CHEMICAL AND BIOLOGICAL PROPERTIES OF IRRIGATED SIEROZEM-MEADOW SOILS

The agrochemical, chemical, agrophysical, and biological activity of the irrigated sierozem-meadow soils in the conditions of the Khavas district of the Syrdarya region was comprehensively studied. Soils are of varying degrees of salinity, and their content of ammonifiers, spore formers, actinomycetes and nitrogen fixers has been determined according to the salinity level and types. In the conditions of irrigated sierozem-meadow soils, changes in biological activity were observed in winter wheat and repeated mash crop fields according to options, and the number of soil ammonifiers, nitrogen fixers, axinomycetes and spore-forming microorganisms in the mash planted area. As soil salinity increased, it was found that ammonifiers and nitrogen fixers decreased. According to the soil profile, the most amount of microorganisms was observed in 0-15 cm and 15-30 cm. The pattern of distribution of phytonematodes in irrigated sierozem-meadow soils according to the level of salinity was also determined.