Effects of phosphorus on biological nitrogen fixation in soybean under irrigation using saline water
A field experiment was conducted on Serdang soil, to study the effect of both phosphorus application and bacterial inoculation on the growth and yield of soybean crop under irrigation by saline water (3.5dS/m). Factorial experiment was used with randomize complete block design (RCBD) for phosphorus and Rhizobial inoculation factors, the phosphorus levels were 0, 40, 80 and 120 Kg P /ha, while Rhizobial inoculation contained two treatments( Rhizobial inoculation and control) with three replicates. The following parameters were measured: number of nodules, weight of nodules, plant dry weight, plant height, number of pods, weight of pods and root dry weight. The results showed that the inoculation treatment was significantly higher than non – inoculation treatment, also results showed increasing in all parameters at 120 Kg P/ ha. We can conclude that the rhizobial inoculation with phosphorus application for soybean crops caused increasing in both yield and its components
