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close this bookAgro-forestry in the African Humid Tropics (UNU, 1982, 162 pages)
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View the documentSummary of discussion: Taungya systems from biological and production viewpoints

Taungya systems: Socio-economic prospects and limitations

E.E. Enabor, J.A. Okojie, and I. Verinumbe
Department of Forest Resources Management, University of Ibadan, and International Institute of Tropical Agriculture, Ibadan, Nigeria


Taungya systems embrace multiple land-use practices involving joint production of forestry and agricultural crops In the tropics, land is a most important factor of production and there is overwhelming dependence of the population on land for livelihood. The introduction of taungya has alleviated the problems created by the wasteful use of land under the traditional agricultural production systems, increased food supplies, and significantly con" tributed to the socio-economic well-being of the rural population. It is indicated in this paper that socio-economic factors favour continued development of taungya in the tropics, particularly if the limitations of labour and capital can be removed through adequate government support of the programmes.


Land is a basic, if not the most important, factor of production in the tropics. The primary occupation of the people is agriculture, which employs more than 60 per cent of the active labour force. Agriculture constitutes the dominant sector of tropical economies, not only as the principal source of food for the majority of the population but also in terms of the sector's share of total national production, which frequently exceeds 50 per cent. For many tropical countries, development prospects depend on the prices of agricultural and forestry products in international markets.

The past concentration on, and bias towards, export cash" crop production in the tropics was a major factor in the incidence of food shortages and malnutrition, the true dimensions of which are only now being appreciated (Okurume 1970). Data available from FAO (1976) indicate that the annual growth rate of food production per person in developing countries fell from 0.6 per cent in 1961-1970 to 0.2 per cent in 1971-1975. In Africa, the annual growth rate in 1971-1975 was-2.1 per cent compared with 0.4 per cent in 1961-1970.

Unless these trends are reversed, the developing countries of the tropics will be confronted by the spectre of chronic food shortages, widespread malnutrition, and mass starvation by the end of the twentieth century.

Tropical agriculture is particularly extensive, relying on a system of shifting cultivation or rotational agriculture whereby the farmers cultivate a piece of land for a few years, abandon it to fallow to regain fertility, and move on to cultivate another piece of land. They may cultivate several pieces of land successively before returning to recultivate the first piece of land at the end of the cultivation cycle. Ordinarily, shifting cultivation requires a large amount of land per farming family,! and its successful practice depends on virtually unlimited land availability or a relatively small farming population (Kio 1972).

The population of the tropics has grown very rapidly in the last two decades, averaging 2.5 per cent a year compared with 1 per cent in the developed countries of the temperate region (UN 1979). Given their small industrial sectors and their limited capacity to absorb excess labour in agriculture, developing countries have faced continuing fragmentation of farm units to accommodate requirements of new families. The institutional framework of land use in most tropical countries directly promotes such fragmentation of holdings.

The fragmentation of holdings and the prevailing institutional framework that does not fully view land as a factor of production have contributed to declining agricultural productivity and food shortages in the tropics. Equally important are the failure to introduce appropriate technologies (superior farming implements, seed varieties, and production techniques) and the inefficient organization of agricultural production. The causes of declining agricultural productivity with particular reference to Nigeria have been well documented by Olayide (1973). To overcome the constraints would require a revolution in agricultural production in the tropics, an event likely to occur only in the distant future.

Solutions to the defects of shifting cultivation as a form of extensive agriculture have been provided by the system known as taungya-combined production of forestry and agricultural crops on forest lands. King (1968) found that the system has been practiced for a long time and existed at some time in all the five continents. He also indicated that, despite the differences in terms or labels used, the taungya system always exhibited certain basic attributes and required some preconditions for its adoption. The preconditions, such as land hunger and low standard of living of the population, are clearly socio-economic in nature. The fact that the system is virtually extinct in the economically advanced countries supports this assertion.

The socio-economic environment is central to the prospects and limitations of taungya systems. Indeed, King (1968) concluded that the system was self-terminating once a country achieved a certain level of economic development.

Socio-economics in the Development of Taungya

The introduction of the taungya system into the humid tropics was a response to various socio-economic factors. For example, in Nigeria a major objective was to solve the problem of high cost of forest regeneration (Enabor 1979). In Ghana, the objective was to solve the existing land hunger problem in the rural areas (Amissah 1978). Whatever the reasons for introducing taungya, King (1968) insisted that the successful establishment and development of taungya depended on the pre-existence of land hunger, underemployment, and low standards of living among the rural communities. Apart from these three prerequisites, other socio-economic factors contributing to the development of taungya include population growth, land availability, farm labour supply, food supply, income-generating potential, availability of infrastructural facilities and organizational institutions.

In Burma, where taungya originated, it was used mainly as a means of regenerating both the soil and the forest by employing and improving upon shifting cultivation. It was essentially a method of shifting cultivation because forest land was cleared, farmed for a few years, and allowed to revert to forest so that fertility was restored naturally. It was an improved system because selected tree species such as Casuarina equisetifolia and Leucaena glauca were sometimes planted to assist in re-establishing the forest fallow (Nao 1978). The indication is that a low population density and a long fallow period were required for the system to be successfully practiced. Under the present high population densities it is doubtful that the system in its original form would succeed in many tropical countries.

The modern taungya system seems to differ significantly from the original concept. The practice has been reserved to forest estates, and rapidly growing rural populations have often put pressure on foresters and forced them to adopt taungya within the estates. Kio (1972) concluded that until the industrialization of tropical countries becomes large enough to absorb the increasing rural population, pressure on forest estates by farmers would continue. The greater the pressure on forest lands, the more taungya would be sustained.

At the time when the present forest estates of many tropical countries were constituted, land was abundant, forests dominated the landscape, and shifting cultivation was successfully practiced. Agricultural expansion, introduction of permanent cash crops, and over-cultivation of available arable land have resulted in rapid soil deterioration and lower crop productivity in the unreserved land areas. The reserved forest lands have remained fertile, thus constituting highly productive farmland potential. Such imbalance in soil fertility between reserved and unreserved areas may facilitate successful development of taungya. King (1968) reported that, despite the existence of unoccupied and uncultivated land outside reserves in Uganda, farmers still participated in taungya because of higher fertility of the reserved land. Similarly, Lowe (1974) stressed that one of the major reasons that farmers participated in taungya in Nigeria was the opportunity to use the residual fertility of newly cleared land.

With population growth, an increasing number of farmers have found it difficult to acquire more land for farming. Immigrant labour required for the various forest operations may not get land outside the reserve to grow food to meet their own consumption requirements and that of their families. The introduction of taungya would be a big relief to such farmers. Thus, in some parts of south-west Nigeria, Ijalana (1979) found immigrant fishermen (llajes) constituting about 90 per cent of taungya farmers because they could not get land outside the reserves. Nigerians working their way to or from Mecca have similarly been mentioned by King (1968).

In general, where arable land is too scarce to permit agriculture or forestry as single land uses, taungya will develop. Over the past 54 Years in Nigeria, the adoption of taungya has constituted an effective means of providing more farmland to the farmer and, at the same time, transforming the natural forest into more productive forest plantations at relatively low direct cost to government.

Labour and Other Inputs

The growing of both agricultural and forestry crops is involved in the taungya system. The activity is labour-intensive, especially as modern farming techniques are at present nonexistent in taungya operations. For a successful implementation of taungya, the supply of labour must be ensured, In this way the absence of alternative non-farm occupations also favours taungya. Some farmers in southwest Nigeria were apparently unwilling to practice taungya because they were not unemployed (King 1968).

Several authors, including Mergen (1978) and Nao (1978), have contended that the taungya farmer is exploited by participating in the establishment of plantations without being adequately rewarded. King (1968) went further, to suggest a sharing of the savings in the cost of establishing the forest plantation between the farmer and the forester. The thinking is that if there are other job opportunities in the rural areas, the farmer may prefer them. However, 99 per cent of farmers in south-west Nigeria reported that they gained from participating in taungya (Kio and Bada 1981). The indication is that even if farmers are being exploited they are not aware of it and they are quite willing to participate.

Taungya, whether traditional or departmental, 4 is an arduous task. The labour has to be drawn from the existing pool of farm workers because out-migration to the urban areas has depleted other sources. As long as out-migration continues taungya will suffer a drain in the most productive labour force, the young men and women. In order to sustain the system rural life must be made attractive and comparable to urban conditions so that rural labour is retained. The introduction and success of the departmental taungya system in southeast Nigeria seems to be a manifestation of the importance of this factor in the development of taungya (Enabor and Adeyoju 1975). What still remains largely unsolved is the introduction of improved farming techniques so that the work becomes less arduous and the system more productive.

Food Supply and Income Generation

Nao (1978) estimated that taungya systems in Nigeria have directly provided enough food for about 700,000 people, constituting about 1 per cent of the country's food needs. In Thailand the indication is that taungya farmers produce enough food to feed themselves and sell the surplus to the market, and in China, taungya farmers contirbute about 56 per cent of the country's food requirements

It is not clear from these figures whether the taungya farmers enjoy a higher standard of living than their nonparticipating counterparts. It is sometimes argued that farmers would be more willing to participate in taungya only if their standard of living, measured by level of income,were improved. However, King (1968) maintained that the taungya farmers' income is improved only if they are provided with wageearning employment in the forest plantation. In this respect departmental taungya would satisfy the income requirement for the successful development of taungya, because it ensures regular income comparable with that obtainable in other sectors of the economy.

Under the traditional taungya system, income generation is left entirely in the hands of the farmer, who may find it difficult to get a ready market for the produce. However, Kio and Bada (1981) found that although most of the taungya farmers sold less than half of the total crop volume harvested, they obtained between N500 and N2,000 per year. Also, Lowe (1974) maintained that most of the food produced by taungya farmers is consumed locally, yet farmers may earn between N600 and N800 a year if they concentrate on yam production. If maize and cassava are produced, the estimated income would be N100-N200. Another estimate by Enabor (1979) was that per capita income of taungya farmers in Nigeria is about N72, which is below the N90 estimated for urban centres but well above the N30 estimated for rural areas.

Despite such improved income estimates for the taungya farmer, Olawoye (1975) contended that the living conditions of the traditional taungya farmers have not improved as compared with those of other rural villagers. In contrast, the departmental taungya farmer has enjoyed substantial benefits in terms of provision of infrastructure and other amenities. The indication is that, although a low standard of living is required as a prerequisite for the introduction of taungya, its continued successful development depends on the extent to which it improves the standard of living of the farmer. As long as improvement does not occur, the capable farmer will look to the urban centres in search of a better living standard, the practice of taungya being left to less efficient hands.

Infrastructural Facilities and Social Amenities

Some of the major infrastructural facilities that may affect the development of taungya systems include transport, marketing, and storage facilities. To the farmers who do not have means of transportation and have to walk to the farm, the distance from home to the farm is a major determinant of their level of participation in taungya. In well-organized taungya systems accommodation at very convenient locations may be provided for the farmers.

Where transport facilities are readily available or where land shortage is acute, farm distance is less important in determining the farmer's participation. For example, King (1968) showed that farmers in Trinidad travelled up to 16 km to participate in taungya because transportation was relatively cheap and easy. In Kerala (India), there was no distance limit because of the acute land shortage problem and low standard of living of the farmers. In Nigeria, Ijalana (1979) found that taungya farmers travelled between 3 and 6 km by motor vehicle or bicyle to the farms.

Distance may not constitute a limitation to participation but it surely has an effect on productivity. Farmers who travel long distances may reach the farm already exhausted. They may arrive late and have little time to participate before closing time. Thus Mergen (1978) estimated that 3-5 km should be the maximum walking distance.

The improved crop yield obtained from taungya farms is not meaningful if there is no means of storing the excess food produced or transporting it to the market for sale. Farmers can only be encouraged to produce more if they get reasonable returns.

The availability of schools, sanitary and health facilities may encourage farmers, particularly young ones, to stay in the rural areas and participate in taungya rather than migrate to the cities. Moreover, such facilities would improve the farmers' capabilities and make them more contented and productive workers.

Easy access to credit facilities for taungya farmers would enable them to improve their methods of cultivation and to store, process, and sell their produce at the right time to obtain maximum profit. Credit facilities are also necessary to enable farmers to acquire improved farm inputs, such as fertilizers, herbicides, and farm machinery.

Prospects and Limitations

Numerous studies confirm the positive role of the taungya system in augmenting food supplies and fostering the socioeconomic improvement of rural communities in tropical countries. The system has also been instrumental in preserving forests. The prospects for the taungya system hinge on the continued interest of the farmers and the foresters in its maintenance, aided by the government.

The socio-economic prospects of taungya systems in the tropics depend on such factors as development trends of the economy in general (and of agriculture in particular), population growth, unemployment, income-generating potential, effectiveness of forest management, and the role of government in providing necessary incentives.

The disappointing development performance (UN 1978) of tropical countries has prompted a rethinking of growth strategies to solve the mounting problems of poverty, ignorance, disease, and malnutrition. In the 1980s emphasis has shifted to self-reliance and self-sustaining economic growth in which high priority is given to food and agriculture, raw materials, and natural resource development (ECA 1980).

The economic growth strategy demands action by government to improve agricultural productivity and rural income, provide infrastructure and social amenities, and promote diversification of employment opportunities that will stabilize rural communities. In the short term, measures to stimulate rural development must focus on the smallholder farmers rather than on large-scale capital-intensive agricultural projects. The taungya system should constitute an ideal development tool. Its adoption on a large scale should greatly expand food and wood supplies, increase rural employment opportunities, and raise living standards. Many of the inputs to a successful rural development programme, such as improved seed varieties, fertilizer, infrastructure, and social amenities, are complementary to the operation of the taungya system.

At the level of the smallholder, income considerations are the dominant concern. The income prospects depend in turn on such factors as soil fertility, crop combinations, production costs, and prices, as well as on the efficiency of harvesting, transporting, and marketing. While the taungya farmer initially has access to highly fertile soil in newly cleared areas (Lowe 1974), the soil fertility may be depleted after two or three years, depending on the particular crop combinations used and cultural practices. Fertilizers or other inputs must be used to maintain soil fertility and high yields. The effects of combining crops on each other as well as on soil fertility in forest lands need to be investigated. There are signs, however, that more flexibility is being introduced into the system, as farmers in some countries are given permission to grow fodder crops and cash crops such as cocoa and coffee, and raise livestock.

Production costs also affect income prospects. Under the traditional taungya system, the bulk of the production costs to the farmer is implicit and consists of the labour provided by himself and members of his family.

The farmer's needs for cash will probably increase under a well-developed taungya system for the purchase of superior seed varieties, farm equipment and tools, and services of hired labour during intensive operations such as land preparation and harvesting.

With population growth and improved living standards, the prices of food and livestock feeds are bound to rise. Taungya farmers are thus assured of good prices for their output, especially where they are able to transport and market their own products. In Nigeria, where good road systems have been extended to many rural communities, farmers can now convey their surplus produce to markets about 100 km away, obtain good prices, and return home the same day. They can now dispense with the services of intermediaries, who, in the past, absorbed the bulk of the profits from production efforts.

Several estimates of income earned by the farmer under taungya have been made. In Nigeria, the estimates of annual income range from N50 (Ball 1977) to N600 (Okojie 1975). In Zambia, the profit (net present value) from maize intercropped with pines in an industrial plantation increased 7 per cent in one year compared with the pure pine plantation (Kufakwandi 1980). Although the figures vary widely, they provide evidence that the farmers inside taungya earn higher incomes than those outside. A majority (55 per cent) of farmers interviewed in Oyo State, Nigeria, reported definite improvements in income (Kio and Bada 1981). Taungya is especially profitable for farmers who obtain supplementary employment in forestry or have privileged access to forests to hunt, collect wood for sale, gather fruits and nuts, or harvest other forest produce freely. If income-generating potential alone were considered, the taungya system's prospects would be bright.

For taungya systems to be successful, however, it is necessary to have a regular supply of labour. The estimated agricultural labour force of developing countries rose from 648.1 million in 1965 to 709.2 million in 1975 (FAO 1980), representing 31 per cent and 34 per cent, respectively, of the total rural population. At present a high proportion of the labour force in tropical agriculture is unemployed or under-employed. The taungya system provides a unique and attractive opportunity for absorption of unemployed rural labour. In particular, it represents the only alternative available to landless rural farmers.

Ironically, however, many unemployed farmers are reluctant to participate in taungya. First, the majority of young potential farmers in rural areas find rural life dull and uninteresting. They are migrating to urban centres, where life is less arduous and monotonous, in search of jobs. Rural-urban migration on a large scale has been encouraged by the worsening rural-urban terms of trade (FAO 1980). Thus, the majority of farmers participating in taungya in the tropics are people aged 40 years and over (Kio and Bada 1981). A high proportion of such farmers tend to be under-nourished and in a poor state of health, so their productivity is low (Enabor 1978). Some unemployed farmers are willing but unable to participate in taungya because they lack the necessary inputs to cultivate the land allocated to them in forest reserves. The youth must be retained in the rural areas by the creation of more attractive living conditions. To some extent, the establishment of departmental taungya schemes based on integrated forest villages provided with all the basic social amenities has enhanced participation of younger farmers in taungya systems (Enabor and Adeyoju 1975),

The effectiveness of forest management also affects the prospects for taungya in the tropics. The objective of forestland management under taungya is to obtain the maximum rent from the soil under use. This requires viewing the system as an integrated joint enterprise. Profit is to be maximized for the whole enterprise rather than for the component parts (Enabor 1978). Currently, forest management in the tropics is still very weak or ineffective and lacks necessary information, trained personnel, and adequate financial inputs. It is, therefore, not surprising that most foresters distrust farmers who, in turn, are discouraged by the host of restrictive regulations in taungya schemes. A possible solution to the problem is to strengthen forest management with adequate legislation and supply of productive inputs. Alternatives are: (1) departmental taungya, in which the forestry department owns both the agricultural and forest crops, or (2) agro-forestry, where total ownership rests with the farmer.

King (1968) postulated that the taungya system would die a natural death once farmers' incomes reached a sufficiently high level. However, a survey in Ando State indicated that highincome farmers were more interested in agro-forestry than were low-income farmers (Ijalana 1979). Taungya in the modern sense is a multi-product enterprise rather than a system that provides supplementary income through a forestland tenancy. There is evidence that the concept of agro-forestry as a rational and profitable multiple land use is gaining increased attention in some economically advanced countries (anon. 1978).

The most important limitation of the taungya system is the lack of adequate inputs of land, labour, and capital. An adequate supply of land is particularly critical to traditional taungya confined to forest reserves, because in most tropical countries the chances of further expansion of the land area under reserves are slim indeed. In practice, only parts of the forest estate will be effectively available for taungya. With time the problem of land hunger is bound to surface as the population of taungya-dependent communities expands. Where the physical availability of land for taungya is not limiting, the difficulty of transportation would still proscribe the area that farmers can effectively cultivate.

The problem of shortage of labour for taungya systems in the tropics was mentioned above. The available evidence indicates that more and more farmers are relying on hired wage labour to perform essential farm tasks. On the other hand, many more farmers are unable to afford high cash wages, and therefore spend longer hours in cultivating their food crops. Less time is thus available for planting and tending forest tree crops from which they receive no direct income. Increased capital resources of farmers would enable them to recruit the hired wage labour needed to effectively cultivate an optimum farm size under the taungya system. Loans for this purpose should be granted to the farmers by the forestry departments, which are in a position to ensure repayment at the time of harvesting and sale of the farmers' crop.

Another limitation of the taungya system is management. There is an acute shortage of the funds and trained personnel needed to institute effective management. Necessary information on performance of alternative crop combinations and their impact on the soil is lacking. So foresters may prefer reversion to monoculture, with which they are more familiar, or to natural regeneration. Some recent studies (Kio 1978) have concluded that natural regeneration systems are at least as productive as artificial plantations, and they do not incur the loss of vital ecological benefits.

The limitations of taungya systems in the tropics are more those of operational constraints than those of concept and meaning. With real economic progress, the constraints should gradually disappear so that the practice can be rationalized into a permanent and profitable system of land use.

The socio-economic factors favour the survival and expansion of taungya systems in the tropics, at least up to the end of the present century, provided the practice is backed by adequate government support. As Adeyoju (1980) has stressed: The future of agro-forestry depends not merely on the quantity and value of joint products arising from the enterprise, but largely on the package of sociopolitical strategies built into the programmes.

Establishment of forest villages in Gabon

J. Leroy Deval and Faustin Legault
Directors of Reforestation, Libreville, Gabon


Gabon is a country whose dense forests constitute the main natural resource. The forests are stocked mainly with okoume (Aucoumea klainiana) and, because they have been exploited by industry, the government has established a reforestation programme of natural stands. This paper describes the means used to attain this objective and the results of initial endeavours. The conclusions include recommendations for improving the programme.

Gabon-A Country of Forests

Seventy-five per cent of the area of Gabon is covered by dense, humid, evergreen forest of low and medium altitude, while 15 per cent of the country is savanna. Gabon produces a great deal of wood (particularly okoume, Aucoumea klainiana) and its forests have been subjected to intense exploitation for more than half a century. For many years the government has been working on a reforestation programme in over-exploited forests and an improvement programme for dense natural okoume stands.

The vacant, unclaimed forests of Gabon and the reforestation areas belong to the government and constitute part of its private domain. This is the basic legal status governing the forests but rural communities, which account for 86 per cent of the population, exercise their customary right to use the government-owned forest, a right strictly limited to meeting the personal and community needs of users (collecting firewood and building materials, picking medicinal and edible plants, and so on).

In this way, the forest is a reservoir from which rural people can obtain basic essentials. Various food-producing crops are also raised in these forests. This situation dates back to precolonial times and, unfortunately, has not developed since then. This explains why rural communities have failed to evolve. For obvious financial reasons, the forests are systematically exposed to a well-established exploitation operation, with solid financial backing. The forestry activities of big businesses do not meet the fundamental rural development criteria, namely that the basic structure for any development effort must be the village.

Forestry regulations in effect in Gabon have provided for a forestry permit which allows rural people to acquire a certain amount of forest land, if they meet fairly simple requirements. These provisions have actually favoured the development of some geographically superior areas. The permits apply to what are known as family-cutting areas, which are most sought after in zones rich in okoume located close to transportation routes. This made exploitation inexpensive and required only rural manpower. Over the years, however, these activities, along with demographic pressure and intensified exploitation, have led to forest shrinkage. Favourable zones are now in distant locations and are becoming rare. Nowadays, this type of permit has lost its original character. It has been diverted from the traditional practice and has been used to benefit tenant-farming contracts which, as they become more common, make the lot-owner a "shareholder" in the forest. This runs counter to efforts in Gabon to develop a class of native contractors in rural areas.

Reforestation Centres

The most important activity of reforestation centres is the creation of artificial stocks of okoume. Studies and research on forest ecology and on the biology of this species have made it possible to develop a sophisticated silviculture technique. The artificial regeneration of the stocks of this species no longer poses major problems. Twenty-six thousand hectares of okoume have been planted so far.

The establishment of a reforestation centre always begins with plans for a road network and home construction. Under normal circumstances, each of these centres consists of a staff of between 100 and 400 people. Including families, approximately 1,000 people live in a centre. The staff should be broken down as follows: 70 per cent unskilled workers; 25 per cent technicians (experts); and 5 per cent training personnel.

In an effort to alleviate insufficient food crop yields among elderly villagers and the families of staff (who are mainly seeking self-sufficiency), the reforestation authorities decided to introduce intercropping in the reforestation plots. they had both social and economic objectives in establishing an agro-forestry system. The social objective was to encourage the population to participate in the artificial regeneration of the forest, and thereby to solve the conflicts of interest that often divide forestry specialists and farmers when the latter feel they are being deprived of arable land and are not benefiting from reforestation activities. The economic objective was to increase the quality and value of the plantations.

An agro-forestry solution was thus chosen, aimed at increasing the value of plantations by the incorporation of food crops. There was a choice between two types of crops: the traditional food crops such as cassava, cocoyam, and corn; and the profitable cash crops such as coffee, cocoa, oil palm, and bananas.

For the traditional food crops, experiments were conducted on the Nkoulounga reserve located north-east of Libreville; cocoyam and cassava were planted between rows of okoume, either the same Year as the okoume was planted or the following year. The okoumes were planted 3 x 3 m, 5 x 5 m, and 6 x 6 m apart. An attempt was also made to introduce okoume in a one-year-old cassava plantation where the okoumes were planted 12 x 12 m apart. It soon became apparent that the requirements of the okoumes and the food crops were incompatible. To grow well, okoume needs a lateral screen of young forest undergrowth to protect its bole. Food crops, on the other hand, need rich soil, must be well maintained, and should be kept free of competing vegetation. The work required to maintain the food crops in densely planted areas favoured the development of crowns on the okoume, which finally overshadowed the food crops. In lowdensity plantations (where trees were at a distance of 5 x 5 m or 6 x 6 m apart), the boles of planted trees became exposed over the years-a situation that leads to the growth of suckers and poor form due to the lack of natural pruning.

A good silviculture method for okoume, then, does not permit intercropping. Instead, spaces were set aside in the reforestation zones for food crop production, and cash crops were sought for long-term cultivation. In future, however, an agro-forestry method for okoume may be designed, using traditional food crops, so that people living in reforestation centres and neighbouring villages can grow their own food. Land left fallow will be used by the villagers after the growing cycle. This land will be interplanted with okoume, or prepared for natural regeneration if the presence of seed-bearing trees permits this.

Agro-forestry experiments aimed at cash crops have identified four crops whose essential requirements are known: cocoa, coffee, oil palm, and banana.

The search for practices that would reconcile the silvicultural management of okoume (which is characterized by difficulties in terms of pruning and the shape of the bole, sensitivity to changes in light, and requiring forest undergrowth between the rows of plants) with those of selected cash crops (which require as much light as possible and demand the supression of forest undergrowth during the first growth stage and the elimination of all competing growth during the second stage) is stymied by two technical problems: the distance between the okoume plants and the other crops; and the mode of transplantation for the okoume, given the differences in the natures of the species in question. Experiments were therefore conducted using different planting techniques: arrangement of seed spots, open planting, strip planting, and so on.

The most interesting results were obtained with the GrosMichel variety of banana. The production experiments yielded an average harvest of 10 t/ha during the first cycle, 25 to 30 months after planting. This is not high for a cash crop, but it is enough, given the extensive interplanting with okoume, since the object is to involve the population in agro-forestry activities.


In future, consideration must be given to transforming reforestation centres into rural development centres. Combining agro-forestry activities and wood-processing cottage industries, such centres would make more productive and rational use of the forest, as well as involving the local population economically. They would then be ready to be integrated into the life of the centres. It is also imperative that more thorough professional training be provided on the site for specialists (machine operators, assistant diesel mechanics, drivers, nursery personnel, and so on), for junior staff (supervisors, foremen), and for intermediate-level staff from technical schools who would spend periods on the site to augment their theoretical training.

This is the beginning of a process that will lead to the creation of private forests using plantations created by the villagers through agro-forestry methods. Experience to date shows that the forest cannot play an effective role unless the management objectives envisage real profits for the rural inhabitants. For this reason, development plans should be simple and well adapted to the environment. they should be designed in such a way as to allow the rural people to participate in their implementation and to derive maximum benefit from them.

Small processing industries in the villages will afford villagers access to semi-finished construction materials to improve their homes. A source of employment and income, they could become real centres of activity around which a multitude of related activities could arise.

Taungya in Sierra Leone

Aiah P. Koroma
Forestry Division, Ministry of Agriculture and Forestry, Freetown, Sierra Leone


The paper briefly describes the agriculture and livestock industry, the method of afforestation by the taungya system, and the evolution of silvicutture and agro-forestry in Sierra Leone.

Two factors necessitated the introduction of agro-forestry- namely, the rapid rate of deforestation of unreserved forest lands due to increased agricultural activity, and the reluctance of landowners to set aside any more lands for forest conservation, which did not yield immediate financial returns.

The acute and increasing demand on forest lands is being alleviated by modified forest management and silvicultural techniques, which include various agricultural crops as understoreys in forest plantations. The idea is to conserve the vegetation, minimize soil erosion, and encourage active participation of farmers in the production of both food and wood on the same piece of land.


Sierra Leone has a tropical climate with high temperatures, high humidity, and heavy rainfall. The rainy season extends from May to October, with the heaviest rains falling in July and August. The rainfall decreases from the coast inland, e.g., 3,800 mm in the coastal city of Freetown to 2,100 mm in Kabala in the far north-east.

Topographically, the country can be divided into three main zones: (1) the low-lying, swampy coastal area; (2) the interior plateau (about 450 m in elevation); and (3) the mountain ranges of the north-east with peaks of over 1,800 m.

The total area of Sierra Leone is 72,326 km², and this can be classified into agricultural land (60 per cent), pastures (18 per cent), mangroves and inland swamps (8 per cent), forest (4.25 per cent), and other (9.75 per cent).

Agriculture is the largest sector of the economy, but, in spite of the economic and social measures applied, this sector has the lowest income level. Annual productivity per worker is estimated to be Le 100,* or less than half the average (Le220) for all sectors. This figure compares with Le880 for mining and between Le330 and Le900 for the other sectors. The poor productivity of the agricultural sector indicates the need for more effective approaches and practices. The current farming systems need to be reevaluated and upgraded.

Farming Systems

In the northern half of the country, the long dry season limits production to cattle and annual crops, whereas the south has rainfall and climate suitable for the production of cocoa, coffee, and oil palm, which together form the backbone of agricultural exports. The important food crops grown in Sierra Leone are rice, sorghum, millet, maize, cassava, sweet potatoes, groundnuts, and sesame, with rice being by far the most important. It accounts for more than 75 per cent of the area under food crops and provides employment for more than 80 per cent of the farming population. Yearly production is currently estimated at 800,000 tons.

The total area under upland rice in 1970 was about four times that in swamp rice (236,400 ha compared with 60,800 ha), even though the average yields of the former are generally much lower and are showing a downward trend owing to shorter fallow periods.

Traditionally, upland farming has consisted mainly of the bush fallow or grass fallow system in which a few years of cropping is followed by an interval of fallow-8-12 years in the Eastern Province, 4-6 years in the Northern Province. After the fallow, the natural groundcover is cut and burned. Rice seed is mixed with other upland crops such as maize, guinea corn, millet, sesame, pigeon pea, okra, beans, etc. and is broadcast by the farmers over a series of separate strips. The rice is harvested first. Cassava, the major root crop in the country, is planted as the last crop before the land is fallowed.

Although swamp rice farming has been found to be more profitable than upland crop farming, many farmers are reluctant to adopt it, either because they do not know about swamp rice farming or because they prefer upland farming for the variety of crops it produces.

Coffee, cocoa, and oil palm are the primary agricultural exports; therefore, tree crops constitute an important source of foreign exchange. The total area under oil palm is estimated at about 4.5 million ha in natural stands, varying in density from 15 to 150 trees/ha. Under cocoa, there are about 2,240 ha, confined mostly to the Eastern Province. Other tree crops are cola nuts, cashews, coconuts, and citrus fruits.

The growing of tobacco started not so long ago. In 1961 there were 24 tobacco farmers and by 1971, more than 15,000. Cultivation, which was originally confined to the Northern Province, has recently been introduced into the Southern Province.

The livestock industry is centred on cattle. The cattle population is concentrated mainly in the northern part of the country, which comprises vast tracts of natural savanna pastures interwoven with gentle slopes. The mild climate and sparse population increase the potential production. The cattle are N'dama, their estimated numbers being between 250,000 and 300,000. Nomadism is a basic social and economic problem, and settlement schemes by the Livestock Division have been unsuccessful.

The estimated population of smaller livestock in the country for the year 1975 was 62,000 sheep and 175,000 goats. They are spread throughout the country, but the largest flocks are kept by cattle owners of the Northern Province.

Agro-forestry: From Modest Beginnings

During the mid-1940s the native administrations became interested in forestry and began to plant timber-producing trees, often on roadside strips not more than 170 m wide. This effort led to the examination of the afforestation techniques and the search for ways to reduce the costs of clearing the bush fallow for the trees and reduce the long waiting period from the time the plantation was established to the time it began to yield revenue.

Taungya was considered as a means of reducing time and costs involved in establishing the forest. The first real attempt to establish forest plantations by the taungya system was made in the late 1930s, using 50 per cent indigenous species and 50 per cent of the exotics, Gmelina arborea, Tectona grandis, and Cassia siamea. It was observed that the 50 per cent indigenous and 50 per cent exotic species mixture was not a useful proposition, as the exotics grew faster and the indigenous species lagged behind.

Subsequently, underplanting the established Gmelina stands with local species was tried. The aim was that if any of the more valuable indigenous species showed signs of succeeding, thinning in their favour would be resorted to later. In general this was a reaffirmation of the policy of preferring indigenous species to exotics. But Gmelina, being a fast-growing species, eventually swamped all the indigenous species.

In the early years of the system, there was one notable effort to reduce the time between plantation establishment and plantation exploitation through the introduction of an understorey of cocoa. Demonstration and observation plots were established under various light conditions. The plots were successful, and afforestation along these lines was gradually extended as the local administration nurseries produced more planting stock. The cocoa, which replaced part of the natural understorey, yielded quick monetary returns as minor forest produce. Unfortunately, as a result of staff changes and the difficulty of growing cocoa in unsuitable soils, these experiments were neglected and eventually discontinued.

The taungya system, however, is still in operation and is based on co-operative efforts between the government and farmers. Each year planting areas are demarcated in December or January and invitations issued through the Paramount Chiefs to the farmers who formerly owned the land. It is the original landowners who have the first rights to farm the land in exchange for clearing the bush fallow and following the planting guidelines set out by the government. Only the original landowner can reject the offer to farm, and pass on the rights to someone else.

After the bush is felled, the cut vegetation is allowed to dry and is then burned about March-April. The forestry department lists crops that are allowed to be cultivated and lays down other requirements. In June-July, the young forest trees are planted by the forestry staff, and this is done after the farmer has planted his own crops.

Spacing for the forest trees varies according to site and species to be employed. The general trend is toward wide spacing, e.g., 2.5 x 2.5 m, 3 x 3 m, and 4.5 x 4.5 m for Gmelina arborea, Terminalia ivorensis, T. superba, Cordia a/liodora, and Nauclea diderrichli.

The principal agricultural crop used in taungya is rice, but farmers are allowed to sow maize, guinea corn, peas, sorghum, cassava, and okra. During this time, the farmers tend the young trees in addition to their agricultural crops.

After the second, and sometimes the third, year the farmer is allotted another plot. In most cases where there is no land hunger and in remote areas where the forestry department is obliged to carry out rapid afforestation, the farmers are the forestry employees. Forest villages are built for them, and all the agricultural crops they cultivate belong to them.

The idea of simultaneous production of timber and agricultural crops on the same piece of land was revived as a result of certain developments in the country during the implementation of the first five-year national development plan. These developments included the rapidly diminishing unreserved high forest as a result of the rising population, the return to the land of people previously engaged in mining, and the government emphasis on increasing food and cash crop production to conserve and obtain much-needed foreign exchange.

Most land in the country is held communally with individual right of usufruct: there is no formal tenure except on the Freetown Peninsula, i.e., the old colony area. Also, there was a growing feeling in the country that landowners who had given up land for forest reserves and protected forests generally did not receive adequate or immediate compensation. Thus, it became extremely difficult for the government to obtain additional land for forest plantations or even to retain the existing forest estate.

The forestry department, therefore, began in 1976 to introduce cocoa, coffee, and cola, as understoreys in Terminalia ivorensis and T. superba plantations. Initial experiments at Kasewe Forest Reserve in the late 1950s had proved satisfactory, and the indications are that coffee will soon become the main understorey in extensive areas of wide espacement plantations in forest reserves and the lineplanted areas in native administration forests.

These perennial crops are being introduced as understoreys at spacings of 7.5 x 7.5 m, 9 x 9 m, and 10.8 x 10.8 m such that the final crop will be 178,121, and 85 stems/ha respectively when the plantations are between 12 and 15 years old. It is hoped that when the agricultural crops have outlived their usefulness (about age 30), the whole area will be clear felled and replanted by the taungya system. Maintenance from the time the agricultural crops are planted will be carried out by the farmer (the original landowner or holder), to whom the plantation would be leased on payment of an annual rent to be mutually agreed upon. Cassava and sweet potatoes have also been recently introduced in nearly mature T. ivorensis, T. superba, C. alliodora, and G. arborea plantations. No measurements of yield have so far been made.

Taungya practices in Togo

O. Nadjombe
Directeur General de l'Office de Developpement et d'Exploitation des Forêts (ODEF), Lomé, Togo


This report briefly describes the development, brought about by demographic pressure, of agro-forestry practices in Togo. The first part describes the balance that existed between traditional land-use methods and the land's capacity for natural regeneration at a time when population density was still low. With population growth and the need for increased agricultural production, this balance was upset, the forest ecosystems were destroyed, and the traditional farming methods were made obsolete. The second part describes the taungya system, as it was introduced for the first time in Togo in 1954, and its development up to the present

Togo has approximately 4,794 km² of dense, semi-deciduous forests, generally divided into clumps of fewer than 5,000 hectares, for the most part heavily planted with coffee and cocoa. Present agro-forestry practices are closely linked to the traditional land-use system.


Traditional land use derived from the tribal organization of the population, and is characterized by the occupation of independent pieces of land by communities made up of descendants of a common ancestor. The basic principle underlying traditional land tenure was collective ownership, whereby land did not belong to anyone in particular; all land within the territorial boundaries of a tribe was regarded as a unit, at the disposal of all members of the tribe. The traditional land-tenure system was perfectly suited to the extensive shifting cultivation that was, and still is, practiced by the populations concerned.

Shifting cultivation has gradually claimed vast areas from forests through indiscriminate clearing practices. Forests have been progressively and unavoidably destroyed in direct proportion to the increase in population density.

As the tribal forest reserves diminished, the natural capacity for regeneration of the "grassed" lands was also endangered by bush fires. Only a few species of grass vital to the life of the rural people were preserved and cultivated. Human activities had a remarkable effect on the landscape, with Butyrospermum parkii (or Vitellaria paradox&l, Parkia big/obosa, and Adansonia digitata stands being maintained because of their importance to the life of the local communities while many other species of trees practically disappeared.

Agro-forestry, defined here as the combination of trees and agriculture to obtain ligneous products, does not exist as a farming system in Togo. Nevertheless, in the south-west of the country, coffee and cocoa are cultivated among tall shade trees to the extent that at present all the woodlands of this region have been replaced by coffee and cocoa plantations.

Taungya System

Aware that the forests in the vicinity of rural settlements were in serious danger of extinction, the forestry department decided to introduce taungya. As early as 1954, farming in forests was authorized in some areas of the country on condition that the farmers would not only plant food crops but would also cultivate teak, a forest species that was introduced during German colonization and is well adapted to conditions in Togo.

At first, the farmers were allowed to select their own site and desired acreage in a forest reserve, according to their own criteria and abilities. Using traditional methods, they prepared the ground and planted and nurtured the seedlings supplied by the forestry department, which, in principle, supervised all operations. The food crop harvests belonged entirely to the farmers, who were authorized to open up new plots according to their needs. When the cover of the teak plants began to hamper the development of food crops, the forestry department resumed responsibility for the care of trees. The farmers were also allowed to choose the food crops they wanted to grow, according to practical experience. Only perennial crops, such as oil palms, citrus fruits, coffee, and cocoa, were forbidden. Later, following an evaluation of the results by the forestry department, some changes were made to the formula.

As early as 1958, farmers were compelled to cultivate plots in a continuous block rather than interspersing them throughout the forest. This regulation derived from the difficulties associated with managing small heterogeneous plots that were spread throughout the forest and that included seedlings of many different ages.

With regard to the kind of crops to be grown, it was recommended that only corn, yams, and beans be cultivated together with teak. This recommendation was based not on scientific evidence but rather on observations of poor teak growth in combination with other crops such as cassava, cotton, and sorghum.

In spite of the generous concessions by the forestry department in allowing food crops to be grown in reserved forests, the hostility of traditional farmers towards the principle of reserving forests intensified and resulted in a massive and uncontrollable invasion of the forests by the traditional custodians, who went as far as planting forbidden crops- oil palm, coffee, cocoa, etc. This situation led the forest service, in the early days of the country's independence, to suspend the taungya system in order to protect the reserved forests. The hostility shown by the population towards the taungya programme stemmed from discontent with the principle of systematically setting aside forest reserves. The farmers felt the reserves were unjustified because no development was carried out in them.

With FAO (Food and Agriculture Organization) assistance, the Office de Developpement et d'Exploitation des Forêts (Forest Development and Exploitation Authority: ODEF)

  • a government organization set up in 1971 to stimulate reforestation activities-reintroduced the taungya on its sites in 1972, adding new elements such as incentives in the form of bonuses in cash and in kind. The cash bonus was fixed at 6,000 fr CFA (in 1981, 400 fr CFA = US$1 ) and there were supplies worth 23,000 fr CFA for the first year of the contract. These incentives made it possible to plant more than 1,200 ha of Terminalia superba before the system encountered two difficulties that led once more to its abandonment:
  • The Terminalia superba plantations were established in dense, semi-deciduous woodlands that are much sought after by farmers, who clear them for food crop production. The new taungya system allowed the planting of corn, which in Togo is generally grown on forest clearings and is not the leading rotation crop. Because the ODEF was unwilling to allow rotation of crops under the taungya system, farmers felt it was pointless to continue with the system, as grasslands were readily available all around the forest reserves; and
  • T. superba and teak plantations were usually handed over to the forestry department after two years of cultivation by farmers. Since these plantations were far from human settlements, there was inadequate labour for maintenance and reforestation activities. A great many of the plantations were thus left in a deplorable state.

Given that the taungya system faced virtually insurmountable difficulties at the sociological and technical levels, a new formula had to be found. Thus, under state supervision, a semi-mechanized eucalyptus reforestation site was established near a major urban centre capable of supplying needed labour. Both food and tree crops were to be cultivated as before but the state would reap the benefits of all harvests and would pay labourers a wage (often described as "departmental taungya"). This formula was expected to solve some of the problems of the taungya system for T. superba plantations.

For the first time in Togo, the theory of maximum gross yield from land under agro-forestry was advanced. Although this theory is inherent in the taungya system, the basic difference is that in conventional taungya the aim is to get maximum food and timber production, regardless of cost (with the main cost being the farmer's labour), whereas in the new statesupervised version, the production cost must be taken into consideration. Experiments have been conducted and will continue, stressing both improvement of yields and appropriate technology (e.g., food-crop density in forest plantations).

At present, the cost of food crop production under state supervision and within the framework of agro-forestry exceeds acceptable limits. This situation is not peculiar to agro-forestry but applies also to the traditional system of agriculture, which is based on obtaining staple foods through the investment of minimum human effort.

Besides efforts to alleviate both timber and food shortages through the taungya system, the state is also supporting an experimental programme in north Togo to shorten fallow periods. In this part of the country, where the population density (40 people/km² ) makes it impossible to observe the traditional fallow period of 25 years, techniques that accelerate the natural regeneration of soils are essential because farmers are financially unable to maintain fertility through the use of chemical fertilizers.

Development trends in Taungya systems in the moist lowland forest of Nigeria between 1975 and 1980

J.B. Ball and L.l. Umeh
Federal Department of Forestry, Ibadan, Nigeria


This paper investigates trends in the development of two taungya systems in southern Nigeria between 1975 and 1979-1980. The two systems are traditional taungya, where the farmer retains the proceeds of the food crops raised during the establishment phase of the forest plantation, and departmental taungya, where employees raise the food crops and the forest authority retains the proceeds The area of land devoted to traditional taungya has declined very slightly, but there has been a large decline in the number of farmers participating. The reasons for this are not clear. The area of departmental taungya has declined considerably for administrative and financial reasons. The system is likely, however, to expand in at least two states from 1981. The economics of the two systems became much more favourable between 1975 and 1980 because of increases in forest fees and volume yields as well as agricultural prices. There are also large potential reductions in costs, despite increases in wages. It is recommended that monitoring of the taungya systems continue but that socio economic studies be included in the future.


One of the most challenging problems of modem times is the production of sufficient food and forest resources to sustain the ever-increasing world population. The problem would be greatly simplified if one type of land use would expand without impinging upon the land needed for other purposes. Unfortunately, the fixed nature of the world's land resource base makes the realization of this ideal impossible. Accordingly, each new upward spiral in the demand for land may be expected to contribute further to competition and possible conflicts between existing land uses. In Nigeria, this competition for land is increasing because of population upsurge, industrialization, urbanization, and farming. According to Allen (1981), farmland covers nearly 35.9 million ha or 39.5 per cent of the total area of the country. Only 0.3 per cent of the farmland area consists of plantations and agricultural projects. Most of the land has been impoverished by shifting cultivation and has a low productivity. A system of management that would accommodate the production of different natural commodities on the same piece of land becomes most desirable.

It is in this light that taungya, a healthy marriage between agriculture and forestry, is considered a dynamic tool of resource management. It was first introduced to Nigeria in Sapoba, Bendel State, some 54 years ago, but quantitative data were not generally available until recently. The information that had been produced was brought together in 1975-1976 by Ball (1977), and the present paper is an attempt to update that review and to detect trends in the development of taungya in Nigeria.

Taungya Systems

There are basically two types of taungya systems, called, in this paper, the traditional and departmental systems. The traditional taungya system is the earlier and more widely practiced of the two in the tropics. It is widely practiced in Nigeria. Under it, local farmers are recruited by the forestry department to undertake arable farming in allocated areas within a forest reserve. The size of the farm ranges from 0.4 to 2.87 ha, depending on the total land the department plants in the season as well as the size of the farmer's family.

Each Year the farms are demarcated and allocated between November and December. The farmer clears the bush, burns the slash, and generally prepares the site between January and March the following Year. There is little or no cost to the forestry department. Under certain conditions, the forestry department cuts down the big trees in the reserve before the farmers move in. Onyeagocha (1966) stated that farmers in the Emo River Forest Reserve were reluctant to accept farming of areas stocked with large trees. Even when they accepted it, they took a long time to prepare the sites, and the forestry programme consequently ran late. To avert this situation, all remaining trees are usually poisoned after exploitation for timber but before agrisilvicultural operations start. After site preparation the farmers plant crops according to specifications laid down by the forest department. Soon after, the forestry department interplants forest tree seedlings with the farm crops using paid labour. In the first year the farmers tend the food crops as well as the forest trees. Between July and October in the first year the farmers harvest most of their crops. They store enough for their families and for planting the next season and any surplus is sold. In October they may plant a second crop such as maize, which they harvest in December or early January of the second year; however, the forestry department may by then have taken over the tending of the tree crops. The farmers sometimes continue raising crops for two to three years, after which they are allocated another plot in a new area. Farmers who have not tended the tree crops well are not given new allocations.

Departmental taungya was introduced in the Cross River State of Nigeria in 1971. The scheme is operated by forest labourers who may have no previous experience in farming. It differs from traditional taungya in that:

  • The farmers are paid wages and do not own the farm crops harvested;
  • There is no allocation of fixed plots to individual farmers. Instead, the farmers are allocated to different phases of the programme such as nurseries, site prepara tion, planting, harvesting, processing, and sale of crops; and
  • Employment of farmers is not based on family units but on individuals. Thus, it is possible for each member of a household to work as a paid employee in the same taungya establishment.

The State of Taungya in Nigeria

The total area of traditional taungya farms in Nigeria in 1979 was 9,226 ha; this is a decrease of about 3.6 per cent since 1975 (table 1). Only two states, Oyo and Ondo, increased their area, whereas taungya in Cross River, Imo, Kwara, and Ogun states declined. Most states could not increase their acreage because of lack of funds and a reduced number of farmers participating in the practice Anambra State does not practice taungya officially, but forest workers still intercrop food crops with trees. There are no data from Anambra state on this.

Only Cross River and Ogun States still carry on departmental taungya, and there was a sharp decline in the area cultivated in 1979 compared to 1975. Ondo State stopped the practice because revenue realized on food crops usually went to the agricultural division of the ministry. The state's Pulpwood Afforestation Project has reactivated the practice and about 250 ha of early maize, cowpeas, and late maize will be planted in 1981. Anambra State is also planning to reactivate departmental taungya in the 1981 planting season.

In 1975, more than 70 per cent of the plantations in the moist lowland forest zone were established under one of the taungya systems. No reliable data are available for 1979, but the proportion is believed to be approximately the same. Some states have been allowing farmers to cultivate their taungya farms but have not been able to plant the trees because of lack of funds. This development can lead to overrecording of the plantation area, and it could result in the forest authority's losing control of all or part of the forest reserves.

In 1975, there were 24,427 traditional taungya farmers in the southern states of Nigeria. It was estimated that 19,500 people had casual employment for six to ten weeks of the year in traditional taungya farms, but no reliable figure could be obtained of the numbers in one family who worked on the taungya farms.

TABLE 1. Area of Taungya Farming in Southern Nigeria in 1975 and 1979


Area (ha)




  1975 1979 1975 1979  
Anambra 858 - 153 - No licensees after 1975. Unrecorded intercropping by forest labourers.
Bendel 4,606 4,596      
Benue - 220 - -  
Cross River 818 770 992 385  
Imo 494 25 121    
Kwara 621 98 - - No taungya since 1978 because of lack of forests.
Ogun 704 460 61 20  
Ondo 1,264 3,000 121 - Stopped because produce goes to agricultural division;will be reactivated in 1981.
Oyo 202 55 - -  
Totals 9,567 9,224 1,448 405  

TABLE 2. Number of Farmers and Area of Traditional Taungya in Southern Nigeria in 1975 and 1979


No. of farmers

Average area allotted (ha)

1975 1979 1975 1979
Anambra 2,120 - 0.40 -
Bendel 11,376 12,000 0.40 0.40
Benue 180 220 1.00 1.00
Cross River 3,580 1,021 0.23 2.00
Imo 1,220 121 0.40 0.26
Kwara 1,202 177 0.52 2.87
Ogun 807 1,150 0.87 0.40
Ondo 3,122 3,000 0.40 0.26
Oyo 1,000 55 0.20 1.00
Total 24,607 17,744    
Weighted average     0.39 0.50

In 1979, however, the number of taungya farmers had fallen to 17,744 (table 2), despite the facts that the area of traditional taungya remained nearly the same and that in some states taungya farms were not planted with trees. This decline may reflect the continuing lack of recruits to traditional taungya farming (Olawoye 1975; Ball 1977). Another factor affecting employment in taungya farming has been the recent introduction of universal primary education; there may be fewer young family members available, resulting in an increase in casual employment during land preparation, mounding, and harvesting.

In 1975-1976 1,221 jobs were created in departmental taungya, either in growing or in processing the food crops. No reliable estimate is now available, but the figure has been considerably reduced because the area has fallen considerably (from 1,448 ha to 405 ha) and because none of the cassava crop is processed into gari. It is anticipated that departmental taungya will increase in Ondo and Ogun states from 1981 onwards.

In Nigeria the agricultural crops cultivated in traditional taungya farms are many and varied (table 3); they are chosen because of the dietary habits of the farmers' families or the available markets rather than because of their interaction with the tree crop.

Yams, maize, and vegetables, which make the greatest demands on soil fertility, are grown first, followed by cassava. A second crop of maize may be grown, but it is low-yielding and is generally used for seed the following year.

In departmental taungya the only two crops grown are maize and cassava. In Cross River State, in rare cases, two crops of maize are grown, the second being for seed. A new development is that the Ondo Afforestation Project will introduce cowpeas in 1981.

In the past, it was forbidden to grow certain crops, such as cocoa, rubber, plantains, etc., because they were permanent or semi-permanent crops that competed with the forest crop and could lead to alienation of the forest reserve if they grew long enough. Crops such as rice or guinea corn were banned because they are aggressive root competitors, and tobacco was banned probably because of root eel worm. Spreading cassava was also banned, and in Bendel State, where taungya started some 40 years ago, all cassava was forbidden. These rules have now been considerably relaxed. Plantains may be grown in Ogun, Ondo, and Oyo states as boundary markers and in Bendel State throughout the plot. Rice and guinea corn are raised in Bendel, Kwara, and eastern states.

The tree crops planted in Nigeria are Gmelina arborea, teak (Tectona grandis), opepe (Nauclea diderrichii), and white afara ( Terminalia ivorensis) (table 4) .

Generally the licensees are responsible for tending the tree crop from after planting until they harvest the final food crop, which is usually cassava. In Bendel State, however, the forestry department staff do the lining out and pegging while the licensees plant the trees. This practice can lead to problems, as poor planting and lack of weeding have been noted at several centres in other states and in some places there has been deliberate damage to trees.

TABLE 3. Crops Grown in Private Taungya in Southern Nigeria in 1975

State Crops (in decreasing order by area)
Anambra Yams, cassava, maize, rice
Bendal Yams, maize, cassava, rice, plantains, vegetables, cocoyams, beans
Cross River Cassava, maize, yams, cocoyams, plantains, vegetables, guinea corn, groundnuts
Imo Yams, cassava, maize, rice
Kwara Yams, maize, cassava, rice, vegetables, guinea corn
Ogun Cassava, yams, maize, vegetables, rice
Ondo Yams, cassava, maize, plantains, vegetables
Oyo Maize, yams, vegetables, cassava

TABLE 4. Tree Species Planted in Taungya Farms in Some States of Southern Nigeria in 1975

State Tree species (in decreasing order of importance)
Anambra Gmelina arborea, teak ( Tectona grandis)
Bendel G. arborea, teak, opepe, white afara (Terminalia superba)
Cross River G. arborea
Imo G. arborea, teak, white afara, opepe
Kwara G. arborea, white afara, teak
Ogun G. arborea, teak, opepe
Ondo Teak, G. arborea, white afara, opepe
Oyo G. arborea

Economic Trends

There have been several changes in the factors affecting the economic and financial returns of taungya since the last review. Those considered here are:

  • The recent general increase in the minimum wage: the rate now used is 5 naira,* or double the previous daily pay;
  • The collection of more reliable data by the Inventory Unit of the Federal Department of Forestry; this has resulted in an increase in the average annual yield figure for G. arborea plantations in the moist lowland high forest zone of 25 per cent, to 25 m³/ha; the Federal Department of Forestry; this has resulted in an increase in the average annual yield figure for G. arborea plantations in the moist lowland high forest zone of 25 per cent, to 25 m³ /ha;
  • The general increase in forest fees, either enacted already (for saw logs) or proposed (for pulpwood), as well as a general increase in producer prices for agricultural produce; and - The demonstration of the benefits of both incentives and better nutrition in terms of increasing output.

These changes have been used to recalculate net discounted revenue (NDR) in the basic models for G. arborea and teak that were used before (Ball 1977). The reason that NDR is used as a basis for comparison and not economic rate of return (ERR) is that ERR in some cases gives such a high figure as to be misleading. The interest rate used for the NDR calculation was 8 per cent. The systems considered are traditional taungya, departmental taungya, and direct planting (i.e., no taungya). With the current higher benefits and lower costs an increase has occurred in NDR (table 5).

ERR, calculated for direct planting for the two species, increased for G. arborea from 5.8 per cent in 1975 to 18.0 per cent in 1980; corresponding figures for teak were 4.0 per cent and 6.6 per cent. The comparison of ERR shows that the rate of return has increased considerably with G. arborea, due to both the lower costs and the higher returns used. With teak the returns have increased slightly, due mainly to the lower costs.

Departmental taungya has continued to show for both species the best returns, followed as before by traditional taungya and direct planting. It must be stressed that these increases are true only for the figures used in this calculation, and organizations considering taungya options should collect data relevant to their locale.

For G. arborea in traditional taungya and direct planting systems, the NDR appears to be more sensitive to increases in revenue than to reductions in costs, whereas in departmental taungya reduction in costs and increases in forest fees had an equal effect. Because of high costs early in the rotation for both departmental taungya and direct planting, the NDR for teak in them appears to be more sensitive to reductions in costs than in traditional taungya. With traditional taungya, it appears equally sensitive to decreases in costs and increases in revenue (table 6).

TABLE 5. Comparison of NDR (Net Discounted Revenue) for Gmelina arborea and Teak with Different Systems of Establishment (in naira/ha)


G. arborea

Teak ( Tectona grandis)

Traditiona taungya Departmental taungya Direct planting Traditional Departmental Direct planting
1975 195 387 - 113 - 163 - 109 - 479
1980 1,942 2,489 1,639 8 464 182

TABLE 6. NDR for Teak and Gmelina arborea in Traditional Taungya, Departmental Taungya, and

System Species Direct Planting Change in basis NDR (in naira/ha) due to Sensitive to:
25%cost reduction 25% forest fee increase
Traditional G. arborea 178 506 Fees
  Teak 90 95 Both
Departmental G. arborea 423 506 Both
  Teak 292 96 Costs
Direct G. arborea 221 506 Fees
  Teak 138 17 Costs

Although in the 1980 calculations lower cost figures were used for the inputs, there may still be opportunities for further reducing unit costs, possibly by incentive schemes or by some degree of mechanization. Two types of incentive are considered: one is to provide forest workers with subsidized food from departmental taungya and the other is to provide them with some assistance in land clearing, crop processing, and crop storage. In the first case, a 25 per cent reduction in costs is assumed, as well as a 25 per cent reduction in agricultural produce revenue. In the second case, an increase of N290/ha is divided between the costs in years 0-2 inclusive (table 7).

These incentives are believed to be very generous, so that the NDR for G. arborea is reduced to just below that for direct planting. With departmental taungya, the 25 per cent reduction in agricultural revenues, representing subsidized food for the workers, would have virtually no effect on the NDR for both species, provided there was also a reduction in costs of 25 per cent.

However, it is not reasonable to expect these reduced costs to be achieved immediately. With the introduction of new techniques and incentive schemes, a period of worker and supervisor training will be needed. While this is happening costs will be higher than the basic model, and alternatives were therefore considered with a cost increase of 50 per cent. Another calculation assumed that most of the costs of the basic model were incurred quickly but that the land preparation costs were N500/ha rather N162/ha. This increase may arise because of the need to have the job done on contract or with high mechanization (table 8).

Departmental taungya remains a useful method of increasing the returns from teak, but because it is done twice with the G. arborea model the returns are below traditional taungya. If the cost of clearing in the basic model is too optimistic then the effect on returns from G. arborea will not be too great. Introducing wages for direct supervision also does not reduce the returns greatly.

There are also proposals for increases in forest fees; alternalively, the yields used may be conservative in some cases. If a 25 per cent increase in returns from the forest crop is assumed, the direct planting system with teak shows little increase in NDR because of the long rotation. The other alternatives however, all show significant gains.

TABLE 7. The Effects on NDR of Incentive Schemes for Traditional and Departmental Taungya (in naira/ha)


G. arborea


  Trad. Dept. Trad. Dept.
Basic model 1,942 2,489 8 464
Reduction of agricultural revenues and all costs by 25 per cent - 2,445 - 441
Incentives to farmers of N290/ha spread over years 0-2 1,590 - - -

TABLE 8. Effect on NDR of Cost Increases (naira/ha)


G. arborea


  Trad. Dept. Direct Trad. Dept. Direct
Basic model 1,942 2,489 1,639 8 464 - 182
50 per cent increase in costs 1,643 1,528 1,188 -281 - 131 - 471
*500 land preparation - 2,151 1,301      

The net establishment costs (years 0-2 for G. arborea and 05 for teak) indicated that departmental taungya shows a net benefit because of the assumed high revenue from gari; the maize crop is grown at a loss (table 9).

A comparison of the figures for traditional and departmental taungya with the cost of direct planting indicates net financial benefits to the forest authority. Traditional taungya with G. arborea nets N287/ha and with teak, N212/ha; whereas departmental taungya with G. arborea nets N750/ha and with teak, N750/ha.


There continues to be a demand for land for traditional taungya. The desire to farm on forest land is not necessarily caused by a shortage of agricultural land but rather the inherent fertility of the forest land. Agrisilviculture has not succeeded where there is fertile agricultural land.

The area of traditional taungya farms in Nigeria declined very slightly between 1975 and 1979. The area of departmental taungya fell considerably, due to administrative problems and difficulties of funding. It is expected that departmental taungya will expand from 1981, in Ondo and Ogun states in particular.

The number of traditional taungya farmers has fallen, whereas the average area they cultivate has increased. The reasons for this change are not clear. It might be expected that traditional taungya farmers cannot farm a larger area because they are predominantly older than 45 years (Olawoye 1975), and they may not be able to draw on many family members because of the spread of full-time education. They may, however, be employing more casual labour, or the standards of maintenance may have fallen. No information is yet available on this.

Problems with transport from villages to farm areas continue and may increase since the sites for new plantations are becoming further away.

Farmers are still reluctant to fell large trees or to pay for it to be done. Some forest services are poisoning these trees, but others are reluctant to do so because of possible harmful side-effects.

Problems of discipline and control continue. Few states issue licences or charge a fee (which could be refundable).

Incentives could be introduced for traditional taungya farmers. One possibility is to assist them to add value through processing and storage of their crops. To do so would be to reduce the benefits of traditional taungya, but these are sufficiently high to bear such a reduction.

TABLE 9. Establishment Costs and Benefits of Plantations

Species System Cost (naira/ha) Benefit (naira/ha) Net Cost (Benefit) (naira/ha)
Gmelina arborea Traditional 369 0 369
(years 0-2) Departmental 1,361 1,455 (94)
  Direct 656 0 656
Teak Traditional 315 0 315
(years 0-5) Departmental 1,232 1,455 (223)
  Direct 527 0 527

A cash bonus might even be introduced for tree crops that have been successfully established. Subsidized food could be provided from departmental taungya at little loss of return provided there is an increase in productivity.

Agricultural yields from departmental taungya continue to be low, but the appointment of agricultural officers to schemes in two states should improve the situation and demonstrate to other forest services the value of such personnel. These projects may also be a source of data on the agricultural component.

An analysis of economic trends shows that large changes occurred in economic and financial returns between 1975 and 1980. The reasons for these are increased prices for agricultural crops, increased timber fees, increased forest yields, and (potentially) reduced costs, despite large increases in wages. The calculation of net discounted revenue for various alternatives shows that:

  • There has been a large increase in returns since 1975;
  • Departmental taungya is still more profitable than traditional taungya or direct planting;
  • The return from long rotation crops such as teak is especially sensitive to cost increases or reductions. If such species are to be profitable then a taungya system is necessary, whereas species such as G. arborea are still profitable even if the taungya system is not used.
  • Increases in the revenue from the forest crop improve the returns of both taungya systems with short- and longrotation species but do not greatly benefit long-rotation species grown without taungya; and
  • The net financial benefits to the forest authority of using taungya systems are considerable, particularly with long-rotation species.

The need to continue monitoring trends in taungya systems has been demonstrated by the large changes that are reported in this paper, even over so short a period as four to five years. The economic figures presented here are, however, indicative only, and calculations should be done with reliable local figures for individual projects.

Socio-economic studies are needed on benefits accruing to the farmers, the forestry employees, and the nation.

Food crop yield under gmelina plantations in southern Nigeria

O. O. Agbede and G. O. A. Ojo
Forestry Research Institute of Nigeria, Ibadan, Nigeria


Experimental taungya plots were established at six different locations in southern Nigeria to investigate the productivity and competitive relations of intercropping agricultural crops (yams, maize, and cassava) with trees (Gmelina arborea). Experiments were set up in 1978 and 1979 at Gambari, Ore, Sapoba, Ukpom-Bende, Ikom, and Awi-Calabar. With the exception of Gambari, the locations are in the tropical rainforest zone of Nigeria. Results of the experiments showed that cassava depresses Gmelina arborea, especially when planted at close intervals. This effect tends to diminish at age 12 months, when the trees usually attain canopy closure. Trees under yams and maize tend to perform better than those planted a/one or with cassava.

Varying the space between Gmelina arborea plants markedly influenced the trees, while the different spacings of agricultural crops had no effect Likewise for crops, the space between trees was not important but the spacing between crops was significant. Yams planted at 1.5x 1.5 m were found to be the most profitable.


A recent trend in Nigeria is towards the production of sufficient pulpwood, fuel, poles, and timber. Hence, state forestry services have set up annual planting targets of 20,000 and 6,000 ha for Gmelina arborea and teak, respectively. Similarly, the recent food crisis in Nigeria has become a major concern in official circles. In 1977, the value of Nigerian food imports was approximately N270 million (Enabor 1978). Adequate food supply for the increasing Nigerian population demands the harnessing of both the productivity of Nigerian agriculture and the contribution of forestry through the management of forest lands for the simultaneous production of wood and food.

Taungya is a form of agrisilviculture, or farm forestry, whereby food crops are interplanted with tree crops at the time of establishment (or regeneration) of the tree crop, and in which the forestry agency collaborates with peasant farmers (King 1968). The farmers are responsible for clearing, burning, and packing operations within their allocated plots. The Forestry Department may assist with the felling of large trees. In return for their labour, farmers are per misted to grow food crops until the tree crop canopy closes, which is generally for one to three years, depending on the species planted and the spacing. Gmelina arborea, for example, which produces pulpwood in 10 years and timber in 20 years, closes its canopy within 12 to 15 months when planted at 2.5 x 2.5 m. Taungya is a land management system used extensively by state forestry services to reduce the cost of plantation establishment and maintenance.

Usually, peasant farmers involved in taungya are allowed to cultivate the food crops of their choice, with some control as to how and when to plant the crops, especially in the case of plantains and cassava. The crops commonly raised are yams, maize, cassava, and rice, usually intermixed with melon, okra, pepper, tomatoes, beans, and other vegetables. In Cross River State, where the forestry staff are directly involved in food crop production, greater attention is paid to maize and cassava than to labour-intensive crops such as yams. The Forestry Research Institute of Nigeria is currently growing yams, maize, and cassava in its taungya farms at six research locations in southern Nigeria.

The taungya farms established by the Forestry Research Institute of Nigeria are located at Gambari (Oyo State), Ore (Ondo State), Sapoba (Bender State), Enugu-Ngwo (Anambra State), Ukpom-Bende (Imo State), and Ikom and Awi (Cross River State). Since the participation of local farmers has resulted in variations in and damage to the tree crop during the agricultural cropping, the work is now undertaken by the Institute staff. In this way they can ensure that the crops are spaced, treated, and harvested according to plan, and thereby validate the results. Both land preparation (clearing, felling, burning, and packing) and cultivation for arable cropping, especially yams, are carried out by the staff of the Institute. The harvesting and marketing of the food crops are also undertaken by the Institute.

The purpose of this study was to determine quantitatively the yields of food and tree crops and their competitive relations under taungya in selected locations in Nigeria.

Materials and Methods

Experimental taungya farms were established at six different locations in southern Nigeria where taungya is widely practiced. With the exception of Gambari, the locations are in the tropical rainforest zone of Nigeria.

In 1978, 0.80 ha of Gmelina arborea was established in combination with three agricultural crops-yams, maize, and cassava. These crops were selected because they are the most widely grown crops in all the states where the experiments were located. Other important arable crops such as rice, cocoyams, plantains, and vegetables, and tree crops such as Tectona grandis, Nauclea spp., and Terminalia spp., are proposed for future experimental work. For 1978, each experimental farm was divided into five blocks, of four plots each. Each plot was 20 x 20 m and contained 64 trees at 2.5 x 2.5 m. A randomized complete block design was used. The treatments and the control were Gmelina arborea (control), Gmelina arborea + yam, Gmelina arborea + maize, and Gmelina arborea + cassava. Yam (Dioscorea rotundata), Nigerian selection no. 1 maize, and a local cassava variety were grown on all the sites. All the arable crops were planted at 1.2 x 1.2 m. Maize and yams were planted during MarchApril, whereas cassava and stumps of Gmelina arborea were planted in June-July of the same year.

In 1979, separate areas were used for each arable crop (yam, maize, cassava), and G. arborea was used as the tree crop. The experiment was to study the interaction of both agricultural and tree crops when interplanted at different densities. The design was a 4 x 4 x 3 factorial, i.e., three planting distances plus a control for Gmelina arborea and each agricultural crop. G. arborea was planted at spacings of 2.0 x 2.0 m, 2.4 x 2.4 m, and 3.0 x 3.0 m, while yam, maize, and cassava were planted at spacings of 1.0 x 1.0 m, 1.5 x 1.5 m, and 2.0 x 2.0 m. There were 16 treatment combinations replicated three times for each arable crop. The experimental area for each arable crop was 50 x 160 m divided into three blocks of 48 x 48 m: each block was further divided into 16 small plots (12.0 x 12.0 m). Crop varieties and time of planting were the same as in the 1978 experiments.

All farm operations, including land preparation, planting, tending of arable crops, weeding, harvesting, and marketing, were carried out by departmental labour so as to minimize mishandling of the tree crop and to have firm control over the farms and the crop yields.

At maturity (i.e., 3 months, 8 months, and 12 months for maize, yams, and cassava respectively!, the agricultural crops were harvested, weighed, and marketed fresh. The tree crop was assessed for height, girth, and percentage of survival 6 and 12 months after planting.

Results and Discussion

Growth assessment of G. arborea interplanted with yam, maize, and cassava in 1978 indicated that the growth of the trees under agricultural crops was superior to trees grown alone. Nevertheless, the performance of trees under cassava was slightly less acceptable than trees intercropped with yam and maize (table 1). Observations indicated some competition for space between the trees and cassava as shown from the whiplike, weak, and deformed stems of the G. arborea trees.

The trees that were planted at 2.4 x 2.4 m had attained canopy closure at 12 months in all the sites. Thus the growth of any crop under the Gmelina had become impracticable. The depressing effect of cassava on the survival and girth of Gmelina trees observed during the assessment 6 months after planting was still evident at 12 months though in a diminishing magnitude. This finding shows that, though Gmelina is a fast-growing species, it takes some time before the tree can overcome the effects of being intercropped early with cassava. The good performance of trees with agricultural crops (table 2) was possibly due to the initial cultivation and regular cleaning of the yam and maize plots in the taungya farm.

TABLE 1. Survival and Heiaht of Gmelina arborea Six Months after Plantino in Taungya Farm, 1978

Treatment Survival % Mean height (cm)
Gambari Sapoba Bende Awi Ikom Gambari Sapoba Bende Awi Ikom
G.arborea(control) 58a 99a 66a 95a 85a 87a 193a 131a 107a 225a
G. arborea and yam 68 b 95 b 78 b 90 b 97 b 84 a 205 a 168 a 123 a 227 a
G. arborea and maize 75 c 94 b 66 a 92 b 93 c 80 b 173 b 200 c 130 c 223 a
G.arboresandcassava 67b 98a 69a 93b 81d 91 c 216a 159d 126b 161 b
Standard error ±3.12 ±1.06 ±1.68 ±1.02 ±1.91 ±2.08 ±8.2 ±3.37 ±2.24 ±4.00

The figures represent the means of five replicates.
The means in anv given column with the same letters in common are not significantly different at P = 0.05.

At each of the three yam spacings, the height growth of Gmelina tended to decrease as planting distance between the trees increased (table 2). This supports observations that the denser the tree population the more they compete for space and light. The performance of Gmelina under maize and cassava followed the same trend (table 3).

Data have been collected on the yield and revenue accruing from each of the agricultural crops, and these have been converted to a per hectare basis (table 4). Actual measurements of yam, maize, and cassava crops were made, and their values obtained from organized sales made at the various sites where the experiments were carried out. The higher yield of yams in 1979 than in 1978 is a reflection of better weather conditions and improved management practices (e.g., earlier land preparation and planting time). The yields compare favourably with those of peasant taungya farmers in the state forestry services (Ball 1977).

The influence of different densities of agricultural and forest crops on the yields of agricultural crops is exemplifled by the values obtained for yams: the yields per hectare increased with increasing agricultural crop density at each level of the tree crop spacings. However, there was a slight decrease in the yields of yams, as the planting density of G. arborea was increased. In plots where no G. arborea was planted, the yield of yams was 17.8 tonnes ha; this yield dropped to 13.08, 12.68, and 12.86 tonnes ha at Gmelina spacings of 3.0 × 3.0m, 2.4x2.4 m,and2.0 x2.0 m respectively. The implication of the above observations is that, though agricultural crops have positive effects on the establishment of trees, the latter tend to have a slight negative effect on the yields of agricultural crops.

TABLE 2. Survival and Mean Height of Gmelina arbores at Three Different Sites after Six Months of Interplanting with Yam

Treatment levels Survival % Mean height (cm)
Y-levels G-levels Sapoba Awi Ikom Sapoba Awi Ikom
Y0 G0 - - - - - -
G 1 82 90 96 127 134 334
G2 85 63 96 117 147 325
G3 81 81 99 109 170 329
S.E. 1.2 3.0 1.1 2.5 3.5 1.7
Y1 G0 - - - - - -
G1 74 93 96 95 161 350
G2 93 94 95 116 116 316
G3 95 85 99 102 150 298
S.E. 3.9 1.8 1.2 2.7 4.0 4.2
Y2 G0 - - - - - -
G1 87 90 94 117 136 333
G2 89 81 100 107 139 349
G3 77 87 97 110 1 35 315
S.E. 2.1 1.8 1.4 1.8 1.7 3.4
Y3 G0 - - - - - -
G1 88 88 96 105 132 348
G2 84 94 99 92 167 332
G3 80 86 98 95 175 332
S.E. 1.6 1.7 1.1 2.1 3.9 2.5

Key to tables 2 and 3
G0 = No Gmelina arbores planted;
G1 = G. arbores planted at 2.0 x 2.0 m;
G2 = G. arbores planted at 2.4 x 2.4 m;
G3 = G. arbores planted at 3.0 x 3.0 m;
Y0 = No yams planted;
Y1 = Yams planted at 1.0 x 1.0 m;
Y2 = Yams planted at 1.5 x 1.5 m;
Y3 = Yams planted at 2.0 x 2.0 m. The same spacings used for yams were used for maize (M0, M1, M2, and M3) and cassava (C0, C1, C2, and C3).

TABLE 3. Effect of Different Spacings of Yams, Maize, and Cassava on the Survival and Height of Gmelina arborea Six Months after Planting

Factor Levels Survival % Height (cm)
Y0 83 118
Y1 87 104
Y2 84 111
Y3 84 97
Standard error +1.2 +6.4
M0 79 58
M1 89 73
M2 86 64
M3 84 64
Standard error +3.0 +4.4
C0 75 113
C1 77 142
C2 84 136
C3 85 161
Standard error +3.5 +14.0

For key see Table 2.

The most profitable yam spacing in the experiments was 1.5 x 1.5 m. At this spacing, the yield of yams was almost equal to those at 1.0 x 1.0 m, whereas the inputs were about half.

Practical Implications

Agricultural cultivation during the establishment of G. arborea was found to be desirable. In all cases of taungya farming, the growth of G. arborea usually improves with the additional advantage of achieving reasonable agricultural yields. The results presented in this paper tend to support earlier observations made by Jaiyesimi (1966), King (19681, and Agbede and Ojo (1978) that the combination of agricultural crops with tree crops during the establishment phase of the latter is not detrimental.

On plots of Gmelina grown alone or interplanted with food crops, the trees reached a mean height of 5.80 m and 6.50 m respectively in 12 months; the equivalent girths were 29 cm and 33 cm. G. arborea interplanted with yam and maize performed better than those planted alone or with cassava. The provision of shade for the newly-planted tree crop by the sprouting maize and the improved soil conditions in both the maize and yam plots positively affected the growth of G. arborea.

TABLE 4. Yields and Revenue Obtained From Agricultural Crops in Taungya Research Plot. 1978


Yield (fresh weight in tonnes/ha)

Revenue (naira*/ha)

Food Crop Gambari Ore Ukpom-Bende Gambari Ore Ukpom-Bende
Yam 7.7 3.3 6.4 1,540 660 1,070
Maize 4.5 2.0 1.0 410 185 93
Cassava 6.6 4.5 12.4 130 90 250

* In 19781 naira = US$1.60

Summary of discussion: Taungya systems from biological and production viewpoints

From the papers presented, and subsequent discussion, it was clear that taungya systems have met with widely varying success in different countries and-at least in the case of Nigeria-in different sections of the same country. In large part this has not been due to technical or even economic problems, but more to basic political decisions and social acceptance. In particular, lack of continuity was cited as a problem. In Togo taungya has generally failed because the government has claimed forests as its property. This has led to widespread discontent and the destruction of timber trees in favour of fruit trees, which provide regular income after a relatively short period of establishment. In Kenya the taungya system is being phased out because labour costs are relatively high, there is a problem with the labourers or their relatives trying to settle in the forest, and very large areas need to be planted as industrial plantations.

With regard to the experiments on taungya in Sierra Leone, it was clarified that the plantations are used for food crops for the first one or two years, and then the farmers must stay out of the area until the final thinning is carried out. The farmers are then allowed to return and plant tree crops such as cola, citrus, coffee, and cocoa. It is expected that the timber crop will mature and the tree crops will decline in yield at about the same time (about 30-35 years after planting the timber crop), and the area will be clearfelled in order to begin a new cycle. It was noted that in Nigeria a similar system had been tried but had failed because the farmers began to think the forest reserve belonged to them and acted accordingly. The importance of crown shape and density on the yields of the tree crops was raised, but long-term data were not available.

The long-term effect of tree plantations was also discussed, although there was, again, a lack of decisive evidence. It was noted that fertilization may well be necessary when establishing second or third generation tree crops, depending on the inherent soil fertility, and that an initial dose of fertilizer at an early stage of growth could be far more effective than fertilization at establishment. The type and frequency of the products removed are also important. The export of timber, for example, might remove large quantities of calcium, while palm oil is almost pure carbohydrate. In most cases the harvesting and removal of forest products would remove far fewer nutrients than represented by the harvesting of food crops on an annual basis.