What is phase?
phase meaning in Soil Science terminology / glossary / dictionary is:
A utilitarian grouping of soils defined by soil or environmental features that are not class differentia used in U.S. system of soil taxonomy, e.g., surface texture, surficial rock fragments, rock outcrops, substratum, special soil water conditions, salinity, physiographic position, erosion, thickness, etc. Phase identifications are introduced into soil names by adding them to a taxon name as modifiers. See also taxon, component soil.