Structure of the soil mantle

Abstract

Initial units of the soil mantle are elementary soil areals which break up into three groups: homogeneous, sporadically spotted, and regular cyclic. Soil combinations consist of elementary soil areals which are genetically linked to various degrees and which produce a definite pattern in the soil mantle. These combinations are the smallest integral sectors of the structure of the mantle. Multiple spatial repetition of a certain soil combination or several soil combinations alternating in a definite order creates various forms of structures of the soil mantle. At the same time, soil combinations can be regarded as models of structures of the soil mantle. According to the character of genetic links between the components and the degree of contrast, the following six classes of soil combinations are singled out: complexes, spottinesses, catenas, variations, mosaics and tachets. Soil combinations are characterized by their composition, genetic and geometric forms, differentiation factors, history of development, degrees of stability, complexity and contrast. A classification of genetic and geometric forms of soil combinations is suggested which reflects the history of the soil mantle development and factors of its differentiation. The structure of the soil mantle is usually a multi-stage one, i.e., the simpler combinations constitute more complex ones. The study of the soil mantle structure provides the grounds for the elaboration of a system of cartographic units to show more completely and accurately the soil mantle on maps of different scales and purposes. The data on the structure of the soil mantle make it possible to effect more accurately all kinds of soil regionalization and predictions of the evolution of the soil mantle under natural conditions and under the influence of man.