Dear biochar researchers,
I am here in SouthWest Cameroon, implementing the Biochar Fund's field
trials. During a workshop in Kendem, a small village at the forest
frontier between Mamfe and Bamenda, we stumbled upon a very
interesting piece of information. As we were introducing the biochar
concept, several of the participants -- small subsistence farmers who
practise shifting cultivation-- said they know about an ancient soil
improvement technique based on charcoal. The technique is supposedly
still practised in the "Batibo region", further up north. Soils there
are notoriously poor, but, according to our informants, the charcoal
people seem to succeed in getting good yields. This information got
us excited. Could there be an ancient African "terra preta" tradition?

The Batibo technique was described to us as to work as follows: before
the planting season, farmers collect big piles of elephant grass or
any other type of savannah grass, which they spread out over their
fields to dry it. After the grass has dried, they pile it so as to
make long strips, on which they will grow their crops. Then they cover
the big rows of grass with a layer of mud, which they leave to dry
again. After the mud has dried and hardened, they open one part of the
strip and set fire to the grass contained in this "container". The
fire travels slowly through this "kiln", providing a low oxygen
environment, and chars all the biomass. After this operation, they
crush the mud layer, and the char beneath it. They repeat the effort
several times to create layers of char and crushed mud. This then
becomes their soil bed, on which they start planting crops when they
rains arrive. The rains turn this soil layer into an apparently
fertile soil. To our own amazement, the farmers of our workshop in
Kendem immediately understood the biochar concept, because of their
knowledge of this Batibo technique.

We are now planning an expedition to this Batibo region, because if
the technique has been practised for a long while, there must be
enough traces of it in the soil. This expedition needs to be planned
carefully and will be quite costly, as the region is very remote (our
own presence in Kendem is already very heavy on the logistics.) I hope
we can get to the area before the rains arrive (mid March) and take
loads of pics. But in any case, perhaps we have stumbled on a very
interesting soil improvement technique, not dissimilar to the
Brazilian terra preta? Has anyone else heard of this apparently simple
"biochar" technique?

Best regards,
Laurens Rademakers