Study the effects of organic and chemical fertilizers on oil yield and essential oil components in Satureja spicigera Jamzad in Esfahan

Plant nutrition management is an important factor in the success of cultivation of medicinal plants, which leads to the improvement of their quantitative and qualitative yield. Therefore an experiment was conducted as a randomized complete block design with three replications and 8 nutritional treatments during three growing seasons on Satureja. spicigera Jamzad.The treatments were different levels of chemical fertilizers (N50P25K25), different levels of organic fertilizers (Cow Manure30, Cow Manure60 and 5 ton/ha Vermi-compost) and combination of chemical and organic fertilizers (N50P25K25+ Cow Manure30, N50P25K25+ Cow Manure60, N50P25K25+ 5 ton/ha Vermi-compost). These treatments were compared with the control. The aerial parts of plants were harvested at 50% flowering stage and after drying, the essential oil was extracted using water distillation and Clevenger apparatus. Essential compounds were identified using gas chromatography (GC) and gas chromatography-mass spectrometry (GC / MS). According to the results, the maximum essential oil percentage and oil yeild in S. spicigera was 2.96% and 58.02 kg/ha during the second year. Based on the results of the experimental years, the highest oil yield was observed in the combined treatment of 50 kg/ha nitrogen, 25 kg/ha of phosphorus and 25 kg/ha of potash plus 5 tons per hectare of vermicompost, in the third year. During the experimental years, 13 compounds were observed in S. spicigera that dominant composition were thymol (26.14-56.15%), g-terpinene (12.83-30.95%) and p-cymen (7.24-16.85%) with a total of more than 97%, had the highest amount. According to the results, the qualitative yield of essential oil of plant was less affected by soil fertility treatments, but the quantitative yield of essential oil had a significant increase that indirectly increases the qualitative yield of essential oil. Also, it could be recommended to use vermicompost along with the chemical and biological fertilizers to increase the essential oil yield of Satureja spicigera.