Effect of Biological and Chemical Fertilizers of Nitrogen and Phosphorus on Quantitative and Qualitative Yield of Sunflower

Biological fertilizers are one of the most important supply source of nutrients in sustainable agriculture. In order to study the effect of bio-fertilizers on sunflower and compare the it’s efficiency with chemical fertilizers، a field experiment was carried out in Eyvangharb in summer of 2011. Treatments were arranged in a split factorial experiment based on RCBD with three replications. The main plot included 4 levels of phosphorus and nitrogen chemical fertilizer (0، 33، 66 and 100% of nitrogen and phosphorus fertilizer requirements) and subplot comprised of factorial of Nitroxin biofertilizer application with two levels (inoculation and non inoculation) and Phosphate Barvare2 biofertilizer with two levels (inoculation and non inoculation). Results showed that the interaction of chemical fertilizer and Nitroxin had a significant effect on yield، So that at levels of 0، 33 and 66% of requirement chemical fertilizer application، inoculation with Nitroxin compared to the non-inoculated increased grain yield 31. 64، 9. 78 and 5. 73%، respectively، but at level of 100% of requirement chemical fertilizer application، the Nitroxin application didn’t have significant effect on this trait. Biological and chemical fertilizers application significantly increased oil yield، as the highest oil yield was achieved at 100% requirement chemical fertilizer use and Nitroxin and Phosphate Barvare2 inoculation. Nitroxin application also increased 2. 63 percent seed oil content، compared to control. Finally، based on these results، to achievement of maximum sunflower oil yield، seed inoculation with bio-fertilizers in combination with chemical fertilizers is recommended.