Effect of different types of nitrogen fertilizers on quantitative and qualitative characteristics of Satureja hortensis L

Summer savory (Satureja hortensis L.) is one of the most important medicinal plants as its essential oil is used in different industries including pharmaceutical, cosmetic and food.In this research, effect of different types of nitrogen fertilizers on quantitative and qualitative characteristics of summer savory was evaluated in a complete randomized blocks design with three replications. The treatments included chemical fertilizer (150 kg/ha urea), biofertilizer (Azospirillum & Azotobacter), combinations of biofertilizer and 50% chemical fertilizer and control. Different characteristics such as plant height, number of lateral branches, flowering shoot dry weight, shoot dry weight, essential oil yield and essential oil percentage were recorded.According to the results, all studied characteristics were affected by different types of nitrogen fertilizers and the highest records were obtained at 50% chemical fertilizer. Percentage of essential oil was also significantly affected by fertilizer treatments as the most percentage of essential oil was respectively obtained at chemical fertilizer (2.07%), combination of biofertilizer and 50% chemical fertilizer (1.91%) and biofertilizer (1.90%). Application of different nitrogen sources significantly increased essential oil yield compared to the control treatment and the highest essential oil yield was obtained at combinations of biofertilizer and 50% chemical fertilizer (30.23 kg/ha). Afterward, chemical fertilizer and biofertilizer respectively produced the most essential oil yield. Our results indicated thatapplication of bio-fertilizers alone or in combination with chemical fertilizer has positive effects in improvement of qualitative and quantitative traits of Summer savory; so it could be considered instead of continuous use of chemical fertilizersas a shift towards sustainable agriculture and reduce pollution from chemical fertilizer.