A farming technique practised for centuries by villagers in West Africa, which converts nutrient-poor rainforest soil into fertile farmland, could be the answer to mitigating climate change and revolutionising farming across Africa.

A global study, led by the University of Sussex, which included anthropologists and soil scientists from Cornell, Accra, and Aarhus Universities and the Institute of Development Studies, has for the first-time identified and analysed rich fertile soils found in Liberia and Ghana.

They discovered that the ancient West African method of adding charcoal and kitchen waste to highly weathered, nutrient poor tropical soils can transform the land into enduringly fertile, carbon-rich black soils which the researchers dub 'African Dark Earths'.

From analysing 150 sites in northwest Liberia and 27 sites in Ghana researchers found that these highly fertile soils contain 200-300 percent more organic carbon than other soils and are capable of supporting far more intensive farming.
Similar soils created by Amazonian people in pre-Columbian eras have recently been discovered in South America – but the techniques people used to create these soils are unknown. Moreover, the activities which led to the creation of these anthropogenic soils were largely disrupted after the European conquest.