The soluble mineral fertilizers introduced to the soil, first of all, are dissolved, and then interact with salts of soil solution, with a firm phase of soils, microorganisms and roots of plants. Interaction with salts of solution involves in most cases formation of difficult soluble connections, there is a so-called chemical absorption. Interaction with a firm phase of soils, with the soil absorbing complex is followed by physical and chemical absorption and their transfer to the adsorbed state. Interaction of soluble fertilizers with microorganisms and roots of plants causes biological absorption and transfer to an organic form.
The fertilizers introduced to the soil are exposed to difficult transformations. Interacting with soil solutions, soil colloids and other high-disperse particles of the soil, water-soluble fertilizers undergo the chemical and water and chemical changes accompanied with the phenomena of absorption and fixing of their cationic and anion part. The fertilizers fixed by the soil are not washed away down a profile at infiltration of water and further are used by plants. There is it thanks to that the considered soils have high absorbing ability concerning cations and anions.
The profile of chernozems lixivious consists of the humic and accumulative horizon And, the transitional horizon of AV, the lixivious carbonate horizon In, illuvial the horizon of VSK and the horizon of Sk. On an arable land it has the following structure.
Thus, the group structure of a humus connected with biochemical activity of soils testifies to existence of some specific features of hymification in chernozems of different particle size distribution. More definitely these specifics come to light in the analysis of fractional structure of a humus which is function of salt and mineralogical structures, alkalinities and acidity and other conditions of interaction of organic compounds with mineral part of the soil/8/. As the particle size distribution of soils and breeds is closely connected with mineralogical structure, it considerably defines fractional structure of a humus and condition of its fixing in chernozems. It is confirmed by a ratio of fractions of humic substances and fractional structure of groups of group of companies and FC.
According to statistical processing of results of mass analyses, the average content of exchange calcium and magnesium, the arable horizons fluctuates in such limits: chernozems typical corpulent powerful and easily clay srednemoshchny – 41-43, srednegumusny powerful and tyazhelosuglinisty srednemoshchny – 37-39, low-humus tyazhelosuglinisty – 33-35, low-humus and srednegumusny srednesuglinisty – 25-29 mg-ekv on 100 g of the soil. With depth of a sou of the exchange bases and mainly the content of calcium gradually decrease after decrease in quantity of a humus. In the horizon And srednegumusny it is 1,5-1,7 times higher than the most widespread chernozems in comparison with the horizon of Vk and maternal breed that testifies to intensive biogenous accumulation of exchange calcium.
Distinctions between tyazhelosuglinisty and easily clay chernozems according to the maintenance of the main granulometric fractions are small. Tyazhelosuglinisty soils contain in the horizon And 55-59% of physical clay, 35-43% largely clays and 25-35% of silt, in a middle part of a profile respectively 60-65, 30-38 and 34-38%. Easily clay chernozems have in the horizon And b1-64% of physical clay, 28 — 35% of large clay and 29-36% of silt; in the horizon In respectively 64-70%, 27-32% and 37-44%.
The highest rates of physical and chemical properties of soils belong to options of lixivious chernozems of clay and tyazhelosuglinisty mechanical structure, and the lowest indicators are observed at lungs on mechanical structure of lixivious chernozems. The variation of physical and chemical properties will well be coordinated also with a soil humus. As a rule, the more a humus in the soil, the there are more than absorbed cations, above their sum and capacity of absorption.
The conclusion follows from the told that use of fertilizers on fields has to be carried out taking into account features of typical chernozems concerning the udobritelny substances brought in them taking into account properties udobreniy./2/
Srednesuglinisty chernozems typical already on all humic profile have a humus of fulvatno-gumatny type with the relation of group of companies/FC equal 1,8-1, Extent of hymification of substance in them remains very high (40-43%), contents of the "free" Civil Code – low (8-10%).