Zaï Pits — Bringing Dead Soil Back to Life
Small holes dug by hand into ground too hard for rain to enter. A handful of manure in each one. In the Sahel, this brought back land everyone had given up on.
At a glance
• Origin: Yatenga Province, northern Burkina Faso — Yacouba Sawadogo (died 3 December 2023), farmer. An ancient technique he revived and improved.
• Maturity: Scaled — practised across Burkina Faso, Mali and Niger, with documented trials in Kenya.
• Cost: No money required. A hand hoe or pickaxe, and manure you already have.
• Labour: This is the real cost. Roughly 100 person-days of digging per hectare, in the dry season, by hand.
• Licence: Open — ancient community knowledge, no patent, free to anyone.
The story
In the early 1980s the Sahel was dying. Twelve years of drought had turned farmland to dust. Rain still fell, but the soil had set so hard that water ran straight off it, carrying the topsoil away and making each storm worse than the last. Farmers walked away from their land. Villages emptied.
In northern Burkina Faso, a farmer named Yacouba Sawadogo looked at his family’s abandoned fields and refused to accept it. He remembered zaï — an old technique of digging small planting pits into hard ground, largely forgotten in better years.
He did not simply revive it. He made the pits wider and deeper. He put manure and compost in each one, which the old method had never done systematically. And he laid lines of stones across the slope to slow the runoff and push water into the pits.
The manure did something he had not planned for. It drew termites, and the termites bored channels through the crust, opening the soil far deeper than a hoe could reach.
Land that had been bare became a forty-hectare forest holding more than sixty species of trees and shrubs — arguably the most diverse forest ever created by one farmer in the Sahel. Wells in nearby villages rose by five to seventeen metres. Communities that had gone without water eight months a year had it all year round.
Yacouba Sawadogo died on 3 December 2023. This entry exists so his knowledge travels further and faster than he could carry it.
▸ Photograph or illustration goes here, with the “Illustration (AI-generated)” caption if generated.
What it does
Zaï works where rainfall is roughly 300 to 800 mm a year — low, unpredictable, and arriving in hard downpours that run off baked ground instead of soaking in.
Each pit does four things at once. It breaks the hardened crust so water can enter. It catches runoff and holds it where a plant can reach it. It concentrates scarce manure exactly at the roots instead of scattering it across a whole field. And it attracts termites, whose tunnels carry water and nutrients deeper than digging alone ever could.
What to expect — and what not to
Where it works: degraded, crusted dryland soil on slopes under 5%, in the 300–800 mm rainfall band, where soil-dwelling termites are present.
Yields: reported gains vary widely by site, soil and season. The most-cited figure is up to a 500% increase on severely degraded land where the technique is well executed. Treat that as a documented best case, not a planning baseline. Most farmers should expect real improvement, not a fivefold one.
Where it does not work: slopes above 5%, where pits can worsen erosion instead of preventing it. Wetter climates above about 800 mm, where waterlogging becomes the risk instead of drought. And regions without soil-dwelling termites, where results are meaningfully weaker.
The honest cost: digging is hard physical work, possible only in the dry season, and one person manages roughly 100 pits a day. At around 10 000 pits per hectare, that is roughly 100 person-days for a single hectare — usually spread across a family and several weeks. No money changes hands. That does not make the work free.
How it is done
Dig pits 20–30 cm wide and 10–20 cm deep, spaced roughly 60–80 cm apart, in staggered rows across the slope. Pile the excavated earth into a small ridge on the downhill side of each pit so it catches runoff. Put about a handful of manure or compost in each pit. Sow sorghum, millet or tree seeds when the rains arrive. Stone lines laid across the slope are not essential, but they make a substantial difference.
How we checked this
The termite effect is not a guess. Soil researchers working in Burkina Faso measured it directly in the nineteen nineties — they dug into crusted ground and recorded how much more water got through where termites had been at work. Others have since tested it and found the same thing. Their full write-ups are in the sources at the bottom of the entry, if you want to read them yourself.
The yield figure is shown as a best case rather than something to expect, because the reports vary and we would rather you plan on the honest number.
