Differential ability of the environment implies a special characteristics of the soil  allowing to divide the breeding material into  qualitatively different productivity  genotypes.

The use of natural selection in the breeding process is a key challenge in modern breeding, as the acquired characters of resistance to changing environmental factors during several cycles of crossbreeding will disappear if such indications are not confirmed in the process of natural selection.

The analysis of natural factors influence on the selection process of crops such as spring vyka (Vicia Sativa L.), winter wheat and sugar beets for over the 90-year period of the Bila Tserkva Research Breeding Station functioning was carried out, which was associated with the research relocation.

The location of the research on these agricultural crops selection changed from two to four times. Thus,  it was relocated four times for spring vyka, three times – on sugar beets, twice – on winter wheat. Accordingly, this made it possible to analyse the effect of the relocations on the selection results.

The example of the cultivation Bilotserkivska 88 variety of spring reveals the technology of determining the differentiative ability of selected area’s environment, and the way the research relocation positively influenced the study results.

The natural mechanism the soil complex influence on the selection efficiency remained undisclosed.

In the second half of the twentieth century, foreign publications on the differentiative ability of the environment were revealed in studies on crops selection.

It is highly important to define the concept of "differentiative ability of the environment".

The French word "différenciation" literally means: "the division of the whole into separate qualitatively different parts (Encyclopedic Dictionary, Moscow, 1963). The dictionary of the Ukrainian language is: “differentiated – divided, unequal”.

It is well-known that relocation of plant breeding research in most cases contributes to increased productivity. Crops growth conditions make the main component of obtaining a new high-quality variety of crops. Particularly important role is played by the soil complex, which includes, in addition to mineral and organic compounds of water and air, a large number of microorganisms that interact with plants in dynamics.

Therefore, the question is how to transfer selection crop rotation to a new breeding area with high differentiative capacity.

A technology of determining the differentiative ability of the selected plot can be revealed on the example of the Bilotserkivska 88 breed of spring vyka selection.

To identify a plot with a high differentiative environmental ability (DEA-C), a scheme of primary seed production can be used to test the first year families that have just been included in the State Register of varieties of any crop with a well-defined morphotype.

It is worth mentioning, that selection crop rotation is being used for a long time in scientific institutions: from three or more rotations of tenfold crop rotation, which is one of the reasons for breeding decline due to the loss differentiative environmental ability (DEA-C) on the plot.

Key words: differentiative ability of environment, crop, soil, spring vyka, sugar beet, winter wheat, natural selection.