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Filtering by: Advisor Boersma, Larry Remove constraint Advisor: Boersma, Larry Non-Academic Affiliation Oregon State University. Graduate School Remove constraint Non-Academic Affiliation: Oregon State University. Graduate School

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  • Effects of soil moisture-tension on rubidium uptake by sunflowers

    Creator:
    Stevenson, David Stuart
    Abstract:
    There is considerable evidence that the growth and elongation of plant roots increases linearly or almost linearly with increasing water contents or decreasing moisture-tension of soil. If this is true it is difficult to distinguish the effects of different water contents on absorption phenomena such as water or ion uptake...
    Resource Type:
    Dissertation
    Full Text:
    appreciatiDn to Dr. Larry Boersma for his assistance and council during the period of research and

  • The transpiration process as a function of environmental parameters

    Creator:
    Cox, Lloyd Morris
    Abstract:
    The influence of soil moisture stress and soil temperature on transpiration has never been determined explicitly. This relationship has been neglected mainly because of the lack of a satisfactory method to control soil moisture stress. A technique was developed to evaluate this relationship by controlling soil moisture stress with osmotic...
    Resource Type:
    Dissertation
    Full Text:
    encouragement given by Dr. Larry Boersma who served as major professor for this research. Words cannot

  • Effects of petroleum mulch on soil water content and soil temperature

    Creator:
    Kowsar, Ahang
    Abstract:
    Petroleum mulch applied on the soil surface over a row of planted seeds promotes a more rapid and a more uniform germination of seeds, enhances elongation of seedlings and in some cases increases the yield of the crop. The beneficial effects of petroleum mulch have usually been attributed to increased...
    Resource Type:
    Masters Thesis
    Full Text:
    WATER CONTENT AND SOIL TEMPERATURE Abstract approved: Larry Boersma Petroleum mulch applied on

  • Pore size distributions as measured by the mercury intrusion method and their use in predicting permeability

    Creator:
    Klock, Glen O.
    Abstract:
    A number of investigators have proposed equations to predict the permeability of porous media. Most of their equations are based on the distributions of the sizes of the various contributing pores in the medium. Presently the pore size distributions of agricultural soils are most commonly obtained from soil water release...
    Resource Type:
    Dissertation
    Full Text:
    PREDICTING PERMEABILITY Abstract approved: Redacted for privacy (Larry Boersma) A number of

  • Soil physical conditions and nitrogen fixation of soybeans (Glycine max. Merrill, var. Chippewa 64)

    Creator:
    Kuo, Tsungmin
    Abstract:
    The effect of soil water suction and soil temperature on rates of transpiration, photosynthesis, respiration and nitrogen fixation of soybean (Glycine max. Merrill, var. Chippewa 64) seedlings was studied. A special apparatus was developed in which the soil water suction of several cells with soybeans growing in them could be...
    Resource Type:
    Masters Thesis
    Full Text:
    his deep appreciation to Dr. Larry Boersma for the great help, advice, guidance and encourage- ment

  • Temperature and water potential effects on physiological functions of sudangrass (Sorghum vulgare var. Piper)

    Creator:
    Young, Richard Su-Shung
    Abstract:
    Temperature and water potential effects on the growth, transpiration, total nonstructural carbohydrate (TNC) content, and nutrient uptake of sudangrass (Sorghum vulgare var. piper) were investigated in laboratory experiments. The effect of nitrogen supply on the growth and nutrient uptake at constant soil water potential was also investigated in this study....
    Resource Type:
    Dissertation
    Full Text:
    express his deepest gratitude to Dr. Larry Boersma for the great help, advice, guidance, and

  • Measurement and interpretation of physical properties of soils

    Creator:
    Nagpal, Narender Kumar, 1942-
    Abstract:
    One of many important physical properties that must be known to understand transport phenomena in soils is pore size distribution. Presently the pore size distributions of soils are most commonly obtained from soil water characteristic curves. The soil water characteristic curves are usually obtained by the pressure plate technique. It...
    Resource Type:
    Dissertation
    Full Text:
    OF SOILS Abstract approved: Redacted for Privacy Larry Boersma One of many important physical

  • An evaluation of soil warming for increased crop production

    Creator:
    Rykbost, K. A.
    Abstract:
    In regions where soil temperatures limit plant growth, artificial soil warming may be an economically feasible practice. This hypothesis was evaluated in a soil warming experiment near Corvallis, Oregon. This experiment was prompted by the observation that multiple use of waste heat discharged in the condenser cooling water of thermal...
    Resource Type:
    Dissertation
    Full Text:
    . Larry Boersma for his valuable guidance, encouragement and constructive criticism which made the

  • Theoretical and experimental evaluation of transfer of 2, 4-dichlorophenoxyacetic acid in porous media

    Creator:
    Saxena, Subodh Kumar, 1942-
    Abstract:
    Experiments were conducted to study the effect of pore size distribution on the diffusion of 2, 4-Dichlorophenoxyacetic acid (carbon- 14) through water saturated porous media. Eight size fractions of glass beads were used representing the porous media. It was found that as the average particle radius, and hence pore radius,...
    Resource Type:
    Dissertation
    Full Text:
    to Dr. Larry Boersma for his valuable guidance, encouragement and constructive criticism during the

  • Nitrogen uptake by wheat (Triticum aestivum VILL., Host) as a function of root temperature and plant water stress

    Creator:
    Sepaskhah, Ali Reza
    Abstract:
    The effect of soil temperature and plant water stress on nitrogen uptake, growth rate and transpiration rate of wheat (Triticum aestivum VILL. , Host) seedlings was studied. A special apparatus for the control of plant water stress and root temperature was used. Leaf area was measured by the air flow...
    Resource Type:
    Masters Thesis
    Full Text:
    for Ali Reza Sepaskhah ACKNOWLEDGMENTS The author wishes to acknowledge deeply Dr. Larry Boersma