A Systematic Review of Drivers and Constraints on Agricultural Expansion in Sub-Saharan Africa

Understanding the dynamics of agricultural expansion, their drivers, and interactions is critical for biodiversity conservation, ecosystem-services provision, and the future sustainability of agricultural development in Sub-Saharan Africa (SSA). However, there is limited understanding of the drivers of agricultural expansion. A systematic review of the drivers of agricultural expansion was conducted from 1970 to 2020 using Web of Science, Elsevier Scopus and Google Scholar. Two researchers reviewed the papers separately based on inclusion and exclusion criteria. Fifteen papers were included in the final systematic review. The paper proposed expansion pathways in a conceptual framework and identified proximate and underlying drivers. Population dynamics and government policies were found to be key underlying drivers of agricultural expansion. The proximate drivers include economic opportunities such as agriculture mechanisation and cash crops production, and more troubling trends such as soil fertility decline and climate change and variability. This paper further explores the constraints that have been found to slow down agricultural expansion, including strong land institutions and good governance.