Content of crude protein in bread winter wheat grain depending on nitrogen fertilization and foliar application of effective microorganisms

The aim of this study was to determine the grain protein content of wheat varieties grown under different application rates of effective microorganisms (EM) and nitrogen, and two sowing rates. Three-year research was conducted at the experimental filed of the Scientific Institute PKB Agroekonomik Padinska Skela, using four varieties of wheat (Ratarica, Pobeda, Nogal and Apache), two sowing densities of 400 and 500 seeds/m2 and T1 fertilization (150 kg/ha N); T2 (150 kg/ha N + one foliar treatment, T3 (100 kg/ha N + two foliar treatments), and T4 (50 kg/ha N + three foliar treatments). The preparation EM Aktiv 7 l/ha, a mixture of multiple selected microorganisms, was used for foliar treatment with EM. The average protein content was 13.95% and was statistically significantly dependent on the variety, fertilization, and their interaction p