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Book: Tomography of Soil-Water-Root Processes
Published by: Soil Science Society of America, American Society of Agronomy, and Crop Science Society of America



  1.  p. 87-97
    SSSA Special Publication 36.
    Tomography of Soil-Water-Root Processes

    S. H. Anderson and J. W. Hopmans (ed.)

    ISBN: 978-0-89118-931-2


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Gamma Ray Tomography Measurements of Soil Density Variations in Soil Cores1

  1. G. O. Brown,
  2. M. L. Stone,
  3. J. E. Gazin and
  4. S. R. Clinkscales
  1. Oklahoma State University, Stillwater, Oklahoma


Small scale density variations in soil cores were measured and quantified using a gamma ray tomography scanner. The dry bulk density distribution was measured on samples of Norge silty loam (fine-silty, mixed, thermic Udic Paleustoll). The samples differed in size and sampling method. With these measurements the natural density variation within the samples and the effects of sample collection were defined on the scale of 5 mm3. Driven, 50.8-mm cores were adequate to describe the density variations of the soil matrix. None of the samples were considered adequate to define the soil macropores. The mean density distribution was found to vary over small vertical distances. All samples had density distributions with negative skew and kurtosis less than three. The standard deviation and kurtosis of the density distribution was found to increase with increasing numbers of macropores.

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Copyright © 1994. Copyright © 1994 by the Soil Science Society of Agronomy, Inc., 5585 Guilford Rd., Madison, WI 53711 USA