The role of biological nitrogen in the mineral nutrition of oilseeds in the Rostov region

The article is devoted to the study of mineral nutrition, in particular nitrogen nutrition of oilseeds in the arid steppe conditions of Russia. The results on the content of mineral nitrogen in soil and plants when bacterial preparations of an associative nature are used in the mineral nutrition system are presented. The use of biologics in combination with the pre-sowing application of mineral fertilizers in doses of N30P30 led to an increase in the level of nutrients in the soil compared with the use of biologics alone. The increase was 10-11.6 kg/ha. In comparison with the control variant, where fertilizers were not used, the difference in yield was 12.9-14.0 kg/ha. The use of microbiological preparations in the nitrogen mineral nutrition system has had a significant impact on oilseed plants. There was an increase in the amount of nitrogen in flax plants compared to the control variant in the flowering phase by 0.9-1.6% per absolutely dry substance. A significant relationship has been established between the concentration of total nitrogen in flax plants at the stage of the herringbone phase and their yield. The average value of the correlation coefficient during the study period was 0.903±0.099. Bacterial preparations have been installed in the black soils of the Rostov region, ensuring high productivity of oilseeds in these soil and climatic conditions. When growing oilseed flax, it is recommended to treat the seeds immediately before sowing with the microbiological preparation Extrasol at a dosage of 200 ml per ton of seeds based on the rhizospheric bacteria Bacillus subtilis H-13. The combination of mineral fertilizers and Mizorin 204 in sunflower cultivation provided a significant increase in oilseeds – 0.31 t/ha or 22.6%. The replacement of mineral fertilizers with biological products in the sunflower fertilizer system for the production of organic products leads to a statistically significant increase in yield by 0.16-0.20 tons per hectare. At the same time, there is an increase in conditional net income by 2.3-2.7 thousand rubles/ha, profitability – up to 20%, however, it requires solving the problem of replenishing the increasing removal of nutrients from the soil.