Physico-chemical characterization of biochars from vacuum pyrolysis of South African agricultural wastes for application as soil amendments
Résumé
The physico-chemical properties of biochars from the vacuum pyrolysis of black wattle and vineyard
annual prunings were investigated for their potential as soil amendments and compared to biochar
from sugarcane bagasse. Biochar from sugar cane bagasse seems to be a promising sorbent and soil
conditioner due to its high surface area, high surface acidity, and microporous structure. This biochar can
be applied to a wide pH range of soils for enhancing nutrient and water retention. On the other hand, the
biochars from black wattle and vineyard possessing high concentrations of aromatic carbon, nutrients,
and alkalinity are potential soil amendment agents. Black wattle biochar is more beneficial compared
to biochar from vineyard due to its higher surface area, microporosity, and cation exchange capacity.
Therefore, this study recommends the utilization of biochars from black wattle as soil amendment agents
especially in subtropical regions.