Potencial do biochar e de Trichoderma harzianum na remediação de solos contaminados por cádmio

Abstract

Heavy metal pollution in soil is considered a global problem, being responsible for affecting the quality of the environment and causing imminent damage to human health. The origin of this type of pollution can be natural or from anthropogenic activities, such as mining. The objective of this study was to analyze the potential effects of cashew biochar and Trichoderma harzianum on the remediation of Cadmium-contaminated soils. The experiment was developed between May and November 2025, in a greenhouse located at the Federal University of Ceará, PICI Campus, Fortaleza-CE. The experimental design was a $2 \times 4$ factorial, with four replications, totaling thirty-two experimental units. The factors consisted of the presence or absence of Cadmium (Cd) contamination and the application of four treatments: control, biochar, T. harzianum, and biochar + T. harzianum. The plant species used was Mimosa caesalpiniifolia. At the end of the experimental conduction, lasting 110 days, the following plant growth parameters were evaluated: Shoot Dry Mass (SDM), Root Dry Mass (RDM), Height (HGT), Stem Diameter (SD), Number of Leaves (NL), and Root Length (RL); plant aspects; and Cd concentration in the shoots, roots, and soil. Cd contamination promoted a significant reduction in plant growth parameters and morphological aspects, including HGT, SDM, RDM, SD, NL, and RL. The application of biochar and/or T. harzianum attenuated the phytotoxic effects of Cd, promoting increments in plant growth, regardless of the metal's presence. Overall, no interaction effect was observed, indicating independent main effects of contamination and treatments. Regarding Cd, the treatments with biochar, isolated or associated with T. harzianum, reduced the Cd concentration in the shoots, while T. harzianum favored greater metal retention in the soil and roots. It is concluded that biochar and T. harzianum translocation of the metal to the shoots.