FEATURES OF AIR NITROGEN FIXING BY FREE-LIVING MICROORGANISMS AND CLUB BACTERIA IN SYMBIOSIS WITH PINE CULTURES
The article deals with the biological fixation of nitrogen in the air by symbiotic and non-symbiotic microorganisms. It is noted that among free-living microorganisms, anaerobic nitrogen is fixed several times more than aerobic. The greatest practical importance is the fixation of nitrogen in the air by nodule bacteria in symbiosis with leguminous plants - bean rhizobialsymbiosis. Alfalfa has the maximum nitrogen-fixing ability among legumes. Perennial legume grasses absorb more nitrogen from the air than annual cereals. The intensity of the fixation of atmospheric nitrogen by soybeans is influenced by the group of ripeness of the variety, the method of sowing and the seeding rateseed.