VOZHEHOVA, Raisa, TYSHCHENKO, Andrii, TYSHCHENKO, Olena, PILIARSKA, Olena, KONOVALOVA, Vira, SHARII, Viktor, and FUNDIRAT, Kateryna
The aim of the work was to study the influence of rhizobacteria, arbuscular-mycorrhizal fungi and their combination on alfalfa seed productivity and the economic effect of their use. The research was conducted during 2018−2020 in a three-factor field experiment under different conditions of moisture (irrigated and non-irrigated) and three varieties of alfalfa under inoculation with bacterial and fungal preparations at the experimental field of the Institute of Irrigated Agriculture of the NAAS, located in the steppe zone of Southern Ukraine. In the first year of the life of the herbaceous plant, the seed yield under irrigation was 187.0 kg/ha, which was 83.5 kg/ha more than under natural irrigation conditions. Alfalfa cultivars also differed in seed yield. The minimum seed yield was obtained on the control variant (without inoculation) with irrigation - 147.9 kg/ha in the Unitro variety, 180.6 kg/ha in the Elehiya variety and 161.8 kg/ha in the Luyiza variety, while without irrigation 79 .9, 106.5 and 89.0 kg/ha, respectively. The highest seed yield was obtained by complex (AMF and Sinorhizobium) seed inoculation with Drugs 2 and 4. In the sum of two years, the lowest seed yield was also obtained by the control option (without inoculation) and amounted to 588.5 kg/ha when irrigated in the Unitro variety, of the Elehiya variety - 695.9 and 631.9 in the Luyiza variety, under natural moisture conditions - 386.5, 463.8 and 417.3 kg/ha, respectively. The highest seed productivity under complex inoculation (Drug 2 and Drug 4), which amounted to 715.7–725.7 kg/ha with irrigation in the Unitro variety, 842.2–864.0 kg/ha in the Elehiya variety and 769.9– 780.5 kg/ha in the Luyiza variety, while under conditions of natural moisture – 451.5–454.1 kg/ha, 534.9–547.2 and 485.4–488.0 kg/ha, respectively. The best indicators of economic efficiency were obtained with irrigation, namely the cost price was 1.30 €/kg, conditional net profit – 1,775.40 €/ha. The highest seed productivity was characterized by the Elehiya variety, which, when irrigated, had a seed cost of 1.19 €/kg, conditional net profit of 2,008.36 €/ha, under conditions of natural moisture 1.21 and 1,297.60, respectively. Among the inoculants, the lowest cost price and the largest conditional net profit were obtained with the use of drug 2, which amounted to 1.30 €/kg and 1,779.09 €/ha for irrigation in the Unitro variety, 1.10 €/kg and 2,288.00 for the Elehiya variety €/ha and 1.21 €/kg and 1,980.88 €/ha in the Luyiza variety. Under conditions of natural moisture, the values of these indicators in alfalfa varieties were: 1.39 and 1,074.06, 1.16 and 1,416.63 and 1.29 €/kg and 1,198.69 €/ha, respectively. Inoculation of seeds with fungal and bacterial drugs contributed to the increase of seed productivity, regardless of the year of life of the grass stand, variety and moisture conditions. However, the highest seed yield, and correspondingly the lowest cost and the highest profit, was obtained by complex (AMF and Sinorhizobium) seed inoculation. [ABSTRACT FROM AUTHOR]