From Latin acris meaning sour, very acid, indicative of a low base saturation of the cation exchange capacity at pH 7.0.
an argic horizon, which has a cation exchange capacity (in 1 M NH 4OAc at pH 7.0) of less than 24 cmol c kg −1 clay in some part, either starting within 100 cm from the soil surface, or within 200 cm from the soil surface if the argic horizon is overlain by loamy sand or coarser textures throughout, and
a base saturation of less than 50% (in 1 M NH 4OAc at pH 7.0) in the major part between 25 and 100 cm.
Soils characterized by the presence of a well‐defined B horizon, with a blocky, prismatic, granular or massive structure (depending on water content, amount of Fe sesquioxides, and mineralogy of the fine fraction), which has a markedly increase in clay content (argic horizon) relative to the overlying horizons, and a cation exchange complex in which acidic cations (ionic Al species and, to a lesser extent, H +...
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