Biometric and physiological responses of Virola Surinamensis to cadmium and biochar in amazonian soil

Objective of this study was to assess the mitigating effects of biochar derived from açaí seeds on the biometric and physiological responses of Virola surinamensis plants grown in soil contaminated with cadmium. Experiment was conducted in a controlled greenhouse environment, utilizing V. surinamensis seedlings grown in soils contaminated with varying concentrations of Cd (0, 10, 20, and 30 mg L ^− 1 ) and different biochar proportions (0%, 5%, and 10%). Statistical analysis was performed using the F-test, and when significant, the Tukey test was applied. At a Cd concentration of 10 mg L ^− 1 , the number of leaves was greater in the absence of biochar application; however, this did not significantly differ from the treatment containing 5% biochar. In terms of the chlorophyll an index, the application of 5% biochar was the most effective in maintaining the chlorophyll content in the presence of Cd. Furthermore, for plants exposed to 10 and 20 mg L ^− 1 of Cd, the inclusion of 5% biochar mitigated the toxic effects of the metal, leading to increased rates of photosynthesis. Plants treated with 20 mg L ^− 1 of Cd also presented higher transpiration rates with 5% biochar application. For intercellular CO ₂ concentrations, soils contaminated with 10 mg L ^− 1 of Cd demonstrated an increase in carbon concentration when treated with biochar. Thus, the addition of 5% biochar was effective in attenuating the toxic effects of cadmium on biometric parameters, photosynthetic pigments, and transpiration rates in V. surinamensis plants, suggesting its potential as a mitigation strategy for cadmium-contaminated soils.