The base saturation requirement sets the umbric horizon apart from the mollic horizon, which otherwise is very similar. Limits with base-desaturated fulvic and melanic horizons are set by the combination of the intense dark colour, the high organic carbon content, the thickness and the characteristics associated with andic horizons in these two horizons. Otherwise, umbric horizons frequently occur in association with andic horizons. These horizons can usually be recognized in the field by the presence of artifacts, spade marks, contrasting mineral inclusions or stratification indicating the intermittent addition of manurial material, a relative higher position in the landscape, or by checking the agricultural history of the area. Vertic horizon General description.
Vertic horizons are clayey, and have a hard to very hard consistency.
When dry, vertic horizons show cracks of 1 or more centimetre wide. In vertic horizons the COLE is more than 0.06. Relationships with some other diagnostic horizons. Several other diagnostic horizons may also have high clay content, viz. Vitric horizon General description.