TY JOUR TI EFFICIENCY OF THE MODIFIED FERTILIZER AND MICROBIOLOGICAL PREPARATION ON SPRING BARLEY IN THE CONDITIONS OF THE FOREST-STEPPE OF THE VOLGA REGION KW mineral fertilizer KW biological product KW chernozem KW food elements KW spring barley (Hordeum vulgare L.) JO Vestnik of Kazan State Agrarian University AU Saydyasheva, G.V. AU Zayceva, K.G. PY 2021 IS 16 PB Kazan state agrarian University