Fertilization system for thuja seedlings Smaragd when grown in containers in the conditions of the Lower Don region

Field studies were carried out in 2021–2023 in the nursery of Rostovsad LLC, Aksay District, Rostov Region. Smaragd western thuja (Thuja occidentalis Smaragd) seedlings were used as the research object. The seedling growing period started in April. A mixture of neutral peat (fraction size 5–20 mm) up to 80 % and agroperlite up to 20 % by weight was used as a growing substrate. Potassium humate and Kornevin organomineral fertilizers were also used as research objects with fertigation after planting seedlings. Bazakot and azofoska (16:16:16), that are prolonged-release fertilizers, were applied during the preparation of the peat substrate, and the water-soluble Aquarin fertilizer (18:18:18) was applied with fertigation during seedling growing. According to the results of 3-year studies, the highest average weight coefficient (5.0) was in the variant using Kornevin (5 g/5 l of water) in combination with Bazakot (4 g/l of substrate) and Aquarin (18:18:18) (0.2 kg/1000 l of water) during fertigation. The most optimal economic efficiency in growing thuja seedlings was in the variant of fertilization according to the scheme: Bazakot (4 g/l) and Aquarin (18:18:18) and in the variant of Kornevin, Bazakot (4 g/l) and Aquarin (18:18:18) (daily). An increase in indicators by 181 % and conditional net income by 395 rubles/item exceed the indicators of the control variant (128 % and 247 rubles/item).