Agroecological efficiency of biological preparations in growing alfalfa for seed

Purpose. Development of a technology for biologization of growing alfalfa seeds of the high-yielding synthetic variety Radoslav, tolerant to increased soil acidity of the right-bank Forest-Steppe of Ukraine, with the aim of forming seeds with high sowing and yield properties. Methods. Field, laboratory, visual, measuring, weight, quantitative, trial sheaf method, mathematical, statistical. Results. Aspects of the technology for growing alfalfa seeds of the Radoslava seed variety, adapted to increased soil acidity, have been developed by pre-sowing bacterization of seeds with biological preparations Rhizobofit and Rice P, with foliar feeding during the growing season with chelate-based microfertilizers Ecoline Bean and Growth Potassium Humate to improve the fixation of atmospheric nitrogen by nodule bacteria and increase the supply of macro- and microelements from the soil against the background of the main fertilizer for the cover crop with mineral and limestone fertilizers. In the conditions of 2022-2024, this ensured the maximum yield of alfalfa seeds in the first (455 kg/ha) and second (466 kg/ha) years of use. The yield increase was, respectively, 117 and 120 kg/ha. Conclusions. When growing alfalfa for seed, the most effective is pre-sowing treatment of seeds with bacterial preparations in combination with foliar top dressing with chelate-based microfertilizers twice in the phase of budding and the beginning of bean formation against the background of the main fertilizer (N30P60K60) and fast-acting lime fertilizer Ca(OH) (slaked lime “Pushonka”) – 0.5 of the norm for hydrolytic acidity for cover crop (spring barley), which contributed to an increase in seed yield by 34-35% and an increase in seed quality by 6-10% compared to the control without seed treatment and foliar top dressing.