The mode of management and use of whatever system of agroforestry parks depends on the types of agroforestry parks. The type of agroforestry park varies in turn according to pedologic and climatic conditions. The ICRAF team used a climatic gradient to design the mapping of the types of agroforestry parks and to establish typologies.

The driest zone mapped was the region of Dori in the Northern part of Burkina Faso with an annual rainfall of 300 to 400 mm. In that region, research activities made it possible to identify five (5) types of agroforestry parks. The most common one was the pure Faidherbia albida system which occupied about 30% of cultivated land followed by the mixed Faidherbia albida – Hyphaene thebaica system (about 25 % of cultivated lands); the pure Balanites aegyptiaca system (15 %); the mixed Hyphaene thebaica - Balanites aegyptiaca system (10 %); the pure Hyphaene thebaica system (8 %) and others (12 %).

In the less arid regions of Gondo-Morondo in Mali where the annual rainfall reaches about 500 mm, the studies enabled to identify 17 types of agroforestry parks among which many are dominated by tree species like Faidherbia albida, Balanites aegyptiaca, Sclerocarya birrea and Acacia raddiana (Table 1).

Table 1: Types of agroforestry parks in the Gondo-Morondo region in Mali

In the Bani-Niger region in Mali, with an annual rainfall of 700 to 800 mm, 18 types of agroforestry parks are identified, each type of park corresponding to the dominant tree-species in the system (table 2). These data clearly show the importance of species like Vitellaria paradoxa, Adansonia digitata, Faidherbia albida and Sclerocarya birrea.     

Such knowledge of the diversity of the species in the different types of agroforestry park systems and their respective functions is fundamental for the evaluation activity we are currently undertaking on the enrichment methods of the agroforestry parks and the rehabilitation of the strained traditional system.

Table 2: Types of agroforestry parks in the medium basin of the Bani-Niger river

There are no longer many possibilities of practicing fallow in the Sahel because there is less available land (Mortimore and Turner 2005). If a farm is under continuous agricultural use, the trees tend to disappear after a period of 20 years (source A. Nikiema, ICRISAT). The roots of the young trees are cut/hurt mainly when ploughs are used.

Natural regeneration occurs if the farmers protect the trees when they perform their farm activities. But in case very little natural regeneration takes place, it is necessary to plant additional trees by directly sowing seeds or planting potted trees. The artificial regeneration is only possible if the farmer is convinced of the usefulness of having more trees in his field. For Parkia biglobosa (Néré), we can have up to 23 trees per ha in a farm without negatively impacting on the millet yields. The density of Parkia biglobosa population is less than 23 trees per ha in many fields. As for Vitellaria paradoxa (Shea), a higher density is possible.

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