Positive biochemical, physiological and nutritional evidence from the use of biochar in the growth of eucalyptus plants

Abstract

ABSTRACT Brazil has approximately 7.8 million hectares of planted forest, with 72% of the total area being occupied by species of the genus Eucalyptus. Brazil is the main producer of Acai fruit (Euterpe oleracea) in the world; however, for every 100 tonnes of processed fruit, it generates approximately 80 tonnes of waste, and this waste is considered an environmental problem. This research seeks to investigate whether the application of biochar (BC) derived from Acai agroindustry waste can improve nutritional status and biomass by testing different proportions of BC and evaluating anatomical, physiological, biochemical, and morphological aspects of young Eucalyptus urophylla plants. BC had the best effect on nutritional status and biomass at a concentration of 7.5% (w/w), inducing increases of 67%, 37%, 90%, 61% and 20% in the dry matter content of leaf, root, stem, total and stem diameter, respectively. This study demonstrated that BC derived from Acai agroindustry waste improved nutritional status, and this result was explained by improvements in root development, mainly the vascular cylinder diameter (52%). Interestingly, BC also stimulated the photosynthetic machinery, as evidenced by the effective quantum yield of photosystem II photochemistry (36%) and net photosynthetic rate (59%), positively contributing to biomass accumulation.