The effect of applying various norms of mineral fertilizers on the biological indicators of crop plants during their growth and development in the Central non-black earth region in 2017-2019 was studied on the varieties of spring barley Vladimir, Reliable and Yaromir.such indicators as plant height, photosynthetic apparatus area, green mass growth, and elements of the yield structure were Studied. It was revealed that on average during the growing season, when the norms of mineral fertilizers were increased, the area of leaf plates increased and, as a result, the increase in green mass growth relative to the control variants increased by 56.3 % at (NРК)30, 82.3 % at (NРК)60, and 126.7 % at (NРК)90. The introduction of mineral fertilizers also influenced the formation of the crop structure. There was an increase in the tillering coefficient of varieties by 15.7%, 5.7 % and 21.3 % (Vladimir, Reliable and Yaromir, respectively) relative to the control, an increase in the number of grains in the ear from 15.1 to 22.4 PCs., the weight of 1000 grains from 48.0 to 55.7 g. and the weight of grain per ear from 0.7 to 1.2 g. There was a strong correlation between the doses of mineral fertilizers and the grain yield from + 0.80 to +1.0, and the variability was calculated.
