Indigenous people may have created the Amazon’s ‘dark earth’ on purpose

CHICAGO — Indigenous people in the Amazon may have been deliberately creating fertile soil for farming for thousands of years.

At archaeological sites across the Amazon River basin, mysterious patches of unusually fertile soil dot the landscape. Scientists have long debated the origin of this “dark earth,” which is darker in color than surrounding soils and richer in carbon.

Now, researchers have shown that indigenous Kuikuro people in southeastern Brazil intentionally create similar soil around their villages. The finding, presented December 16 at the American Geophysical Union meeting, adds evidence to the idea that long-ago Amazonians deliberately manufactured such soil too.