Abundant and Stable Mollisols: The “Terra Preta” of the Midwest US

Central to the story of biochar is Amazoinian Terra preta, fertile anthropogenic (meaning human made) dark earths in Amazonia that were enriched with char more than 8000 years ago. 1 Terra preta is the result of char and  household waste (bone, broken pottery, compost and manure) mixed into the native soil, Oxisol, which transformed this otherwise low fertility soil into a more productive soil. But is Terra preta, ancient carbon rich soil only found in the Amazon basin?