Reaction of Sweet Bail (Ocimum bacilicum L.) to Different Fertilizing System in Organic Farming

Introduction: The tendency to produce aromatic and medicinal plants and the demand for natural products is increasing especially in the world of ecological agriculture. Ecological agriculture of medicinal plants guarantees their quality and reduces the possibility of negative effects on their medicinal quality and yield. One of the most important medicinal plant species is basil, which is widely used in food and pharmaceutical industries. Common basil (Ocimum bacilicum L.) is the most important economic species of Ocimum and is cultivated and consumed in almost all warm and temperate regions. Evaluation of different plant nutrition systems is one of the important principles in the production planning of medicinal plants in order to achieve high yield and quality of effective ingredients. Proper fertilizer management is one of the important factors in agricultural production. Identification of fertilizers compatible with nature and suitable for plant growth can have favorable effects on quantitative and qualitative indices of the plant. Organic fertilizers are genuine and risk-free products that can be suitable for agricultural sustainability. Soil organic matter improves fertility and water retention, provides proper ventilation, long-term storage of plant nutrients and microorganisms, so replacing chemical fertilizers with fertilizers such as vermicompost and biofertilizer can reduce the above-mentioned effects. Biofertilizers are one of the operations that is nowadays in accordance with the principles of sustainable agriculture for soil fertility. Biofertilizers include the compost of one or more types of useful soil organisms or as metabolic by-products of these organisms that are used to provide the plant with the nutrients it needs in an agroecosystem.Materials and Methods: In order to investigate the effect of biochar and organic and biological fertilizers on the quantity and quality of Ocimum bacilicum L., a factorial experiment was done in a randomized complete block design with three replications. Experimental treatments included two levels of biochar (0 and 20 ton ha-1) and five levels of fertilizers (vermicompost (10 ton ha-1), Mycorrhiza, Azotobacter, Pseudomonas and no fertilizer application). Prior to planting sweet basil seed, biofertilizers and vermicompost were mixed with soil to the depth of 15 cm. Mycorrhizal fungi were mixed with seed. Azotobacter and Pseudomonas bacteria were also incubated with seeds (seed inoculated). It should be added that in this study no chemicals were used to control weeds and pests. Before flowering stage, morphological traits of basil (plant height, stem diameter and number of branches) were measured. Also, to measure the dry weight of the shoots, basil was scalped from one square meter and weighed, and their fresh weight was thus determined. Then, to determine the dry weight, the samples were transferred to an oven at 70 ° C for 48 hours and finally weighed. Also in the flowering stage, the amount of total phenol and flavonoids and antioxidant activity (DPPH) were evaluated. Finally, the data were analyzed using SAS statistical software and Excel software was used to draw the graphs. Also, the means were compared by LSD test at the level of 5%.Results and Discussion: According to the results, the highest height and number of main branches was in biochar application with vermicompost (49.37 cm and 7 respectively), which was significantly better than other treatments. The intraction effect of biochar and fertilizer had a significant effect on fresh and dry weight of leaf and stem of the plant. The results of the mean comparison of treatments showed that the highest leaf and stem fresh weight were obtained in biochar + Pseudomonas application (792 and 876 g m-2, respectively), which had no significant difference with biochar + vermicompost; and also, the maximum leaf dry weight and stem dry weight were obtained in biochar with Pseudomonas application (166 and 175 g m-2, respectively). The interaction between biochar and fertilizer on phenol, flavonoids and antioxidant activity of basil showed a significant differences between treatments. ConclusionIn general, the results showed that the use of biochar and biological and organic fertilizers can be effective in both the quality and quantity of sweet bail, where, the use of the bacterium Azobacter and Pseudomonas with biochar had the greatest effect on the quality and quantity of sweet bail. Finally, it can be cocluded that the combined use of biochar with biological fertilizers have a significant impact on the quantitative and qualitative increase of sweet bail in ecological or low input agricultural.