The influence of microelement fertilizers on the symbiotic activity and productivity of soybeans in the Central Chernozem Region

Abstract

The study was conducted to evaluate the impact of microelement fertilizers on the symbiotic activity and productivity of soybeans in the Central Black Earth Region. The work was conducted from 2023 to 2025 in the Kursk Region on the Osmon soybean variety. The effectiveness of liquid organomineral complexes of the Urozhainaya Liniya brand (Extra Mo, Extra B, Extra Cu, Extra B/Mo, Micro Complex) was studied. The experimental design included pre-sowing seed treatment and two foliar applications at the 3[rd] and 6[th] trifoliate leaf stages. The field test was conducted on typical deep, heavy loamy chernozem with a humus content of 5.5%. The use of microfertilizers optimised the legume-rhizobium symbiosis, stimulating the growth of the number and weight of nitrogen-fixing nodules relative to the control by 4.5-7.4 pcs/plant and 0.54-0.78 g/plant, respectively. The highest yield in the experiment was recorded in the Extra B/Mo variants 2.74 t/ha (+0.39 t/ha compared to the control) and Micro Complex 2.71 t/ha (+0.36 t/ha), the lowest Extra Cu 2.61 t/ha (+0.22 t/ha). In the dry year of 2024, the value of this indicator in the Extra B/Mo and Micro Complex variants remained at the level of 2.47-2.54 t/ha (control 2.27 t/ha). Protein yield per hectare reached 0.96 t/ha (Extra B/Mo) and 0.95 t/ha (Micro Complex) versus 0.80 t/ha in the control; oil yield was 0.63 t/ha and 0.61 t/ha, respectively (control 0.53 t/ha). The highest profitability was achieved with Extra B/Mo 146.8% (+24.7% compared to the control), Micro Complex 143.5% (+21.4%), Extra Mo 143.3 % (+21.2%), and Extra B 140.8 % (+18.7%); the lowest was achieved with Extra Cu 134.5% (+12.4%).