Application of biopreparations on alfalfa (Medicago varia Mart.) in conditions of the north-west of the Russian Federation

Three year researches were conducted on alfalfa ( Medicago varia Mart.) varieties Taisiya, Nakhodka, Blagodat. The reaction of each variety on inoculation by strains of the biopreparations basing on bacterium of a genus Sinorhizobium meliloti were studied. There were involved in testing strains of nodule bacterium basing on rhizotorphin: 404, 415б, 425, А-1, А-2, А4, А-9. During three years the growth dynamics, intensiveness of sprout formation, crops infestation, formation of green mass and seeds yield were observed. The positive impact of inoculation on these processes was revealed, the best varieties-microbial systems were determined. The complex influence of a strain 404 of nodule bacteria on all three varieties was noted. The variety Blagodat had the highest green mass yield (31.5 t per ha), the variety Nakhodka - on seed yield (61.2 kg per ha).