Co-inoculation Effect of Multi-functional Rhizobacteria on Productivity of S. tuberosum

Abstract

The simultaneous introduction of nitrogen-fixing bacteria and plant growth-promoting rhizobacteria (PGPR) into crops has been shown to significantly enhance plant growth. S. tuberosum (commonly known as potato) is a key dietary source of high-quality protein for human consumption. PGPR are known to improve various aspects of plant development, including overall growth, nodule formation, and nitrogen fixation capacity. This study aimed to investigate whether the co-inoculation of potato plants (Solanum tuberosum) with Pseudomonas putida and Bradyrhizobium japonicum could enhance plant growth, productivity, and nutrient uptake. The findings demonstrated that the combined inoculation of B. japonicum and P. putida resulted in significantly greater growth and yield benefits compared to plants inoculated with B. japonicum alone or the uninoculated control group. Specifically, co-inoculation with P. putida and B. japonicum increased the nutrient content of potato plants: nitrogen (N) by 45%, phosphorus (P) by 35%, potassium (K) by 42%, magnesium (Mg) by 20%, sodium (Na) by 84%, and calcium (Ca) by 42% relative to the control. In contrast, inoculation with B. japonicum alone resulted in a smaller but still significant increase in nutrient content, raising N by 17%, P by 19%, and K by 17% compared to P. putida inoculation or the control. The highest values for N, P, and K were observed with co-inoculation treatments, which also enhanced soil nutrient levels. Under normal conditions, co-inoculation with P. putida  and B. japonicum produced a marked improvement in both crop yield and soil nutrient composition compared to other treatments, underscoring the synergistic potential of these microbial inoculants.