The row method of sowing led to an increase in total water consumption by an average of 11–24 m^3/ha. During the growing season, soybean varieties consumed almost the same amount of water. Diadema Podillia variety consumed 6356–6380 m^3/ha of water Mentor –6390–6435 m^3/ha. It was established that the reserves of soil moisture in the 0–30 cm soil layer ranged from 32,4–40,5 mm depending on the studied options. During the branching period, soybean plants consumed 40,7–55,0 kg/ha of nitrogen, 10,6–12,5 kg/ha of phosphorus, and 43,2–50,7 kg/ha of potassium. The yield of soybeans was 155,4–279,7 kg/ha of nitrogen, 34,5–63,0 kg of phosphorus, and 39,0–70,9 kg/ha of potassium, which depended significantly on the variety, seed sowing rate, and width spacing. The highest removal of nitrogen, phosphorus and potassium was observed in the Mentor soybean variety under the wide-row sowing method and the seed sowing rate of 500000 ha. Under this option, the removal of nitrogen was 279,7 kg/ha, phosphorus – 63,0, and potassium – 70,9 kg/ha. Soybean plants used 99,3–159,5 kg/ha of biological nitrogen and provided 60,6–61,9 % of their nitrogen needs due to nitrogen fixation. It was investigated that the duration of the growing season in plants of the Diadema Podillia variety was 109 days, and in the Mentor variety – 114 days. The application of the sowing rate of 700000 ha of soybean seeds in the studies accelerated this period to one day in Diadema Podillya plants and to two days in the Mentor variety compared to the sowing rate of 500000 ha. A clear regularity of the decrease in field germination of seeds due to an
increase in the width of the rows and the rate of seed sowing has been established. At the rate of 500000 ha of similar soybean seeds of the Diadema Podillia variety, in the continuous (15 cm) agrocenosis, it was 93,1 %, in wide-rowed (30 and 45 cm) – 89,9 and 84,2 %. It was established that the accumulation of dry mass of soybean plants depended on the studied agrotechnological factors and the development phase. The highest mass of dry matter was in the pouring phase of soybeans. In the Diadema Podillia variety, this indicator was the highest at a row width of 45 cm and a seeding rate of 600000 ha – 27,2 g. An increase
in the seeding rate from 500 to 700 thousand/ha led to a smaller area of the leaf apparatus of one plant in the flowering phase, on average, in the Diadema Podillia variety from 15,7 to 19,7 %, Mentor - from 19,4 to 21,9 %. The area of the leaf surface decreased the most with 15 cm row spacing in the Diadema Podillia variety - by 97 cm^2, in the Mentor variety with 30 cm row spacing by 155 cm^2. It was established that the photosynthetic potential of Diadema Podillia soybean during the period of germination - full maturity was 1,95–2,21 million m^2 days/ha, in the Mentor variety it was 2,16–2,56 million m^2 days/ha. It was established that an increase in the height of attachment of beans of the lower tier was observed at different widths between rows at an increased seeding rate. The research results showed that the development of all elements of soybean productivity changes significantly under different sowing rates. Sowing rate soybean seeds significantly determine the conditions for the formation of productivity elements.
