Introduction Catnip (Nepeta cataria L.) is one of the most important medicinal plants belonged to the Lamiaceae family that referred to considerable pharmacological, antimicrobial, antibacterial and pesticides activities of its essential oil in most of the literatures. The harmful effects of chemical fertilizers on the environment and human health and lack of soil organic matter in arid and semi-arid regions have resulted in an increase in the use of chemical fertilizers in these

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... use of these fertilizers has led to serious environmental pollutions during the last decades. With respect to the hazards of chemical fertilizers and the importance of medicinal plants, researchers have recently considered the application of biofertilizers and organic materials. According to literatures, the application of biofertilizers and organic fertilizers can be recommended as a proper alternation for the improvement of the quantity and quality of essential oil in Catnip. Material and Methods This research was conducted as factorial layout based on a randomized complete block design (RCBD) with three replications at the research farm of the faculty of agriculture, Shahid Chamran University of Ahvaz, Iran. The first factor was included fertilizer treatments in five levels (Control (C), Azetobarvar-1 (Az), Phosphatbarvar-2 (Ph), Combination of Az and Ph (M), chemical fertilizer (Ch) included 150 kg.ha-1 granular urea (46% N) and 100 Kg.ha-1 triple superphosphate (46% p < sub>2O5)) and the second factor was comprised humic acid in two levels (0 and 20 Kg.ha-1). The studied traits in this research included soil microbial respiration and biomass carbon and soil organic matter contents, leaf nitrogen and phosphorus amounts, number and size of secretory trichomes, essential oil content, yield and composition. Leaf nitrogen and phosphorus concentrations were measured at the beginning of reproductive stage by Kjeldahl method and colorimetric method using a UV-2100-Unico spectrophotometer, respectively. Moreover, the soil mic [...]