EFFICIENCY OF USING HUMIN FERTILIZERS IN VEGETABLE GROWING

Aim. To determine the effectiveness of using the humic fertilizer Humifriend in technological schemes for cultivating vegetable crops (sweet corn, tomato, sweet potato, turnip, and leek) under open-field conditions. Methods. The research was conducted in accordance with standard experimental methodologies in vegetable production for open-field vegetable crops. Results. The study proved the effectiveness of applying the humic fertilizer Humifriend in the cultivation of a number of vegetable crops, including tomato, turnip, sweet potato, sweet corn, and leek. Conclusions. When growing sweet corn in a grain–row crop rotation, effective practices included soil spraying during pre-sowing cultivation with Ekostern Trichoderma; foliar application of Helprost Zinc + Organic-Balance + Liposam at two stages (4–5-leaf stage and 10–12-leaf stage); and foliar spraying at the 4–5-leaf stage with the humic fertilizer Humifriend at a rate of 0.5 L/ha. These practices ensured an increase in ear yield by 6.8 t/ha (34.1%) and an increase in sugar content in kernels (9.31%). The combined use of the humic fertilizer Humifriend for seed treatment and foliar feeding resulted in turnip yields that did not differ significantly from those obtained with mineral fertilization (N60P60K70). At the same time, a positive effect of Humifriend on increasing dry matter content in turnip roots (up to 16.4%) was observed, along with a positive trend toward higher protein content (up to 5.7%) and vitamin C content (up to 18.9 mg/100 g). Integrated application of the fertilizer Humifriend led to improvements in several biometric parameters of tomato plants, an increase in tomato seed yield by 10.33 kg/ha (25.2%), and a positive trend toward higher laboratory germination of the obtained seeds (97.2%). In sweet potato cultivation, the combined application of Humifriend with the microbial preparation Groundfix and the fertilizer HelpRost for vegetables proved effective, providing an increase in tuber yield by 28.6–55.4%, as well as higher total sugar content (3.85–3.90%) and carotene content (4.76–5.0 mg/100 g) in tubers. The use of the humic fertilizer Humifriend within a system that included various microbial preparations and biofertilizers (Groundfix, Azotohelp, Organic-Balance, Helprost Vegetables) ensured an increase in marketable yield of leek by 2.1 t/ha (8.8%), along with an increase in dry matter content (19.11%) and a reduction in nitrate content in the produce (543 mg/kg).