This research provides further data for the long-term C storage
potential of low ash-high C and high ash-low C biochars when
applied to soils of differing mineralogy. The tomato biochar, with
high inorganic C content (18%),was less stable in the acidic soil with
a high acid buffering capacity (Ferralsol); whereas the blue mallee
biochar was more stable in this soil, probably due to the organomineral
interactions. The long-term soil C storage potential of the
blue mallee biochar is much greater than that of the tomato biochar.
The PE results for the low- and high-ash biochars are crucial in
aiding in the establishment of the net C storage benefits from
different biochars. The blue mallee biochar applied to the Solonetz
at a 2% rate resulted in a net negative PE, giving a higher potential
than the tomato biochar for long-term C storage. The research
further highlights the role of biochar and soil characteristics in the
long-term storage of C in soils.