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Best Practices on Indigenous Knowledge MOST/NUFFIC (IK-Unit)


Zaï, an indigenous water harvesting and soil fertility management practice in Burkina Faso



Natural resources, resource management, soil fertility, soil improvement


Introducing the practice

The method of water harvesting reported here is practised by Mossi farmers in Yatenga Province in the northern part of Burkina Faso, in sub-Saharan Africa. The Mossi are the major ethnic group in Burkina Faso, making up about two-thirds of the total population. They derive their livelihood essentially from agriculture. They also ruled the region for over eight centuries, establishing five independent kingdoms, of which Ouagadougou was the most powerful. Even today, the traditional Mossi chiefs hold significant power in Burkina Faso.

The zaï method of water harvesting is seasonal, practised each year as necessary. The method is used to rehabilitate strongly degraded land known as zî-peele, which is usually found on relatively flat land on which no crops can be grown.

At the beginning of the dry season, farmers use traditional picks to dig holes 10-20 cm deep and 20-40 cm in diameter. The resulting shallow pits are spaced 80-120 cm apart throughout the area being treated. The earth removed from each pit is carefully piled in a half-moon shape along the pit’s lowest edge so that runoff water will flow downhill into the pit. Throughout the dry season, the pits collect sand, loam and other organic materials carried by the wind.

In early May, with the first rainfall, farmers begin to prepare the pits for planting. In each one they put about two handful of organic waste, generally from animals. Attracted by the organic matter, termites dig deep tunnels beneath the pits, which by now are shaped like funnels. Water from the first rains flow into the termite tunnels, creating pockets of moisture so deep inside the soil that it resists evaporation.

Through the practice of zaï, both water and nutrients are concentrated in the pits, where in early June the farmers plant the seeds. The increased water retention capacity of the soils helps crops tide over drought spells during the rainy season. The following year the practice is repeated, except that new pits are dug between the old ones. Within five years, an entire area of land that had been degraded and useless can be totally rehabilitated to produce yields where previously nothing could be harvested.

The practice, documented in the 1980s, originated among Mossi farmers in Yatenga Province. It is a survival strategy in this semi-arid area. Zaï is still in use today. In fact, because it is so effective in restoring soil fertility and thus in increasing agricultural production, the practice is expanding. It is now used by many farmers, in particular on the northern part of the Central Plateau of Burkina Faso. Both government and non-governmental organizations support the practice.

Zaï is a labour-intensive technique practised by both men and women. Its three main steps are digging, manuring and sowing.


The role of indigenous knowledge

Local knowledge about soil conditions and about the use of organic materials is essential. All members of the community know how to practise zaï. They learn by observation and imitation. Zaï is a strategy for survival and thus very important in the lives of the people who practise it. The practice has been documented in writing, and is discussed on radio programmes for farmers, which are broadcast in local languages.


Achievements and results

The practice addresses a major problem, helping to feed the population in a country that is not self-sufficient in basic foods. Recent inquiries among farmers in Yatenga Province revealed that in years when rainfall is average for the area, zaï enables them to harvest an annual 500 to 1000 kilos per ha of sorghum, millet, maize or other cereals.

The practice is entirely sustainable, very cost-effective, and easy to manage locally. Local farmers benefit from it directly through improved productivity. The practice has three main strong points:

·           It keeps organic waste in the pits, where the most benefit can be derived from it.

·           It restores fertility to depleted soil.

·           It increases agricultural productivity.

Its only possible weakness is that it is physically demanding, but among the Mossi farmers of Burkina Faso, who are known for being hard-working, this is not a problem.

The practice could perhaps be improved if the farmers had more modern tools for digging the holes, or if zaï could be more systematically combined with stone bunds. This combination with another improved indigenous practice designed to slow water runoff would encourage the penetration of moisture into the soil.


Source of inspiration

There is no reason why zaï should not prove useful in other semi-arid regions. In 1989, farmers from the neighbouring country of Niger travelled to Yatenga Province to learn how to improve their own planting pits (Reij 1993, IK&DM, Vol. 1, nr.1).

If you think that this case could be useful in a different context than the one described here, please get in touch first with the contact person listed below (Administrative data). Intellectual property rights could be an issue.


Administrative data

Organizations involved

Association Internationale des Six, S‰ (a non-governmental organization)

B.P. 100 Ouahigouya, Province du Yatenga, Burkina Faso

Tel.: +226 55 0038

Contact: Dr Bernard Lédia, Ouedraogo, Burkina Faso


Association pour la Promotion des Oeuvres Sociales


B.P. 70 Ouahigouya, Province du Yatenga, Burkina Faso

Tel.: +226 554052

Contact: Mr Justin, Tiemtore, Burkina Faso


Person(s) who have described this Best Practice

Emile Dialla


02 B.P. 5154 Ouaga 02

Burkina Faso

Tel.: +226 360746 or +226 613061

E-mail: emile_dialla@yahoo.fr


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