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4.0 Tree cultivation, the household economy and food security

The presence of managed trees in farming systems can contribute to both the nutritional and income components of food security, providing foods, inputs into other food producing parts of the farm system, fuel for cooking, and products which can be sold. They may also contribute to the farm economy in other ways. At the same time their presence draws on the resources of the farm household and imposes costs of various kinds. In the present chapter we attempt to identify more clearly the linkages between trees and the rest of the farm household economy, the factors involved in farmer decisions for or against tree growing, and the impact of cash crops on household food security.

4.1 Benefits and costs of tree components in farming systems

Farmers have historically protected, planted and managed trees on their land in order to maintain supplies of sought-after products no longer readily available from the natural forest which is cleared, degraded or is no longer accessible. For example, Campbell et al. (1987), in a recent study in hill areas in Nepal where there has been progressive reduction in the forest resource, found that the households surveyed have decreased their reliance on supplies of forest products by increasing the number of trees on their own land. More than half of the average 41 trees owned have been planted in the previous five years (Table 4.1). Fodder trees figure prominently among those grown, with an increasing share of timber species among those planted recently.

Another important factor affecting the presence or absence of trees within a farm system is land suitability and land use. Much tree growing or retention is intended, at least in part, to maintain the benefits of site productivity achieved in shifting cultivation through a period of bush fallow. Trees are also retained or planted on sites unsuited to other crops, or where their presence as an intercrop is needed in order to prevent or diminish soil erosion. For example, Table 4.2 shows how in an upland area of eastern Java (Indonesia) the balance between crops, tree/crop mixtures and tree cover shifts toward predominantly tree cover as the steepness of slope increases (McCauley 1983).

Decisions for or against tree growing, or any other farm activity, are also subject to more direct economic factors -- absolute and relative availability of land, labour and capital; subsistence needs and market opportunities; etc. In addition, they are often influenced by social, cultural and institutional considerations. A house garden in Java is an important status symbol (Soemarwoto and Soemarwoto 1984). In many regions, particularly in Africa, trees are intrically linked to land rights. The existing land/tree tenure system is a crucial factor in stimulating and inhibiting tree growing (Fortmann 1984). In the hill areas of Nepal referred to earlier, increased tree growing reflects inter alia attitudes toward the alternative of strengthened communal management of remaining forest resources. Molnar (1981) has shown that these attitudes were determined by, among other factors, local perceptions of the state of the resource and of the consequent potential for increased production should it be brought under more effective collective management, and of the prospects for effective collective action.













All Dryland

Garden Types






























Mean Percent of Slope

for Each Garden Category






The figures refer to the percentage within each ga rden category occurring in a given slope class. Thus, each column su ms to 100. The far right-hand column shows the percentage of all garde ns which fall into each of the five slope classes.

The percent of slope was estimated on the basis of field observation, and the figures shown roughly represent th e mid-points of the slope classes into which each parcel was grouped. Percent measurements represent the tangent of the angle of the slope ( that is,-'45 degrees equals 100 percent).

For the computation of the mean slope of each gard en category, 75 percent was used for the extremely steep class to mo re closely represent the data. The figure of 60 percent was used for the Universal Soil Loss Equation estimations because there were no data available for slopes of 75 percent.

Source: McCauley 1983

Within the broader framework of the factors affecting tree growing we look in this section at available information from economic studies of farm systems with significant tree components, in order to try and identify both the contributions that the trees make to these farm economies and the economic considerations that have caused farmers to adopt them. This is approached by defining the advantages that tree growing appears to offer to famers as an efficient means of using available resources in order to meet production goals.

4.1.1 Home Gardens

Home gardens (also known as compound farms and as homestead and mixed gardens) are usually located, where they exist at all, close to the household as one of the more intensively cultivated parts of an overall farm. They are characterised by a mixture of annual or perennial species grown in association. They commonly exhibit a layered vertical structure of trees, shrubs and ground cover plants which recreate some of the properties of nutrient recycling, soil protection and effective use of space above and below the soil surface found in forests. Home gardens are widely used to supplement outputs from other parts of the farm by cultivating a variety of other subsistence and commercial crops. They are also used to spread farm work, output and income more evenly throughout the year (Ninez 1984).

In Java, Indonesia, a range of different dry land production systems incorporating tree management have long existed. Their extent, structure and place within the overall farm system varies with population density, altitude and land type (Tarrant, personal communication). The information reviewed here refers primarily to the home gardens found in the densely populated lowland areas of central Java. These home gardens form the principal farming system on dry lands while irrigated rice cultivation forms the other main component of the farm system. The gardens are traditionally dominated by perennials rather than annuals, and by woody rather than herbaceous plants.

On farms with sufficient rice land to enable households to meet their basic food needs, priorities in labour and capital allocation are directed to rice production. The garden areas in these larger farms are essentially forest gardens of trees with commercial value (Wiersum 1982, Hunink and Stoffers 1984, Stoler 1978).

With growing pressure on the land and decreasing area of crop land per head, the proportion of land under home gardens has been increasing to up to 75 percent of cultivated land (Stoler 1978). Meanwhile, access to rice land has declined and a large proportion of farmers now have no rice land, or at least not enough to meet their basic rice requirements. As the proportion of land devoted to rice production decreases, home garden areas are cultivated more intensively, becoming mixed rather than forest gardens as annual plants are progressively intercropped to provide food and income.

Table 4.3: Income from home gardens compared to total income

Management is intensified by increasing labour inputs. The scope for increasing productivity is such that labour inputs in small gardens are reported to be on average three times as high as those for larger gardens. Returns to both land (see Table 4.3) and labour are high (Soemarwoto and Soemarwoto 1984).

Table 4.5: Miri: Coconuts, value added per year (per farm average)

Farm groups ranked according to area of land controlled


Sugar and/or rent from own Fruit

Total from own trees

Return from tapping the trees of others

Value added (income) per family

Sugar as proportion of total








Largest single farm

first quintile

Village average

fifth quintile

























a) This figure shows the income per family from their own capital (trees) and what they earn from tapping and manufacturing coconut sugar.

b) The figures in this column are for pure labour income.

Source: Penny and Singarimbun (1983)

Intensive garden management has been reported to produce up to 20 percent of household income (see Table 4.4) and 40 percent of calorie intake (Stoler 1978).

Another approach to intensification of garden area use has been to increase the value added from home garden produce. Penny and Singarimbun (1973) describe how some of the poorest farmers shift from the production of coconuts to the production of coconut sugar which is a highly labour intensive process but leads to increased returns to coconut bearing land despite low returns to labour (see Table 4.5). Other farm related income earning activities include pit-sawing and fuelwood gathering (Hunink and Stoffers 1984).

As land holding size continues to decline, income is increasingly sought from off-farm employment. At this stage, cultivation of annuals is reduced in order to allow more time for income earning activities. Trees and other perennials, requiring only low labour inputs, come to form the main component of the garden (Stoler 1978).

The shift to greater dependence on, and greater intensity of, cultivation of tree gardens in lowland Java thus appears to be because, as land holding size decreases, they permit more productive use of the land. This shift in landuse is better matched to farmers' changing resource endowments and production objectives than alternative land management options.

In a study of farming practices in southeastern Nigeria, Lagemann (1977) found a similar relationship between population pressure on the land and intensity of tree cultivation. Farms comprise a mixture of fallow, outer and inner fields, and permanently cultivated compounds around the household. The latter contain a variety of tree species, including oil palm, raphia palms, coconut, banana and plantains intercropped with cassava, yams and other arable crops.

Growing population pressure is accompanied by decreasing farm size and declining soil fertility. As pressures on the land heighten, the proportion of land under compound systems is increased, as is the density of both tree and arable crop cultivation within the compound areas. Lagemann argues that this shift reflects farmer's perceptions that such land use, combined with increased mulching and manuring, offers the most effective way of using their resources to slow down the process of declining soil fertility and to maintain production. Though labour inputs per hectare are no higher than in the fields, yields in monetary terms are five to ten times as much per hectare and returns to labour four to eight times as much. Lagemann identifies phasing of planting and harvesting in the compound areas to reduce peak workloads, and better physical working conditions under the shade of trees as factors contributing to this higher labour productivity.

With increasing population density, compound areas account for up to 59 percent of crop output and a growing proportion of total farm income, with the proportion of income generated from tree crops rising to a share nearly equal to that from arable crops. Livestock becomes an increasingly important part of the farm system, both as a source of income and of manure. However, as population density continues to increase, yields and returns to labour eventually decline to a point at which farmers have to turn increasingly to non-farm sources of income. As people shift to working off-farm, a lower labour input to the compound areas is adopted, leaving the areas dominated by trees and other perennials.

The overall picture, therefore, as in Java, is one of farmers responding to decreasing land availability by moving to greater dependence on agroforestry systems. Initially this is because they permit more sustainable intensification of land use and higher returns from available labour inputs, than alternative land uses. When pressures on the land increase further, to the point where income has to be generated mainly from off-farm employment, these agroforestry systems have the added advantage that they can be maintained, in a modified form, as low input, low management forms of land use.

A study of tree cropping in the homesteads in Kerala, India, records a similar process in a system which combines intensive management of perennial and annual crops with more extensively managed areas. As rising population pressure on the land leads to decreasing land holding size, uncultivated land is first brought into use, resulting in removal of natural tree cover. This is followed by more active management of the home gardens, with the range of cultivated trees being narrowed down to those with multiple uses. Priority 'is given to those species valued for fruit, fodder and mulch and suitable as supporting structures for cultivation of pepper, betel and various climbers. In the process, the density of trees and intensity of their cultivation increases (Nair and Krishnankutty 1984). As pressure on the land increases further, land holding size falls to the point where farming ceases to provide the main source of income. As labour on the farm declines and moves to off-farm employment, the tree component increases even further as the vegetation reverts toward a forest condition.

However, unlike the cases in Java and southeastern Nigeria, in this area of Kerala capital has become increasingly available, enabling some farmers to intensify land use further through purchased inputs such as fertiliser and herbicides. This reduces the importance of the multipurpose trees for soil nutrient maintenance and weed suppression. Consequently, they tend to have been removed as they have become impediments rather than complements to agriculture. Removal of trees has been accelerated by rapid rises in the prices of timber and land; the latter leading to the shift of land use into cash crops. Trees are then cultivated only where they are competitive as a cash crop. For example Ailanthus triphysa is grown to supply wood stock to the match industry.

Thus, the Kerala experience broadly parallels that of Java and Nigeria up to the point where farmers were able to invest substantial capital into their farms. The subsequent displacement of agroforestry practices seems to confirm that, in the absence of capital, farmers employ trees primarily to provide substitutes for purchased inputs and as crops requiring lower inputs than other crops.

4.1.2 Farm Woodlots

The farm woodlots examined in this section essentially involve the growing of trees as field cash crops. Farmer decisions could therefore be expected to be governed by the question of whether or not the tree crop is more profitable than alternative crops or other uses of the land. In all of the situations discussed here, tree growing on farms is rapidly expanding.

One of the most fully documented farm woodlot experiences is in the Philippines, where. small farmers grow trees to produce pulpwood as a cash crop. In an area of previously low density extensive agriculture, farmers now grow Albizia falcateria on a 6 to 8 year rotation for sale to a nearby pulp company (PICOP). The average size of landholding is 11 hectacres, some of which is devoted to cultivation of food crops. At least part of the land on 45% of the farms had been previously used for growing food crops, and other non-food crops had been raised on some parts of 31% of the farms. Credit for tree-farming was available but was utilized by only 30% of the farmers eligible; generally these were farmers with above average woodlot sizes (Hyman 1983b).

Ex post analysis showed that farmers were able to earn an acceptable return from their woodlots in most prevailing circumstances, with an internal rate of return of 22% to 31% for successful tree-farmers on costs other than land costs. The data do not exist for comparing these returns with returns from alternative land uses, but farmers cite low labour inputs as the principal reason for preferring tree growing (Hyman 1983b). In an area where average land holding considerably exceeds the size that can be cultivated under food or other crops with family labour, pulpwood production enables farmers to expand the area they can put to productive use.

Another instance where growing of trees as a cash crop has recently been successfully introduced to farmers is in Haiti. This programme has been the subject of several social and economic studies, the results of which provide considerable information about farmer motives. Tree growing was introduced to hill farmer"s as a means of earning additional income. In this instance, there was already an existing market for charcoal and poles, a strong orientation towards income generation and cultivation of cash crops. In addition, most farmers owned their land. It was hoped that incorporating trees into their land use systems would also help them control the serious erosion problems they were experiencing.

Since 1982 approximately 110,000 farmers have planted more than 25 million seedlings. Patterns of planting vary considerably from farmer to farmer, but increasingly they have moved from species suited only to output of fuelwood and poles to multi-purpose species, and to intercropping trees with agricultural crops such as maize, sorghum and beans.

A recent cost-benefit analysis indicates that most such tree/crop mixtures should have a higher net present value than continued cropping without trees (see Table 4.6), and that adoption of tree/crop mixing appears to be an economically viable decision for most people (Grosenick 1986). Surveys of participating farmers confirm that they perceive increased income as the principal benefit, but are influenced by other motives as well.

Many plan to use their trees as a form of savings and value the fact that they can draw down such savings, by harvesting the trees, at a time of their choosing. In an area subject to drought and crop failure trees are seen as being less susceptible and as such reduce uncertainty. Eighty one percent of those interviewed must employ agricultural labour, but are constrained by a lack of cash. Thus, tree cropping is attractive as a lower cost use of land. As was the case in the Philippines, growing of trees may enable poor farmers to increase the amount of land they are able to work (Conway 1986, Balzan 1986 cited in Conway 1987).

Available information about the rapid recent expansion of cash crop growing of trees in parts of Kenya has been assembled by Dewees in a study for the World Bank (World Bank 1986). Two popularly cultivated species are eucalyptus, grown for poles, and black wattle, grown for poles, charcoal, fuelwood and sticks for "mud-and-wattle" house construction. Markets for these wood products - and for pulpwood and saw timber, in some places - are growing strongly, with farm level production accounting for a large part of the supply.

Tree growing tends to be practised by poor farmers unable to meet their basic food needs and for whom it is a principal source of farm income. In Vihiga, in Kakamega District, for example, average farm size is about 0.6 ha., of which approximately 25 percent is under eucalypt woodlots (Gelder and Kerkhof 1984).

Gross income per hectare in this area is considerably lower from tree growing than from other agricultural crops. Dewees suggests that farmer preference for tree crops in these circumstances is conditioned by availability of capital and labour, and by attitudes to risk management. Alternative crops often require substantial investments, at levels beyond small farmers' access to capital. Trees, by contrast, require very little expenditure. Tree growing is also attractive to farmers because of the low labour inputs it requires. There is a shortage of labour in this area because of widespread outmigration of the farm households' men, who seek off-farm employment. Where markets for tree products are good, returns to labour from pole production have been estimated to be some 50 percent greater than from maize production (World Bank 1986). Tree growing is consequently a rational use of resources for poor farmers needing to devote a substantial part of their labour to non-farm employment.

A number of recent evaluation reports, though lacking the detailed quantitative field data of some of the studies cited above, have provided considerable insights into farmer motivations in some of the very large expansions of farm-level tree growing taking place in many areas in India. The discussion that follows draws, in particular, on studies of social forestry programmes in the states of Gujarat (Noronha 1982, FAO 1985, Skutsch 1987), Maharashtra (Blair 1983), Tamil Nadu (Arnold et al. 1988a), and West Bengal (Tushaar Shah 1987). `

In all cases tree growing occurs where there are strong and expanding markets for poles and other wood products (e.g. pulpwood). The principal factors motivating farmers to move to cultivation of trees rather than other cash crops include: rising labour costs and increasing shortages of labour, declining yields, and more frequent crop failure in face of drought and diminishing access to irrigated water. The advantages of trees in these circumstances are usually perceived to be: low labour inputs, thus, reducing costs of labour and problems of labour management; minimal annual operating costs in most years; low water requirements once established and thereafter greater resistance to drought - and hence reduced risk and uncertainty. The prospect of accumulating capital through tree growing is another important factor which encourages tree growing, particularly among poorer farmers.

Table 4.6: Net benefits of sample tree/crop associations [NPV(1)] in comparison with crops alone [NPV (2)] 1 Southern Region (US $)












Maize, sourghum

congo bean

Maize, beans

Yam, patat

(Ipomoea batatas)

Maize, manioc


Maize, sorghum

Sorghum, patat, yam


































































Maize, sorghum congo bean

Maize, beans

Yam, patat (Ipomoea batatas)

Maize, manioc Patat

Maize, sorghum

Sorghum, patat, yam























































Source: Based on Grosènick 1986

Much of the tree cultivation is being undertaken by larger farmers for whom the principal advantages seem to be higher returns to labour as labour costs rise, and better returns to those parts of their land subject to declining availability of irrigation water. Small farmers tend to take up such cash cropping with trees once annual cropping is no longer viable or sufficient and they have had to turn to other sources of income at which time trees have the attraction of needing few inputs and of creating a capital asset. A survey in an area of West Bengal of poor farmers who had recently sold tree crops grown on agriculturally marginal land, disclosed that about 40% of the proceeds had been invested in buying paddy land, and a further 20% spent on other productive investments (with most of the rest going toward marriages and other contingencies) (Tushaar Shah 1987).

Planting by both small and larger farmers is narrowly focussed on monocrops of a few predominantly wood producing species, mainly eucalyptus. Even among smaller farmers there has been very little development of agroforestry tree cultivation practices.

In all of the farm woodlot situations reviewed, choice of tree growing appears to have been influenced by one or more of three main factors. First, income generation, as distinct from food production, played a prominent role in the farmers' production objectives. Second, tree cultivation offers advantages in situations of scarce capital and labour. And, finally, tree crops provide risk reduction.

4.1.3 Extensive and Intermediate Systems

The discussion in the two previous sections suggests that farmers employ tree cultivation practices primarily because they perceive tree cultivation as being the most efficient way of meeting their production goals using the resources of land, labour and capital available to them. As their resource endowments change, their strategies are likely to alter. Equally, their assessment of the most efficient farm strategy to employ is likely to be influenced by a broad framework of needs and opportunities linked to offfarm opportunities. Analysis of what is an efficient use of resources, therefore, has to be assessed in terms of the production objectives being pursued in a given situation. In the present section, the review is extended to more extensive forms of agroforestry, beginning with shifting cultivation.

resources. The resources at the disposal of the shifting cultivator are predominantly family labour. Where there is sufficient land to support a fallow period, no other farming practice will produce a higher return to labour without inputs of capital. The fallow vegetation maintains soil productivity, and the process of clearing and burning provides conditions for crop cultivation which require minimal inputs for soil preparation and weeding. Though cultivation periods could be extended by increased weeding, it is easier, in terms of requiring less labour, to clear and burn a new area. Similarly, yields per hectare could be increased by more intensive cultivation, but at the expense of lower output per unit of labour. As long as farmers can satisfy their production objectives through less labour-intensive methods, they will logically stick to them (Rambo 1984, Raintree and Warner 1986).

A broad sequential process can be identified whereby as reduced access to land prevents continuation of sustainable shifting cultivation, farmers do eventually start to intensify agricultural practices (Olofson 1983, Raintree and Warner 1986). This usually takes the form of small incremental changes involving increased labour, and sometimes of capital in the form of fertilizer, herbicide, etc. This evolutionary process away from shifting cultivation may move away from tree cultivation altogether, but it can include tree components.

A common practice at early stages in this process is enriching the fallow by encouraging or planting tree species which either accelerate or enhance the regeneration of soil fertility or produce outputs of subsistence or commercial value, or both. The cultivation in Sudan and elsewhere in the semi-arid areas of Africa of Acacia senegal as a fallow crop is an example of a species that does both: a leguminous species, A. senegal, improves soil fertility, as well as produces gum arabic for sale, and fuelwood, medicine, fibre and other products for use in the household. Other examples include the management of the Babassu Palm for both commercial and subsistence products in conjunction with shifting cultivation over large areas of the mid-north of Brazil (May et al. 1985a); the planting of rattan as a commercial crop in the swidden cycle in Borneo (Weinstock 1983); the multiple-product-managed swiddens of the Ifugao in the Philippines (Conklin in Olofson 1983); and market-oriented cyclic agroforestry systems practised in parts of the Peruvian Amazon (Padoch et al.' 1985). Although quantitative information on inputs and outputs is limited for these systems, it can be expected that, as they generate additional income with only minor increases in labour inputs and minimal changes to the basic swidden system, they will provide fairly high returns to labour (Raintree and Warner 1986).

At the next step in intensification, as pressures on land force the transition towards continuous cultivation, various forms of intercropping are encountered. By incorporating soil enriching species with food crops, these practices introduce the functions of fallow on a continuous basis. Numerous examples of such continuous fallow strategies are to be found, such as the maintenance of Acacia albida in cultivated areas in much of Africa.

An example of plant mixtures of this nature is the intercropping of Sesbania sesban, a leguminous tree, with maize in areas of western Kenya. When the maize is shaded out (after about three years) the Sesbania sp. is left as a fallow crop for one to two years, and then cleared and used for fuelwood. The cycle is then repeated. Practised in an area of labour shortages, over a ten year cycle it has been estimated to produce less than half the maize per hectare when compared with monocropping but to require less than half as much labour and to give higher maize yields per unit of labour input - in addition to the fuelwood and soil protection benefits (World Bank 1986).

Considerable attention has been directed recently to an intensively managed "continuous fallow" system known as alley cropping. Alley cropping involves the growing of field crops between hedgerows of nutrient cycling trees or shrubs, which are periodically pruned during the cropping season to reduce shading and provide green mulch for food crops. Data from an economic analysis of the results of alley cropping research conducted at the International Institute for Tropical Agriculture (IITA) in Nigeria are summarised in Table 4.8. The research involved intercropping of maize with Leucaena leucocephala and treatments with nitrogen fertiliser and herbicide. Leucaena intercropping gave the highest economic returns and yields of maize of all the alternatives, but required higher labour inputs than cultivation of maize alone or with fertiliser/herbicide applications. Returns to labour from intercropping, however, were higher than in maize monocropping (Ngambeki 1985).

The potential for improving the efficiency of such low input agroforestry practices adopted by farmers in order to progressively intensify their farming efforts, therefore, appears quite encouraging. However, further work in testing the research results under on-farm conditions is needed to ensure that the labour availability and farmer skills assumed are realisable in practice, that the costs and values are consistent with those actually experienced or perceived by farmers, and that the physical input-output relationships and performance are replicable on farms (Balasubramanian 1983, Hoekstra undated).

Economic information is also available for some other intermediate agroforestry practices. A study of coconut farmers in an area in Sri Lanka, for example, showed that intercropping increases net returns.. Labour intensive crops such as betel, ginger and turmeric are being adopted primarily by small farmers with family labour available, while those crops which gave higher returns to labour, such as pepper and coffee, are preferred by larger farmers dependent on hired labour (Karunanayake 1982). once again, therefore, farmers are shown to be responding to interrelationships between resource availability and production objectives.

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