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The Centre for Development Cooperation Services of the Free University Amsterdam recently made, at the request of the International Fund for Agricultural Development (IFAD), an evaluation of experiences in the field of soil and water conservation in sub-Saharan Africa. They arrived at the conclusion that most projects carried out since colonial times more or less failed to reduce soil loss and increase yields. Drs. Chris Reij, who is working for the Centre, participated in this evaluation. ILEIA asked him for the reasons for these failures and what criteria projects have to meet to make water and soil conservation more effective.

ILEIA Newsletter • 1 nº 5 • August 1986

Construction of stone bunds. Photo: Chris Reij

In 1983 Chris Reij studied the evo1ution of erosion control projects in Burkina Faso. This study plus a project report by Mr. P. Wright about the OXFAM "Projet Agro-forestier" in Yatenga, Burkina Faso were used to illustrate his arguments.

The Mossi Plateau

Place of action is the Mossi Plateau in the centre of Burkina Faso. This region has a high population density (100-150 inhabitants/km2). Rainfall is between 500 and 800 mm/year, and highly erratic with high rainfall intensities. In good years (one out of four), agricultural production is just enough to cover local needs. Migration to other regions and temporary migration of the labour force are very high. Natural resources like soil fertility, wildlife and ground water are under severe pressure. Soil erosion by runoff is very high (ca 20 ton/ha/year), and soil erosion by wind is becoming a greater problem (for the land is nearly stripped of natural vegetation).

A Mossi farmer told: "Our fields are depleted and the millet does not produce as before. We have to cultivate more fields to get the same production as some years ago." In the period after independence (1960), Upper Volta, now called Burkina Faso, implemented three types of erosion control projects:

• A a project based on the use of heavy machinery,
• B projects based on partial participation of the farmers,
• C projects based on full participation of the farmers.

"GERES"

A - The GERES (Groupement Europeen de Restauration des Sols) project in the region of Ouahigouya. In a period of two years (November 1962 –February 1965) e.g. 35.000 km of earthen contour bunds for water and soil conservation were constructed on 120.000 ha land. This impressive performance was made possible by using heavy machinery and many expatriates. There was no participation of the local population at all. Already in 1965 it was clear that the project was a failure. The farmers did not maintain the earthen contour bunds which degraded rapidly. They even provoked more erosion than occurred on untreated fields.

"FDR"

B - The FDR ( Fonds de Developpement Rural) project, funded among others by the World Bank, and executed in e.g. several regions of the Mossi Plateau, is the major exponent of the second group. This project was initiated in 1972 and is still continuing. Earthen bunds (at the base 1.0 m. wide and 0.5 m. high) are constructed by the local population, an activity which is usually rewarded with food for work. only a tractor is used to open the soil where the bunds have to be constructed. Contour lines are measured by a special team of surveyors. From 1982 on, each year an area of around 10.000 ha. is treated in this way. The success of this project is open to question. Critics are:

• Necessary labour input for the construction and maintenance of the bunds is higher than what farmers are usually willing to spend on them. Smaller -but more- bunds means less work and may give a better result (see tables 1 and 2), 
• Compaction of the bunds is necessary but only possible with the use of water, which is mostly not available,
• Where the infiltration capacity of the 8011 is low, waterlogging takes place in front of the bunds, while on the back side of the bunds the land can be too dry,
• The population is rewarded for the construction of the bunds. For their maintenance, however, they are not rewarded. As the bunds have either no or only a limited positive effect on crop yields, farmers are not interested in maintaining them.
• The work rhythm is high but after 12 years, only a tiny fraction of the fields have been treated,
• The population cannot continue the work after the project is finished because they were not trained how to determine contour lines themselves. The repeatability of the techniques is therefore extremely limited.

"Projet Agro-forestier"

C - A project based on full farmers' participation is the Agroforestry project of the English organisation OXFAM in Yatenga initiated in 1979. This project developed in close collaboration with the farmers' water harvesting techniques which are capable of decreasing soil erosion while increasing water infiltration and soil productivity. In the first phase of this project, the GRAAP method (see ILEIA newsletter no 4) was used to stimulate discussion on environmental degradation and possible actions. These discussions were followed by one year of experimentation with the farmers. Different water harvesting techniques for tree and crop planting were tried out and evaluated. Farmers showed a clear preference for the construction of stone bunds on their own fields.

These methods are based on local traditional techniques which had fallen into disuse. The farmers constructed bunds of 10 to 30 cm. high and 50 to 100 m. long, placed along the contour lines which were determined with a water level. These bunds, which are mostly permeable, permit runoff water to pass slowly and to infiltrate into the soil evenly over the field. Construction materials used are rocks, stalks or branches tied in bundles. Rocks are preferred as construction material, and farmers would transport them with donkey carts and even bicycles from distances up to 4 km. Spacing between bunds were chosen by each farmer and varied from 10 to 50 m. for slopes of 0,5-3%.

As a guideline, the project recommended that the top and base of two following bunds should be on the same height. In a number of fields crops were planted in small microcatchments or water-pockets, traditionally called "zai". Manure is applied to these water-pockets, thus representing an efficient traditional method of water harvesting and management of organic matter e.g. manure.

Year	Annual Rainfall	Control Number	Plots yield	Treated Number	Plots yield	Z
	mm		kg/100 m2		kg/100 m2
1981	692	3	5.10	14	8.57	-
1982	421	45	4.42	47	4.95	1.26
1983	413	37	2.95	63	4.18	3.01
1984	383	72	1.53	74	2.92	3.89
Table 1: Evolution of yearly rainfall and cereal yields, sorghum and millet.

Promising results

The results of these measures are very promising (table 3). Especially in dry years, yields on treated fields are much higher than on untreated fields. The yield increase is due to improved water management and improved soil fertility. Crop failure after seeding occurs less often due to better moisture availability, and the plants show better drought resistance throughout the growing season. These methods were also used with success to reclaim degraded, crusted soils. In the extension phase of the project training was given to farmers and to extension agents. Intergroup visits were used to facilitate observations and the exchange of ideas between innovative farmers.

The empirical nature of the activity was underlined: farmers must adapt the techniques to each situation. The training concerned principally the use of the water level to determine the contour lines. After each training session of two or three days, each "groupement" was given a water level and the members were invited to try the techniques on their own fields. The project may be considered very hopeful, the yield improvement is substantial, the techniques -practicable by the farmers themselves- are easily transmitted and are assimilated. Costs per ha are relatively low. Training courses have now been given in 115 villages, and although the number of hectares treated (ca. 1000) is still quite low, the area is increasing rapid1y.

Conclusions

What can be learned from these three very different approaches?

Chris Reij:

1. The majority of the farmers have not been reached by any project;
2. Only a fraction of the agricultural land that needs treatment has been covered;
3. The only chance to stop this degradation will be general participation of the farmers in water and soil (fertility) conservation. When every family treats every year part of their fields (0.5- 1.0 ha.) more progress will eventually been made.

To make this possible, the propagated techniques have to meet the following criteria:

• They have to be simple. cheap. and may not be too labour-demanding; they must be practicable by farmers without much external help. so that they are repeatable;
• They must be effective. In the first year they must give a yield increase of at least 40%;
• The conservation works must be permeable in most cases. Their purpose is not to prevent the entrance of runoff from outside the field. but to force it to flow more gently over the fields. allowing part of it to infiltrate;
• Most projects treat an entire watershed or parts of it. Technically this is right, but farmers cannot identify themselves with watersheds. For them this way of working is difficult to understand. Even a village territory is difficult to grasp for farmers. Private fields are more a reality. Thus it seems necessary to shift from a large scale, collective approach to a small scale, individual approach and thereby to leave farmers free in their choice of which fields they want to treat when and in which rhythm;
• Far more than before, accent has to be placed on the introduction of simple improvements of traditional techniques of water and soil(fertility) conservation. These traditional techniques are used in Africa in many more places than expected by development workers. Knowledge of these traditional techniques is still minimal and usually they have been neglected. Projects mainly introduce imported techniques (e.g. erosion control techniques of the USA) designed and proven to be good for a particular situation, but they fail under African peasant conditions.

In the combat against desertification many errors are made and still much has to be learned.

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