Effect of soil applied organic amendments and microbial inoculant on the improvement of growth and yield of soybean (Glycine max L.)

The usage of organic amendments and microbial inoculant together can be a reliable solution to avoid soil heavy metal pollution and to increase crop production in sustainable farming. This study was done to determine the effectiveness of organic amendments and Bradyrhizobium sp. in improving soybean (Glycine max L.) growth and yield. Control (T₁) and the other seven treatments were comprised as, field soil + compost (15% by weight) (T₂), field soil + wood biochar (15% by weight) (T₃), field soil + synthetic chemical fertilizer [0.01 kg m^–2 urea, 0.01 kg m^–2 P₂O₅ (triple super phosphate) and 0.008 kg m^–2 K₂O (muriate of potash)] (T₄), field soil + Bradyrhizobium inoculum. (10⁸ CFU ml^-1) (T₅), field soil + compost (15% by weight) + Bradyrhizobium inoculum (10⁸ CFU ml^-1) (T₆), field soil + wood biochar (15% by weight) + Bradyrhizobium inoculum. (10⁸ CFU ml^-1) (T₇), field soil + synthetic chemical fertilizer (111.5 kg N ha^–1, 111.5 kg P ha^–1, and 82.9 kg K ha^–1) + Bradyrhizobium inoculum. (108 CFU ml^-1) (T₈), The experiment was arranged in a completely randomized block design with ten replicates. In wood biochar amendment together with Bradyrhizobium sp. inoculation significantly (p< 0.05) enhanced plant height and the soybean yield compared to all the other treatments. All the organic amendments added treatments were positively influenced by the inoculation of Bradyrhizobium sp. The present study concludes that soybean yield can be significantly enhanced by the application of Bradyrhizobium sp. and wood biochar amendment.