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Filtering by: Creator Groman, David B. Remove constraint Creator: Groman, David B. Advisor Myrold, David D. Remove constraint Advisor: Myrold, David D.

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  • 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
    Full Text:
    AN ABSTRACT OF THE DISSERTATION OF Shannon B

  • Toward understanding the nature of the soil microsite in relation to nitrogen and carbon cycling

    Creator:
    Cliff, John B.
    Abstract:
    My research has focused on understanding N and C cycling in soils at small scales. Isotope dilution methods commonly used to estimate gross rates of soil chemical transformations assume homogeneous distribution of label. I explored the effects of diffusion limitations on isotope dilution experiments in soil aggregates using spherical diffusion-reaction...
    Resource Type:
    Dissertation
    Full Text:
    AN ABSTRACT OF THE THESIS OF John B. Cliff for the degree of

  • Quantifying the fertilizer value of algal meal : an evaluation of an integrated dairy-anaerobic digester-algae production facility

    Creator:
    Andrews, Shannon B.
    Abstract:
    Algae have shown great potential as a source for renewable fuels. However, current production schemes have not been able to prove a sustainable energy return on investment due in part to the high costs of nutrient addition and the energy required for drying the biomass. Integrated algae-dairy production systems have...
    Resource Type:
    Masters Thesis
    Full Text:
    THESIS OF Shannon B. Andrews for the degree of Master of Science in Soil Science presented on May

  • Litter controls of microbial community composition and function in forest soils

    Creator:
    Brant, Justin B.
    Abstract:
    Most carbon (C) transformations in soil are carried out by a diverse and complex soil microbial community. The size and composition of the soil microbial community is determined by poorly understood interactions between the quantity and chemical composition of plant inputs, as well as climate. Given the metabolic diversity of...
    Resource Type:
    Masters Thesis
    Full Text:
    THE THESIS OF Justin B. Brant for the degree of Master of Science in Soil Science presented on March

  • 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
    Full Text:
    : ______________________________________________________ David D. Myrold Anne E. Taylor Amendments and fertilizers applied to optimize crop

  • Contributions of ammonia-oxidizing bacteria and archaea to nitrification in forest soils

    Creator:
    Lu, Xinda
    Abstract:
    Prior to 2005, ammonia oxidation, the first step of nitrification, was thought mediated mainly by ammonia-oxidizing bacteria (AOB). However, the discovery of Thaumarchaeota carrying the genes coding for the ammonia monooxygenase (AMO) enzyme led to the discovery that ammonia-oxidizing archaea (AOA) also contribute to nitrification. Despite the uptick in studies...
    Resource Type:
    Masters Thesis
    Full Text:
    : _____________________________________________________________________ David D. Myrold Prior to 2005, ammonia oxidation, the first step of nitrification, was

  • 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
    Full Text:
    Input. Abstract approved: ______________________________________ David D. Myrold

  • Functional profiles of soil microbial communities in second-growth Douglas-fir forests of the Pacific Northwest

    Creator:
    McGinnis, Megan L.
    Abstract:
    Forests are one of the largest repositories of terrestrial C. Understanding factors that drive organic matter transformations and nutrient efflux from these systems is therefore highly important. Temperate forests are of particular significance due to the large fraction of C that is stored below ground in the soil. Characterizing nutrient...
    Resource Type:
    Masters Thesis
    Full Text:
    -growth Douglas- fir Forests of the Pacific Northwest Abstract Approved: David D. Myrold

  • The genetic diversity of Ceanothus-infective Frankia

    Creator:
    Ritchie, Nancy J.
    Abstract:
    Frankia from root nodules of nine different species of Ceanothus were characterized. DNA was amplified directly from nodular material using the polymerase chain reaction (PCR). The amplified region includes the 3' end of the 16S rRNA gene, the intergenic spacer (IGS), and a large portion of the 23S rRNA gene....
    Resource Type:
    Masters Thesis
    Full Text:
    approved: David D. Myrold Frankia from root nodules of nine different species of Ceanothus were

  • Linking soluble C to microbial community composition and dynamics during decomposition of ¹³C-labeled ryegrass

    Creator:
    McMahon, Shawna K.
    Abstract:
    Ryegrass residue consists of three main C fractions: readily available soluble C, intermediately available cellulose and hemicellulose, and slowly available lignin. Changes in chemical composition during decomposition influence rate of degradation as well as composition of the microbial community involved. Use of ¹³C-labeled plant material coupled with analysis of phospholipid...
    Resource Type:
    Masters Thesis
    Full Text:
    advisors, David Myrold and Peter Bottomley, and Mark Williams for helping me grow into myself as a