Effect of Silicic Acid and Phosphate Solubilizing Bacteria on the Availability of Micro Nutrients

Considering that most of the calcareous soils of Iran are deficient in one or more micronutrients, optimal nutrition of nutrients such as silicon under the influence of biological treatments can be highly effective in these conditions. Therefore, this study was conducted to investigate the effects of silicon and phosphate-soluble bacteria on the availability of micronutrients for wheat. We used a completely randomized design in three replications and treatments included 0, 150, 300, 600 mg/kg silicon from a source of silicic acid and three levels of bacteria (non-inoculation of bacteria, Bacillus and Pseudomonas). The study was conducted in the greenhouse of Soil and Water Research Institute. The results showed that the combined use of silicon and phosphate-solubilizing bacteria increased the uptake of manganese and iron compared to the control treatment. However, the antagonistic effect between nutrients reduced zinc uptake at higher levels of functional silicon. The effect of inoculation with Bacillus and Pseudomonas on the amount of zinc, manganese and iron uptake by wheat was superior to the control bacterium. On the other hand, application of silicon (600 mg silicon/kg soil with Pseudomonas bacteria) significantly increased the concentration of phosphorus in wheat to the optimum level. Since excessive use of phosphate fertilizer in calcareous soil reduces absorption of micro nutrients, the combined use of silicic acid and phosphate-soluble bacteria can be recommended as an effective method for increasing availability of micro nutrients in greenhouse conditions.