Effect of Bio Phosphate Fertilizer and Triple Super Phosphate Application on Yield, Yield Components, Phosphorus and Cadmium Concentration of Sunflower (Helianthus annuus L.) Seeds

The high cost of chemical fertilizers used in agriculture and the environmental problems due to their use reveal the need to reappraise conventional plant nutrition practices. Integrated use of biofertilizers combined with synthetic fertilizers is one of the essential sustainable agricultural strategies. To this end, this study was carried out by using a factorial experiment based on randomized complete block design with three replications at the experimental field of Islamic Azad University, Ahvaz Branch during 2018 cropping season. The first factor was different amounts of triple superphosphate fertilizer with three levels (0, 50 and 100 kg.ha-1) and the second factor was phosphorus biofertilizer also with three levels (0, 100 and 200 g.ha-1). Result of analysis of variance revealed that the effect of different levels of biophosphorus fertilizer and triple superphosphate on all measured characteristics were significant but the interaction effect of treatments was not significant. Based on the results of this study, the highest seed yield, 1000 seed weight, seed oil percentage, head diameter and number of seed per head and lowest empty seed belonged to the use of 100 kg.ha-1 triple superphosphate with 200 g.ha-1 biophosphorus fertilizer. It seems triple superphosphate fertilizer to increase the concentration of soil cadmium by 54%, due to its impurities, including heavy elements, but increasing the levels of phosphorus fertilizer in the soil reduces the concentration of cadmium by 45%. According to these results, the application of 100 kg.ha-1 of triple superphosphate and 200 g.ha-1 of phosphorus fertilizer per hectare, compared to other treatments, may increase seed yield and absorption of elements of sunflower in this region.