Goal. The purpose and tasks of the research are to study of the effect of the main tillage minimization and fertilizers on the
microbiological activity of ordinary chernozem in grain-row crop rotation.
Materials and Methods. Field and laboratory investigations were carried out in the conditions of the western Steppe of
Donetsk region during 1993-2006 at the experimental field of the National Scientific Center «Institute for Soil Science and
Agrochemistry Research Named after O.N. Sokolovsky». The soil of the experimental sites is chernozem ordinary.
Results. It is determined that a subsurface non-turning soil tillage in arid conditions forms a layer of soil at a depth 20-30
sm which closed from above by a compacted layer of 10–20 sm. For no-till in such conditions, a layer of 10–20 sm «closes»
by a seal of a 0–10 sm layer. Such “closures” adversely affect aerobic processes, complicate the wetting of deep soil layers
with atmospheric precipitation and increase the drying of the soil from the surface, and reduce cellulolytic activity.
The effect of the main fertilizer on the microbiological activity of the soil depends on the hydrothermal conditions of main
tillage and the period after tillage before the winter.
It is shown that the results of evaluation of soil microflora activity can be used as an indicator of the efficiency of the selected
tillage system and fertilizer.
Conclusion.The effect of plowing failure on the microbiological activity of the soil significantly depends on the hydrothermal
conditions of the main tillage period. No-till in the conditions of unstable moisture of the Eastern Steppe reduce activity of the
microflora of chernozem ordinary. The main fertilizer causes the initiation of successive changes in the soil microbiota, which
is shifted in time in accordance with the characteristics of the main treatment and the hydrothermal conditions of the year.
Acknowledgment. The author expresses his gratitude to PhD (Agricultural Sciences) Tetyana Laktionova, for advice on
Microorganisms, succession, cellulolytic activity, nitrogen-fixing microflora, proteolytic activity of the soil, tillage, fertilizers, meteorological conditions