Burkina Faso Soil and Water Conservation
Research has found average yield increases ranging from 38 for white sorghum grown in other regions of Burkina Faso to 310 kg/ha in Niger. When the zaï technique is paired with manure or inorganic fertilizer, the gains increase: in Illela, yields rose to an average of 388 kg/ha for cereals when manure was added, versus the 125 kg/ha averaged previously, and with the addition of a dose of inorganic fertilizer they further increased by 640 kg/ha. Similarly, trials in Mali found that over two seasons with zaï and manure combined yields rose by 719 kg/ha on average.
Source: http://www.sei.se/pubs/agricultural_water_management.pdf