The soil cover of Selenga River delta consists of the following soil types: soddy forest soils, soddy grey forest soils, soddy-gley soils, meadow-chernozem soils, meadow soils, alluvial soils, meadow-marshy soils and marshy soils. The soil as an indispensable and inadequately renewable natural resource is an indispensable participant in the biochemical cycles of any level, having the active function to absorb the substances. The concept of soil capacity is developed in detail by physicochemistry and it has the capacity of physical absorption of uncharged integral molecules of matter and mechanical retention of particles of different dimensions which includes substances of different origin.