Revalorization of Arracacia xanthorrhiza waste for controlled carboxin release in potato crop

Supporting a productive rural population is essential for ensuring a society's food security. In this context, the reuse of agro-industrial waste represents a strategy with significant environmental and economic benefits. This study characterizes the residues from the cultivation of Arracacia xanthorrhiza, which were used for starch purification and low-temperature pyrolysis to obtain biochar. As an application aligned with the principles of the circular economy, the resulting biochar was characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherm analysis. Biochar was impregnated with carboxin for application in a potato crop. Results indicated that each Arracacia plant generates an average of 3,485 ± 384 g of biomass, approximately 30% of which constitutes residues (4% leaves and stems, and 26% rootstock and corms). The rootstock and corms exhibited a starch content of 21% and the residual biomass was subsequently used for biochar production. The amorphous carbonaceous material exhibited an average pore size of 14.9 nm, formed spherical aggregates of approximately 4.5 μm, and demonstrated a carboxin adsorption capacity of 260.3 ± 0.4 mg/g of adsorbent. The incorporation of both raw and carboxin-impregnated biochar into the potato crop led to a 35% increase in total biomass per plant and a 23% increase in the mass of tubers exceeding 4 cm in diameter, indicating a notable improvement in crop yield and quality.