Environmental pollution is one of the fundamental challenges of today's world that has significant impacts on agriculture and food security. The use of water resource management methods and biofertilizers as strategies to reduce the effects of environmental stresses is of interest to researchers. Facilitating the use of water resources in agriculture is one of the key strategies in improving crop yield and maintaining environmental quality. This study aimed to investigate the effects of different irrigation levels and the use of biofertilizers such as Azospirillum lipoferum and mycorrhizal fungi on environmental traits and quantitative and qualitative performance of barley cultivars. This study was conducted during two crop years (2018-2019) in a farm located at kilometer 4 of the Ardabil-Khalkhal road as a factorial experiment in a randomized complete block design with three replications. The main objective of this study was to reduce the negative effects of water stresses on the yield and yield components of barley cultivars using biofertilizers. The results showed that under normal irrigation conditions, Kavir cultivar showed the highest grain yield with 7755.5 kg/ha, while Valfajr cultivar showed the lowest yield with 5650 kg/ha. Under water stress conditions (irrigation only up to 50% of the spike stage), Nosrat cultivar showed the best yield with 6209.4 kg/ha, while Kavir cultivar showed the lowest yield with 4167.7 kg. The results showed that Nosrat cultivar has the highest stress tolerance, while Valfajr cultivar showed the lowest stress tolerance. In the second year, the application of Azospirillum growth-promoting bacteria and mycorrhizal fungi increased grain yield by 2.02, 2.38 and 3.31 percent, respectively, compared to the control group (without the application of mycorrhizal and bacteria). Full irrigation during the plant growth period increased grain yield by 4.43 and 10.04 percent compared to the limited irrigation and rainfed treatments. Principal component analysis showed that the first three components with eigenvalues higher than one explained 99.6% of the total variation in physiological traits. This first component included traits such as plant height, peduncle length, number of grains per spike, and grain weight per spike, which had a positive effect on grain yield. Therefore, the Valfajr cultivar is recommended due to its ability to increase grain yield.
Somarin et al. (Tue,) studied this question.