Effects of nutritional treatments on morphological characteristics and essential oil yield of Satureja khuzistanica Jamzad

To investigate the effects of different nutritional treatments on morphological characteristics, essential oil yield, and the amount of some elements in the soil and plant branches of Satureja khuzistanica Jamzad, an experiment was conducted as a randomized complete block design with three replications and 14 nutritional treatments during two growing seasons (2017-2018, 2018-2019). Treatments included 1- C (control), 2- NPK (Chemical fertilizer 50-25-25 kg.ha-1), 3- CM30, 4- CM60 (CM: Cattle manure 30 and 60 ton.ha-1), 5- CM30+NPK, 6- CM60+NPK, 7- V5 (Vermicompost 50 ton.ha-1), 8- V5+NPK, 9- GM (Glomus mosseae), 10- GI (Glomus intraradices), 11- S0+T, 12- S250+T, 13- S500+T (S: Sulfur 0, 250, and 500 kg.ha-1, T: Thiobacillus), and 14- V5+T. The analysis of variance showed the significant effect (p < /em>≤0.01) of year×fertilizer treatments on the all morphological characteristics, percentage and essential oil yield, and the amount of potassium and sulfur of plant branches. The highest plant height in the first and second years was related to the CM30+NPK and CM60 treatments, respectively. The highest number of branches in the first and second years was observed in the CM30+NPK and GM treatments, respectively. The CM30+NPK treatment had the highest shade width in both years. Also, the highest amount of dry matter of flowering branches in the first and second years was related to the CM30+NPK and V5+T treatments, respectively. According to the results, the highest essential oil percentage in the first and second years was observed in the GM and S0 + T treatments, respectively. The application of V5+NPK and V5 +T treatments significantly increased the essential oil yield in the first and second years, respectively. The results also showed that the highest potassium content of branches in the first and second years was related to the GI and V5 + NPK treatments, respectively. Also, the highest sulfur content of branches in the first and second years was obtained in the V5 and S500 + T treatments, respectively. In general, the present study showed that the use of biofertilizers increases the efficiency of essential oil percentage and the amount of nutrients in this plant. Also, it could be recommended to use vermicompost along with the chemical and biological fertilizers to increase the essential oil yield of Satureja khuzistanica.