. The OA application altered the mineral matrix and the structure of C, promoting greater surface functionalization and potentially nutrient availability, although with a slight reduction in C recalcitrance. The incorporation of ASi increased the total K content and promoted mineral compositional differentiation in the new fertilizers. The results suggest that the developed BBFs constitute highly tunable organomineral systems, in which the manipulation of pyrolysis temperature and chemical activation enables targeted modulation of the balance between C structural stability and reactivity. Although OA reduces the stability of C, our results show that it is possible to synthesize formulations tailored either for greater structural stability (SSB500-based) or for enhanced reactivity and potential nutrient release (SSB300+OA-based), depending on the intended agronomic application. This approach may contribute to the rational design of multifunctional fertilizers, enabling the development of formulations tailored to diverse management strategies and soil conditions.
Santos et al. (Mon,) studied this question.