Determining soil color
A soil scientist compares a hand sample from a horizon within a soil profile to a standard color chip in the Munsell Soil-Color Charts®.
(Photo courtesy of John Kelley)
Illustrated Guide to Soil Taxonomy (p. 1-9)
Determining soil color is an important criterion in many of the keys, as well as in the definitions of the diagnostic horizons and features, is soil color. The operational definition for soil color uses the Munsell Soil-Color Charts®. Hue, value, and chroma are identified for a soil sample. Colors are recorded to the closest matching color chip in the charts. The quality of light has an effect on the visual perception of color, so it is best to evaluate color outdoors in natural sunlight, neither too early nor too late in the day, and without wearing sunglasses. Soil moisture state can also influence the hue, value, or chroma observed for the soil (value is particularly susceptible to change in soil moisture state). Because of this, the keys often specify the moisture state (i.e., moist or dry) for the evaluation of color. However, in cases where moisture state is not specified, the criterion is met if the required color is observed either moist or dry.
For more information about describing and sampling soils, visit the "Field Book for Describing and Sampling Soils" or "Chapter 3" of the Soil Survey Manual. From these sites the reference may be viewed or printed, and a pdf file may be created and saved.
For a video on "How to Use the Field Book for Describing and Sampling Soils", Click HERE.
Determining soil color
A soil scientist compares a hand sample from a horizon within a soil profile to a standard color chip in the Munsell Soil-Color Charts®.
(Photo courtesy of John Kelley)
Illustrated Guide to Soil Taxonomy (p. 1-9)
Determining soil color is an important criterion in many of the keys, as well as in the definitions of the diagnostic horizons and features, is soil color. The operational definition for soil color uses the Munsell Soil-Color Charts®. Hue, value, and chroma are identified for a soil sample. Colors are recorded to the closest matching color chip in the charts. The quality of light has an effect on the visual perception of color, so it is best to evaluate color outdoors in natural sunlight, neither too early nor too late in the day, and without wearing sunglasses. Soil moisture state can also influence the hue, value, or chroma observed for the soil (value is particularly susceptible to change in soil moisture state). Because of this, the keys often specify the moisture state (i.e., moist or dry) for the evaluation of color. However, in cases where moisture state is not specified, the criterion is met if the required color is observed either moist or dry.
For more information about describing and sampling soils, visit the "Field Book for Describing and Sampling Soils" or "Chapter 3" of the Soil Survey Manual. From these sites the reference may be viewed or printed, and a pdf file may be created and saved.
For a video on "How to Use the Field Book for Describing and Sampling Soils", Click HERE.