Well over 50 percent of Africa’s arable land is cultivated
under mixed farming (crop/livestock), agropastoral and
pastoral farming systems, forest-based or coastal artisanal
fishing farming systems1
. In the absence of widespread
technological change during the past decades, rapid population
growth has led to the expansion of the cultivated
area. This has involved mainly the conversion of large areas
of forests, wetlands, river valley bottoms, and grassland
savannah to cropland. Good pastureland is diminishing as
the most productive tracts are converted to cultivation. The
mobility of pastoralists’ herds is further reduced as settlers
increasingly cultivate bottomlands previously available to
herders during dry season migration.