Protected cultivation of vegetable crops in sub-Saharan Africa: Limits and prospects for smallholders. A review
This article in the Agronomy for Sustainable Development journal presents an overview of the agronomic, economic, and environmental performances of low-tech protected cultivation techniques (PCT) in sub-Saharan Africa. Vegetable production in sub-Saharan Africa faces numerous agronomic constraints to feed the increasing population and to fight malnutrition. Technology transfer and the adoption of low-tech PCT affordable for smallholders are believed to be able to meet this challenge. PCT are a set of agricultural practices aimed at artificializing the crop environment to increase the yield and quality of vegetable crops and extend their production periods worldwide. However, the transfer of these techniques in sub-Saharan Africa raises questions about their agronomical performances, their profitability and their environmental impacts. So the question is if low-tech protected cultivation techniques are adapted to the sustainable production of vegetables by smallholders in sub-Saharan Africa? The major conclusions are; 1) Low-tech PCT are not suitable in all climatic conditions in sub-Saharan Africa and need to be combined with other methods to ensure adequate pest control; 2) The profitability of PCT relies on the capacity to offset increased production costs by higher yields and higher selling prices to be obtained with off-season and/or higher quality products; 3) Major obstacles of adoption of PCT are breaking with existing cropping systems, the lack of technical support and skills, and the limited access to investment funding; 4) Life cycle assessments suggested that more efficient use of agricultural inputs would offset the negative impacts of protected cultivation techniques if they are properly managed. Further research is needed to; 1) Understand the impacts of low-tech PCT on climatic conditions and insect pest populations; 2) estimate the profitability of the techniques for smallholders so as to design suitable and affordable cropping systems.