Document Type : Research Paper


1 Department of Agronomy, Khuzestan Science and Research Branch, Islamic Azad University , Ahvaz, Iran

2 Department of Agronomy, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.


Application of Azotobacter as a substitute or suitable companion of nitrogen chemical fertilizer with higher efficiency of inputs in safflower plant as a plant adapted to different climates is one of the sustainable agricultural strategies. There for in order to study the effects of Azotobacter and nitrogen fertilizer on nitrogen uptake, grain nitrogen and straw, nitrogen efficiency indices and grain yield of six safflower genotypes under rainfed conditions, as a factorial experiment based on a randomized complete block design with three replications in during growing season of (2015-2017 ) was conducted at the Agricultural Research Station Ilam . Experimental factors inoculated a combination of seed inoculation with Azotobacter chroococcum with urea chemical fertilizer application at four levels (Non-inoculated with Azotobacter , seed inoculation with Azotobacter, inoculation with Azotobacter chroococcum + 50% N from urea and inoculation with Azotobacter + 100 Percent N from Urea) and six genotypes of safflower. The combined analysis of variance for two years showed that the main effects of nitrogen source and genotype and also year× nitrogen source had significant effect on all of the measured traits and nitrogen efficiency indices. The results of comparison of means showed that inoculation treatment with Azotobacter + 50% nitrogen fertilizer had higher Nitrogen use efficiency than 100% nitrogen fertilizer use and there was no significant difference in grain yield between the two treatments. Sina genotype with the highest grain yield and nitrogen use efficiency compared to other genotypes is more desirable for cultivation in rainfed conditions of the region.