Study the impact of various levels phosphate fertilizer and gtowth promoting bacteria on availability of some of nutrients and wheat yield indices

In order to study the effect of plant growth promoting bacteria and phosphate fertilizers levels on nutrient availability and yield of wheat, an experiment was conducted as factorial based on completely randomized block design in three replications in a fielf located in Eyvan town, Ilam province. Studied factors include five levels of phosphorous fertilizer (control, 25, 50, 75 and 100 kg/ha phosphate fertilizer) and seed inoculation with bacteria at four levels (no-inoculation (Control), inoculation with Azotobacter, inoculation with Pseudomonas, and inoculation with Azotobacter and Pseudomonas. Results showed that 100 kg P/ha along with seed inoculation with Azotobacter and Pseudomonas showed greatest effect on increase in growth and yield and yield components of autumn wheat. Wheat grain nitrogen content significantly increased by inoculation with Azotobacter and therefore protein content of grain and consequently grain quality increased as well. Seed inoculation with plant growth promoting bacteria at 4thphosphate fertilizer level resulted to increase in grain N and P by 43.5 and 62.7 percent, respectively. Results showed that all fertilizer treatments increased wheat yield compared to control which of them 100 kg/ha P treatment along with inoculation with Azotobacter and Pseudomonas resulted in highest impact on studied growth parameters. Though by increasing P phosphorus level, studied traits increased as well, but the effect was more when applied with biological fertilizers.