Soil Complex

mosaic soil cover consisting of alternating small areas (patches) of soils of different types; the patches alternate with each other every few meters (more rarely, dozens of meters) and are repeated over and over again.

This alternation of soil is most often observed in the chestnut and brown semidesert soil zone, where comparatively small variations in moisture, usually related to microrelief, cause sharp changes in conditions of development for soils and vegetation. The number of types of soils in the soil complex may differ; complexes with two and three types are most common. The soils that are part of the complexes are usually sharply different in the nature of their formation, although they are closely interrelated in origin. For the most part the boundaries between patches of different soils are very clearly defined. The economic importance of soil complexes is determined by the properties of the complex as a whole and by the properties of the poorest soils in the complex, because the separate patches occupied by the different soils in the soil complex are so small as to be insignificant from an economic point of view.