Temporal dynamics of nutrient elements in biochar and biochar-amended soils over three years: a comparative micro-XRF and SEM-EDX study.
A three-year field study found that adding biochar made from longan wood to tropical soil causes complex, wave-like changes in soil minerals — not a simple one-time improvement. Iron and aluminum levels spiked, dipped, then rose again, and phosphorus remained locked away despite regular fertilizing.