At a modern level of development of agronomical sciences agriculture can be defined as the science developing ways of the most rational use arable share on physical, chemical and biological.
Agriculture as science is based on the latest theoretical developments of the major fundamental scientific disciplines, such as soil science, physiology of plants, land management and land use, agrochemistry, microbiology, plant growing, biotechnology, agricultural meteorology, melioration, ecology, economy, etc.
Thanks to Dmitry's researches Nikolaevich of Pryanishnikov and his pupils the destiny of nitrogen of ammonia and nitrates in a plant, conditions for the best assimilation of a certain form, and consequently, and ways of effective use of ammoniac and nitrate forms of nitric fertilizers became known.
The scientific agronomics, in W. R. Williams's understanding grows in an organic complex of knowledge with the special specifics determined by her commitment and relationship of the separate parts which are closely connected with natural-historical disciplines. The facts separated still unite in the harmonous filosovsky system especially close to a socialist system.
Dokuchayev — the representative of sciences about Earth — comprehended the chernozem in scales mainly global: in system of natural geographical zones, climatic factors, geological conditions. As the true naturalist, he considered the soil as a special natural body.