The Daily Croissant

"Making charcoal may sound like a strange way to boost crop production, but the concept was proven more than 2,000 years ago in South America, where native farmers added charcoal to the poor soils of the Amazon rainforest to create a rich, fertile soil known by the Portuguese name "terra preta," or black earth."

“When it’s done right, adding biochar to soil can improve hydrology and make more nutrients available to plants,” says Rice University biogeochemist Caroline Masiello, the lead researcher. To make the soil additive biochar, charcoal must reach at least 450 degrees Celsius to ensure that water and nutrients get to plants.