Emergence and expansion of pearl millet cultivation in West and Central Africa – the archaeobotanical evidence
by Alexa Höhn
Archaeobotanical evidence from Eastern Mali attests to the domestication of pearl millet (Cenchrus americanus (L.) Morrone, syn. Pennisetum glaucum (L.) R.Br.) around 2500 BC. By the middle of the second millennium BC, pearl millet was cultivated over large regions of West Africa and subsequently found its way into the Central African rain forest towards the end of the first millennium BC.
During the following centuries, an increasingly diverse set of crops, accompanied by the continuous exploitation of wild plants, is archaeobotanically evidenced in West Africa. These are the roots of the traditional West African land use system where intercropping legumes with other crops in a parkland savanna aims for food security under highly variable climatic conditions until today. For the rainforest, archaeobotanical evidence is still sparse: pearl millet remains unattested in the first millennium AD, but reappears in Late Iron Age contexts of the Inner Congo Basin (ICB).
Today pearl millet is not cultivated in the central African rain forest zone and is mainly restricted to savanna and woodland with a pronounced dry season. Climatic reasons have been advanced as explanation – also for the gap in pearl millet evidence in Central Africa during the first millennium AD. However, experimental cultivation of domestic pearl millet with simple horticultural maintenance strategies has proven highly successful in the ICB. Other explanations need to be considered, if climate is not the decisive factor.