Soil: A Cyclic Terrestrial Bio-Abiotic Elastic–Viscoplastic Flow-Type Body Nonlinearly Functioning in Time and Space, the Key Resource of the Biosphere that Maintains the Carbon Budget and Ensures Food, National, and Social Sustainability of Territor

Three definitions of soil have been developed and still exist in the Russian school of pedology; the functional definition by V.V. Dokuchaev, the attributive definition by V.R. Williams, and the functional-attributive definition based on a combination of the two (D.G. Vilensky, V.M. Fridland, G.V. Dobrovolsky, B.G. Rozanov, and others). Among the most important ecological functions and ecosystem services performed by soils, it is necessary to stress the role of soil cover in maintaining the carbon budget and ensuring the food, national, and social sustainability of territories.