The paper presents the results of a long study of the ordinary cernozems structure of natural ecosystems and field agrocenoses. Structure is the most important indicator of soil fertility. The change of the structure under the influence of factors of intensification of farming is shown, its ecosystem essence (determinism) is highlighted. On the basis of modern (orheological) studies, the parameters of the strength characteristics of the structure are presented - plastic strength and ultimate load of destruction of structural bonds, which is of great importance when using soil as a means of production. The basis of fertility is the relationship between the content in the soil of organic matter and the formation of agronomically valuable aggregates (Cojocaru, 2016). Structural soil is more resistant to machine deformations, less energy is expended on its processing, it provides more efficient use of environmental factors of the habitat and anthropogenic energy spent on fertilizers, processing, pesticides, and other cultivated plants. Strong structure - the basis of erosion resistance of the soil. The purpose of the aggregate analysis is to establish the relative content of aggregates of various sizes in the soil.