INCREASE IN BIOMASS AND DRY MATTER ACCUMULATION OF SPRING BARLEY DEPENDING ON THE MINERAL NUTRITION LEVEL AND METEOROLOGICAL CONDITIONS
The article presents the results of a study of the effect of applying doses of mineral fertilizers (N0P0K0, N30P30K30, N60P60K60, N90P90K90) when cultivating varieties of spring barley (Vladimir, Reliable, Yaromir) on the formation of the area of leaf plates, the growth of green biomass and the accumulation of dry matter by crop plants in different years of moisture in the South of the Central non-Chernozem region. It was found that the use of mineral fertilizers in doses N60P60K60, N90P90K90 contributed to the greatest increase in the area of the assimilation apparatus and the growth of plant biomass. In the phase of entering the tube, the leaf area on the above backgrounds exceeded the control variants by an average of 49,6 and 63,3 % (Vladimir variety), 62,3 and 45,4 % (Reliable variety), and 44,6 and 53,2 % (Yaromir variety). The average growth of biomass in 2017-2019 with the use of N60P60K60, N90P90K90 increased compared to the control variants by 83,3 and 182,7 % (Vladimir variety), by 68,9 and 88,3 % (Reliable variety) and by 82,0 and 107,5 % (Yaromir variety) in the beginning of earing phase with further growth of this indicator to the phase of milk ripeness of plants. The percentage of dry matter in plants depended not only on the doses of mineral fertilizers, but also on weather conditions, namely, on the value of the Selyaninov hydrothermal moisture coefficient (SCC). With an increase in the applied rates of fertilizers, at values of GTC in the range of 0,37 – 0,44, dry matter is accumulated by plants, at values from 0,64 to 1,2, due to the provided moisture and greater water consumption by spring barley varieties, the percentage of dry matter content decreased. Yield – the final indicator of all conditions. Reliable and Yaromir varieties showed the greatest stability in obtaining a good harvest, which exceeded the values of control variants on average for 2017-2019 by 89,1 and 79,0 % on backgrounds N60P60K60 and N90P90K90 respectively. Correlations were determined for all the studied indicators.