Biochar como condicionante de substrato na produção de mudas de Libidibia ferrea

Abstract

Biochar is a residue from agro-industry resulting from the carbonization process that can be used as an alternative substrate in seedling production, owing to its physicochemical properties that contribute to increased porosity, water retention capacity, and aeration quality. Thus, the aim of this study is to facilitate the use of biochar in the composition of substrates for the production of Libidibia ferrea (Mart. ex Tul.) L.P.Queiroz seedlings. The experiment was conducted in a completely randomized design, consisting of five treatments: (T0) organic compost (100% - control treatment); (T1) organic compost (90%) + biochar (10%); (T2) organic compost (80%) + biochar (20%); (T3) organic compost (60%) + biochar (40%); (T4) organic compost (50%) + biochar (50%). The evaluated variables were: stem diameter, seedling height, number of leaves, height/stem diameter ratio, dry root system mass, dry aboveground mass, total dry mass, aboveground dry mass/root system dry mass ratio, height of aboveground part/dry mass of aboveground part ratio, and the Dickson quality index. The seedlings of Libidibia ferrea did not show statistical differences in most variables compared to the substrate without the addition of biochar. Despite the lack of significant difference, it is possible to state that all biochar increments provided satisfactory conditions for promoting seedling growth. Positive values were observed in dry mass and Dickson quality index variables in the highest biochar increments. The use of substrate with a 50% biochar increment is recommended for Libidibia ferrea seedling production, providing a viable alternative for the utilization of this residue and reducing production costs with organic compost.