Sage (Salvia officinalis L.) contains valuable compounds such as polyphenols and terpenoids. This plant has many medicinal effects and it is used in the treatment of various diseases. The use of superabsorbent polymers (hydrogel) along with providing optimal nutrition, for better access of medicinal plants to water sources and also to reduce the effects of drought stress, has received much attention in recent decades. This research was carried out as a completely randomized block design in order to investigate the effect of nitrogen, plant growth-promoting bacteria (PGPB), superabsorbent polymer and their combined effect on the morphological, physiological and biochemical parameters of sage. Nitrogen in the form of urea 46% (200 kg/ha), bacterial (Pantoea agglomrans) inoculation, and super absorbent polymer (1500 kg/ha) were used. The results showed the positive effect of superabsorbent and bacteria on the biological yield of sage. Also, the bacteria had a significant effect in maintaining the stability of the cell membrane, which caused a decrease in the amount of electrolyte leakage. Photosynthetic activity increased significantly due to the use of superabsorbent. Biochemical traits such as phenolic compounds, flavonoids and antioxidant capacity increased under the influence of nitrogen and bacteria. The results of the analysis showed the effect of nitrogen in increasing thujone and decreasing 1,8 cineole and camphor. The superabsorbent caused an increase of 1,8 cineole and camphor. In general, the results explained that access to optimal water and nitrogen (as the most widely used nutritional element) sources, improves growth and biochemical parameters.
