Comparative Study of Chemical, Biological and Organic Fertilizers on Growth and Essential Oil Production of German Chamomile (Matricaria chamomilla L.)

The management of different types of chemical and organic fertilizers and their residues in soil in terms of plant performance and environmental effects, especially in dry and semi-dry regions such as Iran, is of great importance. In order to investigate the effects of some chemical, biological, animal, humic acid, vermicompost fertilizers, and their residues on growth rate, flower yield, essential oil yield, chamazulene yield, and medicinal plant components of German chamomile (Matricaria chamomilla L.), an experiment was conducted in pots in a completely randomized design with four replications at Varamin Station of Agricultural Research and Education Center of Tehran Province, during one growing season during the years 2017–2018. Chemical fertilizer treatment (NPK) was applied at two levels. Level 1 consisted of 1.5 g of urea (250 kg/ha), 3 g of triple superphosphate (TSP) (500 kg/ha), and 1.3 g of potassium sulfate (216 kg/ha). Level 2 was a combination of 3 g of urea (500 kg/ha), 4 g of TSP (665 kg/ha), and 2.6 g of potassium sulfate (432 kg/ha). The vermicompost treatment was applied at two levels: 30 g (5 t/ha) and 60 g (10 t/ha). Farmyard manure was also applied at two levels: 120 g of decomposed bovine manure (20 t/ha) and 180 g of decomposed bovine manure (30 t/ha). Humic acid was used in two application methods—fertigation through irrigation and foliar spray—at a concentration of 5 per thousand (5 g /L of water). The biological fertilizer (BNPK), containing nitrogen-fixing, phosphate-solubilizing, and potassium-solubilizing bacteria, was applied at 125 mL/pot for each of the ten treatments, including a control (no fertilizer).The results indicated that the application of the second level of chemical fertilizer significantly enhanced the growth parameters of chamomile compared to the control. The highest values recorded were for plant height (34.35 cm), number of flowers (92 flowers), flower diameter (1.51 cm), dry weight of flowers (18.70 g), percentage of essential oil in flowers (0.503%), and essential oil yield per ten plants (0.939 g) were observed in the treatment utilizing the second level of NPK chemical fertilizer. The highest essential oil yield and chamazulene yield were also observed in the biological fertilizer treatment, which had a significant difference compared to the control. The biological fertilizer treatment was also able to create desirable flower, essential oil, and chamazulene yields, which is recommended for use according to the goals of organic and sustainable agricultural production. Based on the results, positive effects of biological fertilizers on the medicinal plant chamomile can be expected. In the light of the favorable performance of the biofertilizer treatment, its application is advisable in alignment with the objectives of organic and sustainable agriculture.