Рeculiarities of sunflower (Helianthus L.) growing on dried tury-podzolistic soil in the conditions of climate change

In the conditions of global warming, the area of cultivation of thermophilic crops, in particular sunflower, is shifted from the southern regions of cultivation to the Polissya zone. Therefore, it is necessary to investigate the efficiency of growing sunflower on drained soils without regulating the water regime with different fertilizer systems. The study analyzes the state of moisture supply of drained sod-podzolic soil during the growing season 2018–2019. It is established that in the summer total reserves of productive moisture in the 0–100 cm soil layer decreased to critical parameters (60 mm), and the groundwater level dropped to 2.5–3.0 m (depth bookmarks drains — 1.1 m). The results of the influence of different levels of fertilizer on the yield and quality of sunflower seeds (Jason hybrid), which was placed in the crop rotation after winter wheat, are presented. It is established that in the conditions of deficit of moisture in the soil, use of the norm of mineral fertilizers recommended for the Polissya zone (N60P60K90) with 40 t/ha of manure, increased 1.5 times more than norm (N90P90K135) against 4,0 t/ha of straw and the recommended one — against the background of straw and foliar fertilization with microfertilizer Yarilo were equivalent. When using them, the same seed yield was obtained — at the level of 2.30–2.33 t/ha. When applying the recommended rate of mineral fertilizers in conjunction with the straw of the predecessor, there was a decrease in seed yield by an average of 14.0%. Double fertilization of crops with complex chelated microfertilizerYarilo significantly increased the yield of sunflower on the options without mineral fertilizers and when using N60P60K90 on a background of straw. The oil content in the seeds was 47.5–50.1%, no significant dependence on the fertilizer system was observed. The most cost-effective fertilizer system was identified — N60P60K90 compatible with straw and microfertilizer Yarilo, at which the yield of sunflower seeds was 2.3 t/ha and the level of profitability was 43.5%.