Stability of Biochars Produced From Fast Pyrolysis Using Biomass Feedstocks.

Biochar materials are assumed to be chemically and biologically recalcitrant and able to store carbon in soil with longer turnover time. But there is little knowledge about the quantification of mean residence time of biochars and underlying mechanism of their C sequestering ability. A laboratory experiment has been designed to quantify the turnover time of biochars and the changes in soil organic C mineralization with addition of biochars using natural C isotopic differences between biochar-C and soil-C. Three plant based biochars produced from corn stover, switchgrass, and Ponderosa pine wood residue are incubated with soil. The total CO₂-C and δ1³C are periodically measured in biochars and soil-biochar mixtures using isotope ratio mass spectrometer.