Evaluation of efficiency parameters of phosphorous-solubilizing and N-fixing bacteria inoculations in wheat (Triticum aestivum L.)

Abstract

Chemical fertilizers play a significant role in increasing plant production; however, they may have a negative impact on soil fertility and cause environmental degradation in cases of excessive use. In addition, the highest levels in chemical fertilizer use have already been reached, and further yield increases do not seem possible. Due to their negative impact on soils and the environment, alternatives to chemical fertilizers are needed. Today, biological alternatives are yielding promising outcomes. Biological nitrogen fixation may constitute a significant alternative in organic farming. Therefore, in the present study, the effects of single, dual, and triple combinations of phosphorus-solubilizing [Bacillus megaterium var. phosphaticum (M-13)] and nitrogen-fixing bacteria [Stenotrophomonas maltophilia (82) and Ralstonia pickettii (73)] treatments were compared with chemical fertilizer and control treatments with regard to wheat efficiency parameters. The efficiency parameters of the triple bacteria inoculation (73 + 82 + M-13) treatment were close to those of chemical fertilizers: up to 94.3% of the nitrogen uptake efficiency, 94.1% of the nitrogen translocation efficiency, 85.9% of the nitrogen use efficiency, 91.9% of the agronomic efficiency, and 91.7% of the water use efficiency of chemical fertilizers were reached. In terms of efficiency, the triple combination (73 + 82) was followed by the nitrogen-fixing dual bacteria treatment. Therefore, the triple bacteria combination may be recommended as an alternative fertilization method in organic wheat farming.