Semi-Arid Ethiopian Rift Valley: A Case Study of Agricultural Intensification in Sub-Saharan Africa

The study explores indigenous soil fertility management (SFM) practices and their transition in the semi-arid Ethiopian Rift Valley in sub-Saharan Africa. Two ethnic groups, the Amhara and Oromo, used distinct SFM practices until the mid-1970s in the northern part of the semi-arid Ethiopia Rift Valley. The Amhara carried compost from their house yards and applied it to crop fields, whereas the Oromo who are pastoralist/nomadic and/or semi-agriculturalist lifestyle repeated short-distance transfers (house move) to amend the soil in their vicinity. Land constraints caused by population increase, government policy (villagization), and the introduction of inorganic fertilizers (IFs) techniques were the primary drivers for the Oromo to change their SFM practices. They changed it to what the Amhara had established after the mid-1970s; the combined use of organic fertilizers (OFs) and IFs (i.e., integrated SFM). Despite the continuous deterioration in the limited availability of animal dung and increasing commuting distances to the crop fields, the proportion of manured fields has not changed much over time. Future resource shortages will likely encourage farmers to use more IFs, according to a population-induced agricultural intensification hypothesis in sub-Saharan Africa. The conditions for sustainable SFM in the semi-arid Ethiopia Rift Valley include (i) OFs technique development thorough utilization of organic materials in farmers’ neighbourhoods, such as compost techniques, and (ii) their dissemination through links between research, extension services, and farmers.