Slash and burn farming techniques and a diverse range of crops yields abundant and reliable harvests.
The first Bantu-speaking groups to undertake migrations beyond the savannah regions of modern-day Cameroon were farming communities whose staple diet consisted of pearl millet. This forms the basis of several theories put forward to explain the rhythm and frequency of their movements.
It is highly probable that these populations had a preference for slash-and-burn cultivation. This particular technique enables fields to be cultivated for periods of three to five years but then requires them to be fallowed for periods of 15 to 20 years. This practice involves extensive farming of territories by small communities forced into high mobility to find a way around the combined impact of soil depletion and demographic pressure.
For these reasons, some scientists present the demographic and territorial expansion of the Bantu-speaking peoples as a possible cause of the reduction in forest cover in central Africa at that time.