Glossary of Soil Science Terms

TERM OF THE WEEK

Mollisols: [soil taxonomy] An order of very dark colored, base-rich mineral soils that have a mollic epipedon that commonly overlies mineral material with a base saturation of 50% or more (measured at pH 7). Mollisols may have an argillic, natric, calcic, or less commonly an albic, or petrocalcic horizon, a histic epipedon, or a duripan, but not an oxic or spodic horizon. Mollisols may have any temperature regime but do not have permafrost.