Biochar-Based Nutritional Nanocomposites Altered Nutrient Uptake and Vacuolar H+-Pump Activities of Dill Under Salinity

Application of enriched biochar with essential nutrients can modify soil properties and nutritional value. So, this research was aimed to investigate the efficacy of biochar-based nutritional nanocomposites on nutrient uptake, H+-pump activities in tonoplast, and growth of salt-stressed dill plants. The effects of pristine biochar (30 g kg−1 soil) and biochar-based nutritional nanocomposites (BNCs) of iron (30 g BNC-FeO kg−1 soil), zinc (30 g BNC-ZnO), and their combined form (15 g BNC-FeO + 15 g BNC-ZnO kg−1 soil) on soil properties, H+-ATPase and H+-PPase activities of root tonoplast, nutrient content, and performance of dill were evaluated under various salinity levels (non-saline, 6 and 12 dSm−1). This experiment was carried out as factorial on the basis of randomized complete block design with three replications. Addition of different forms of biochar to the soil increased soil pH, cation exchange capacity values, and absorption rates of K, Ca, Mg, Fe, and Zn, and decreased sodium adsorption ratio, exchangeable sodium percentage of soil, sodium and chloride absorption rates of plants, and activities of H+-ATPase and H+-PPase, with the superiority of BNCs. The higher root and shoot K+/Na+ ratios in biochar-related treatments especially BNC-FeO + BNC-ZnO were associated with the high sodium sorption capacity of these treatments that improved the growth of dill plants. The results suggested that biochar-based nanocomposites of Fe and Zn can potentially alleviate salt toxicity and improve root and shoot growth of salt-subjected plants by decreasing Na uptake as well as by enhancing essential nutrients.