In presented study the efficiency of bacteria preparations and growth regulators applied to one variety and mixed crops (barley + pea) depended on the level of nitrogen nutrition. Applying of Rhizobacterin on one variety barley crop against the background of 60 kg N·ha⁻¹ resulted in a maximum yield, while the maximum yield of pea was obtained after applying of Sapronit at dose of 30 kg N·ha⁻¹. At mixed crops the highest yield of plants was achieved when two components of the mixture (Saprofit + Rhizobacterin) were applied together with 30 kg N·ha⁻¹. Epin efficiency on one variety crop was the highest without N application whereas the second growth regulator Homobrassinolid was most effective at the background of 60 kg N·ha⁻¹. On the objects without nitrogen fertlization maximum increase of barley yield in mixed crop was noted after inoculation of pea seeds with Epin preparation. Whereas Homobrassinolid caused the highest increase of barley yield in variant without pea seed inoculation.