INFLUENCE OF FERTILIZER NITROGEN AND BIOLOGICAL PREPARATIONS ON SPRING WHEAT YIELD AND GRAIN QUALITY

In dark-gray forest soil, the influence of fertilizer nitrogen and microbial biopreparations was assessed on spring wheat yield and grain quality. The use of this method increased grain yield from 328 g/m² to 479-517 g/m². When seeds were inoculated with various biopreparations, grain yield on PK-background reached 397-456 g/m², on the background with NK-fertilizer - 490- 497 g/m². Both strains exceeded the standard one made with strain Ch-13 in terms of effectiveness on grain yield of spring wheat. Biomass of spring wheat (grain + straw) increased from biopreparations in relation to PK-background by 14-21%, and its higher increase was obtained when seeds were inoculated with biopreparation based on endophytic strain V417, which is equal when N45 is applied in effectiveness. On the weight 1000 grains, all studied biopreparations in the experiment on the background of PK - fertilizers showed an increase by 2.8-3.8g in weight of 1000 grains of spring wheat. The positive effect was observed on biopreparations V167 and V417 when N45 was applied. The protein content of spring wheat grain varied from 12.4 to 13.1-13.9% over the three years of the experiment. Inoculation of seeds with microbial biopreparations contributed to an increase of protein content in spring wheat grain by 0.7-1.2%, and there was a tendency to increase protein content from biopreparations based on strains V167 and V417 compared to standard Ch-13.