Zai in Sahel region. A traditional farming practice to face desertification and climate change

In the West Sahel Region, particularly in Burkina Faso (former Alto Volta), Mali and Niger local cultivation techniques used by farmers for centuries have been adapted to the new climate conditions. Sahelian farmers dig holes called Zai with dimensions varying with the type of soil. Pits are dug during the dry season from November until May and the number of Zai pits per hectare varies from 12,000 to 25,000.(The number of zai per hectare and their dimensions determine how much water they harvest. The bigger the number and the smaller their size, the less water they each harvest.)
After digging the pits, composted organic matter is added and after the first rainfall, the matter is covered with a thin layer of soil and the seeds placed in the middle of the pit.
Zai fulfils three functions: soil and water conservation and erosion control for encrusted soils.
By concentrating water and fertility in pits, crop yields increase. Tiny trees began to sprout amid his rows of millet and sorghum, thanks to seeds contained in the manure. It became apparent that the trees–now a few feet high–were further increasing crop yields while also restoring soil fertility.

The tree-based farming technique adopted in the Sahel could help millions coping with climate change. Already these practices have spread across vast portions of Burkina Faso and neighboring Niger and Mali, turning millions of acres of what had become semi-desert in the 1980s until th 2000s into more productive land.

Further information:

• Donor funds for creation of Great Green African Wall
• The Sahel green again
• The emergence and spreading of an improved traditional soil and water conservation practice in Burkina Faso
• West Africa Land Use and Land Cover Trends Project