Did natives use special microbial brews to innoculate the soil to create terra preta?
There is no proof that a “mother” culture was used for starting terra preta. Current research indicates that the incorporation of charcoal of certain qualities (created in relatively low heat, for example) in combination with appropriate initial fertilization (often, in university tests, with conventional fertilizers that are damaging to soil life) will produce a substantial increase in yields. It is assumed that the char provides such an effective habitat for microbes that effective communities will rapidly develop within most soils. What we don’t know yet is whether the simulated terra preta will have the ability to maintain its fertility for as long as the ancient form.