Introduction: Thyme (Thymus vulgaris L.) plant is one of the most important medicinal plants with unique medicinal properties in Iran. In arid and semi-arid regions of the world, such as Iran, the level of soil organic matter is usually very low. Therefore, maintaining and improving soil fertility is essential to maintain soil health and agricultural sustainability. Plant nutrition is considered one of the practical ways to improve the production and quality of medicinal and aromatic plants, which has largely led to the improvement of production and quality in different plants. In order to support the production of agricultural products and achieve global food security and with the aim of reducing the negative effects on the environment, a lot of emphasis has been placed on the identification and exploitation of alternative nutrient sources, such as organic and biological fertilizers. Vermicompost is one of the most important organic fertilizers that increases the growth and production of various plants, including medicinal plants. Also, biochar is a carbon-rich solid material that affects nutrient availability, water storage, and cation exchange capacity. On the other hand, arbuscular mycorrhizal fungi play an important role in the growth and productivity of the host plant by improving the acquisition of nutrients and also affect the quality of plants.
Materials and Methods: Morphological traits (biomass peoduction, plant height, root weight and volume), chlorophyll and carotenoid content and nitrogen and phosphorus uptake of thyme were investigated in an experiment during two growing seasons (2019-2020 and 2020-2021). In this field experiment, the effect of different nutritional treatments including control (without fertilizer), vermicompost (12 tons per hectare), chemical fertilizer (100 kg nitrogen and 120 kg phosphorus per hectare), combined treatment of 50% vermicompost and 50% Chemical fertilizer (6 tons per hectare of vermicompost + 50 kg of nitrogen and 60 kg of phosphorus per hectare), combined treatment of 50% vermicompost and biochar (6 tons of vermicompost + 5 tons of biochar per hectare) and combined treatment of 50% of chemical fertilizer and biochar (50 kg of nitrogen and 60 kg of phosphorus + 5 tons of biochar per hectare) that were applied to ploanting bed during two years were investigated. In each fertilizer treatment, the planting bed was subjected to inoculation and non-inoculation with arbuscular mycorrhizal fungus (Funneliformis mosseae).
Results and Discussion: the integrated treatment of vermicompost and biochar increased biomass (57%), plant height (30%), root volume (58%), root dry weight (109%) and nitrogen uptake (65%) compared to control. The highest amount of phosphorus uptake was obtained from the integrated treatment of vermicompost and biochar in the second year of growth, which showed an increase of 113% compared to the control treatment of the same year. The integrated treatment of chemical fertilizer and biochar caused an increase of 92% in the content of chlorophyll a and 64% in the content of total chlorophyll (a + b), in both of them there was no significant difference with the treatment of chemical fertilizer. All fertilizer treatments increased carotenoid content (10-18%) compared to the control, but no significant difference was observed between fertilizer treatments. In general, the first year showed higher chlorophyll a, a+b and carotenoid content than the second year. Except for chlorophyll b and carotenoid, other studied traits were significantly affected by inoculation with arbuscular mycorrhizal fungi.
Conclusion: All investigated traits except chlorophyll b and carotenoid were significantly affected by inoculation with arbuscular mycorrhizal fungi. In general, fertilizer treatments were effective on morphological characteristics, chlorophyll and carotenoid content, and nutrient uptake in thyme plants. Among the fertilizer treatments, the integrated treatment of vermicompost and biochar had the greatest effect on the studied traits.


Materials and Methods: Morphological traits (biomass peoduction, plant height, root weight and volume), chlorophyll and carotenoid content and nitrogen and phosphorus uptake of thyme were investigated in an experiment during two growing seasons (2019-2020 and 2020-2021). In this field experiment, the effect of different nutritional treatments including control (without fertilizer), vermicompost (12 tons per hectare), chemical fertilizer (100 kg nitrogen and 120 kg phosphorus per hectare), combined treatment of 50% vermicompost and 50% Chemical fertilizer (6 tons per hectare of vermicompost + 50 kg of nitrogen and 60 kg of phosphorus per hectare), combined treatment of 50% vermicompost and biochar (6 tons of vermicompost + 5 tons of biochar per hectare) and combined treatment of 50% of chemical fertilizer and biochar (50 kg of nitrogen and 60 kg of phosphorus + 5 tons of biochar per hectare) that were applied to ploanting bed during two years were investigated. In each fertilizer treatment, the planting bed was subjected to inoculation and non-inoculation with arbuscular mycorrhizal fungus (Funneliformis mosseae).

Results and Discussion: the integrated treatment of vermicompost and biochar increased biomass (57%), plant height (30%), root volume (58%), root dry weight (109%) and nitrogen uptake (65%) compared to control. The highest amount of phosphorus uptake was obtained from the integrated treatment of vermicompost and biochar in the second year of growth, which showed an increase of 113% compared to the control treatment of the same year. The integrated treatment of chemical fertilizer and biochar caused an increase of 92% in the content of chlorophyll a and 64% in the content of total chlorophyll (a + b), in both of them there was no significant difference with the treatment of chemical fertilizer. All fertilizer treatments increased carotenoid content (10-18%) compared to the control, but no significant difference was observed between fertilizer treatments. In general, the first year showed higher chlorophyll a, a+b and carotenoid content than the second year. Except for chlorophyll b and carotenoid, other studied traits were significantly affected by inoculation with arbuscular mycorrhizal fungi.

Conclusion: All investigated traits except chlorophyll b and carotenoid were significantly affected by inoculation with arbuscular mycorrhizal fungi. In general, fertilizer treatments were effective on morphological characteristics, chlorophyll and carotenoid content, and nutrient uptake in thyme plants. Among the fertilizer treatments, the integrated treatment of vermicompost and biochar had the greatest effect on the studied traits.