In Burkina Faso in only 15 years, farmers using zaï in Burkina Faso have made tens of thousands of badly degraded acres productive and contour stone bunds, reducing erosion, have been built on a at least 250,000 acres with the help of development organizations. With the addition of manure is added, the results are stunning – with cereal yield increasing sevenfold or more without fertilizer.
Daniel Kabore and Chris Reij, “The Emergence and Spreading of an Improved Traditional Soil and Water Conservation Practice in Burkina Faso,” Environmental and Production Technology Division o f the International Food Policy Research Institute, Environment and Production Technology Dividsion, Discussion Paper No. 114, February 2004, 2. Accessed on 2/23/09 at www.ifpri.org/divs/eptd/dp/papers/eptdp114.pdf - page 24