How biochar, ‘agriculture's black gold’, is helping cocoa trees to thrive By Anthony Myers Biochar, known as ‘agriculture's black gold’ is made from agricultural waste, such as weeds, leaves and cocoa pods, and can be used as a natural fertilizer to improve soil quality. Agri-business giant Barry Callebaut said over the past two years it has run field trials in Ghana and Indonesia, and also at various research institutions in Germany and the UK, to test which biochar formulation works most effectively on cocoa and other native tree species found in cocoa growing areas. Climate change, poor soil, overuse of fertilizers and pesticides, and a lack of natural inputs, such as shade and pollinators, are adding more pressure on cocoa farmers who are already experiencing declining cocoa yields.