Effect of biochar and biofertilizers on photosynthetic pigments, yield and nutrients content of peppermint (Mentha piperita L.)

In order to investigate the effect of biochar and biological fertilizer on photosynthetic pigments, yield and nutrient content of peppermint (Mentha piperita L.), an experiment was conducted as factorial based on a randomized complete block design in three replications at Sari Agricultural Sciences and Natural Resources University in 2017. Treatment consisted biochar on two level (0 and 10 ton ha-1) and organic and biological fertilizers on five level (no fertilizer (F0), vermicompost (10 ton ha-1) (F1), Pseudomonas fluorescens (F2), Azotobacter (F3) and Arbuscular mycorrhizal (Glomus mosseae, G. intradicces and G. etunicatum) (F4)). The results of this study showed that the main effect of biochar and bio-fertilizer had a significant effect on leaf, stem and total fresh weight of the plant. In addition, the use of biochar and also mycorrhiza treatment increased average of leaf fresh weight (294.73 and 306.8 g.m-2), stem fresh weight (366.73 and 361.15 g.m-2) and total fresh weight (661.46 and 667.95 g.m-2). The interaction effect of treatments had a significant effect on leaf, stem and total dry weight. The highest rate of these traits was observed in biochar treatment with mycorrhiza, which had no significant effect with by a combination of vermicompost + biochar. Therefore, with respect to the production of medicinal plants in the low-input cropping systems, environmental protection, and achievement of sustainable agricultural to improve plant growth and photosynthesis of peppermint application of biochar + mycorrhiz and biochar + vermicompost treatment is recommended.