Case study: Conserving soil and water in West Africa

Country: Niger/Burkina Faso

Background: Farmers in semi-arid West Africa understand the value of water, and how its lack limits crop production. In addition, they have to face unreliable rainfall and short, unpredictable rainy season. For this reason, farmers need good strategies for capturing and conserving rainfall and making the best use of it.

SSTC Solution: As part of the Special Programme for Niger (PSN), thirteen farmers, including four women, from Niger visited the Province of Yatenga in Burkina Faso in 1989. Here they learned about the method of the zai pits, which acted as the catalyst of a major change.

The zai pits in Yatenga were a low-cost (some US$8 per hectare), low-maintenance method of conserving water in the field in small hand-dug pits, some 20-30 cm in diameter, 15-20 cm deep and 8 meters apart. The removed earth was placed on the downstream side of the pit to form a small ridge and thus retain more water. The bottoms of the holes were covered with manure to provide nutrients and enhance water infiltration and retention. When it rained, the holes filled up with water and farmers planted millet or sorghum in them.


  • By reviving tassa, the traditional soil and water conservation practice that resembled the fruitful technique observed in Burkina Faso, some farmers rehabilitated 4 hectares of land, including one field next to a main road so that people traveling by would see the impact;
  • The following year tassa use increased to 70 hectares. This was a drought year and only those farmers using tassa got a reasonable harvest;
  • Since the first rehabilitation of land, tassa has spread at a surprising rate in Niger and today is again an integral part of the local farming scene;
  • A new industry of young day labourers spawned: they have mastered the technique and, rather than migrating to find work, tour the villages working for local farmers.