Abstract
Introduction: The use of biological fertilizers to reduce the use of chemical fertilizers and increase the yield of plants is an important issue in moving towards sustainable agriculture. Organic fertilizer, compost, vermicompost and microorganisms that enhance plant growth can be used to improve the physical and chemical properties of soil. In order to reduce these risks, resources and inputs should be used that, in addition to supply the current plant needs, will also lead to the sustainability of agricultural systems in the long time.
Materials and methods: This experiment was carried out in a randomized complete block design with 3 replications at agricultural research filed of Islamic Azad University, Khorramabad Branch during cropping season of 2015. The experimental treatments including 1) Control, 2) Azotobacter chroococcum, 3) Pseudomonas putida, 4) Azotobacter chroococcum + Pseudomonas putida, 5) Azotobacter chroococcum + Pseudomonas putida + vermicompost (2 ton/ha), 6) Azotobacter chroococcum + Pseudomonas putida + vermicompost (4 ton/ha) and 7) Azotobacter chroococcum + Pseudomonas putida + vermicompost (6 ton/ha). The characteristics including plant height, root weight, stem diameter, essential oil yield, and essential oil content (such as estragole, limonene, anethole and fenchone) were measured.
Results: Results showed that the biological fertilizers and vermicompost had different significant effects on studied traits. According to data, the highest plant height (104.8 cm), root weight 76.68 (gr/m-2), stem diameter (3.66 mm), essential oil yield (12.63 kg/ha), estragole (5.76%) and limonene (4.90%) were obtained in treatment of Azotobacter chroococcum + Pseudomonas putida + vermicompost (6 tons/ha), while the lowest were observed in the control treatment. Also, the highest anethole (59.32%) and fenchone (7.76%) were obtained from control treatment.
Conclusion: In general, biological fertilizers and vermicompost have a positive effect on some of morphological characteristics and essential oil yield. Application of these treatments by providing the water and nutrients for the plant and causing the development of the root of the plant and finally, increasing the characteristics mentioned.
Keyword: Biological fertilizers, Vermicompost, Morphological properties, Essential oil, Fennel |