Dark Gray Luvisol (D.GL)
Common horizon sequence: LFH, Ah or Ahe, Ae, Bt, C or Ck
These soils have the properties specified for the Luvisolic order and the Gray Luvisol great group. They differ from Orthic Gray Luvisols by having an Ah or Ahe horizon 5 cm or more in thickness. These horizons generally have eluvial features, such as gray streaks or splotches when dry, or platy structure. In the case of disturbed soils, the dry color value of the Ap horizon is 3.5-5.0 and some of the Ae horizon remains below the Ap. The differentiation of Dark Gray Luvisols from Dark Gray Chernozemic soils was outlined previously in this chapter. Dark Gray Luvisols have a mean annual soil temperature less than 8°C. They may have a Btnj or a Bm horizon above the Bt horizon.
Note: Diagnostic horizons are underlined.