The added value of biochar when applied along with fertilizers, beyond that of the fertilizers themselves, has not been summarized. Focusing on direct comparisons between biochar additions (≤ 20 t ha-1) – separately considering the addition or not of inorganic fertilizers (IF) and/or organic amendments (OA) along with biochar – and two different controls (with and without the addition of IF and/or OA), we carried out a meta-analysis to explain short-term (1-year) field responses in crop yield across different climates, soils, biochars, and management practices worldwide.
Compared with the non-fertilized control, a 26% (CI:15-40%) increase in yield was observed with the use of IF only, whereas that of biochar along with IF caused a 48% (CI:30-70%) increase. Compared to the use of IF only, the addition of biochar along with IF caused a 15% (CI:11-19%) increase in yield, indicating that biochar was as effective as fertilizers in increasing crop yields when added in combination.
