The effect of various inoculants on the productivity, chemical composition of soybean seeds (<i>Glycine max</i> (L. Merrill) Magnolia PZO) and chemical properties of soil in southwest part of Poland – preliminary studies

Abstract The introduction of bacterial inoculations into soybean cultivation is becoming an essential agronomic practice. The procedure of inoculating soybean seeds with microorganisms capable of fixing atmospheric nitrogen is recommended in situations where there is a deficit in soil native strains of symbiotic bacteria or their number is limited. The nodule bacteria enter the soil with the inoculated seeds and develop on the roots of the plants. Through this process, plants can use atmospheric nitrogen directly from the air. In 2023, a one-factor field experiment in a randomized block design in three replications was conducted at the Variety Evaluation Experiment Station (SDOO) in Zybiszow, Lower Silesia that belongs to Research Centre for Cultivar Testing. One soybean cultivar, Magnolia PZO, and four different inoculants – Liquifix Glycine 120, Turbosoy, Rhizobium Soi and Bi Soya – were applicated in the study. The inoculants were applied to the seeds immediately before sowing. The aim of the study was to determine the effect of the applied inoculants on soil abundance of basic elements, selected plant biometric traits, yield and chemical composition of soybean seeds. The soil was analyzed before the establishment of the experiment and after its liquidation for pH values, phosphorus, potassium and magnesium content. The applied inoculations had a positive effect on yield and number and weight of nodules and soybean yield. The greatest yield was observed under using Liquifix Glycine 120 (6.90 t/ha), while the lowest under using Rhizobium Soi (5.19 t/ha) compared to control plots (5.59 t/ha). Similar relation was observed in a case of nodule weight and number with the greatest value under Liquifix Glycine 120 (2.97 g and 27.33 pcs) compared to control plots (0.12 g and 1.33 pcs). However, there was no effect on the chemical properties of the soil and the results of chemical analyses of the seeds. The research presented here is preliminary field experiments using bacterial inoculations in soybean cultivation. Their aim was to evaluate the potential of these inoculants in increasing yields and improving biometric traits, which can contribute to sustainable agricultural development by reducing the need for mineral fertilizers. The results of this study may provide a basis for further work on biological methods of promoting plant growth, which is particularly important in the context of the growing need to reduce the environmental impact of agriculture.