<Articles>A Transition in Soil Fertility Management Practices in the Semi-Arid Ethiopian Rift Valley: A Case Study of Agricultural Intensification in Sub-Saharan Africa

Abstract

Two ethnic groups, the Amhara and Oromo, used distinct soil fertility management practices until the mid-1970s in the northern semi-arid Ethiopia Rift Valley. The Amhara carried compost from their house-yards and applied it to crop fields, whereas the Oromo repeated short-distance transfers (house move) to amend the soil in their vicinity. Soil fertility decline and the introduction of inorganic fertilisers (or chemical fertilisers: IFs) techniques were the primary drivers for the Amhara to change their soil fertility management practices after the mid-1970s. Land constraints caused by population increase, the introduction of IF techniques, and government policy (villagisation) were the primary drivers for the Oromo to change their soil fertility management practices. Since then, their soil fertility management practices merged into what the Amhara had established after the mid-1970s, the combined use of organic fertilisers (OFs) and IFs. Despite the continuous deterioration in the limited availability of animal dung and increasing commuting distances to the crop fields, the adoption rate of the OF techniques and the proportion of manured fields have remained unchanged. A hypothesis of population-induced agricultural intensification in sub-Saharan Africa indicates that future resource constraints can encourage farmers to use more IFs and improved seeds. To enhance the OF-IF integration, OFs technique development of thorough utilisation of organic materials in farmers' vicinity, such as compost techniques, and their dissemination through linkages between research, extension services, and farmers, are the requirements for sustainable soil fertility management in the northern semi-arid Ethiopia Rift Valley.