CHANGES IN THE WATER-PHYSICAL AND MICROBIOLOGICAL PROPERTIES OF CHERNOZEM WITH TILLAGE MINIMIZATION IN THE CONDITIONS OF THE SOUTH-EAST OF THE CENTRAL BLACK EARTH REGION

Abstract

The studies, which were carried out in the soil and climatic conditions of the southeast of the Central Black Earth Region in order to identify the effectiveness of minimizing
soil cultivation, established that the use of shallow nonmoldboard cultivation, surface and zero tillage did not significantly change the water-physical properties of chernozem soil in comparison with classic tillage – plowing to a depth of 20-22 cm. Such tillage leads only to a tendency to increase the density of the soil consistency without significant reduce of the content
of available moisture during the growing season. The consistency of ordinary chernozem was in the optimal range for most of the crops 1.0-1.2 g/cm3. There was a decrease in the available
moisture content in the arable soil layer of 0-20 cm with surface and zero tillage. The maximum average vegetation total number and the number of ammonifying microorganisms were
in the cultivated soil – plowing to a depth of 20-22 and 14-16 cm, which was due to the large
intake of organic matter of plant residues into the cultivated layer. The use of methods of minimizing soil cultivation (nonmoldboard, surface and zero) led to a decrease in the microbiological activity of ordinary chernozem by 2.2-12.3%, respectively, and the group of humus
mineralizers up to 5.8% in comparison with conventional tillage – plowing to a depth of 20-
22 cm. Also, with an increasing effect during the years of using the minimization of soil cultivation, a general trend of activity decrease in the groups of microorganisms associated with
the nitrogen cycle was traced. The most significant development decline of azotobacter colonies was observed with the extreme option of soil cultivation minimizing – direct seeding.