[Terrapreta] rice hull charcoal

[Christoph Steiner]

Looking on basic elemental analyses of rice husk charcoal shows that it is
very rich in ash (relatively low C content). Potash is providing nutrients
and increasing the pH. Therefore increased rood growth and crop
performance is not surprising. For biochar research it is important to
separate effects due to charcoal applications per se (maintenance and
improvement of water infiltration, water holding capacity, structure
stability, CEC, healthy soil biological activity, soil temperature,..)
from those due to its nutrient content.