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Prospects for agro-forestry in Benin
Department of Agronomic Research, Cotonou, Benin
Benin's forest resources have been impoverished by 25 years of sawmill operations, bush fires, clearing by state farms and corporations, insufficient fallowing periods, and the encroachment of the Sahel in the north of the country and the savanna in the south. The country must depend on imports to make up a growing deficit in firewood, timber, and lumber. This report describes the objectives for an agro-forestry research programme aimed at improving Benin's forest economy.
Situated on the Bight of Benin between Togo, Nigeria, Niger, and Upper Volta, the People's Republic of Benin - with a surface area of 112,000 km² - is a country with limited forest resources.
A brief outline of the ecological factors affecting Benin helps explain the country's forest situation. The southern and coastal regions correspond to the terminal continental shelf and have soil of variable quality derived from long-shore drift materials, alluvial deposits of silicon clay, and cretaceous formations that have developed into Vertisols. Further north, in central Benin, thre is crystallized rock, granite jutting out of the Precambrian substratum, with ferruginous types of tropical soils, occasionally with lateritic concretions.
According to surveys by the Food and Agriculture Organization (FAO) and the United Nations Development Programme (UNDP), 60 per cent of the country's surface is covered by natural, uncultivated vegetation, which is threatened every year by bush fires. Most of Benin's classified forests are located in the country's northern and central regions. For a full appreciation of Benin's forest situation and the problems that have arisen, other factors must be added to these ecological data; these include the extent to which state farms and corporations have been clearing the land, the inadequate natural fallow periods on most traditional farms, the encroachment of the Sahel in the northern areas and the savanna in the southern areas, and the development of urban areas.
Benin's national forests cover a total of 2 million ha, or 19 per cent of the country's territory. However, commerically valuable forests represent a mere 2 per cent of the land area. Classified forests account for 1,580,028 ha and plantations (mostly teak) cover 10,000 ha. These plantations, between 14 and 30 years old, are mainly located in the country's southern region and are intended for timber production. In teak farming, both short-term (45-55 years) and long-term rotations are used. To these teak plantations must be added the existence of a natural reserve in the Djougou-Bante-Beterou triangle; in the immediate future, however, this reserve's annual timber production will not exceed about 35,000 m³ of Khaya grandifoliola and K. senegalensis, and 40,000 m³ of Antiaris sp. and Triplochiton sp. Corrent production is low as a result of 25 years of overexploitation by local sawmills.
In addition to the 10,000 ha of plantations already mentioned, there must be added 6,000 ha of cashew trees, which supply a small shelling plant in Parakou (annual capacity: 1,500 tons). Furthermore, although lumbering in Benin is not sufficient to keep a foreign trade going, other forest products such as Karite (Vitellaria paradoxa) and cashew nuts have made possible a considerable influx of foreign exchange-about 542 million CFA francs. in 19771978. Production rose sharply in 1979-1980. National parks and wildlife preserves cover a total of 578,000 ha.
Shortage of Wood
The problems that arise from a scarcity of forest products can be expressed in terms of needs. Wood is the leading domestic fuel and is used for cooking in Benin. It comes to people's homes in the form of firewood or charcoal. Wood is currently in chronically short supply in all urban centres and even in rural areas. The rural district of Ouake in Atacora Province, where millet stalks and cow dung are used for cooking fuel, is a good example of the problem.
In the south, this shortage is aggravated by the progressive shortening of natural fallow periods. According to Huart (1976) of the FAO/UNDP forest industries advisory group for Africa, an increase of 15 per cent in the total area sown to crops would cause a deficit for cities such as Cotonou and Porto-Novo of 57 per cent (table 1).
TABLE 1. Fuel Requirements, Present and Predicted
|Firewood equivalent (in m³)|
|Present requirements||Estimated requirements in 1990|
|Parakou and Djougou||180,000||315,000|
|Rural areas and other localities||2,640,000||3,470,000|
However, the country's wood shortage affects more than the supply of fuel; there is also a widespread shortage of timber that is felt at every level of society. To the figures for annual timber consumption must be added 1,500 m³ of plywood and fibreboard, most of which is at present imported. This analysis indicates an annual deficit of 6,000 m³ of saw timber and plywood and 1,000 m³ of roundwood.
Prospects for Agro-forestry Solutions
Attempts have been made to combine and integrate farming, forestry, and animal husbandry methods for improved farm management with a view to continually increasing production without causing major deforestation and yet obtaining a substantial yield from marginal land.
In concrete terms:
Agriculture, forestry, and animal husbandry are not rigidly compartmentalized in Benin. Maize is sown, trees are planted, and animals are raised by the same labourer on the same farm. Rural development structures devised and implemented by the government of Benin take into account the concern for integrating these systems. Specifically, regional rural development action centres (CARDERs) bring together all government aid services in rural areas.
The involvement of rural populations in forest development is a proven technique in Benin. The taungya planting method is one agro-forestry production system in which farmers take part in setting up state plantations. This practice has made it possible to plant 6,000 ha of teak in southern Benin.
There have been many variations in the practice of taungya. In the south, maize is cultivated in combination with the establishment of teak plantations. In North Zou, maize or groundnuts are grown on cashew plantations. Mixed cultivation of cotton and cashew has not proved as successful because of the high risk of attacks by parasites, notably Heliotis, a cotton parasite that causes a great deal of damage. In the north, millet and cashew have been successfully combined; cashews and yams can also be cultivated together if the yam's twining stalks are kept from winding themselves around the young trees.
Generally speaking, agro-forestry experience to date in Benin has been based on the taungya method.
Agro-forestry Research Objectives
The shortened fallow periods currently noted in southern Benin, and the resulting problems-decreased soil fertility, decreased firewood production, and reduced natural fallow areas-motivated the Department of Agronomic Research to start a research programme in 1980 with a view to including timber trees in traditional crop rotations.
The objective of this programme is to upgrade soil fertility and obtain substantial forest production over a relatively short fallow (three to four years). Acacia auriculiformis and Leucaena leucocephala are being grown as fallow species and being observed for their positive contribution to soil fertility and firewood production. If successful, this programme will enable agro-forestry to play an important role in improving Benin's forest economy.
Summary of discussion: Traditional agro-forestry systems
In the discussions on traditional agro-forestry systems and their prospects for development, the first major point which emerged was that insufficient attention had been paid to the improvement of traditional cropping systems, in short, to make them economically viable as well as to meet subsistence needs. To continue to divorce agriculture from forestry was to be moving in the wrong direction, and this was especially true in the humid tropics. One participant observed that the value of mixed cropping systems was being demonstrated all around us, but that we have been blinded by the success of monocultures in the temperate zone. A "farming systems" approach was strongly advocated, although it was recognized that such an approach was relatively rare and demanded large inputs of scarce, trained personnel to be effective.
It was pointed out that the rapidly increasing population density was leading to smaller farms, yet these had to meet the basic food needs as well as provide cash income. Stable systems must be developed, and research must be carried out to determine whether agro-forestry will indeed provide greater benefits to the small farmer. The claim that higher diversity will increase stability (i.e., lessen risk) was questioned, as the data were still ambiguous. Certainly from a management viewpoint a higher diversity of crops makes it difficult to maximize the yield of the individual components. The problem of crop compatibility was also raised, and it was noted that there was great variability in the demands of annual crops for light, nutrients, water, etc. Similarly, crops vary greatly in their response to different management practices such as weeding. This means that each component within a given system will have to be tested independently and in situ in order to fully evaluate the potential of the system in question. Because of this inherent complexity we must use existing systems as guideposts, and only test systems which could fit in the existing socioeconomic milieu.
The question of tree root architecture was brought up, and the trade-off in the humid tropics between trapping nutrients with a dense, shallow root system vs. increased root competition was recognized. In this case further complications arise because the tree root system is also affected by the herbaceous component, and one would expect the balance to vary in accordance with rainfall, soil type, management practices, etc.
Several speakers felt that insufficient attention had been paid in the past to the development and management of the tree crop component. In this context the point was again made that one has to work within the context of the existing system by looking at the farmers' needs and then providing new plant material or other inputs which are demonstrably better. Improved coconut varieties and the Crop Diversification Project in Sri Lanka were cited as examples from outside Africa. It was also suggested that a type of planted fallow might be developed which would hasten the fertility recovery rate and provide a crop which could be harvested at the end of the fallow.
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