This is the old United Nations University website. Visit the new site at http://unu.edu

Contents - Previous - Next

Agro-forestry developments in Kenya: Prospects and problems

F. Owino
Forestry Department, University of Nairobi, Nairobi, Kenya

Abstract

The paper argues the case for adopting agro-forestry in Kenya, with the emphasis being on marginal lends. Developments in the agricultural and forestry sectors are highlighted, particularly their parallel but heretofore unintegrated natures. The future of taungya as an agro-forestry subsystem is discussed. Recommendations regarding the various factors to be taken into consideration when developing an agro-forestry package are given. Finally the paper emphasizes that the "magic agro-forestry tree or animal'' approach is unlikely to prove successful.

Introduction

Historically, Kenya has adopted a sectoral approach to agricultural and forestry management and production. There has been a near total lack of co-ordination at the policy level for the two sectors. For instance, the three major agricultural development plans (the ALDEV plan in 1945, the Swynnerton plan in 1954, and the Agriculture Act of 1967) have all dealt with agricultural production quite in isolation from forestry developments; there has even been a tendency to relegate forestry development to a service in increasing agricultural productivity. More significantly, there has been a great imbalance in the planned and realized contribution to national socio-economic development between the forestry and agricultural sectors, with the scale tilting heavily in favour of agriculture. The fact that the two have continued to be implemented by two different government ministries has further hindered co-ordination of activities that could lead to the development of agro-forestry systems.

The sectoral strategy is unlikely to continue to yield success in Kenya for three main reasons:

• The rapidly changing concepts in forestry management-i.e., the move of foresters away from traditional sustained-yield ideas to multiple-use policies, including agro-forestry;
• The ecological precariousness of Kenya's productive land surface-only about one-third of Kenya's land surface receives sufficient precipitation to sustain recurrent cropping; closed indigenous forests and forest plantations, mainly of fast-growing exotic species, are found within this very limited productive land surface. Any future expansion in forestry development must, therefore, directly impinge on agricultural production. Furthermore, traditional agricultural practices, including shifting cultivation, are land destructive and can only be tolerated at low human population levels. An integrated forestry-agricultural production system like agro-forestry appears the most logical strategy; and
• The extension of agriculture and forestry production to marginal lands-in much of the marginal lands of Kenya, soil degradation and destabilization have progressed to such a level that agro-forestry (most likely some forms of silvopastoral systems) remains the only hope.

Given this background, this paper attempts to review the prospects and problems of agro-forestry developments in Kenya.

Forest Production

The dominant forest policy in Kenya is the protection of forests for the preservation of the water-catchment function, although the sustained supply of wood-based products like fuelwood, timber, pulp and paper, etc., has become more prominent in recent years. Natural and cultivated forests cover some 2 million ha, i.e., less than 3 per cent of the national land base. Of this, about 0.5 million ha are already planted with fast-growing exotic monocultures, mostly of Cupressus lusitanica, Pinus patula, Pinus radiate, Eucalyptus saligna, and Eucalyptus grandis.

Consistent with Kenya's wide altitudinal variation, there is a wide variety of natural forests, ranging from the lowland forests on the east coast to the alpine moorland boundaries on the snow-covered peaks of Kenya's mountains. Thus, five different biomes and nine subtypes have been identified among Kenya's forests (Lamprey 1977). Compensatory forestry practice is currently confined to the high altitude, high potential lands and incorporates the shamba or taungya subsystem.

The last three years have seen a great shift in national emphasis to forest development in the arid and semi-arid parts of Kenya. In these efforts, important lags in the development of appropriate methods have been analysed (Owing 1980). In general, the experience already gained tends to suggest that tree crops alone, no matter how fast they grow, cannot be economically attractive to the smallscale farmer and that some package combining trees and crops, or trees and livestock, or trees and crops and livestock is more desirable in arid areas of Kenya.

Agricultural Production

Kenya has an agricultural economy and relies heavily on exports of high-quality tea and coffee. The country has a fairly well developed beef and dairy industry with substantial exports to neighbouring countries and overseas. The production of staple cereals and beans to meet internal demands is reasonably efficient, and these commodities are imported only when drought or flooding hits the country. Agricultural production activities are organized on both a large scale (co-operatives and large-scale farmers) and a small scale, with the national average for agricultural land holding per family about 1.25 ha.

Traditionally, a few trees have been left on the farm even if there is no apparent use. In general, however, there is little rationalized agro-forestry in the country.

Current Agro-forestry Practices

Taungya is the most conspicuous example of an agro-forestry system in Kenya. It has been estimated that annual maize production under this subsystem averages 4.5 t/ha and that about 10 per cent of the total national maize production comes from this forest development practice (Wanyeki 1980). However, this forestry practice is very labour-intensive and is rapidly being phased out because of labour costs and settlement implications.

There are other, much less spectacular examples on the Kenyan coast. These include coconut palm-crop mixtures, coconut palm-grazing mixtures, cashew nut-grazing mixtures, and cashew nut-legume mixtures. Other combinations in other areas include Albizia gummifera and grazing in the highlands, Acacia albida and cereals in the arid areas to the north, Balanites aegyptiaca and grazing in Baringo and Samburu districts, etc.

The dominant conclusion from such a survey is that the existing agro-forestry examples are those that have evolved in traditional agriculture as a result of constraints in given localities and they are in the experimental stages. This clearly suggests that the next important step in agro-forestry development in Kenya should be the further identification and scientific rationalization of the most appropriate agro-forestry packages for the different ecological zones.

Future Prospects

Although there is a plausible case for agro-forestry as a realistic land-use system in Kenya, one is still faced with the real and large problem of how to sell an appropriate agro-forestry package to the farmer or the individual landholder. It must be recognized that the farmers, just like the professional agriculturalists or foresters, carry out land productivity operations with a polarized mind. There are major barriers to be broken down before they can readily accept agro-forestry proposals, and these barriers have been created by the discipline's short history and the more remote history involving the evolution of cultural values. There are important socio-economic factors that are often specific to a locality and ethnic group.

Given the Kenyan situation, I believe that a systematic development of sound agro-forestry systems should be undertaken through a critical appraisal of the:

• Cultural predisposition to trees and agricultural crops: the cultural value of individual tree species differs markedly from one part of the country to the other, but most farmers have at least a few indigenous and exotic trees on their farms. This fact can be a good starting point in a programme to convince farmers to adopt agro-forestry systems, i.e., developing agro-forestry along the line of least cultural resistance;
• Size of the operation: the traditionally trained foresters are used to operating in large blocks of hundreds of hectares. Farm and rural forestry are very recent ideas that still require experimentation and experience. Farmers, on the other hand, see trees as useful for windbreaks and hedges. There is an urgent need for trials with different tree planting designs for different sizes of land holdings, and the determination of the minimum land size for effective agro-forestry operations given specific productivity objectives;
• Economic returns: most of the recommendations for agro-forestry have been based on the big-physical complementarily of the total production system, including soil quality improvement and stabilization. Relatively little attention has been given to the economic returns from the proposed systems. Economic justification of a proposed agro-forestry system is a prerequisite for acceptance;
• Land capability and its dynamics: the ecological zones recognized for agricultural productivity in Kenya differ in some important respects from those recognized for forest productivity. Land capability classification for agro-forestry systems will differ even more markedly, and needs to be carried out;
• End-product diversity: the existing agro-forestry systems have little diversity of end products. These include fodder, timber, nitrogen fixation, shade, edible seeds, and fruits. It is necessary to investigate other uses for the other plant parts-e.g., tannins, medicine, essential oils, latex, etc.;
• Stability of the productive system: in general, agricultural plantations and forest monocultures are unstable production systems and are maintained at high cost. The recent drive among agriculturalists to return to older, mixed-crop systems should lead to more stable production systems. Agro-forestry systems should prove even more stable. In arid parts of Kenya, the stability of the production system over time is an important factor in the settling of nomadic ethnic groups.

Conclusion

In conclusion, nothing much can be accomplished from a recount of agro-forestry practices, either indigenously evolved or exotic, including the splashing here and there of the "magic" agro-forestry plants and animals. A more systematic development is needed that takes into account socio-cultural factors, scale of operation, economic returns, land capability, end-product diversity, and stability of the productive system. Such an approach would probably result in an agro-forestry package that is readily acceptable in different parts of Kenya.

Barefoot agro-foresters: A suggested catalyst

Peter Poschen
Faculty of Forestry, University of Freiburg im Breisgau, Federal Republic of Germany

Agro-forestry is meant to be a concept for the solution of the tremendous land-use problems in the tropics. In many parts of the tropics agro-forestry schemes, or at least starting points for them, have developed spontaneously. The problems in the extension, optimization, and adaption of such autochthonous techniques are many. The exclusive application of scientific methods to the investigation of existing techniques and the synthesis of new agro-forestry techniques are not feasible because of the costs, time, and staff required. For the development of traditional schemes and the improvement and extension of agro-forestry techniques, I suggest the introduction of "barefoot" agroforesters with a role in agro-forestry similar to that of barefoot doctors in the health services in China-namely, researchers in the field who are also extension workers. In this way they can apply simple and effective scientific methods to local starting points in agro-forestry and thus make an impact without major financial inputs.

These barefoot agro-foresters would serve as catalysts, undertaking field research and publication and extension work, using local knowledge and experience, and applying the most elementary scientific methods like observation, comparison, and systematization. Although there are problems in agro-forestry that call for sophisticated research instruments, in many cases small-scale science may be more efficient.

Barefoot agro-foresters will also need a good understanding of the local population's problems, conditions, and mentality. Therefore, they should be limited to areas where the basic conditions of life, ecology, social, cultural, and economic structure are relatively homogeneous from the agro-forestry point of view. The size of the area must be small enough or accessible enough for them to visit regularly. Close contact enables the co-operation between farmer and catalyst necessary for effective improvements.

Important functions of catalysts are to introduce know-how (e.g., simple methods for wood preservation, useful pruning tools); to establish contacts (e.g., sources for seeds or planting material, outlets for produce); and to analyse the deficits of the institutional and legal framework. In the case of alder with pasture, for example, the forestry law of Costa Rica does not take agro-forestry into consideration at all. People are needed to draw the attention of the authorities to this deficiency. Other paragraphs of this law, concerning tax reductions, etc., could be beneficial to farmers, but the farmers are not aware of them. A guideline for the catalysts' work must be to begin where the farmers are and move forwards from there. Techniques that have been developed on trial plots and in laboratories often do not comply with this rule.

Since the problems of tropical land use are growing at a speed that traditional scientific procedures cannot keep up with, fast-working, efficient, and low-input measures are required if agro-forestry is to play a positive role in development. Observations and experience within Costa Rica suggest that the introduction of such catalysing personnel could multiply several-fold the importance of agro-forestry within a few years, and thereby contribute to meeting the basic needs of the local people.

Gliricidia sepium: A possible means to sustained cropping

Akinola A. Agboola
Department of Agronomy, University of Ibadan, Ibadan, Nigeria

G.F. Wilson and A. Getahun
IITA, Ibadan, Nigeria

C.F. Yamoah
University of Ibadan/llTA, Ibadan, Nigeria

Abstract

Gliricidia septum is a small leguminous tree of tropical American origin. It is currently used on farmers' fields in several locations in Oyo State, western Nigeria, where it seems farmers value this introduced woody legume in restoring soil fertility. Despite its widespread use here, and farmers' acceptance, there is hardly any study or account of this woody legume, especially in this West African subregion. This paper reports the major observations made during a field survey in the Ibadan area. Leaf protein content was calculated to be 23.6 per cent and soils under G. septum fallow had higher nutrient status than comparable sites under natural bush fallow.

Introduction

With increasing population, the traditional shifting cultivation system tends to break down, for the natural bush fallow becomes too short to fully restore soil fertility. A substitute system is therefore essential, and a planted tree fallow is one possibility. Leguminous woody plants such as Cajanus cajan, Tephrosia candida, and Leucaena leucocephala are fastgrowing and improve soil fertility in a shorter time than does the natural regeneration. Farmers in the Ibadan area claim that the small leguminous tree Gliricidia septum has the potential of maintaining and even improving land productivity under continuous arable cropping. The purpose of this study was to investigate that claim.

Gliricidia septum was introduced into Nigeria during the colonial days by the Department of Forestry. Its original use was for fences, but now it is also used as supports for yam vines, erosion control, shade in forestry and agricultural nurseries, feed for livestock, fuelwood, and as a soil improvement agent.

Methods

A field survey was made in a number of locations within Ibadan, including Polytechnic, Eleyele, Ahmadiya, Nihort, Jericho, the Forestry Research Institute, Apata, and Ring Road. Interviews and personal observations were the methods employed to determine how Gliricidia septum is used in the farming systems. Soil and leaf samples were collected, digested with H2SO4, and autoanalysed. Nitrogen obtained was multiplied by 6.6 to estimate protein content. In all, 14 soil samples were collected at 0-15 cm and were analysed for pH (Beckman pH meter with soil:water ratio 1:1), percentage of organic carbon (Walkley-Black method), percentage of total nitrogen (micro-Kjeldahl method), available phosphorus (Bray-1P), extractable cations (by 1 N NH4OAc), and total acidity (extraction by NaOH with phenolphthalin as indicator).

The farmer interviewed at Polytechnic said that the land had been continuously cultivated with yams for four years, and Gliricidia was used as support for the vines. It was then left under Gliricidia fallow for five years. Two soil samples were collected, one bulk sample from the fallow area (sample 1 ) and the other (sample 2) from an adjacent site cultivated with yams, vegetables, and maize.

Eleyele was a farm belonging to the Ahmadiya secondary school. Gliricidia was planted two years ago as a support for yams. Two soil samples, one (sample 3) from the farm and the other (sample 4) from nearby natural bush, were collected.

On a farm near Ahmadiya school, the land was reported to have been continuously cropped for three years without fertilizers. Two soil samples were collected, the first (sample 5) from this farm, where Gliricidia was being intercropped with maize and cassava, and the second (sample 6) from an area free of Gliricidia.

No farmer was found to be interviewed in Nihort. However, observations indicated that Gliricidia had been growing for one to two years, and it was assumed to have been used as yam stakes. One soil sample (7) was collected from the area under Gliricidia.

The farmer in Jericho claimed he had been using the land for the past 12 years to cultivate yam, maize, and vegetables. He said that he planted yams ten years ago using Gliricidia as stakes and that he prunes the Gliricidia periodically so that there is space to plant maize and vegetables. One soil sample (8) was collected.

Gliricidia was found to be on two fallows at the Forest Research Institute: one fallow was two years old and the other three years. Soil samples (10, 11, and 12) were taken from the sites under Gliricidia. One sample (9) was taken from the same area but from a different plot where Gliricidia is intercropped with yams, maize, and vegetables as follows: yam is planted in November with Gliricidia stakes serving as supports for the yam vines; maize follows in March after the stakes have been pruned; finally cassava is planted in July.

The farmer at Apata has cultivated the land continuously for three years, intercropping Gliricidia with maize, cowpeas, and cassava. He pruned the shrub before each planting. One soil sample (13) was collected. The location on Ring Road was a thick bush of Gliricidia, and many earthworm casts were observed. No farmer was interviewed but a soil sample (14) was collected. Leaves were collected from all sites and analysed for protein content.

Potential for Agro-forestry

The following facts about the legume emerged during the survey:

• The shrub is fast-growing and covers the land very quickly;
• The fallen leaves add organic matter to the soil. The organic matter, besides checking erosion, supplies nutrients like N, K, Ca, and Mg on decomposition;
• The deep rooting system helps in recycling nutrients from lower depths;
• Cuttings of Gliricidia will take root, nodulate, and fix atmospheric nitrogen:
• Fuelwood is another benefit derived from Gliricidia, and it can produce about 30 t/ha;
• The commonest use of the shrubs in the farming system is for the support of yam vines, the farmers planting them beside the yam mounds; and
• Gliricidia is one of the shrub legumes suitable for forage production for livestock.

TABLE 1. Results of Soil Analvses for 14 Soil Samples

Results and Discussion

The results (table 1 ) indicate that soil under Gliricidia fallow is better than soils where Gliricidia has not been grown in terms of pH, organic matter, available phosphorus, and cation exchange capacity. They also show that the level of soil fertility increases with the length of the fallow period. Also the protein content of G septum leaves is relatively high, with values ranging from 20.65 to 27.39 per cent. The mean value of 23.6 per cent compares favorably with other woody legumes like Leucaena leucocephala (14.2 per cent) and Cassia spp. (12.6 per cent) (NAS, 1979).

IITA (1980) reported on the effects of planting maize and cowpeas between rows of Cajanus cajan, Gliricidia septum, Leucaena leucocephala and Tephrosia candida. The crops were intercropped in alleys 2.25,3.75, and 6.75 m wide. The results indicated that G. septum at an alley width of 3.75 m resulted in a maize yield of 5,055 kg/ha and a cowpea yield of 586 kg/ha. These were the highest figures recorded among all the yield data. No information was obtained on the amount of nutrients supplied by the shrubs in this experiment. In view of its potential in aiding continuous arable cropping as evidenced by these observations, Gliricidia deserves greater research attention. Further work should emphasize:

• Its nodulating ability under different soil conditions;
• Its effects on the chemical and physical properties of the soil;
• The yield performance of early and late maize when intercropped with Gliricidia; and
• Its suitability as an in situ mulch and in alley cropping on contours.

The role of trees in the production and consumption systems of the rural populations of Senegal

Madicke Niang
Senegalese Institute of Agricultural Research (ISRA), South-Central Sector, Koalack, Senegal

Abstract

In the Thies region of Senegal, the Serer practice a combination of agriculture, animal husbandry, and forestry. The species most valued in the southern part of this region for their multiple domestic and industrial uses are Borassus flabellifer (palmyra), Adansonia digitata, and Acacia albida, which are cultivated together with millet, sorghum, and groundouts, or in stands for livestock to browse.

Palmyra is used by Catholics and animists for wine-making and by Muslims for other products Although a system of agro-forestry may be said to exist among the Serer of western central Senegal, research needs to be conducted into ways of improving the system, notably by determining optimal spacing; the influence of trees on soil fertility and microclimate; ways of developing mineral fertilizers; and the profitability of tree-derived products.

Summary of discussion: Considerations for the future development of agro-forestry

In discussing the future of agro-forestry the supposed links between agro-forestry and poverty were mentioned. Contrary to what is often believed, those practicing agro-forestry are not necessarily resistant to modernization, nor are they limited to a life of bare subsistence. The case of the Kandy gardeners in Sri Lanka was cited as one example where a stable agro-forestry system can provide both subsistence needs and a substantial cash income. It is probably true that most of the people now practicing agro-forestry are in the lowest income brackets, but one can argue that for this reason alone there should be greater efforts to investigate the possibilities for improving yield. In many cases there simply may not be a feasible, sustainable alternative to agro-forestry.

The suggestion for "barefoot agro-foresters" to encourage agro-forestry practices was welcomed, but it was cautioned that they must have some training. In particular they would have to be familiar with the farming systems approach, even though their basic training might be only in agriculture or forestry.

A final comment was simply that there must be more exchange between the different regions within Africa. Each area has its own experience and its own crops, and much of this information could be of use in other areas. Given the tremendous lack of knowledge about agro-forestry, such an exchange could be considered essential for the understanding and development of agro-forestry.

Contents - Previous - Next