The objectives of this study were to (i) investigate the effects of different biofertilizers on yield, (ii) compare root morphologies, and (iii) observe the effect of different biofertilizers on the concentration of nutrients (NPK) in seeds, leaf, and soil. Such an experiment would shed light on the relationship between root morphology, the concentration of nutrients, and yield and provide a theoretical and practical foundation for high-yielding cultivation with PGPR application. Two field studies were conducted at the Faculty of Agriculture, the Ferdowsi University of Mashhad, Iran in, 2018 and 2019. The study was based on a completely randomized block design arranged in a factorial with three replicates and two mung bean genotypes (G) (Dezfouli and Indian). Treatments were 1-free-living nitrogen fixating bacteria (NFB), a set of strains Bacillus subtilis NCBI Accession No. MT102419, Enterobacter cloacae NCBI Accession No. MT102416, Bacillus cereus NCBI Accession No. MT102418; 2- phosphate solubilizing bacteria (PSB), a set of strains Paenibacillus polymyxa NCBI Accession No. MT102424, Bacillus pumilus NCBI Accession No. MT102425; 3- potassium solubilizing bacteria (KSB), a set of strains Enterobacter hormaechei NCBI Accession No. MT102420, Enterobacter sp. NCBI Accession No. MT102421; 5- Nitrogen fertilizer (source of urea 46%, NF), and 6- Control (without biological and chemical fertilizer). The result demonstrated the heights of grain yield (GY) recorded at NFB+PSB+KSB treatment, increased by 52% over the Control. As a result, compared with Control and NF, all fertilizer application treatments improved total root length, root area, root volume, and the number of nodules per root to different extents; the effects of NFB+PSB+KSB and PSB treatments were maximum over two years. Also, the biofertilizer treatments\\\' application recorded the highest N, P, and K concentrations of grain, leaf, and soil, compared with the Control. Additionally, linear regression indicated that the GY had a positive and significantly associated with the increase in root morphology and NPK concentration, and PGPR application increased correlation coefficients between them. In conclusion, biofertilizer has been identified as an alternative to chemical fertilizer to improve crop production in sustainable agriculture and provide healthy food for the world\\\'s expanding population

Keywords