Biometria, pigmentos fotossintéticos e enzimas antioxidantes em mudas de paricá (Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby) submetidas a ação de cromo e biocarvão no solo.

Abstract

The objective of this study was to evaluate the effects of biochar on growth, photosynthetic pigments, and antioxidant systems in Paricá seedlings (Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby) subjected to different doses of chromium. The experiment was conducted in a greenhouse located in the experimental area of the Federal Rural University of the Amazon (UFRA), Belém Campus. Biochar was produced from açaí seeds collected from commercial establishments in the metropolitan region of Belém. A completely randomized experimental design (CRD) with two factors (3x3) was used, consisting of six treatments, including control plants (without chromium or biochar) and treatments with two doses of potassium dichromate (K₂Cr₂O₇) (400 mg L⁻¹; 800 mg L⁻¹) and two doses of biochar (2.5%; 5%), with four replicates, totaling 36 Paricá seedling units in the experiment. Data were subjected to analysis of variance using the F-test, and when significant, Tukey's test was applied to compare treatment means at a 5% probability level. The addition of biochar generally contributed to increased root length and chlorophyll content but was insufficient to reverse the negative effects at concentrations of 800 mg L⁻¹. Based on the results obtained, the species demonstrates tolerance to chromium-contaminated environments. However, further studies are essential to assess the phytoremediation potential of the species, particularly in association with biochar application to the soil.