With the human eye being unreliable at color determinations
(Thompson et al., 2013), other soil scientists have turned to spectrophotometers
for determining soil color. In a study conducted
by Shields et al. (1968), soil samples from Chernozemic and Podzolic
soils in air-dried and field-capacity conditions were analyzed
for color using the Munsell Color Chart and a Bausch and Lomb
model Spectronic 600 laboratory spectrophotometer. The spectrophotometer
results had low standard deviations showing that
the spectrophotometer was more precise than the visual measurements
using the Munsell Color Chart. Moisture also caused the
Munsell color results to vary in hue more than expected. Spectrophotometers,
therefore, do eliminate much of the human error
involved with color analysis of soil samples. The wide application
of spectrophotometers to soil color determination has been limited
because of their expensive cost and lack of portability making
spectrophotometers an undesirable replacement for the Munsell
Color Chart for quick analysis of a soil’s color.