Integrated Soil Fertility Management (ISFM) in sub-Saharan Africa: Concepts and Practice

摘要

Agricultural intensification is a necessity in the densely populated areas of sub-Saharan Africa (SSA). The integrated soil fertility management (ISFM) paradigm has been accepted by the research and development community as a viable set of principlesto foster agricultural intensification. Integrated soil fertility management involves a set of soil fertility management practices that include the use of fertilizer, organic inputs and improved germplasm combined with the knowledge on how to adapt thesepractices to local conditions, aiming at maximizing agronomic efficiency (AE) of the applied nutrients and improving crop productivity. All inputs need to be managed following sound agronomic principles. An alternative approach being promoted in SSA isconservation agriculture (CA). In this paper, the major concepts underlying ISFM are highlighted with a focus on nitrogen (N) fertilizer on maize across Africa through a meta-analytical study consisting of published papers with data on AE as affected byspecific ISFM components. The summary data confirm that the components underlying ISFM do result in increased AE values for N fertilizer on maize. Application of ISFM principles within important farming systems is then considered with a focus on dual purpose grain legume-maize rotations. It is proposed that ISFM could be the initial trigger towards the production of sufficient amounts of crop residues to engage in CA. Due to the lack of organic resources within smallholder farms, when promoted in SSA, CA should be accompanied by a fourth principle: the appropriate use of inorganic fertilizer, applied in the right formulation at the right time, place and rate.