Eignung von Bradyrhizobien-Impfpräparaten zur Inokulation von Sojabohnen

In Europe soybean (Glycine max (L.) Merr.) has gained attention due to its ability to produce high quality protein for human and animal consumption. Under low temperature conditions in Central Europe the inoculation with different Bradyrhizobia inoculants has lead to unsatisfying nodulation results. The aim of this study was to test the ability of commercially available inoculants under cool growing conditions in Central Europe. In 2011 and 2012 four Bradyrhizobia inoculants were tested on three early soybean varieties in a field trial in Germany. The number of nodules was assessed six weeks after sowing and at flowering. Yield and protein content were determined at harvest. Product 1 was inefficient to produce nodules, resulting in a severe reduction in soybean yield and protein content compared to the inoculation with other products. Inoculation with Product 4 resulted in the highest number of nodules for all three varieties in both years. In the first year inoculation with product 4 showed the highest yield and protein content for each of the three varieties (data for year 2 not yet available). A positive correlation between the number of nodules and yield and between the number of nodules and protein content was identified in the first year. The results show the importance of selecting inoculants adapted to cool growing conditions for successful soybean cultivation in Central Europe.