What is the difference between soil organic matter and biochar, which helps form terra preta?
Biochar is a product of fire. It is plant matter that has been burned in a low-oxygen environment. Another word for it is charcoal. It is mostly carbon, and resistant to decay and oxidation. Soil organic matter, by contrast, is the product of biological decay processes. These processes are often slow, and require the participation of millions of microorganisms.
