The present study was carried out to regulate the microbial activity in soil environment to be suitable for soybean so as the increase the activity of rhizobia fertelizering forming nodules and increasing the microbial inoculum activity through providing plant nutrients.
A pot experiment was conducted by culturing soybean seeds (gesa-65)in sandy loam soil. Tow isolates of Bradyrhizobium japonicum and Pseudomonas puteida were used after evaluating their activities in the laboratory as co- inoculums in addition to the treatment of a single B. japonicum as well as a control treatment .
Results have showd the ability of two isolates to produce IAA and dissolve phosphate compounds. P. puteida was able to produce NH3 and HCN as well as sidrophores and inhibit the growth of F. oxysporum mycelium. The co- inoculums of the two isolates were efficient for activity the highest rate of plant growth 93%, and nodules formation estimated after month of plant growth 42 nodule 90% activity. Also, the two isolates improved the nutrient status N, P ( 20.3,210 mg/kg soil) They increase the microbial density that dissolves phosphates and nitrogen fixation in the plant environment (5.26 ,5.32 Log cfu/g).The activity of the two isolates in soil environment was increasing the dry weight of the roots, vegetables, number of nodules , yields( 22.12 ,74.32 ,80 , 85.3 / plant), P and N conteats and protein percentage 36.25%.