ИСТИНА

As it is known, any natural classification is unthinkable without a precise definition of its object. Revealing the essential character of the object, such definition determines differentiating criteria, structure and, on the whole, the scientificity of the classification system. There are many soil definitions, but in spite of this, attempts to give a new soil definition continue. This proves the importance and complexity of the problem. It is suggested to get back to basics, namely, to a soil definition given by V.V. Dokuchaev, however, improved basing on the General Systems Theory approach, which means studying objects as systems and/or as elements of systems. The following soil definition is offered: Soil is a material self-sufficient system and, at the same time, a derived element of a higher order system that is a natural landscape. Soil is a unique landscape element because only it originates from interaction and interrelation of the other (basic) landscape elements - rocks (parent material including peat and buried soils), air, water, and organisms. The definition reveals the essential character of soil (which is its systematic nature) and is taken as a basis for the development of a hierarchical Natural Soil-Landscape Classification System, which objects are both natural landscapes (as systems) and soils (primarily as derived elements of natural landscapes). In the classification system, differentiating criteria are strictly distinguished from diagnostic ones. As distinct from differentiating criteria, the latter are formal (external) and, on a large scale, morphological properties of natural soils and landscapes. At the higher levels of classification, differentiating criteria are essential (internal) properties of natural landscapes (for example, stability/instability of landscape vertical structure), and at the lower levels - essential properties of basic landscape elements directly responsible for essential properties of soils (for example, type of megarelief). Successive division of natural landscapes causes successive division of soils associated with these landscapes. Selection and ranking of the differentiating criteria are conformed to the rules. The classification system combines soil and landscape classification systems, integrates genetic approach with morphological one and thus differs essentially from current soil classification systems, which consider soils primarily as self-sufficient systems composed of genetic horizons.