Pro-Natura has been working in the Ivory Coast with farmers on the edges of the natural parks there to discover ways of helping the farmers cultivate food for local markets and for their families and provide incentives for increased biodiversity.
In the areas where they work, old cocoa and coffee plantations are often not renewed because of of the threats of disease and soil exhaustion. Additionally, full sun cocoa varieties encourage cutting down all of the trees which suppresses biodiversity. (Biodiversity is important to maintaining the health of native species, but it's also important to maintain disease resistance in the crops that these families' lives depend on).
Biochar applied to the topsoil of the trees at the rate of 1kg per square meter have increased crop yields by 50% to 200%. Trials have also shown that trees grown in 5 - 10% biochar soils are more disease resistant, specifically to phytophthora, a family of pathogens that includes Monilia or black pod. Black pod has devastated whole swathes of cocoa growing regions, which has spurred the abandoning of older cocoa plantations.