Efficiency of application of calculated doses of fertilizers in cultivation of spring wheat varieties

The agronomic and energy efficiency of using calculated doses of mineral fertilizers in the cultivation of spring wheat in the forest-steppe of Western Siberia has been assessed. The experiments were carried out on meadow-chernozem soil in 2023–2024 on the durum wheat varieties Omskiy Izumrud and Rusticano, and soft wheat varieties Silantiy and Niva 55. The calculated doses of fertilizers (for a planned increase of 0.6 and a yield of 3.0 t/ha) were applied in the spring before sowing. The use of calculated doses had a positive effect on yield: for the Silantiy variety, the increase, depending on the dose, was 0.44–0.76 t/ha (20.1–6.7% of the control), for Niva 55 0.43–0.91 t/ha (20.3–61.2%), for Omskiy Izumrud 0.44–0.76 t/ha (20.1–66.7%), Rusticano 0.43–0.91 t/ha (20.3–61.2%). When calculating the yield increase (dose N35P70) of 0.60 t/ha, an increase in yield was formed: 0.46 t/ha for the Silantiy variety, 0.49 t/ha for the Niva 55 variety, 0.50 t/ha for the Omskiy Izumrud variety and 0.52 t/ha for the Rusticano variety, which is 76.7–86.7% of the planned. Using the method of calculating the planned yield (the average dose of N65P81), 2.36; 2.53; 2.38 and 2.35 t/ha were obtained, respectively, or 78.3-84.3% of the estimated 3.0 t/ha. The highest agronomic efficiency was achieved in the N65P81 variant: Rusticano – 4.86 kg/kg, Omskiy Izumrud – 4.86 kg, Niva 55 – 4.66 kg and Silantiy – 4.45 kg/kg. The application of calculated doses of fertilizers was energetically efficient when cultivating all varieties, the bio efficiency was always more than one: when cultivating the Sylantiy variety, it was 1.59 (calculated for a planned increase) and 1.35 (for a planned yield); Niva 55 – 1.67 and 1.40; Omskiy Izumrud – 1.71 and 1.47; Rusticano – 1.77 and 1.47, respectively. At the same time, the greatest efficiency was achieved when applying the calculation method for a planned increase in yield.