Chemical and biochemical characterisation of biochar-blended composts prepared from poultry manure

► The addition of biochar enhances the organic matter quality of mature composts. ► Biochar improves compost maturity as shown by the classic stability indices. ► Urease, phosphatase and polyphenol oxidase were enhanced in biochar-blended composts. ► Biochar sorption capacity affects the determination of enzymatic activities.