BACKGROUND: Imbalanced mineral nutrition and scant information about nitrogen (N) in plants may result in reduction in barley morpho-physiological activities. However, farmers use higher or lower fertilizer doses regarding barley growth and yield. Barley is characterized by a rich genetic diversity, making it an important for studies of Azospirillum response with high potential for crop improvement. Moreover, biological fertilizers severely affect barley growth and development, leading to improve yield loss. OBJECTIVES: Plants of an Azospirillum exposed to 0, 2, and 4 h per 100 kg seed were compared with urea fertilizer levels (75 and 100%) to identify growth pathways to barley’s response. METHODS: Current research was done according split plot experiment based on randomized block design with four replications which urea fertilizer (75% and 100%) was in main plot and Azospirillum trends belonged to sub plots. RESULT: Regulation of crop growth was severely impacted in leaves, highlighting the complexity of Azospirillum response mechanisms in this tissue. Functional analyses in tissues indicated that response to Azospirillum trends is mainly achieved through sensing and signaling pathways, strong effects to urea amounts and growth, kernel yield and yield components. Azospirillum trends especially lipoferum involved in growth signaling pathways, as well as 100 kg.ha-1 urea, were identified. This study provides valuable information on early Azospirillum-responsive in growth indices of barley and identifies several important players in response to chemical fertilizers. CONCLUSION: Finally based on result of current research apply Azospirillum lipoferum with 100% urea fertilizer led to produce highest seed yield and it can be advised to producers at studied region. تفاصيل المقالة