Soil is specific natural formation, thin layer of earth surface, "skin" of our planet. Soil has several unique properties sharply distinguish its from rocks and minerals by weathering that soil formed. Science about formation, structure, composition and properties of soils is Soil Science. The Soil Science has raised at the end of XIX century on the border of geology, biology and geography. Professor Vassili Vassilievich Dokuchaev was founder of the science. He was the first who established that soils have particular morphological features which allow to distinguish its and geographical distribution of soils on the earth surface has principles like for plants and animals.
Soil characterize high content of specific groups of minerals, known as clays and secondary minerals - kaolinite, montmorillonite, halloysite, illite, serpentine and some other. They have high adsorption properties, large cations and anions exchange capacity, ability to swelling and holding of water, due to that soil is able to hold practically all entered to it chemical compounds.
As consequence, soil is gaining fertility and it is most suitable substrate and medium for inhabiting of majority of living organisms - microorganisms, animals and plants. It is significant that biomass of terrestrial (soil) ecosystems in 700 times exceeds biomass in World Ocean. At the same time, part of the ground is less than one third of the earth (surface and significant portion of its covers by eternal ices).
Activity of soil inhabiting orgaisms provide the transformation (turnover) of majority of chemical elements (more than 65) and dynamic equilibrium (homeostasis) in the nature. The result of such balance is pure water; pure air and pure food products.
Ability of soil accumulate various chemical elements and compounds (some of them are necessary for the living beings - essential macronutrients and microelements, different physiological active substances, others are harmful or toxic (heavy metals, toxins, halogens, etc.) has impact to plants, animals and people living in such soil region. These relations were known many years ago in medicine, veterinary science and agronomy as various endemic diseases. The cause of the diseases were disclosed after works of soil scientists.
Investigations of last decades have shown that influence of soils reflects on the composition and properties not only biosphere of Earth, but also on other its main spheres - water and air.
Soil has significant impact on composition and properties of hydrosphere of Earth. Water, filtrating through soil layers, extracts from every soil own particular set of chemical elements that characteristic for soils of water gathering territories. Inasmuch as fundamental economic indexes of water (technological and hygienic value) are determined by contents of various salts entered from soils, therefore disturbance of soil cover immediately reflects on the quality of water.
The soil cover is one of main regulator of composition of atmospheric air and influence on climate of the planet by this way. The causes of this phenomenon is grandiose biochemical activity of soil microorganisms producing and consuming various gases (nitrogen and its oxides, oxygen, carbon dioxide and oxide, methane and other hydrocarbons and gaseous compounds). Majority of these gases stimulate "greenhouse effect" and destroy ozone layer. Any changes of soil properties lead apparently to disturbance of dynamic balance of gases in composition of atmosphere and to modifications of climate on Earth, correspondingly.
The present shift of climatic equilibrium on our planet is not casual. At the first turn it connects "with disturbance of soil cover in consequence of improper economical activity; large scales irrigation and drainage, tillage of sandy soils and other.
The clarification of all these properties of soil cover lead to conclusion that soil in the scale of the planet is specific natural membrane (biogeomembrane) which regulates interrelation between biosphere, hydrosphere and atmosphere of Earth. The role of soil for the planet so important as skin cover for man.
Soil is main (and renewable under right exploitation) wealth of any state in the world because 90% of food for people is produced on soil or in soil. The destruction of soil cover lead to the poverty of states and ruin of soils can cause loss of mankind. Knowledge of soil properties allow to specialists - soil scientists, to provide necessary recommendations for prevention from threat of hungry and failure of crops to governments of own states and Organization of United Nations.
Soil Science as interdisciplinary science joint different field of human knowledge, between that not only physics, chemistry, mathematics, geography, biology, but also seems to be not connected between it to others sciences - mineralogy and epidemiology, microbiology and climatology, geology and crop science.
Soil science is considered during long period as one of agronomic discipline and is taught only in agricultural educational institutions. Soil Science as an university science formed mainly due to outstanding Russian scientists - V.V.Dokuchaev, V.I.Vernadskiy, PAKostychev, N.M.Sibirtsev, K.K.Gedroiz, K.D.Glinka, B.B.Polynov and many other specialists. At the first in the world the teaching of Soil Science began in Moscow university in 1906, and single at this time department of soil science was organized on physical-mathematical faculty in 1922.
Presently departments of soil science exist in universities of majority of states in the world and Soil Science has status of fundamental academic science with own, object and studies description, explanation and prediction of processes in soil and connected with soil other components of biogeocenoses.
Soil scientists work in universities, scientific institutes and research laboratories, preserves and national parks, various protective of nature and ecological organizations. Many soil specialists serve in state organizations for control and inventory of lands - main renewable resource of each country. Soil scientists determine quality of soil (their sort or type) and compose register of bills in each region and in all state.
Government is not able to organize rational use of its territory and soils without these information. Right evaluation of soil quality is necessary to any person who would like to acquire land for building and economical activity. Therefore need in soil science specialists is constantly increased.
At the first time in the world independent faculty of Soil Science was organized in Moscow State University (MSU) in 1973 year. It has given basis for new stage in the development of the science.