻). The first step in nitrification is carried out by NH₃-oxidizing bacteria (AOB) and archaea (AOA), and the second by NO₂⁻-oxidizing bacteria (NOB). In addition...
    Resource Type:
    Dissertation
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    graduate experience. I would also like to thank my co-advisor Dave Myrold for his insights, guidance, and

  • Response of soil microbial communities and nitrogen cycling processes to changes in vegetation inputs

    Creator:
    Brewer, Elizabeth Ann
    Abstract:
    Changes in the type and amount of plant inputs can occur gradually, as with succession, or rapidly, as with harvesting or wildfire. With global change it is anticipated that both gradual and immediate scenarios will occur at increasing frequency. Changes in vegetation inputs alter the quality and quantity of soil...
    Resource Type:
    Dissertation
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    State. Eldor introduced me to Dave and Sherri introduced me to soils. Sherri has always had

  • Soil community dynamics in sagebrush and cheatgrass-invaded ecosystems of the northern Great Basin

    Creator:
    DeCrappeo, Nicole M.
    Abstract:
    Sagebrush steppe ecosystems in the Great Basin have become increasingly threatened by the proliferation of cheatgrass (Bromus tectorum L.), an invasive annual grass. Diverse sagebrush and perennial bunchgrass landscapes can be converted to homogenous cheatgrass grasslands mainly through the effects of fire. Although the consequences of this conversion are well...
    Resource Type:
    Dissertation
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    . Dave Myrold was always generous with his time and feedback. Our Tuesday morning journal club meetings