periodically on Indigenous Knowledge (IK) initiatives in Sub-Saharan
Africa and occasionally on such initiatives outsider the Region.
It is published by the Africa Region’s Knowledge and Learning
Center as part of an evolving IK partnership between the World
Bank, communities, NGOs, development institutions and multilateral
organizations. The views expressed in this article are those of
the authors and should not be attributed to the World Bank Group
or its partners in this initiative. A webpage on IK is available
Faso: the Zaï technique and enhanced agricultural productivity
More than 90% of the population in the Sahel lives on agriculture.
The fact that crop production has not kept up with population
growth during the last two decades is attributed to land degradation
and productivity decline resulting in increased levels of rural
poverty, food shortages and chronic food insecurity. In respons,
since the 1980s, Sahelian farmers have experimented with various
soil and water conservation techniques to restore, maintain or
improve soil fertility.
of the most appreciated techniques by farmers in northern Burkina
Faso was the plant-pit system (demi-lunes) or “Zai”
in the local language. The technique originated in Mali in the
Dogon area and was adopted and improved in northern Burkina Faso
by farmers after the drought of the 1980’s.
Farmers apply the Zaï technique to recover crusted land called
“Zippelle”. Zaï is a planting pit with a diameter
of 20-40 cm and a depth of 10-20 cm - the dimensions vary according
to the type of soil.. Pits are dug during the dry season from
November until May and the number of Zaï pits per hectare
varies from 12,000 to 25,000. After digging the pits, organic
matter is added at an average, recommended rate of 0.6 kg/pit
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..
excavated earth is ridged around the demi-circle to improve the
water retention capacity of the pit. Zaï fulfils three functions:
soil and water conservation and erosion control for encrusted
advantages of Zaï are that it :
rain and surface/ run-off water;
(ii) protects seeds and organic matter against being washed
(iii) concentrates nutrient and water availability at the beginning
of the rainy season;
(iv) increases yields; and
(v) Reactivates biological activities in the soil and eventually
leads to an improvement in soil structure.
The application of the Zaï technique can reportedly increase
production by about 500% if properly executed.
of the Burkina Faso Zaï Program
As part of their objective to assist local communities to strengthen
their local capacity by using their local knowledge, the World
Bank program on Indigenous Knowledge for Development provided
support to farmers for scaling up the dissemination of the Zai
technique in three provinces in central Burkina Faso. The Association
pour la Vulgarisation et l’Appui aux Producteurs Agro-écologistes
au Sahel (AVAPAS) provided day-to-day guidance to farmers. Other
local development actors (administration, extension workers, local
authorities, community leaders) supported the initiative to ensure
campaign was carried on through the period 2002 – 2003.
The farmers highly appreciated the technique especially since
it increased productivity. Unfortunately, farmers did not always
follow all the recommended steps so as to make a better profit
from the technique. For example, the dimensions of the pits were
not always as recommended, resulting in poor plant and stem development
Delayed digging of the Zaï pits and inadequate application
of organic matter (timing and quantity) can all contribute to
substantial yield losses.
team proposed a second season of implementation in order to make
it possible for farmers to master the technique and to disseminate
its application among other farmers. This was carried out in 2003
the second campaign, farmers started to cultivate “common
fields”. In the common fields, all the recommended steps
were applied strictly and this became a demonstration site for
the farmers of the sample as well as for the other farmers of
of the zone of activities
The activities were carried out in 32 villages in the following
six provinces of the central zone of Burkina Faso: Kadiogo, Bazega,
Oubritenga, Kourweogo, Sanmatenga and Zoudweogo. Rainfall during
this season was exceptional with only few dry spells.
of the technology
The diffusion of the Zai technique in central Burkina Faso was
organized in three phases:
Information and sensitization sessions - During this phase,
a discussion was organized with farmers on the strengths and
weaknesses of their production systems. Farmers assessed their
cropping lands and proposed solutions to the constraints they
had identified. The AVAPAS team complemented the list of solutions
proposed by farmers,presented a complete description of the
Zai technique and invited farmers to join the experiments.
Demonstration of the technique - The technical team organized
a demonstration session for farmers that included digging pits,
organic manure application and provision of basic equipment.
The equipment is used in rotation and organized by the farmers
Field trips - During the growing season, follow-up visits reinforced
the necessity to apply the entire technical package to achieve
the highest impact.
of various operations during the adoption of the technique
Zaï operations were implemented by farmers at different periods
depending on the availability of labor, organic matter and the
interest of each farmer. Farmers who participated in the earlier
campaign were invested in the technique much earlier. For the
most informed (earlier participants), work started at the beginning
of June and extended until mid-July. For the others, the activities
started at the beginning of July and finished end-July.
Digging Zaï pits
The size of Zaï pits varied by farmers during the first year.
The objective was only to start with digging the holes. Those
who had not followed the minimum dimension rule were obliged to
restart the pits during the second growing season. By the 2002-2003
campaign, a clear mastery of the operation by farmers was noted.
In fact, the size of the seed holes was according to recommendations,
in part attributed to the availability of equipment provided by
AVAPAS (drill, peck axes).
Application of organic manure
The unavailability of good organic matter was one of the constraints
during the dissemination of the technique. Some farmers, in the
absence of compost, applied fresh organic matter in the pits,
resulting in seedling damage. It became apparent and essential
that farmers needed to be better informed regarding this specific
stage of organic matter application which is crucial for the success
of the technique.
the 2003-2004 campaign, the country had exceptionally high rainfall
which resulted in the significant development of undesirable grasses,
leading in turn to the farmers having to clear their plots up
to three times.
development of the crop (sorghum)
To monitor the vegetative development of the crops and especially
to exchange views with the farmers, site visits were organized
in collaboration with AVAPAS to address problems which arose during
the growing season: the seedling stage, the flowering stage and
during maturity. Farmers who encountered difficulties in the implementation
of their activities were invited to visit plots of other participating
Seedlings in the village of Niniogo in the department of Pabré
did not survive in the Zaï plots. Farmers had just adopted
the technology but did not yet have all the necessary experience
to ensure the success of the technique. Zaï seeding holes
were fertilized with manure freshly collected from the park and
seeds sown only two days after that. Farmers attributed the loss
of the seeds to the variety of sorghum used or to the lack of
rain immediately after sowings.
The vegetative development of Sorghum in Zaï fields was particularly
appreciated by all farmers. In Korsimoro, one of the farmers made
it known that the Zaï was the only technique that helped
him recover land which he had abandoned for several years because
of the hardened surface. One farmer’s field became the subject
of curiosity amongst his neighbours in the village who asked him
many questions about the technique.
Farmers noticed that the vegetative development of the crops in
the Zaï fields was normal or better than in those in the
non-Zaï plots. While the sorghum was stunting in the non-Zaï
plots, the leaves were still green in the Zaï fields.
The yield for sorghum grain was evaluated in the Zaï and
the non-Zaï plots during two growing seasons.
Data are from 16 villages in 2002 and 32 villages in 2003. The
results show significant differences between the Zaï and
non-Zaï field. The findings are consistent with those from
other studies on Zaï in other regions which show the effect
of the practice on the yield of sorghum (Sawadogo, 2001, Dakuo,
2000, Bamboo, 1996, Kabore, 1991). The yield increase is attributed
to a better use of rainfall and improvement of soil fertility
as results of the application of organic matters in the pits.
and impact of the technique on farmers
the execution of this project, AVAPAS facilitated the transfer
of local technology from a local development organization to
the farmers on the one hand, and subsequently between farmers.
More than 100 farmers in 32 villages benefited from this transfer.
The NGO played a significant role in the knowledge transfer
to and between farmers.
The exchanges between farmers and follow-up visits from the
AVAPAS team made it possible to reinforce the knowledge that
farmers have acquired and to address concerns arising during
the application of the Zaï technique.
The application of organic matter remained one of the least
adopted steps by farmers. The recommended quantity (i.e. two
handles per seed hole) was not always followed which resulted
in the appearance of Striga (bad bleaches on grass indicating
the extreme poverty of the soil) in the plots. Chemical analysis
of the organic matter could be used for designing an optimal
the majority of villages, the surplus production realized by
farmers in one hectare was higher than 0.5 ton. This validates
the effectiveness of the technique in increasing the productive
capacity of the plots.
is especially worthy to mention that in the province of Yatenga
(rainfall between 300 and 600 mm), Zaï remains the single
technique that makes it possible to carry out agricultural performances
on skeletal grounds that are poorer than those in the central
part of the country.
Conclusions and recommendations
Overall, the Zaï technique seemed to have been mastered by
farmers of the central region of the country. From the two years
experiment, the following conclusions can be drawn:
can master the entire technical package if the operations are
well planned, as dictated by the seasonal requirements.
Zaï technique can increase crop yields and reduce the risks
for food insecurity in rural areas
technique does lead to soil improvement and recuperation of
To scale up the benefits of this technique, some scientific
work is necessary in (i) the chemical analysis of organic matters
produced by farmers as well as the proper dosage to use during
the application; and (ii) the testing of high productive cultivars
in order to increase profits.
farmers welcome further support from all partners so that this
technique can be mastered and implemented by the entire farmers’
population of the region and elsewhere in the country.
was reproduced by Suzanne Essama, Knowledge Sharing Officer, Africa
Region, the World Bank, from an activity completion report submitted
by a team composed of Mme Millogo Sorgho Marie-Claire Institut
de l’Environnement et de Recherche Agricoles (INERA),. Korogo
Sylvain and Traoré Karim. Association pour la Vulgarisation
et l’Appui aux Producteurs Agro-écologistes au Sahel
(AVAPAS). Funding for the activity was provided by the BNPP Trust
Fund for Local Community Capacity Building.