Sergey Ilyich Kolesnikov

Bacteria are a sensitive indicator of the state of the soil contaminated with oil and oil products. Aft er the introduction
of ameliorants, the oil content in the soil changes, which aff ects the number of bacteria. Th e aim is to
estimate the number of bacteria in petroleum hydrocarbons contaminated Haplic Chernozem aft er amelioration.
Biochar, sodium humate, nitroammophos, and microbiological fertilizer «Baikal EM-1» were added to petroleum
hydrocarbons-contaminated Haplic Chernozem (5% petroleum hydrocarbons by weight of soil). Aft er 90 days
of the experiment, the number of bacteria in the soil was estimated by the total number of bacteria, determined
by the method of luminescent microscopy, the number of actinomycetes, amylolytic and ammonifying bacteria,
determined by the method of inoculation on solid nutrient media. Th e integral indicator of the number of bacteria
(IINB) of the soil was calculated before and aft er the application of ameliorants. When introducing biochar, it is
possible to use the total number of bacteria to assess the ecological state of the soil, with nitroammophoska — the
number of ammonifying bacteria, sodium humate — the number of actinomycetes, «Baikal EM-1» — the number
of amylolytic bacteria. According to the IINB of soils, the most eff ective dose for remediation with nitroammophoska,
biochar, and Baikal EM-1 is D0.5, and for remediation with sodium humate, D2. It is advisable to use the
results of the study in biodiagnostics and monitoring the state of petroleum hydrocarbons contaminated Haplic
Chernozem aft er amelioration.