The oil flax reaction to mineral fertilizers with permanent sowing

The purpose of research is to study the effect of various doses of mineral fertilizers on the productivity of oil flax with permanent sowing. The method of vegetative-field experiment with dispersion analysis of experimental data was used. Plants were grown permanently in 2017-2020 in plastic vessels without a bottom measuring 25×25×25 cm, which were filled with gray forest heavy loamy soil with the content of mobile forms of nitrogen, phosphorus and potassium: 17.3-13.2-13.8 mg/100 g of soil, respectively. The application of mineral fertilizers in doses of N45P45K45 and N60P60K60 did not increase the field germination of seeds, but had a positive effect on the survival of plants during the growing season. The number of plants before harvesting in these variants was 12-14 % higher compared to the variant without fertilization. Oil flax reacted to the improvement of the background of mineral nutrition by increasing the height of plants (+ 5-8 cm) and the number of bolls (+ 0.6-1.6 pcs) per plant. Mineral fertilizers had no effect on the number of seeds in one box and the share of seeds in the yield of dry aboveground mass. The largest increase in seed yield (4.0-5.6 g/vessel, or 22.2-34.3 %) was obtained with a dose of N60P60K60. On average, over three years of research, this amounted to 5.1 g/vessel, or 30.0 %. It has been established that it is possible to grow oil flax for several years without reducing the yield on lands where this crop has never been grown before.