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.