Extreme droughts leading to the failure of agricultural systems from 1968-1973 caused a human and environmental crisis in Burkina Faso. Between 1975 and 1985, some villages lost one-quarter of their population as people migrated to areas with higher rainfall. Many wells dried up and the average yield of sorghum and millet dropped from between 0.5-1 tonne per hectare to 300kg per hectare, resulting in an annual food deficit of 50% for most households.
In the 1980’s farmers began experimenting with farming methods to reclaim severely degraded land that water could not penetrate. They developed variations of the Zai practice (digging a grid of planting pits), increasing the depth and diameter of the pits and adding organic matter. The pits were prepared in the dry season, enabling early planting for increased yields. Although very labour intensive to construct, by 2001 more than 100,000ha of degraded land was rehabilitated by farmers, with current estimates of the total rehabilitated land at 200,000-300,000ha. Villages with a long history of soil and water conservation rehabilitated an estimated 72-94% of their agricultural lands.
Cereal production is estimated to have increased by an average of 400kg per hectare per year, translating into an annual increase of 80,000 tonnes of grain. Zai planting pits have shown a greater impact when combined with stone bunds or other water conservation methods, and the effects were also synergistic with adding manure. Households that had suffered food shortages of 6 months or more were able to reduce their deficit periods to 2-3 months, or 0 months in some cases. The whole movement improved food security for 3 million households.