Artisanal Biochar Application: Enhancing Sandy Soil Fertility and Rice (Oryza sativa L.) Productivity

The application of biochar as a soil amendment has garnered significant interest due to its potential to enhance soil fertility, promote plant growth, and contribute to sustainable agriculture. This study investigated how the structural and morphological characteristics of artisanal biochars from four different brands (AB1, AB2, AB3, and AB4), purchased in supermarkets, influence the development of rice plants in sandy soil. Spectroscopic analyses demonstrated that AB4 exhibited the highest aromaticity (77%), ensuring structural stability, whereas AB2 displayed greater aliphaticity (47%). Morphological characterization revealed that AB4 preserved the cellular structure of the original biomass. The biochar studied and the doses influenced the parameters evaluated in the development of rice plants in sandy soil differently. The biochar with the highest aromatic structure (AB4) promoted an increase in root area, length, and number of bifurcations, as well as in dry and fresh biomass. The nutrient accumulation in the aerial part of the rice plants was greater with the application of AB1 and AB2 at the dose of 10 t ha−1. Chlorophyll fluorescence analysis indicated improved photosynthetic performance in the AB4 treatment, mitigating initial plant stress and optimizing energy use. This study underscores the potential of artisanal biochar to enhance crop productivity and foster sustainable agricultural practices.