Investigating the effect of biochar obtained from Azolla filiculoides on the morphophysiological characteristics of Kochia prostrata L. under drought stress

Water stress is one of the most important abiotic stresses that harms the growth of plants in arid and semi-arid regions. Plant traits reflect their response and adaptation to environmental changes, which play an essential role in predicting various environmental effects on plants and plant processes. In order to investigate the effect of biochar on the morpho-physiological characteristics of the species (Kochia prostrata L.) in water shortage conditions, a factorial experiment was conducted in the form of a completely randomized design with three replications in greenhouse condition. Drought stress treatments included four levels (25, 50, 75, and 100% of the field capacity), and biochar treatment included four levels (control, 5 g, 15 g, and 30 g). Morphological traits (plant height, root length, aerial biomass weight, and root biomass weight) and physiological traits (photosynthesis, plant water potential, stomatal conductance, and transpiration) of the target species were assayed under drought and biochar treatments. Results showed that the interaction effect of drought stress and biochar on all characteristics except for plant height was significant. Moreover, the main effect of drought stress on all characteristics except for photosynthesis and water potential and also the main effect of biochar on all characteristics except for root length) were significant. The treatment with 30 grams of biochar caused an increase in morphological characteristics (root length, plant height, and plant biomass) by 22%, 36%, and 50%, respectively, compared to the control; this treatment also caused a significant increase in photosynthesis and stomatal conductance by 107% and 32%, respectively compared to control. According to the findings, the biochar treatment of 15 grams resulted in a better performance and can be suitable to increase the efficiency in the species under study. The results obtained from this research can be an essential step toward the practical use of biochar in restoration and improvement of rangelands.