Basic Information | International Commission on Irrigation & Drainage (ICID)

(1585) Soil

The soil is a natural body of mineral and organic constituents, differentiated into horizons, of variable depth, which differs from the material below in morphology, physical make-up, chemical properties and composition, and biological characteristics. In agricultural soil science, the term soil is applied only to the thin upper part of the mantle rock penetrated by the roots of plants, which supplies them with water and other substances necessary for their existence. In civil engineering, soil includes all the loose or moderately cohesive deposits, such as gravels, sands, silts or clays, or any of their mixtures.