Rozhkov, A. O., Karpuk, L. M., Mikheeva, O. O., Ogurtsov, E. M., Romanov, O. V., Mamatov, M. V., Yevsiukov, O. F., Derevianko, I. O., Sevidov, V. P., and Bragin, O. N.
The article presents the results of five-year research on the influence of various combinations of the seeding rate and row spacing width on plant productivity and soybean grain yield under conditions of the Eastern Forest-Steppe of Ukraine. The highest indicators of individual productivity of soybean plants of Annushka and Baika varieties was formed on the variants of combination the seeding rate of 0,8 mln pieces/ha with usual drill sowing method. The number of grains from a plant and their mass with an increase in the seeding rate decreased more noticeably on variants with 70 cm row spacing. By each increase in the seeding rate by the accepted step of gradation of 0,1 mln pieces/ha, the difference between the indicators of plant productivity at all sowing methods became greater. In all years of research higher grain yield was formed by soybean variety Baika. On average, over the years with more favorable weather conditions (2015 and 2016), the highest grain yield of this variety -- 3,18 t/ha was obtained on the variant of combination of drill sowing method with the seeding rate of 1,0 mln pieces/ha. On variants with row spacing of 45 cm, the highest its yield -- 2,71 t/ha was at the seeding rate of 0,9 mln pieces/ha. Under less favorable weather conditions of vegetation, soybean varieties Baika and Annushka formed the highest grain yield also on crops with drill sowing method. In particular, on average for 2017--2019, the highest grain yield of Baika variety --1,60 t/ha, was obtained on variants of the seeding rate of 1,1 mln pieces/ha and variety Annushka at the seeding rate of 1,2 mln pieces/ha -- 1,57 t/ha. On variants with row spacing of 45 cm the highest grain yield of Baika variety was obtained at the seeding rate of 1,1 mln pieces/ha, variety Annushka -- 1,2 mln pieces/ha. However, these indicators did not statistically differ from the indicators obtained at a lower seeding rate, which was 1,0 and 1,1 mln pieces/ha for these varieties respectively . [ABSTRACT FROM AUTHOR]