Efficiency of growing various soybeans varieties, depending on the effect of micronutrient fertilizers and growth regulators

Purpose. To determine the efficiency of growing soybean varieties ‘Ustia’, ‘Cordoba’, ‘Estafeta’ depending on the influence of microfertilizers and growth regulators. Methods. Field, laboratory. Results. The article presents the results of studying the efficiency of growing different varieties of soybeans. It was found that in the cultivar ‘Ustia’ the best values of assimilation of photosynthetically active radiation were obtained for the applications of Yara Vita Mono Molitrak in the budding phase (0.25 l/ha) with growth regulator Radostym, and Yara Vita Mono Molitrak in the budding phase (0.25 l/ha) + in the flowering phase (0.25 l/ha) with two studied growth regulators. Similar patterns of the utilization rate of photosynthetic radiation were obtained for the ‘Cordoba’ and ‘Estafeta’ varieties. According to the indicators of the energy balance, the complex use of micronutrient fertilizers and growth regulators in any case pays off with an increase in the yield, which means it is energetically expedient. The maximum coefficients of energy efficiency in the ‘Ustia’, ‘Cordoba’ and ‘Estafeta’ varieties were obtained with the introduction of micronutrient fertilizers Yara Vita Mono Molitrak in the budding phase (0.25 l/ha) + in the flowering phase (0.25 l/ha) and growth regulators Biosyl and Radostym. However, the use of growth regulators separately does not always provide an economic return on investment. In particular, in the variant without Yara Vita Mono Molitrak microfertilizer, the ‘Cordoba’ variety received 28 873 UAH/ha of net profit, while the introduction of growth regulators did not pay off, since there was no significant increase in the yield, and with the use of growth regulators Biosyl and Radostym net profit was within 28824–29179 UAH/ha. In general, the use of micronutrient fertilizer Yara Vita Mono Molitrak with growth regulators Radostim and Biosyl ensu­red guaranteed yield increase. Conclusions. When gro­wing ‘Ustia’, ‘Cordoba’ and ‘Estafeta’ varieties from an energy point of view, it is better to use Yara Vita Mono Molitrak microfertilizer in the budding phase (0.25 l/ha) with the growth regulator Radostym. Under these conditions, the obtained energy efficiency ratio was 3.24; 3.41 and 3.45, and the profit was 31503, 34072 and 34649 UAH/ha, respectively