Black soils are characterised by a significant content of humified organic matter accumulated in a deep humus layer, meeting the diagnostic criteria for mollic soil, from which the soil type takes its name due to its black or almost black colour.
The second distinguishing feature of black soils is permanent or periodic excessive moisture (or even waterlogging) in the lower and middle parts of the profile, resulting in the presence of soil-gley properties or strongly marked precipitation-gley properties.
Black soils are a type of soil with a varied origin, in which human influence is very often evident. They can form as a result of the drainage of a water reservoir (lake) or marshy area and the deep homogenisation of surface organic and underlying mineral formations.
