About Us | Help Videos | Contact Us | Subscriptions



This article in SSSAJ

  1. Vol. 63 No. 1, p. 18-24

    * Corresponding author(s): ewing@iastate.edu
Request Permissions


Discriminating Dyes in Soil with Color Image Analysis

  1. R. P. Ewing  and
  2. R. Horton
  1. Dep. of Agronomy, Agronomy Hall, Iowa State Univ., Ames, IA 50011



Dyes are useful tools for revealing flow patterns, but because analysis of dyes is time-consuming and often only qualitative, soil scientists have not used them to their full advantage. We developed a method for discriminating dyed from undyed soil in the field and for determining the dye concentration from point to point. The method requires a 35-mm camera, a specially constructed camera stand for uniform illumination during field work, and a color scanner. Working with Brilliant Blue FCF dye on a gray (chroma of one) soil, we determined dye concentrations <2.0 g L-1 with an r2 of 0.85 and a median absolute error of 0.17 g L-1. At concentrations >2.0 g L-1, analysis was more problematic due to dye precipitating out of solution onto the soil surface, but we obtained an r2 of 0.70. Use of this method allows convenient and rapid quantitative analysis of dye concentration and other color contrast patterns.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © . Soil Science Society of America