Biochar produced from rice husk pyrolysis has great potential as a soil ameliorant and climate change mitigation agent. This study is a descriptive, exploratory investigation that aims to characterize the chemical properties of rice husk biochar and evaluate changes in its properties after incubation with functional bacteria, namely Azotobacter sp., Bacillus sp., and Pseudomonas sp. The biochar produced had a pH of 8.5, an organic carbon content of 25.32%, a C/N ratio of 20, a cation exchange capacity (CEC) of 32.52 cmol kg⁻¹, and high P (1.08%) and K (1.95%) content, indicating its potential to increase the pH of acidic soils and supply macronutrients. Proximate analysis showed that this biochar has a high ash content (42.1%), which supports increased CEC and nutrient availability. Incubation with bacteria increased pH, carbon content, CEC, and P, with Bacillus sp. providing the greatest increase in P (100.93%) and CEC (20.91%). Overall, the results indicate that the biochar and bacteria system can improve soil fertility, especially in soils with low nutrient content or acidic properties; however, consistent with its descriptive exploratory scope, further studies with appropriate biological replication and statistical analyses are required to confirm and quantify these relationships.
Afonso et al. (Tue,) studied this question.