Water management practices and carbon sequestration for climate change mitigation in Africa

This paper examines water management practices used in Africa such as rain water harvesting, slope/barriers and terracing and the impact of such practices on carbon sequestration and climate change mitigation. Using a meta-analysis approach estimates of soil carbon and organic matter accumulated due to rain water harvesting, slope/barriers and terracing were standardized due to different units of reporting soil carbon. A review of the scientific literature on soil carbon sequestration in Africa was carried out to assess the greenhouse gas mitigation potential of different water management activities using on-line scholarly and scientific databases as well as more general search engines such as Google. The review covered 56 study estimates across African countries. The results show that the mean carbon through rain water harvesting was 839 kg C ha(-1) yr(-1). This practice is particularly important to framers in the semi-arid and arid region where there are few days of rains but rain-fed agriculture is practiced. The practices of cross slope barriers and terracing sequester additional carbon at the mean rate of 1193 and 421 kg C ha(-1) y(-1), respectively. It is therefore important that these practices be scaled-out to more farmers due to the benign effect on the environment.