Water Harvesting in Sub-Saharan Africa
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Agriculture in Sub-Saharan Africa is constrained by highly variable rainfall, frequent drought and low water productivity. There is an urgent need, heightened by climate change, for appropriate technologies to address this problem through managing and increasing the quantity of water on farmers’ fields – water harvesting. This book defines water harvesting as a set of approaches which occupy an intermediate position along the water-management spectrum extending from in situ moisture conservation to irrigated agriculture. They generally comprise small-scale systems that induce, collect, store and make use of local surface runoff for agriculture.
The authors review development experience and set out the state of the art of water harvesting for crop production and other benefits in Sub-Saharan Africa. This includes an assessment of water harvesting schemes that were initiated two or three decades ago when interest was stimulated by the droughts of the 1970s and 1980s. These provide lessons to promote sustainable development of dryland agriculture in the face of changing environmental conditions. Case studies from eight countries across Sub-Saharan Africa provide the evidence base. Each follows a similar format and is based on assessments conducted in collaboration with in-country partners, with a focus on attempts to promote adoption of water harvesting, both horizontally (spread) and vertically (institutionalization). Introductory cross-cutting chapters as well as an analytical conclusion are also included.
collected for feeding draft animals (oxen, horses, donkeys) and for animal fattening (cattle and sheep). Manure is collected, in turn, from livestock to fertilize ﬁelds. The development of pulse crops is also integral to crop-livestock integration and beneﬁts include the collection of groundnut and cowpea haulms which are used for fattening small ruminants, especially sheep. The maintenance of water harvesting structures has led to a change in the agricultural calendar. After the growing season,
Church Missions as a chosen activity, developed in discrete areas with food-for-work often used Kenya 87 for support. Foremost in this ﬁeld was the Turkana Water Harvesting Project. On the other hand it was implemented, large-scale, by the Turkana Rehabilitation Programme, where the driving force was the need to maintain distribution of food-for-work, utilising rainwater harvesting as one of the main vehicles. The Turkana Rehabilitation Programme (TRP) was established in 1980 with the mandate
break the surface crust on existing farm ﬁelds before the onset of the rains. On the basis of their observations in the Yatenga region of Burkina Faso, some farmers decided to improve their traditional pits by increasing the dimensions and adding manure (IFAD, 1992). Typically, improved tassa would have a 20–30 cm diameter, a 10–25 cm depth and would be spaced about one 0.8 m apart in each direction.9 Farmers would dig approximately 14,000 pits per hectare. The excavated soil would also be placed
they commonly believe that one more rainstorm would have delivered a good crop. A clear win–win solution is to convert the damaging runoff into useful soil-moisture storage needed for crop and pasture growth, but until recently policy makers had not recognized this possibility. Policies have been dominated by two contradicting perceptions. First, that the only solutions to livelihood problems in the drought-prone semi-arid areas were drought-resistant crops or irrigation. Second, that the
always explicitly recognize the critical role of the agriculture sector in poverty reduction and growth, although more recent examples have done so. They have, however, generally still not assigned much prominence to agricultural water development. Consequently, the subsector has tended to be neglected in investment programmes for the agriculture and water sectors. Potential reasons for this neglect are the negative perceptions of agricultural water management. This is due to high cost and