Why is terra preta so fertile?
Terra preta contains three times as much nitrogen and phosphorus as traditional soil, and about 20 times more carbon. These elevated levels can be attributed to an abundance of charcoal, organic matter like animal feces and bone, and crushed clay pottery. Scientists have deduced that the indigenous Amazonians used a slowed version of “slash-and-burn” agriculture, in which they steadily burned large swaths of the forest; the scorched remains of trees and brush produce plenty of charcoal and not as much ash as the traditional slash-and-burn. They would then mix the “biochar” into the soil. The extra carbon trapped in the biochar slows the reproduction of microorganisms so organic fertilizers like feces and bone actually last longer in the soil, allowing terra preta to stay fertile for thousands of years. Terra preta as carbon sink The carbon sequestration involved in terra preta not only does wonders for crops, but could also be a huge boon to the struggle against climate change. While t
