FIELD: chemistry; biochemistry.
SUBSTANCE: invention relates to biotechnology and agricultural microbiology and specifically to making bacterial preparations based on nitrogen-fixing bacteria used in agricultural engineering for increasing soil fertility and yield. The biological preparation contains Azotobacter vinelandii VKPM V-5933 bacteria strain containing not less than 1×109 cells/ml living bacteria in a culture liquid, sodium chloride, trace elements: zinc, magnesium, manganese, cobalt, molybdenum, boron and water with the following ratio of components, in wt %: bacteria strain in culture liquid - 50-60, trace elements - 0.2-0.3, sodium chloride - 1.0-1.5, water - up to 100%.
EFFECT: invention increases soil fertility, crop yield and increases shelf life of the preparation.
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