Evaluation of the effect of nutrition on the quantity and quality of Satureja khuzestanica Jamzad. essential oils in ecological conditions of Khorramabad

This research was carried out to study the effects of chemical and biological fertilizers (manure and vermicompost), as well as their combinations on the quality and quantity of the essential oil content and composition of S. khuzestanica in Zagros Botanical Garden of Agricultural and Natural Resource Research Center of Lorestan based on a complete random block design with 3 replications in 3 years, during 2016-2020. There were 24 plots of 3x3in the study, 100 cm away from each other, in which the plants were sown art a distance of 50 cm. The experimental treatments included 50 kg/ha of NPK (50, 25, 25), animal manure (30 and 60 tons/ha), vermicompost (5 tons/ha), and a combination of NPK combination and animal manure and vermicompost, all applied only once at the planting stage. During the flowering stage, shoots were harvested and their essential oils were obtained by hydro-distillation.  The essential oils were then analyzed by GC and GC/MS. The results of combined analysis of variance showed that the effects of year and interaction of year and fertilizer on the percentage of essential oil were significant at p≤0.05 and p≤0.01, respectively. Furthermore, the maximum essential oil percentage and oil yield in S. khuzistanica were 5.4% and 433 kg/ha with NPK + M60 treatment during the third year. Carvacrol (93.1-88.8, 96.0-89.6,94.9-88.8 percent) was the most important composition of the essential oil in all treatments and years of the experiment. In general, the nutritional treatments increased the amount of essential oil and carvacrol compared to the control, and during the three years of testing, the yield of dry weight and therefore essential oil increased. The results of this research indicated that the use of organic fertilizers alone or in combination with chemical fertilizers has a positive effect on improving the essential oil yields, and the use of integrated nutrition method for S. khuzestania is economic.