The ameliorating effect of biochar PB on soil acidity decreased
to a certain extent in a short-term period when the biochar aged.
However, the PBa lost nutrients (e.g., exchangeable base cations)
during approximately 4 months with air exposure, which was
different from the biochar oxidization or mineralization that
occurred in soils because the nutrients were released to the soils
(Peng et al., 2011). In other words, the modified effect of biochar on
soil acidity may not decrease obviously with the increase of the
aging process when biochar becomes age in soils.
Liable fractions in biochar could be decomposed in a very short
time and the decomposition should be different under ventilated
and unventilated conditions, but the expected difference in the soil
acidity amendment between PBV and PBS was not observed
(Tables 3 and 4), which suggests that the incubation condition has
little effect on soil acidity amendment using biochar.