Soil classification principles: Soil bodies and the environment

The major principles of soil classification are discussed. It is emphasized that information on the stable substantive soil properties is insufficient for the proper assessment of soil classification position. As argued by Dokuchaev in 1886, it is also necessary to have information about the external conditions of soil functioning (the environmental conditions), as well as about the soil bioproductivity. Arguments in favor of the coordinate principle of soil classification are given. This principle suggests the combination of internal soil properties with external factors and regimes on the coordinate basis. The ecologic-genetic soil classification system created by N.N. Rozov and E.I. Ivanova in 1967 is considered to be an example of successful classification decisions.