Effect of Biochar and Mycorrhizal Fungi on the Growth Characteristics and Nutrition of Calendula (Calendula Officinalis L.)

Application of Mycorrhizal Fungi (MF) and biochar can increase water and nutrient uptake in the rooting zone and thus improve crop production. A factorial experiment with completely randomized design with three replications was conducted to investigate the effects of biochar (0, 2 and 4% w/w) and MF (non-inoculation and inoculation with MF) on the morphophysiological characteristics and concentration of elements in calendula (Calendula officinalis L.) in greenhouse condition. The biochar was passed through a sieve of 2 mm and mixed with soil. The application of mycorrhizal fungi was done by direct contact with the root of plant. After six months, the morphophysiological characteristics and the concentration of some macro and micro elements in shoot were measured. The results showed that with simultaneous application of 4% biochar and mycorrhizal fungi increased chlorophyll, flower diameter, plant height, leaf area, stem diameter, plant dry weight and concentration of P, K, Ca and Fe compared to control, significantly. Zn concentration increased in 4% biochar treatment and simultaneous use of 4% biochar and mycorrhizal fungui compared to the control significantly (13.7 and 19.5% respectively). The application of 4% biochar caused a significant increase in Mn concentration compared to the control (91.3 against 86.6 mg.kg-1), while the application of 2% biochar has not a significant difference with control and 4% biochar treatments. The results of the effect of adding biohar to soil after plant growth period showed that available K, Ca, Mg and Mn increased with addition of 4% biochar by 22.2, 18.2, 43.6 and 15.2%, respectively. However, 2% biochar treatment had no significant effect on these soil parameters compared to control. It seems that application of these materials can improve availability of nutrients and plant growth parameters by improving plant growth conditions and affect crop production.