A review of appropriate mechanisation systems for sustainable traditional grain production by smallholder farmers in sub-Saharan Africa with particular reference to Zimbabwe

Climate change and variability is affecting the production of maize, a staple food in Zimbabwe, leading to the advocacy for production of traditional grains (sorghum, pearl millet and finger millet) as complementary crops for food and nutrition security; mainly because of their drought tolerance. Adoption of traditional grains as a climate change adaptation strategy is, however, limited by lack of appropriate field mechanisation technologies, inter alia. The specific objective of this review was to examine the field mechanisation technologies being used in different farming systems across the globe for their appropriateness in smallholder traditional grain production systems in developing countries, using Zimbabwe as an example, and focusing on the prevailing technical, socio-economic and environmental factors which influence sustainable adoption. The review was conducted by searching ScienceDirect, Researchgate, JSTOR, Springer, AGORA and Google Scholar databases for mechanisation strategies, policies, machinery and equipment used in cereal production systems across the globe. The review revealed that the mechanisation of traditional grain production operations is lagging behind that of other cereals and that there is need to work on developing appropriate mechanisation systems for smallholder farmers in developing countries. Various farm power options were analysed and the use of twowheel tractors under service-provision was identified as the most suitable option. Conservation agriculture-based direct seeders and use of mowers or bio-pesticides are the best-suited technologies for crop establishment and weed control, respectively. In terms of harvesting, no available equipment can be recommended for smallholder use as yet. Further research is required to optimize the practical application of mowers and bio-pesticides as well as develop scale-based direct seeders and harvesting equipment. Policy issues were identified and recommendations for improvement made. The findings of the current study can be adapted by other sub-Sahara Africa countries where farming systems, priorities and challenges are similar to that of Zimbabwe.