From adoption claims to understanding farmers and contexts: a literature review of Conservation Agriculture (CA) adoption among smallholder farmers in southern Africa. (Special Issue: Evaluating conservation agriculture for small scale farmers in Sub-Saharan Africa and South Asia.)

摘要

This literature review of Conservation Agriculture (CA) adoption among smallholder farmers in southern Africa (Malawi, Zambia and Zimbabwe) analyses the historical background of the upsurge in CA promotion, the various definitions of CA that have emerged since the 1990s, the barriers to its adoption, as well as uptake figures and adoption studies. First tested as soil and water conservation measures, large-scale promotion followed a reframing of CA as a production-enhancing set of practices. Different definitions of what constitutes and is promoted as CA in southern Africa complicates the assessment of adoption across the region, while a commonly used, reductionist notion of CA adoption - as the uptake of minimum tillage - in adoption data collection, casts doubts on the validity of adoption figures. As CA uptake is often also incentivized by means of input support (fertilizers, seeds, herbicides) provided by promotional projects, adoption claims have limited value. Current CA adoption studies are methodologically weak as they are biased by the promotional project context in which are carried out, and build on farm-scale analyses of standard household surveys. A more thorough analysis of farming households and their resource allocation strategies is required to understand the farm-level adoption constraints different types of farmers face. As contextual factors appear key influences on smallholders' farming practices, studies focusing on the wider market, institutional and policy context are also needed if we are to understand (limited) CA adoption in southern Africa.