The article summarizes the 2020-2021 research results, obtained in a field stationary experiment on leached chernozem in the Republic of Mordovia. The object of the study was spring barley of the Zazersky 85 variety. In its sowings the effectiveness of separate and joint use of the Forsazh (micro) preparation with various doses of mineral fertilizers was studied, including against the background of liming of the soil by 0.5 and 1.0 h.a. in 1999-2000. On average, for two years in the variant without the use of chemicals, the crop yield was 1.82 t / ha. The effect of fertilizers (P40K40, N40-60-80P40K40) was estimated by an increase in the yield of 0.10, 0.40-1.02 t/ha (LSD05 = 0.03 t/ha). The payback of 1 kg a.i. of mineral fertilizers with additional income increased with the rise in the doses of fertilizers applied - 0.94, 1.08, 1.19, 1.38 rubles/rub, respectively. The use of mineral fertilizers significantly increased the mass of 1000 grains and the natural weight of barley grain by 0.6-2.3 g and 9-33 g/l, respectively, and the Forsazh preparation by 0.2 g and 3 g/l. The recommended dose of mineral fertilizers for barley N80P40K40 provides the yield of 2.84 t/ha. Additional use of the Forsazh (micro) preparation will improve the technological indicators of grain quality.

The research was aimed at comparing the characteristics of winter wheat precursors on leached heavy loam chernozem in the conditions of the Republic of Mordovia. The object of the study was winter wheat of the Mironovskaya 808 variety, grown in grain-grass-fallow-row (1996-1997) and grain-grass-row (2008-2009) crop rotations, where the precursors were pure fallow and lucerne grass of the 3d year of use. In the control variant (without lime and mineral fertilizers), the crop yield after pure fallow was 3.27 t/ha, after perennial grasses it was 3.72 t/ha. Liming of the soil introduced in 1989-1990 and 1999-2000 did not make significant changes in crop yield, but the combined action with fertilizers in the grain-grass-fallow-row crop rotation against the background of liming by 1.0 h. a. contributed to a greater increase (0.43 t/ha) than against the background of liming by 0.5 h. a. (0.28 t/ha). In grain-grass-row crop rotation, on the contrary, against the background of liming by 0.5 h. a, more grain was obtained (0.74 t/ha), than against the background of 1.0 h. a (0.51 t/ha). The effect of fertilizers without lime was estimated by a less increase in yield ‒ 0.36 and 0.78 t/ha, respectively by crop rotations. Taking into account the payback of 1 kg a.i. of mineral fertilizers with an additional grain yield and additional income, the following doses can be recommended in addition to phosphorus-potassium: the use of nitrogen fertilizer in the top-dressing in the following doses: in the grain-fallow-grass-row crop rotation not more than 30 kg a. i., in grain-grass-row ‒ 30-60 kg a.i. against the background of soil liming by 0.5 h. a.