News Earth Indigenous people may have created the Amazon’s ‘dark earth’ on purpose The fertile soil may be a massive, overlooked source of stored carbon Growing crops in the Amazon’s nutrient-poor dirt is tough. In a tradition that may be thousands of years old, indigenous Kuikuro people in Brazil overcome this issue by making their own fertile soil from ash, food scraps and controlled burns. Morgan Schmidt Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Freda Kreier January 5, 2023 at 9:00 am CHICAGO — Indigenous people in the Amazon may have been deliberately creating fertile soil for farming for thousands of years.