Annotation

Analyzed the symbiotic nitrogen fixation of legume-cereal grass mixtures during the cultivation on sod-podzolic soils. Symbiotic fixation of atmosphere molecular nitrogen by tuberous bacteria of genus Rhizobium spp. in symbiosis with plants family legumes (Faboceae) - a unique biological phenomenon of nature in planetary significance and is one of the fundamental problems of theoretical biology.

Under stationary research, was studied the symbiotic nitrogen fixation of legume components, depending on various of cereal grass mixtures and fertilizers during the cultivation on sod-podzolic soils.

Studying of nitrogen fixation properties of perennial grasses due to free-exist Rhizobia was shown that the largest symbiotic device was formed by Galega orientalis, Lotus corniculatus, Medicago sativa, contribute to the accumulation of 450–550 kg/ha of symbiotic nitrogen per year. It contribute to increasing of soil fertility and improveing of their phytosanitary condition. After period of hay cut as a result of resetting old tubers, forming of  the new one to the next hay cut was 50 % compared to the first, and their mass did not significantly increase.

The most actively nitrogen absorbing was from soil in option with Lotus corniculatus + P₉₀K₉₀ – 99,3 kg/ha, medium in option with Medicago sativa + Cereals + P₉₀K₉₀ – 94,2 kg/ha, less active was Galega orientalis (87,4 kg/ha), which is logical and corresponds to their biological peculiarities.

Established that in average during 3 years of cultivation legume-cereal grass mixtures on sod-podzolic soil remain the biggest amount of nitrogen (30,6 kg/ha) in option with Lotus corniculatus variety Ajax + Bromopsis riparia variety Bojan + Festuca arundinacea variety Lyudmyla + Elytrigia intermedia variety Chors + P₉₀K₉₀.