Background: Today, peppermint cultivation has spread in different regions of the country. Peppermint is a very important medicinal plant and has wide applications in various pharmaceutical, spice, beverage, food and health industries.
Aim: The use of chemical fertilizers in recent years has played an important role in increasing the yield of agricultural products, but the unprincipled, excessive and one-sided use of these fertilizers upsets the balance and causes environmental, health and economic pollution. To solve these problems, researchers are looking for the use of slow release methods in the production of chemical fertilizers. The dissolution speed of slow-release fertilizers is lower than common chemical fertilizers, and these fertilizers provide nutrients to plants gradually and during the growth period.
Methodology: In this research, peppermint plants in pots filled with agricultural soil, windblown sand and manure were rotted and washed, with proportions of 45, 45 and 10%, respectively, with the application of slow release polymers of urea, iron, zinc and Manganese and the mixture of these polymers were investigated in the form of a completely randomized design with 22 treatments and 3 repetitions in Firozabad, Fars. Measurable traits include shoot length, root length, number of leaves, number of lateral branches, stem diameter, leaf area, fresh and dry weight of shoot and fresh and dry weight of root, essential oil yield, chlorophyll a and b content and Carotenoid and content of nutrients including calcium, magnesium, potassium, sodium, iron, zinc, manganese and nitrogen in the plant were investigated and measured.
Conclusions: The results of this study showed that the fertilizer treatments used in the experiment (both groups of frankincense polymers and mineral fertilizers) had a significant effect on the traits measured in this research. In general, frankincense polymers, especially the hand-made mixed type, were effective in improving the morphologica