COMPARATIVE EVALUATION OF THE REACTION OF DIFFERENT VARIETIES OF SPELLED TO THE INTRODUCTION OF DESIGNED NORMS OF MINERAL FERTILIZERS IN THE FOREST-STEPPE ZONE OF THE MIDDLE VOLGA REGION

The research was carried out in order to study the reaction of various spelled varieties to the application of calculated doses of fertilizer minerals in the conditions of the Middle Volga region. The work was carried out in 2020-2022 in Kama zone of the Republic of Tatarstan. The scheme of the field experiment involved the study of the following options: spelled variety (factor A) - Srednevolzhskaya (standard), Runo, Gremme (naked grain); application rate of mineral fertilizers (factor B) - based on a yield of 2.0 t/ha (N47P18K21), 2.5 t/ha (N59P23K26), 3.0 t/ha (N71P27K32). The soil of the experimental plot is a typical gray forest-steppe zone of Middle Volga region with a humus content of 3.4% according to Tyurin, mobile (according to Kirsanov) forms of phosphorus - 142 mg/kg of soil, potassium - 155 mg /kg of soil. The reaction of the soil environment was close to neutral (pHKCl 6.4). Among the three studied spelt varieties, the Runo cultivar stood out, the average yield of which increased in proportion to the application rates of NPK from 1.68 in the control to 2.72 t/ha in the variant with NPK, based on the formation of the spelled grain yield of 3.0 t/ha. However, from an economic point of view, the most profitable in the experiment was the estimated rate for achieving the planned grain yield of 2.5 t/ha, which, provided that the selling price is 15 thousand rubles/t, ensures the profitability of production of 56.8%, the cost of grain - 9.6 thousand rubles/t.