Effect of Biochar on Soil Respiration from a Semi-evergreen, Moist Deciduous Forest Soil

Mineralization of soil organic carbon has a significant impact on the atmospheric CO2 concentration. Application of organic amendments can affect the dynamics of carbon present in soil through the process of mineralization and immobilization. This study assessed the efficiency of biochar on soil carbon mineralization through respiration and the priming effect (positive or negative) after addition of the external carbon biomass in a controlled incubation experiment (90 days) at two different temperature regimes viz. 15 degrees C and 30 degrees C. A decrease in total CO2 respired was found with the addition of biochar in the soil where 6 t ha(-1) of biochar treatment (T-7) produced the lowest amount of CO2 for both the temperature regimes. The calculated half-life (t(1/2)) and rate constant (k) showed resistivity towards mineralization with increasing doses of biochar. Significantly negative priming effects were observed with addition of biochar in comparison to the control treatment at the end of the incubation period.