where CT is the total C mineralized from the biochar-amended soil,
δT
13CO2 is the δT
13C value of the CO2-C evolved from the biochar-amended
soils, δS
13CO2 is the δT
13C value of CO2-C evolved from the control soil, and
δS
13CO2 is the initial δT
13C value of the biochar. The amount of the soil-C
mineralized (CS,B) from the biochar-amended soil and the priming effects
(PE) induced by the biochar on mineralization of the native organic
carbon in the soils were calculated as: