Methods of increasing the productivity of various varieties and hybrids of variegated alfalfa in the conditions of arable farming biologization

Two-year studies of variegated alfalfa (Medicago varia Mart.) of the following varieties and hybrids were carried out: Pastbischnaya 88, Taisia, Agnia VIC, 506 and SGP, as well as observations of their reaction to inoculation. Strains of nodule bacteria Sinorhizobium meliloti were used as inoculants: SHM1-105, 415, A-1, A-5, and a control variant without inoculation. As a result of research, it was revealed that the minimum length of stems in 2021 was fixed in the Pastbischnaya 88 + 415 variant, and amounted to 12.5 cm, in 2022 — Taisia with A1 and SHM1-105, 8.8 cm each. The maximum length of stems in 2021 was marked by a hybrid 506 in a combination of A1 and SHM1-105 strains, the indicator was 40.4 and 40.3, respectively, in 2022 — Agnia VIC + A5, 28 cm. In 2021, the Pastbischnaya 88 variety with the strain SHM1-105 turned out to be the most competitive, its share prevailed over the unseeded admixture, and reached 54.8%, in 2022 variant Agnia VIC + 415 was distinguished with this indicator, with a mass fraction of 65.45%. The positive effect of inoculation was revealed, the best symbiotic varietal microbial systems were determined. The strain of nodule bacteria 415 is marked by a complex effect on all varieties of variegated alfalfa. According to the yield of dry weight (3.3 t/ha on average), the Taisia variety and the SGP hybrid were distinguished.