|
|
||||||||
a Dep. of Land, Air, and Water Resources, University of California, Davis, CA 95616
b Institute of Soil, Water, and Environmental Sciences, Agricultural Research Organization (ARO), The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
* Corresponding author (geshel{at}ucdavis.edu).
Determination of soil particle-size distribution (PSD) by sieving, hydrometer, and pipette methods as well as by laser diffraction (LD) suffers from inherent flaws, mainly due to the difficulty in defining the size of irregularly shaped particles. Therefore these methods yield only estimates of PSD. The objective of this study was to determine whether a functional relationship exists between the PSDs obtained by the combined sieve-pipette method and those obtained by LD. Samples from 42 California soils were analyzed. For the LD measurements a BeckmanCoulter LS-230 apparatus with a 750-nm laser beam that measures particles in the range of 0.04 to 2000 µm was used, employing the Mie theory for the PSD calculations. Values of 1.5 and 0.2 for the real part and the imaginary term of the refractive index (RI), respectively, gave satisfactory results for the optical model calculations. Volume percentage of the clay-size fraction obtained by LD was generally lower than mass percentage of the clay fraction derived by the pipette method. The opposite trend was noted for the silt-size fraction. Coefficients of determination for the regression equations for the clay, silt, and sand fractions determined by the two methods were 0.702, 0.689, and 0.821, respectively. Good agreement between measured and calculated LD values for one size class was accompanied by poor agreement between measured and calculated values for the other. The LD method provides a continuous PSD curve, which enables a detailed data analysis and a flexible application of different particle-size dependent classification systems.
Abbreviations: LD, laser diffraction PIDS, polarization intensity differential of scattered light PSD, particle-size distribution RI, refractive index
This article has been cited by other articles:
![]() |
E. Segal, S. A. Bradford, P. Shouse, N. Lazarovitch, and D. Corwin Integration of Hard and Soft Data to Characterize Field-Scale Hydraulic Properties for Flow and Transport Studies Vadose Zone J., August 1, 2008; 7(3): 878 - 889. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Eshel, P. Fine, and M. J. Singer Total Soil Carbon and Water Quality: An Implication for Carbon Sequestration Soil Sci. Soc. Am. J., March 12, 2007; 71(2): 397 - 405. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Lee, J. Six, A. P. King, C. van Kessel, and D. E. Rolston Tillage and Field Scale Controls on Greenhouse Gas Emissions J. Environ. Qual., April 3, 2006; 35(3): 714 - 725. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Ginting and M. Mamo Measuring Runoff-Suspended Solids Using an Improved Turbidometer Method J. Environ. Qual., April 3, 2006; 35(3): 815 - 823. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Bedard-Haughn, K. W. Tate, and C. van Kessel Quantifying the Impact of Regular Cutting on Vegetative Buffer Efficacy for Nitrogen-15 Sequestration J. Environ. Qual., August 9, 2005; 34(5): 1651 - 1664. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Eshel, G. J. Levy, and M. J. Singer Spectral Reflectance Properties of Crusted Soils under Solar Illumination Soil Sci. Soc. Am. J., November 1, 2004; 68(6): 1982 - 1991. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||