A zonal soil (US soil classification mollisol, sub-order boroll) with a deep A horizon, rich in humus from decomposed grass, and dark in colour. The B horizon is lighter brown, but often absent. The lower horizons are often rich in calcium compounds.

Chernozem development has been associated with temperate continental climates with marked wet and dry seasons, providing enough moisture to permit the decay of the grass litter into humus, but not enough for leaching to be significant. However, Eckmeier et al. (2007) Geoderma 139, 3–4 claim that there is no consensus on the factors controlling the formation, conservation, and degradation of central European chernozems.