Agricultural diversification in West Africa: an archaeobotanical study of the site of Sadia (Dogon Country, Mali).

While narratives of the spread of agriculture are central to interpretation of African history, hard evidence of past crops and cultivation practices are still few. This research aims at filling this gap and better understanding the evolution of agriculture and foodways in West Africa. It reports evidence from systematic flotation samples taken at the settlement mounds of Sadia (Mali), dating from 4 phases (phase 0=before first-third century AD; phase 1=mid eighth-tenth c. AD; phase 2=tenth-eleventh c. AD; phase 3=twelfth-late thirteenth c. AD). Flotation of 2200 l of soil provided plant macro-remains from 146 archaeological samples. As on most West African sites, the most dominant plant is pearl millet (Pennisetum glaucum). But from the tenth century AD, sorghum (Sorghum bicolor) and African rice (Oryza glaberrima) appear in small quantities, and fonio (Digitaria exilis) and barnyard millet/hungry rice (Echinochloa sp.), sometimes considered weeds rather than staple crops, are found in large quantities. Some samples also show remains of tree fruits from savannah parklands, such as baobab (Adansonia digitata), marula (Sclerocarya birrea), jujube (Ziziphus sp.), shea butter (Vittelaria paradoxa) and African grapes (Lannea microcarpa). Fonio and Echinochloa sp. cultivation appears here to be a later addition that helped to diversify agriculture and buffer against failures that might affect the monoculture of pearl millet. This diversification at the end of the 1st millennium AD matches with other evidence found in West Africa.