Inoculation of seeds as a factor in increasing the productivity of soybean varieties of different maturity groups under irrigation conditions in Southern Ukraine

Abstract

A two-factor study was conducted to investigate the impact of inoculants on the productivity of soybean variet¬ies from different maturity groups under the soil and climatic conditions of the steppe zone of Ukraine, follow¬ing generally accepted methodologies. Factor A consisted of early-maturing (Krynytsia, Rizdvyana, Zlatoslava) and early-ripening (Aurelinа, Bettina, NS Maximus) soybean varieties. Factor B involved seed inoculation with bacterial preparations: control (water treatment), Bioboost Plus, Biomag-Soy, Ekovital, Humisol, Optimize 400, Rhizogumin. The bacterial preparations Rhizogumin and Humisol showed a relatively weak effect, while Ekovital and Optimize 400 contributed to a significant increase in yield – up to 25% compared to the control. The grain yield with the use of Ekovital and Optimize 400 was 3.17–3.25 t/ha, demonstrating their high effectiveness in the technology of growing early-maturing soybean varieties. These same inoculants also demonstrated maximum effectiveness in the cultivation of early-ripening soybean varieties, confirming their high biological activity and ability to improve plant growth and development. The yield increase in treatments using the Rhizogumin prepa¬ration for growing early-ripening varieties was within the experimental error (LSD05), thus its impact on grain yield was determined to be insignificant. Early-ripening soybean varieties in the experiment formed a higher yield level compared to early-maturing varieties. The Zlatoslava variety stood out among early-maturing varieties for its yield, demonstrating a statistically significant advantage. Among early-ripening varieties, the Aurelina variety produced a higher yield, although its indicators did not show significant differences from the NS Maximus variety, indicating their equal potential. Seed inoculation with bacterial preparations had a positive effect on grain quality: Optimize 400 and Ekovital increased protein content, while Rhizogumin enhanced oil content. The conditional yield of protein per hectare of soybean crops increased by 4.63–27.78% due to seed bacterization, and oil yield increased by 7.27–23.64%, with the best results observed when using Ekovital and Optimize 400. This supports the rationale for their application to improve the quality characteristics of the harvest.