For Objectives 1 and 2. Bacterial agents having beneficial activities for soybean growth will continue to be selected among soybean-associated bacteria, and they will be identified based on 16S rDNA sequence information. New bacterial consortia will be constructed and tested along with the previously chosen ones (Set-1 and Set-2) for their growth-promoting activities. Further, they will be tested in the pots filled with field soil for preliminary evaluation of their growth-promoting functions in the field soil condition. Two best-performing bacterial consortia will be chosen to extract DNA samples of the rhizospheric microbiomes from the treated plants for characterization of the microbial community affected by the treated bacterial consortia.
For Objective 3. Effects of the seed treatments with biochar and chitosan on the growth of soybean plants and the suppression of disease development caused by R. solani will be investigated in the greenhouse along with selected bacterial agents and their consortia. Pelletized poultry manure will be modified by addition of biochar, chitosan and biological agents with various combinations. Up to 10 different pelletized formulations will be tested in the greenhouse for their fertilizing efficacy in comparison with a commercial fertilizer. Effects of the pelletized formulations on the suppression of soybean disease will also be evaluated by inoculation of soybean plants with the soybean pathogen, R. solani. Two best-performing formulations on both soybean growth and disease suppression will be chosen for validation trials in the next year in both greenhouse and field conditions.