Economic factors in farmer adoption of agroforestry: Patterns observed in Western Kenya

World Development. Vol. 23, No. 5, pp. i’87-804, 1995 Copyright 0 1995 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0305-75oK/95 $9.50 + 0.00

Pergamon

Economic Factors in Farmer Adoption of Agroforestry: Patterns Observed in Western Kenya SARA J. SCHERR*

International Food Policy Research Institute, Washington DC, U.S.A. Summary. - A study of agroforestry adoption by 3,000 project participants in Siaya and South Nyanza Districts in Kenya supports three hypotheses. (1) Historical increases in tree domestication and management intensity are responses to declining supply of uncultivated tree resources, increased subsistence and commercial demand for tree products, and perceived risks of ecological degradation. Adoption of agroforestry is most likely where consistent with economic incentives for land use change. (2) High variability in individua; farmers’ tree-growing strategies reflects differences in resources and livelihood strategies, and household-level returns to agroforestry relative to alternative options for meeting specific objectives. (3) Farmers reduce risks associated with new agroforestry practices through incremental adoption and adaptation, and cost- and risk-reducing modifications in technology design.

1.

INTRODUCTION

Increased investment in tropical agroforestry and farm forestry research and development has been promoted by donors, governments and grassroots organizations with a wide spectrum of environmental and development goals. These include environmental protection and stability (sustainable low-input agriculture, watershed protection, combating deforestation, biological methods of soil conservation); wood energy (solving the rural energy crisis, sustainable charcoal production); meeting basic needs of rural people (for domestic energy, building materials, medicines, raw materials), and economic self-reliance (substitution for imported agricultural chemicals, building materials, fuels, raw materials for rural industry). With the goals of agroforestry intervention thus set, intervention strategy has often been formulated as one of education, inspiration and provision of planting materials. Most analyses of agroforestry adoption, drawn from extension projects, emphasize technical factors, such as appropriate species-site matching; social factors, such as tenure security; cultural factors, such as gender roles in tree-planting, or extension factors, such as communication styles (Kaudia, 1992; Kerkhoff, 1990). While these are clearly important, they cannot, alone, explain broader, long-term patterns of intensilication and diversification of rural tree-growing and management. Agricultural development theory would suggest that farmers adopt agroforestry practices when there arise clear economic incentives to do so at

the regional and household level, so long as associated risks can be managed. Understanding farmers’ current and historical patterns of agroforestry practice, and likely trends in economic incentives, would then be needed to identify effective technical and institutional interventions. This paper suggests several hypotheses about the patterns and processes of agroforestry adoption, illustrated with case material from Siaya and South Nyanza Districts of Western Kenya. Section 2 lays out these hypotheses. Section 3 describes the research methods and study site. Section 4 assesses regional patterns of agroforestry practice over time, and Section 5 interhousehold variations in agroforestry use and adoption. Section 6 discusses farmer approaches to reduce the inherent risks of long-term *Field research for this paper was undertaken while the author was a Principal Scientist at the International Council for Research in Agroforestry (ICRAF), Nairobi, Kenya. Collaboration of the staff and farmer participants of the Agmforestry Extension Project is warmly acknowledged. We are grateful to the Australian International Development Assistance Bureau, the Ford Foundation, the Government of the Netherlands, for funding assistance to ICRAF and to the Japanese International Cooperation Assistance for funding assistance to JFRRI in support of this project. Comments from Peter Dewees, Steve Franxe.1,Augusta Molnar and two anonymous reviewers are greatly appreciated, as is assistance in data analysis from Patricia Bonnard and secretarial support from Lourdes Hinayon. Conclusions and errors of the paper are the author’s alone. Final revision accepted: December 12, 1994.

WORLD DEVELOPMENT

188

agroforestry investment. Section 7 discusses implications of the study findings for design of agroforestry interventions, and section 8 concludes by suggesting research priorities.

them through technical and organizational innovation, are likely to be more successful (Kerkhof, 1990; Roling, 1988; Scherr 1992b).

(b) Livelihood strategies 2. HYPOTHESES ABOUT AGROFORESTRY ADOPTION Existing theories of induced technical innovation, livelihood strategies and risk management suggest a number of hypotheses about agroforestry adoption at the household and community level,

(a) induced innovation The theory of “induced innovation” posits that increasing land pressures (from population increases or increases in internal or external demand for products from the land) lead endogenously to land use intensification, by inducing technical and institutional innovation (Ruthenberg, 1980; Binswanger and Ruttan, 1978). Extending this theory, we hypothesize that (1) historical increases in tree domestication and management intensity are a response to declining supplies of uncultivated tree resources, increased subsistence and commercial demand for tree products, and perceived risks of ecological degradation. Adoption of agroforestry interventions is most likely where consistent with underlying economic incentives for land use change. Raintree and Warner (1986) first applied induced innovation theory to agroforestry by tracing the “pathways for intensification” of shifting cultivation systems with increased population density. Recent case studies have documented endogenous agroforestry intensification in permanent cropping systems with rising demand and reduced natural supplies for tree products (e.g., Amacher, Hyde and Rafiq, 1993; Dewees, 1993; Warner, 1993). But scarcity alone is insufficient to explain farmer agroforestry innovation. Pressures on tree product supply may result instead in product substitution or reliance on trade, if these are more economic alternatives (Dewees, 1989), or in reduced consumption if there are barriers to innovation. Fuelwood scarcity, for example, has provoked quite different rural responses in Africa, India, Nepal and Central America. Growing ecological problems associated with agricultural intensification may call forth farmer innovation in protective agroforestry systems (e.g.. windbreaks, gully plugs, contour hedges), but only where regional social and economic incentives favor such investments (Scherr and Hazell, 1994). If this hypothesis is true, then agroforestry interventions which reflect the trends in these incentives, and build on farmers’ ongoing efforts to respond to

While general trends in technical innovation and diffusion can be identified for a given regional economy, within the population there is likely to be considerable variation in technology use. The theory of “livelihood strategies” is valuable in explaining this variation (Chambers and Leach, 1989; Scherr, 1994). Rather than assume all farmers are “profit-maximizers,” this theory focuses on “welfare (utility) maximization” and posits multiple household objectives, including secure provision of food and essential subsistence goods, cash for purchase of outside goods and services, savings (resources accumulated to meet future planned needs or emergencies), and social security (i.e., secure access to subsistence goods and productive resources). Households select “livelihood strategies” to pursue these objectives by use of the resources to which they have access (on- and off-farm lands, trees, labor, cash), while reducing critical risk factors. Both the resources available and livelihood objectives change over the life cycle of the household. In applying this theory to agroforestry, we hypothesize that (2) there will be high variability in farmers’ tree-growing strategies, determined by their overall livelihood strategies and resource base. Farmers adopt agroforestry practices which provide returns to household factors of production superior to available alternatives, or which meet “service” objectives more cost-effectively than alternative options. Financial profitability, per se, may be of secondary importance. Returns to labor, land and capital invested in agroforestry must be not only positive, but superior to alternative options for meeting specific livelihood objectives. For example, farmers may be keen to grow timber trees for savings if they have no superior strategy for savings, while they reject growing trees for cash income if they already have a successful strategy for earning cash income from off-farm labor or crops. Understanding this variation is key to appropriately targeted agroforestry intervention.

(c) Risk management Insights from research and development experience on the effects of risk on adoption and management of crop technologies (Holden, Hazel1 and Pritchard, 1991) can be extended to agroforestry. Agroforestry systems, once established, typically serve to reduce farm risk, e.g., reduce wind damage or soil erosion, provide supplemental sources of food during drought,

FARMER ADOPTION

or provide standing timber assets to be sold for cash in an emergency. Adoption of unfamiliar species and systems, however, can present significant risks beyond those associated with crops (Mol, 1989). With multiyear production cycles, cash flow is a problem and farmers carry the risk that there may be no harvest in the end, due to theft, tree damage, or tenure insecurity. If labor becomes unavailable for tree management, there may be considerable decline in associated crop yield. Discounting reduces the present value of future returns, with farmers facing uncertainties related to future yields, product quality, output price and input price and availability. Perennial components are persistent, reducing flexibility in future land-use decisions. Amacher, Hyde and Rafiq (1993) and FAO (1986) found that household attitudes toward risk and expectations of uncertain gains from adoption were among the most critical factors in agroforestry adoption. We hypothesize that (3) farmers reduce the risk associated with new agroforestry practices through gradual adoption and adaptation of new practices, and cost- and risk-reducing modifications in technology design. By identifying the strategies farmers use to reduce risks, these can be incorporated explicitly into the design of agroforestry technologies and interventions.

OF AGROFORESTRY

189

ture, is the main activity. The typical farm size is very small, under two hectares in the higher and wetter areas. Most land has been privatized, defacro, if not de jure. In the drier areas, there are larger private holdings and considerable grazing land still managed communally, but most households control their own crop plots. (b) Agroforestry extension in Siaya and South Nyanza

There were no organized external efforts to promote agroforestry in Siaya and South Nyanza until early in this century. The British colonial Agriculture Department introduced exotic fruit tree species, e.g., cashew (Anacardium occidentale), rubber (Hevea brasiliensis), but few were widely adopted or marketed. Sisal was promoted for fiber and became popular among farmers for fencing. The Forestry Department initiated several small-scale attempts at plantations and farm afforestation, but with little success. New species for commercial timber, such as Eucalyptus spp. and Cassia siamea, were introduced, although the major producers in the 1930s were mining companies and other wood-consuming industries (Kenya National Archives; Scherr, 1993). A more substantive program of afforestation began in the 1940s. Locational nurseries were set up, and farmers were introduced to the technology of seedling 3. AGROFORESTRY EXTENSION IN SIAYA production. Roadside tree-planting was established. AND SOUTH NYANZA Local headmen were required to plant trees, mainly exotics for fuelwood and building poles. In 1955, the (a) Land use systems in Siaya and South Nyunza Kisiani Forest Reserve was set up in Siaya, and Siaya and South Nyanza Districts, home to one of Swynnerton Afforestation Funds became available. A central tree nursery was established in Maseno, and Kenya’s largest tribes, the Luo, are located between sublocational nurseries were set up. Unlike in the Lake Victoria and the western highlands of Kenya. Moving toward the lake, altitude declines from 18OOm more intensive agricultural systems of the Kisii, Luyia and Kikuyu highlands (Barnes, 1984; Bradley, 1991), to ltlom, and rainfall from 2000mm to 800mm. Population density averaged about 250/km2 in 1990, woodlots were adopted only by Luo chiefs and largewith densities much higher in areas adjacent to the holders, although smallholders did experiment with new timber species. densely populated highlands of Kakamega and Kasii, After independence in 1963, there was little public and lower in drier areas. The higher rainfall area is dominated by leached soils, with high soil acidity, low farm forestry activity until the early 1980s. In 1983, CARE International in Kenya (an international nonorganic matter, common stone or laterite layers governmental organization) and the Government of restricting root growth, and low available phosphorus. Kenya Forest Department set up the Agroforestry Soils in the drier areas are variable red loams, of moderate to low fertility, except for areas near the lake Extension Project (AEP). The project became fieldbased in Siaya in January 1984, and in South Nyanza where fertile black cotton soils predominate. Maize is the most important crop, mainly for home in November 1985. Apart from extension, the AEP consumption, but there is still important production of trained extensionists and teachers, established local millets and sorghums in drier areas. Sugarcane and seed orchards, trained farmers in seed collection and cotton are cash crops in small areas. Small stock pre- storage, and, with other Kenyan institutions, developed mechanisms for national and international seed dominate in the densely populated wet zone, though dairy production is still underdeveloped. There are exchange. There was no involvement in tree product still large numbers of herded cattle and goats in the marketing. Other nongovernmental organizations drier areas. Along the lakeshore, fishing, not agricul(NGOs) soon began agroforestry extension in both

790

WORLD DEVELOPMENT

districts, often borrowing from the AEP technology, approach or philosophy. AEP’s focus was on smallholders in already-established women’s groups. Extensionists identified priority land-use constraints with farmers, and selected from over 40 tree species on the basis of farmer preferences and project information about the potential role of different practices in addressing the constraints. Common constraints, which trees in different types of agroforestry systems were designed to address, included soil fertility decline, declining fuelwood availability, scarcity and high price of building poles and stakes, heavy wind damage near the lake, child malnutrition, lack of cash, dry season fodder shortage, damage to unfenced crops and home compounds from domestic and wild animals, and an unpleasant human environment. The typical community nursery raised only 3,000-5,000 seedlings, mainly in the long rains. Farmers were trained in seedling establishment and care in a group; extension workers also visited group members on their farms. Farmers were encouraged to try new species and practices on small plots in their farm, before expanding the area planted (Buck, 1990). By 1989,280 women’s groups (with 3,000 members active in agroforestry nurseries) were participating, as well as 300 primary schools. Most farmers were smallholders, with 82% cultivating less than two hectares of cropland. Over 40 tree species were grown in group nurseries. Four to five million seedlings had been produced in AEP-assisted nurseries, with a 50% average survival rate at two years.

while the total length of dense hedges expanded from 248 to 317 meters per farm (29%) (Scherr, 1992).’ The 1989 survey confirmed the project’s impact in accelerating the rate of farmer tree-growing, as well as the considerable extent of preproject tree husbandry and nonproject factors.

4. REGIONAL PATTERNS OF AGROFORESTRY INTENSIFICATION Average population densities in Siaya and South Nyanza rose from very low levels in the 1700s and 1800s to lOO/km*by 1948, ranging from 24 to 569 in different administrative locations. By 1990, average densities were 250/km* and over 400&n* in the high rainfall zone (Scherr, 1993). Agricultural intensification and loss of natural woodlands and fallows over this period were associated with major changes in the role and configuration of natural and planted trees in the farm landscape. Farmers’ early reliance on gathering from naturally growing trees evolved to management of naturally growing trees. This was followed by establishment and domestication of the more valuable species in order to better protect the trees and control harvest. With further increases in demand, farmers increased the numbers of trees on farms. Finally, farmers increased their management intensity, to increase yields and/or to accommodate intercropping with food and cash crops on a limited land area. This transition varied for different species and products, depending upon their value and scarcity in the natural vegetation.

(c) Data sources (a) Historical pressures for agroforestry Complementary research methods were used to evaluate variation in agroforestry practices in Siaya and South Nyanza over time and within the population. Historical agricultural and agroforestry practices and policies were identified through oral history from key informants, and historical archives and studies (Feam, 1961; Hay, 1972; Kenya National Archives; Ocholla-Ayayo, 1980; Ogot, 1967; Shipton, 1985). Informal individual and group interviews were used to explore farmers’ rationale for agroforestry adoption. Two sample surveys were undertaken in collaboration with the AEP. The first, in 1988, collected information on alley cropping and tree borders established by 110 AEP participants in Siaya. The second, in 1989, censused all agroforestry practices on farms of 336 participants in both districts, distinguishing those established before and during the project, and their design, site, use and management. Findings showed that over an average three-year period of project participation, the number of freestanding trees (as opposed to hedges) jumped from 227 (S.D. 363) to 513 (S.D. 579) per farm (125%).

intensification The area’s dominant land use historically was Savannah woodlands. The woodlands were progressively cleared with immigration by the Luo tribe into the region in the 1600-18OOs, to accommodate pasturage, agriculture, and settlements and to reduce the risk of tsetse. Under shifting cultivation, most tree products for household use were gathered. The most economically important tree uses related to livestock, for pod and leaf fodder, corral construction and shade. In the 1800s. fallow-based crop production became increasingly important, with permanent settlement, rising population densities, animal disease problems and proximity to long-settled agricultural populations in the western highlands. New tree product uses from indigenous species became important, including fuelwood for fish-drying, boat-building, sisal and wooden household goods. Live hedges became the accepted method for demarcating villages and homesteads (replacing earlier stone walls), and fences were built to protect crops from livestock. The earliest trees to be

FARMER ADOPTION OF AGROFORESTRY

protected and then established on-farm were valuable fruit and medicinal species from within and outside the region (e.g., mango). Planting and protection of high-value timber species, such as the indigenous iUarkhamia lutea, was documented by the late 1800s. Fruit trees were protected during clearing, and wildings were transplanted; new fruits were introduced, such as mango and guava. Tree tenure rights evolved so that trees were “owned” by the person who planted them, or whose ancestors had planted them (yadha) (Ocholla-Ayayo, 1980). After 1895, with British colonization, Luo territorial expansion ceased. Most remaining woodlands were cleared and claimed for settlement. A series of epizootics devastated the Luo cattle herds, which never fully recovered. The Luos learned to grow new crops and the area became an important maize-exporting region. With the decline of fallow length and effectiveness, farmers in the more humid areas attempted to modify the fallow, particularly broadcasting seed of Sesbania sesban, a short-cycle tree with prolific leaf. In cropped fields, farmers grew Markhamia Zutea, also a prolific leaf producer, for green manure. Increasingly, crop fields were under permanent cultivation. Useful tree species were now commonly protected during clearing, and valuable wildlings were transplanted to places where they could be protected. With increasing population density, farm and household hedges came to occupy a significant land area. Commercial markets for building poles developed by the 1930s (for railroad, urban construction in Kisumu, etc.), but this market was thin and involved few farmers. Active local markets for wood products arose during the 195Os,particularly fuelwood for local processing activities (fish-drying, brick-drying, beerbrewing) and construction materials for household use in the higher density communities. Still, barter markets between neighbors and kin were the most common systems of exchange.

(b) Contemporary pressures for agroforestry intensification

After Independence in 1963, fallow periods shortened and land use intensified. Agriculture entered a period of stagnation, due to declining soil fertility and crop yields. Fertilizer use was low due to high fertilizer: crop price ratios and poor yield response. Farm size declined through subdivision among sons. In 1989, among AEP participants, half had less than a hectare of cropland. There was large-scale labor migration to urban centers and more dynamic agricultural zones. Availability and access to products from naturally growing trees also continued to decline. The 1989 survey of AEP-assisted farmers showed that 55% still

791

had some natural woody fallow on their farms, but most of these were located in the dry zone and total area was small. In the medium and high rainfall areas, woody fallows have largely disappeared. With the decline in fallow land, households lost an important source of smaller diameter and lower quality wood for building poles and stipes. Although 66% of households obtained fuelwood supplies in 1989 by collecting from off-farm sources, for only 20% of households was this the primary source. Naturally growing trees on farms were universally used as a fuelwood source and were the primary source for 41% of households. But planted trees on farms were overtaking naturally growing trees as the primary source of fuelwood. Similarly, although most households still used some building poles naturally growing off-farm (32%) or on-farm (76%), these two sources were the primary source for only a minority of farmers. A majority (56%) relied primarily on planted farm trees and most of the rest were forced to purchase most of their poles. By the 197Os, increased monetization of the economy and the growth of towns led to a shift from barter to cash markets for woodfuel and construction materials. There were few options to meet new tree product demands under scarcity conditions. The critical shortage of household cash income, together with high transport costs, effectively limited the potential for Luos to meet household needs by importing tree products from outside the region or by finding nonfann substitutes (e.g., kerosene for fuelwood). In Yala Division, Siaya, for example, local purchase of fuelwood to provide the average daily household use of 8.5 kilograms, at 70 cents per kilo, would represent 40% of the local daily rural wage for women’s labor of KSH 15 (Muturi, 1991, p. 106). Informal interviews with farmers in several communities suggested that the alternative of reducing average household consumption of tree products was most widely practiced. There was increasing use of “inferior” fuelwood species (including crop residues), less and lower quality timber in house-building, declining numbers of household animals (requiring fewer fodder resources), and declining use of bush fallow and animal manure, which resulted in declining soil fertility. Community standards for the level of household fuelwood stores reportedly declined. The number of separate dwellings in the homestead has also declined (Muturi, 1991). These reductions in living standards could be countered by most farmers, under the economic conditions prevailing in Siaya and South Nyanza, only by increasing farm tree supplies. This many did, building upon both known practices and inputs from the AEP. In 1989, practically all fruit and timber trees found on the study farms had been planted (by seed, seedling or vegetative propagation) or transplanted. Once house-

792

WORLD DEVELOPMENT Table 1. Changes in primary uses of trees on farms lfor all tree species) Before intervention

After intervention

(330)

96 98

Ornamental Boundary marker Building poles Charcoal Animal fodder Live fencing* Fruit Fuelwood Green manure Rope Soil conservation Seed Shade Medicine Stakes or fitos Timber Windbreaks

116 3875 26637 323 681 1334 5091 18352 288 983 254 1 3039 656 627 6443 1264


433 323 36348 32 1037 8193 7441 9948 13967 456 1590 15 3733 1030 1027 9011 1259

Total

75,964

100

Fuelwood Green manure Rope Soil conservation Shade Medicine Stakes or fitos Timber Windbreaks

10 14031 3754 260 192 50929 1316 17796 92 3536 75 140 947 2325 52 1384

Total

96,839

(n =I

%

Total (335)

% 106

38 Cl 1 9 8 10 15 cl Cl Cl 4 1 1 9 1

549 4198 62985 355 1718 15527 12635 28306 14255 1439 1844 16 6773 1686 1654 15454 2523

<1 2 37 <1 1 9 7 16 8 cl <1 cl 4 1 1 9 1

95,843

100

171,917

100

cl 14 4 cl <1 53 1 18
10 1640 2297 260 1205 2295 1 466 1229 687 30 60 410 181 330 93 120

<1 5 7
20 15671 6051 520 1397 73880 1782 19025 779 3566 135 550 1128 2655 145 1674

<1 12 5 Cl cl 51 1 15 1 3 Cl cl 1 2 cl 1

100

3 1,969

100

128,978

100

(333)

99

Free-standing trees:

Dense hedges: Ornamental Boundary marker Building poles Charcoal Animal fodder Live fencing* Fruit

cl 4

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agrofonstry, Nairobi, Kenya, 1989. *Most live fences are established as dense hedges. Their length in meters was measured, rather than counting individual trees. Figures derived from a 14% sample.

hold needs were met, farmers often became interested in cash income from tree products. Table 1 compares the primary use of trees found on farms before and after project intervention. Earlier emphasis, reflecting agroforestry priorities in the 1960s and 197Os, was on building poles, fuelwood and live fencing. Later plantings reflect continued interest in poles (38% of free-standing trees), but also green manure, while fuelwood is obtained mainly from trees grown primarily for another use. Cash income-earning

opportunities are increasingly important. Over half of surveyed households sold building poles for cash in the previous year, and half had sold fruit. Some farmers near population centers with higher fuelwood: crop price ratios, originally established alley-cropping plots for green manure, but later managed them principally for fuelwood. Of all surveyed households in 1989, a third had sold fuelwood for cash in the previous year; of households in the low-rainfall zone, 43% (Scherr, 1993).

793

FARMER ADGPTION OF AGROFORESTRY

with soil productivity benefits as secondary benefit. This suggests that the rise of tree product markets can encourage tree establishment for environmental benefits.

It is notable that nearly a fifth of trees were grown primarily to improve soil productivity (green manure, soil conservation, windbreak). A larger number were grown mainly for other purposes (product use or sale),

Table 2.

Species

(n =)

Changes infree-standing Before intervention (330)

tree species grown by 336 fonners

% 98

After intervention

%

(333)

99

Main foresfry trees tEucalyptus spp. tCussi0 siameeo Subtotal

12698 2282 14980

2:

20771 5798 26569

Main agroforestry trees *Markhamio lutea *Leucaeno leucocephala Subtotal

10747 348 11095

14 0 15

12417 16638 29055

8

1600 1760 5270 1676 636 2731 3031 2867

Other trees for wood and leaf *Multiple naturally growing speciese 6376 *Agave sisalensis tcupressus lusitonico YG: *Euphorbia tirucalli 5065 *Lantana camara 5252 $Terminalia peruviana 2915 tCu.ssia spectobilis 1141 tCrevillea robusta 230 *Acacia spp. 2843 *Albizia coriario 1711 SMelia azadirach 531 $Parkinsonia oculeata +Sesbania sesban 37: SCallitris robusta 335 $Calliandra calothyrsus *i?uphorbia candelabrum 6476 *Sesbania bispinosa *Bridelia macrantha 42: *Terminalia brownii 661 *Combretum molle 731 Subtotal 37,523 Fruit trees *Psidium guajava t Citrusspp. tCaric0 papaya *Mangifera indica Subtotal OmamentaUshade trees tJocaranda mimosifolia $Terminalia mentalis Subtotal 138 minor species All free-standing species

2,659 670 402 1,043 4,774

202

17

: 7 : 2 Cl 4 2 1 cl <1 cl Cl :, 1

4z 1454 1849 1381 1133 1356 452 785 349 162

f 50

29,0:38

3 1 1

1,505 2,461 2,001

:,

6.2:

2::

<1 <1
887 626 1,513

7,440

9

76,064

100

22

Total

%

(335)

100

2:

33469 8707 42176

2:

1’: 30

23164 16986 40150

1: 23

2

: 1 Cl 1 <1 <1 <1 31

7976 7856 7448 6741 5888 5844 4558 3097 2936 2124 1985 1856 1755 1468 1363 1098 785 773 773 769 67.093

: 2 I 7

4,265 3,131 2,403 1,734 11,533

: 2 1 : 3 <1 <1 2

1

19

: 4 : 3 : 2 1 1 : : 1 Cl cl cl Cl 39

2” 1 :

1

:

1,089 676 1,765


3,096

3

937

I

5

95,923

100

172,088

100

Source: CARE International in Kenya and ICRAF. Agmforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry. Nairobi, Kenya, 1989. *Species introduced to Siaya and South Nyanxa Districts prior to 1900. tSpecies indigenous or introduced to Siaya and South Nyanxa Districts during 1900-50. SSpecies introduced to Siaya and South Nyanza Districts during 1971-89. ~“Multiple naturally growing trees” was indicated for agmforestry practices with a large number of trees in a highly variable species mix. Most were found in bush fallows or dense hedges in homesteads which received little management. Numbers were estimated, rather than counkd.

WORLD DEVELOPMENT

794

By contrast, few farmers are yet planting trees for fodder. Livestock numbers are small and of low productivity, and naturally growing shrubs and by-products of planted species are still widely available for fodder. The exceptions are farmers interested in highprotein, tree-based fodder banks, in a few areas where commercial dairy production is emerging. It is important to note the wide variety of tree products of interest to farmers. Around 37% of all trees and hedges were for 14 “minor” uses (i.e., under 10% of the total). Continued intensification and economic integration of the region may lead to greater specialization in the future. But during a major period of transition from gathered to cultivated supplies, and from extensive to intensive land husbandry, and in an environment of subsistence insecurity, such variety is both understandable and probably desirable.

(c) Changes in tree species diversity Intensification has been associated with a change in tree species diversity. The proportion of naturally growing species has declined, while the number of planted species increased and became more specialized by niche, use and market. The 1989 survey documented 167 different tree species on-farm. Of these, 68 were nearly always naturally growing and another 69 were often planted but found in small numbers. Five dominant species (eucalyptus, markhamia, Leucaena leucocephala, Cassia siamea and sisal) accounted for over half of all free-growing trees. Another 24 species were commonly planted. There was a trend toward a few dominant species; still, the increased specialization by use and site led to a much larger number of species than is typically reflected in agroforestry extension programs (Table 2). Not until production systems become fairly intensive, is there likely to be interest in replacing low-cost natural and vegetative propagation methods with more costly seedlings of selected, high-quality seed. In Siaya and South Nyanza, only 30% of preproject trees were established by seedling (mainly for fruit, poles and timber). With the project significantly reducing the cost of seedling production, and increases in the perceived economic value of trees, 83% trees established in the project period were by seedling. The proportion of farm trees established naturally dropped from 5 1 to 8%.

(d) Changes in site selection and planting arrangement

Intensification is also associated with changes in farmers’ choice of site and planting arrangement. In the early part of this century, farmers planted trees primarily in near fields and protected valuable trees

around the farm, at low densities and in scattered arrangements. In the 1970s and 198Os, there was increasing concentration of trees in “in-between” places (away from crops) and around crop field borders, in clusters or lines. With increases in relative wood: maize price ratios in the 198Os, and more productive tree species amenable to intercropping, there was a move toward intercropping. Dense hedges demarcating homesteads and some fields were the dominant form of tree-planting in the 18OOs,but are relatively less important now. Woody fallows accounted for the largest proportion of farm trees several decades ago; in 1989 for fewer than 10% of free-standing trees. Only a small proportion of all farm trees were found in woodlots (in contrast to smallholder treegrowing in other parts of the Kenyan highlands). Instead, the most important niches for tree-growing in recent years are the cropland (intercropping and field borders, 39%), followed by the homestead (25%). In part this is due to small farm size, where most land is in crops. Trees must be selected and managed to reduce tree-crop competition. A major AEP contribution was the introduction of tree species appropriate for intensive intercropping. Trees are increasingly used in a service function to crop production, as windbreaks (especially in the drier zone where wind damage is a serious problem) or green manure (using alley-cropping, mixed intercropping or planted fallows). In the homestead, trees are valued for shade and aesthetics, fruit, fuelwood and fodder. Trees planted there am easy to protect and harvest. Livestock management has also influenced tree site selection. Where livestock are fed mainly through herding, there may be considerable damage to seedlings and saplings in the field, so farmers concentrate tree-planting in the homestead. With increasing population density, fencing of crop fields becomes the norm (Ruthenberg) and there is greater scope for treeplanting. With intensification, more systematic planting configurations were used. Of all free-standing trees in 1989, only 25% were in traditional scattered arrangements. An estimated 39% were planted in lines, 21% in small blocks, 14% in linear intercropping (alleycropping) and 6% in systematic mixed intercropping.

(e) Regional variation in density of planted frees The average density of free-standing trees (planted and naturally growing) on surveyed farms rose from 179 to 388 per hectare (Table 3). Planted tree density is directly related to population density, a finding consistent with other parts of Kenya (Bradley, 1991; Ecosystems, 1984; Warner, 1993). This effect results from higher total demand for subsistence tree products and services, the rise of local markets from nonfarm

FARMER ADOmON Table 3.

795

OF AGROFORESTRY

Average number and density offree-standing trees (planted and naturally growing) on farms before the initiative and overall, by ecozone

Two reliable rainy seasons (n= 118)

Number of trees: Meant Coe.f. of variation Minimum Maximum

230 158 1 3.073

174 160 2 1.997

189 109 1 937

318 157 2 3.073

Density of trees: Mean Coef. of variation Minimum Maximum

179 130 Cl 2,100

167 138 1 1,280

174 138 4 2,100

195 119
All (n = 330)

Two reliable rainy seasons (n = 119)

Two rainy seasons (n = 96)

One reliable rainy season (n= 119)

Number of trees: Mean Coef. of variation Minimum Maximum

510 113 11 4,150

434 127 25 4,899

4% 90 53 2,826

595 114 11 1,336

Density of trees: Meant Coef. of variation Minimum Maximum

388 147 6 2.571

423 134 1 5.103

380 85 28 1.939

351 108 1 2.57 1

Overall

Two rainy seasons (n = 95)

One reliable rainy season (n= 117)

All (n = 330)

Before the Intervention

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry, Nairobi, Kenya, 1989. *Two outliers were removed: agroforestry area ~307 hectares and tree density t 17,ooO. Information was missing on six farmers. tThe mean was calculated as number of trees per hectare on farm plots with at least one tree present.

households and local industry, and better infrastxucture for regional trade (e.g., in eucalyptus poles and papaya). Interestingly, preproject tree numbers and densities were higher in the dry zone, probably due to the greater area in woody fallow and protection of trees in cropland and pastures. The rate of increase and postproject densities were higher in the higher rainfall zone, where tree growth potential is higher and intercropping less competitive; and where demand is higher. Given higher costs of tree establishment in the dry areas, however, increases are significant. Tree use is different acrOss ecozones. The highrainfall zone farmers used proportionately fewer freestanding trees for fuel, and more for fruit and fencing. The medium-rainfall zone farmers used more trees for timber and green manure. In the low-rainfall zone, a

much higher proportion of trees was used as fuelwood, and fewer for fruit, fencing, timber or green manure. The proportion of trees used mainly for building poles was the same in all ecozones (36-388). Tree-planting appeared to be inversely related to the availability of fallow or common lands. The average number of trees planted per farm for households varied according to their access to gathered tree product sources off-farm (Table 4). Tree numbers were 50% greater for farmers who had no access to building pole supplies off-farm than for those who relied primarily on such off-farm sources; and 70% greater for farmers who had no access to off-farm fuelwood supplies than for those who depended mainly on offfarm sources. Typically, in the process of deforestation, poles become scarce more quickly than does fuelwood (for which many more species and plant

796

WORLD DEVELOPMENT Table 4.

Average number of planied, free-standing trees per farm, by extent of dependence on gathering of poles andfielwood No gathering off-farm

Some gathering off-farm

Building Poles: Mean Coef. of variation n

286 163 226

237 loo 62

1% 92 44

Fuelwood: Mean Coef. of variation n

316 137 112

311 238 94

186 472 125

Tree product*

Primarily gathering off-farm -

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry, Nairobi, Kenya, 1989. *“Gathering” refers only to off-farm gathering and not gathering from naturally growing trees on farms. Sources were ranked from 1 to 4 and included a “not applicable” option as well. The latter would be “no gathering.” For “some gathering,” source rank equalled 3 or 4, and for “primarily gathering,” source rank equalled 1 or 2.

forms can be used). To some extent, tree-planting definitionally reduces dependence on off-farm sources, but the substantially higher cost of planting trees, relative to gathering from nearby sources, suggests that causality is principally in the other direction.

5. HOUSEHOLD PATTERNS OF AGROFORESTRY ADOPTION Household agroforestry practices in Western Kenya were quite variable. Different constraints and strategies of access to land, labor, cash and off-farm tree resources led to different agroforestry choices. Profitability was a necessary, but not sufficient, incenTable 5.

use (n =I

tive. Environmental objectives focused on protection of productive resources and improved human habitat.

(a) Agroforestry for di$erent livelihood strategies The 1989 survey did not support a full multivariate analysis of socioeconomic and agroecological factors influencing farmers’ agroforestry priorities. Findings did demonstrate significant differences associated with differences in household wealth, land and labor resources, as reported also for South Nyanza (Diamond, 1992) and elsewhere in Kenya (Dewees, 1993). Survey enumerators assessed the wealth status of the sample through simple qualitative indicators, cat-

Number and primary use offee-standing trees, by wealth class Poor (98)

Total trees Mean number of trees per farm? % of all trees

43,222

Fuelwood? Fruit Fencing Building palest Timber? Green manure Other

9,736 2,197 3,294 16,313 1,926 3,856 5,900

% 30 100

Averaee

(224) 121,972

%

17,363 9,829 10,745 44,920 13,085 9,916 16,114

8

67

(101

3

100

6,360

100

636 (4)

545 (71) 23 5 8 38 4 9 14

Wealthv

14 8 9 37 11 8 13

1,203 573 1,148 1,634 414 483 905

Total*

%

(332) 171,554

100

512 (1001 19 9 18 26 7 8 14

28,302 12,599 15,187 62,867 15,425 14,255 22,919

16 7 9 37 9 8 13

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry, Nairobi, Kenya, 1989. *Totals am larger than the sum of the specific uses because some minor uses have been excluded. The total refers to all trees on farms. Figures are derived from a 14% sample of project participants. tStatistically significant differences between poor and average households.

191

FARMER ADOPTION OF AGROFORESTRY Table 6.

Mean number and density offree-standing

andprincipal use, by agroforestry land tercile*

trees Small farms n= 115

Medium farms n= 105

Large farms n= 110

240 562 30 11 11 10 9 29

470 355 35 11 11 9 9 2.5

785 210 37 8 17 8 9 21

Number of free-standing trees? Tree density (#/ha)t Trees for building poles (%) Trees for fruit (96) Trees for fuelwood (%)t Trees for green manure (%) Trees for timber(%) Other uses (%)t

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry,Nairobi, Kenya, 1989. *Agroforestry land refers to total area of all farm plots in which trees were found, in most cases it cotrespot& closely to total farm area. Two outliers were removed: agroforestry ha > 307 and density 2 17.000. tStatistica1ly significant differences between size classes of farms. egorizing them as unusually well-off (3%), average (67%) and poor (30%). While there was too small a

subsample to assess differences of the well-off group, there were statistically significant differences in agroforestry practices between the average and poor groups (Table 5). There was greater use of trees for building poles and especially fuelwood among the poor, and of timber by the average group. Obviously, more information on household characteristics and resources is needed, to fully understand the nature of these linkages. Interviews suggest that poorer farmers cannot afford to wait long enough to allow trees to grow to timber size, despite their higher value. Farm size-not necessarily correlated with wealth in many areas (Diamond, 1992) - also affects agroforestry practice. Total numbers of trees in the tercile of larger farms are more than triple those on smaller farms, although tree densities are much lower (Table 6). Larger farms grew trees more often for building poles and fuelwood; small farms for fruit, green manure, and other non-wood uses. On large farms, Table 7.

Percenrage offree-standktg

Niche Are of cropland (range in hectares) Homestead* Cropland* Grazing woodlots* Paths/boundary Total percentage Total number of trees (on 14% sample) % Total trees

only 27% of trees are found in the homestead, compared to 43% of trees on small farms. Large farms have more trees in the cropland and woodlots (Table 7). Farmers were asked to identify their principal constraint to growing more trees on farm, which was most commonly land, labor or water. Scarcity of land appears to be a greater constraint to adoption of alleycropping in this area than is scarcity of labor (Table 8). Overall, many more trees, at higher densities, are found in the cropland of land-constrained farmers, most of whom are found in areas with limited natural wood supplies. Farmers for whom labor is the major constraint use more farm trees for fuelwood, presumably to save labor from fuelwood gathering.

(b) Gender differences

in agroforestry adoption

The land tenure system of the Luos vests control over land in senior male clan members. Sons acquire usufruct rights for their wives at marriage, but do not

trees in differentfam Small farms (I1= 115)

niches, by agroforestry land terciles Medium farms (!I = 105)

Large farms (n = 110)

<.7 43 38 13 4 1

.7-l .5 35 40 16 7 2

167.3 27 44 12 15 2

100

loo 39,626 24

100 94,661 58

29,039 18

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agmforestry Adoption and Impact Survey. International Centre for Research in Agroforestry, Nairobi, Kenya, 1989. *Statistically significant differences in proportion of trees found in that farm niche between different farm size classes.

798

WORLD DEVELOPMENT Table 8.

Effect of household constraints on adoption of agroforestry*

Principal constraint to tree-growing Land constraint Number of farms

Labor constraint

55

41

Number of trees on agroforestry land Mean Standard deviation

459 (486)

(ZZ)

Density of trees on agroforestry land (#/ha) Mean Standard deviation

487 (441)

303 (229)

Number of trees on cropland Mean Standard deviation

(Z)

178 (157)

Density of tree on cropland (#/ha) Mean Standard deviation

562 (797)

229 (185)

29

46

Percentage of trees for alley cropping Mean Standard deviation

(1:)

(;A)

Percentage of trees used principally for fuelwood Mean Standard deviation

(::)

(ii)

Percentage of farms with alley cropping

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry, Nairobi, Kenya, 1989. *Total sample is 335. “Cropland” is the total area in crops on land with at least one agroforestry practice. “Agroforestry land” is the total farm area with at least one agroforestry practice; on most farms this corresponds closely to total farm area.

until their father dies. Polygamy is common, and while most wives are given responsibility for working particular pieces of land, in some households there is joint production. Women also assist their husbands on special plots managed by him. As the planting of trees can be authorized only by those who have inherited land rights, most households participating in the AEP were older, in a later stage of the demographic cycle. Women are responsible for supplying household food, fuel and water. Traditionally men have been responsible for tree-planting and harvest. Women have played a minor role in tree husbandry, although taboos against women’s participation are not as strong as reported for other areas of Kenya (Hambley. 1992; Bradley, 1991). Participation in the AEP significantly increased women’s knowledge and activity. There were gender-related differences in several variables, reflecting women’s greater role in crop production, more restricted role in timber marketing, and more limited ability to mobilize labor and access land. gain control

Although the project was oriented toward women, 3 1% of active group members were men. A few key differences in agroforestry practices were associated with the gender of the nursery group member (Table 9). Men had 50% more trees on their farms and almost 30% higher tree density (indicating that differences in land access did not explain all of the difference in tree numbers). Men’s farms also had higher numbers and density of trees in cropland. Women’s farms had significantly more trees used primarily for fuelwood, which may partially reflect women’s greater emphasis on use for fuel. Bonnard and Scherr (1994) suggested that observed differences may not be due to genderper se, but rather access to land and labor and decision-making authority. Many Luo households depend upon remittances from labor migration, which often conditions labor and cash access. Most of the men participating as group members in the AEP concentrated on on-farm activities, rather than labor migration, suggesting higher levels of on-farm income, access to wives’

799

FARMER ADOPTION OF AGROFORESTRY

Table 9.

Influence of gender and household status on agroforestty practices* Female husband away

Female with no husband

Male

Female

Female with husband on farm

Number of farmers7 % of sample

105 31

230 69

137 42

44 13

47 14

# Free-standing trees Mean (Standard deviation)

643 (6W

428 (472)

426 (471)

458 (557)

406 (392)

Tree density (#iha) Mean (Standard deviation)

(2)

342 (308)

341 (285)

398 (341)

291 (340)

#Free-standing trees on cropland 290 Mean (Standard deviation) (524)

185 (253)

189 (258)

205 (301)

157 (188)

Density of trees on cropland Mean (Standard deviation)

418 (682)

336 (434)

331 (458)

407 (362)

287 (422)

Farmers with alley-cropping Number of farmers % farmers

(Z)

% Trees for alley-cropping Mean (Standard deviation)

(1:)

(1Is)

(16)

8 Trees for fuelwood Mean (Standard deviation)

11 (15)

14 (19)

12 (18)

(E)

15 (20)

16 (22)

Source: CARE International in Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry, Nairobi, Kenya, 1989. *“Agroforestry land” refers to total farm area in which trees are found; in most cases it corresponds closely to total farm area. “Cmpland” is the total area in crops on land with at least one agroforestry practice. tTwo outliers have been removed from the sample, with agmforestry area > 307 hectares, and tree density > 17,OOO/ba.

labor, and larger farm size. Of the AEP women nursery group members, 19% had husbands working away. These women often had more management autonomy (subject to being so authorized by their husbands) than women with husbands at home. Another 20% of women were widows or otherwise had no husband, a very insecure position in Luo society, and were typically acting for their sons. There is little difference between the groups of women in total number of trees, but widows had substantially lower tree densities. Women with husbands away planted more trees on cropland than the other two groups of women, and had much higher tree densities in the cropland. Women without husbands on the farm used a higher proportion of trees for fuelwood. Widows showed a higher preference for alley-cropping than other groups of women, who actually had less alley-cropping than the men. Bonnard and Scherr

also found that women without men on farms employed some form of conservation practice more often than women with husbands resident at home, or men. More data are needed to confirm the economic rationale behind these differences.

(c) Environmental considerations in household decisions Environmental rehabilitation was an important, but secondary, objective for most farmers in adoption decisions. Green manure, soil conservation, shade and wind protection were listed as the principal uses for 21% of planted free-growing trees (Table l), and as secondary uses for another 10%. Ecological objectives were important mainly ‘on sites where land degradation was perceived to threaten household

WORLD DEVELOPMENT

800

Table 10. Change infarmer adoption of selected agraforestrypractices during the project period Percentageof farms Practice

Trees in the homestead Living fences (dense hedges) Trees on crop field borders woodlots Fruit orchards

Plantedfallows or alley-croppingfor green manure Alley cropping with leucaena

Before intervention

Overall

84 68 34 12 9 4 1

93 79 33 23 16 53 25

Source: CARE Internationalin Kenya and ICRAF. Agroforestry Extension Project Agroforestry Adoption and Impact Survey. International Centre for Research in Agroforestry, Nairobi, Kenya, 1989.

livelihoods through the imminent loss of productive resources, e.g., erosion resulting in loss of usable land or nutrient depletion in principal crop fields, resulting in uneconomic yield levels. Noneconomic factors, particularly improvements in the quality of the human environment (ornamental and shade trees, wind protection for the homestead, a more attractive landscape), were important to many farmers. It seemed important that environmental degradation, and the effects of trees in reversing it, be clearly visible to the farmer. Since farmers in Siaya and South Nyanza tended to plant trees on more marginal, exposed or degraded plots of land, visible positive effects could often be obtained in one to two years. Because of small average size of agroforestry plots, hydrological or soil effects have most likely been local. Although there has been a clear visual change in the landscape through increased tree numbers, the study did not evaluate landscape-level ecological effects. Many farmers saw tree-planting activities as a way of increasing the value of assets to be inherited by their children. Farmers associated with some Christian religious groups valued agroforestry activities (particularly environmental rehabilitation efforts) as their contribution to Biblically-mandated “care for the earth.” Other community groups identified the protection of land and water resources as a community obligation.

6. MANAGING RISKS OF AGROFORESTRY ADOPTION Poorer farmers are often unable to take advantage of new economic opportunities, even where incentives are attractive, because of associated risks. The Siaya-South Nyanza example provides some insight into the process by which farmers reduce the risks of integrating agroforestry into their farming system. Key strategies are initial testing of new technologies, building on familiar practices, species diversity, and technology adaptation to better meet management constraints and increase early economic returns.

(a) Testing and evaluation Farmers in Siaya and South Nyanza adopted new agroforestry practices in incremental steps. The first step was small-scale experimentation. Farmers selected a piece of land - typically of lower quality -to establish a small number of trees for observation. Some were reluctant to undertake recommended management of unfamiliar tree species (such as coppicing or pollarding) in this early stage, wishing to observe characteristics of the tree under normal growth. A second step was maintenance and management of an operational plot, to test a new practice for a period of years. This was illustrated particularly in the case of leucaena alley-cropping and contour hedges. The project achieved high rates of farmer testing: over 50% of Siaya participants’ farms surveyed in 1988 had established at least one alley-cropping or plantedtree fallow plot. In addition, 78% of plots were being cut back regularly for green manure. But average alley-cropping plot size in Siaya in 1988 was under 500 square meters, so the proportion of total cropland under alley-cropping was too limited to have any appreciable effect on overall crop yields (Scherr and Oduol, 1988). A third step in the “adoption” process was the establishment of new plots or renewal of the original plot after completion of the production cycle. The 1989 survey showed that 45% of AEP members’ agroforestry plots had been expanded during the project period. There were major increases in the proportion of farmers with alley-cropping, fruit orchards, planted fallows and woodlots (Table 10). There was a small increase in the proportion with homestead trees and living fences, and no change in those with tree borders in crop fields. Many more trees were planted in homesteads and tree borders, by farmers who already had adopted the practice, and often with new species.

(b) Building on familiar agroforesrry practices The Siaya-South Nyanza case confirms experience

in many parts of the world that adoption proceeds

FARMER ADOPTION OF AGROFORESTRY

most quickly where the systems are based on alreadyexisting agroforestry practices (Raintree, 1991). Farmers’ familiarity with components or management systems shortens his or her individual “testing and evaluation” period. The AEP introduced new establishment methods for familiar species, e.g., use of seedlings for Albizia coriaria, Melia azadirachta, and Markhamia lutea, previously propagated mainly as wildings or directseeded. New configurations, such as alley-cropping, were introduced using the familiar, popular species Markhamia lutea, even though this did not turn out to be a suitable species for intensive green manure production. New management systems were introduced for familiar species, such as fruit tree-budding and grafting for mango and papaya. New species were promoted for familiar agroforestry practices, e.g., Thevetia peruviana for hedging. With extensionist credibility and farmer confidence strengthened through these activities, there was greater willingness to try new agroforestry concepts with new species (e.g., leucuena alley-cropping or Erythrina contour hedges). Farmers drew from project ideas to develop their own innovations, such as live staking of passionfruit with Sesbania, single stems of leucaena pollarded for fodder production, and rotational alley-cropping with leucaena.

(c) Diversity Diversification is a well-recognized strategy for managing risk in highly uncertain economic environments. Luo farmers appreciated multipurpose tree species which allowed them to respond flexibly to changing household needs and relative market prices. Leucaena was especially valued, as different management could be applied to produce predominantly green manure, fuelwood, building poles or fodder. Pole species with significant side branching were not necessarily devalued for that reason, as side-prunings were usable as fuel. Farmers often planted several species for a single use, to reduce risks from pest and disease, and meet a range of site and management conditions.

(d) Technology adaptation Farmers did not adopt “trees,” or even “trees with crops.” They adopted specific tree species for priority uses in specific sites. There was considerable modification of agroforestry systems by farmers to meet their own needs, particularly in terms of spacing, pruning regimes and mix of harvested products. The Siaya technology design survey of 1988, for example, showed the purposeful variability in farmers’ border plantings with the familiar species

801

Markhamia lutea. Principle uses were for building poles, fuelwood, windbreaks for crops, and mulch for

crops; each use requires a different spacing, diameter at harvest and field layout. In-row spacing varied from 2-5 meters. Some farmers mixed species in the line, and many others had mixed-age stands. Recommendations for an ideal “technical package” on Murkhamia tree lines would not be particularly useful. But information on the relationship between particular design and management factors, and tree growth, crop competition, mulch production, etc., under particular edaphic and climatic conditions, would help farmers to improve the technical and economic efficiency of their choices.

(e) Improving economic returns from agroforestry Farmers used a number of strategies to reduce the cost of establishing new agroforestry systems. Even where they planned to grow a large number of farm trees, they utilized a pattern of gradual establishment. This reduced discounted net costs over time, spread establishment risks over several years and avoided resource bottlenecks (and cash expenditures) in an initial establishment year. Farmers also established trees for wood production in shorter rotations, with more frequent harvests. They planted more densely in lines or woodlots than recommended in conventional silvicultural guidelines and then utilized or sold the extra thinnings and prunings for fuelwood or poles. For agroforestry systems with short rotations or relatively lower value products, they chose lower cost establishment methods (e.g., direct seed or wildlings, rather than seedlings). Farmers frequently established trees in annual crop fields (often modifying spacing and densities to accommodate the crops), even where the ultimate intention was a pure tree stand, to reduce establishment costs and generate early cash income from the plot. Farmers also followed economic logic in selecting low-cost sites for tree-growing. On larger farms, trees which competed even moderately with crops were typically planted away from crops or at low densities. As farms became smaller, or more intensively managed, trees were established in the “interstices” of the farm - borders or unused or lower quality strips or comers between crop fields. At higher levels of intensification and/or land constraints, one found intercropping systems requiring intensive management to increase total returns and reduce tree-crop competition. Farmers who had not yet begun to utilize marginal plots or farm interstices for deliberate tree-planting were unlikely to adopt intensive intercropping practices.

WORLDDEVELOPMENT

802

7. IMPLICATIONS FOR AGROFORESTRY INTERVENTION Agroforestry experience in Western Kenya supports the hypotheses laid out in the introduction to this paper. Agroforestry practices in Siaya and South Nyanza evolved historically along with land-use intensillcation, to meet new needs for tree products and services. External intervention helped to accelerate the process by widening options and making new germplasm available. The choice of agroforestry practices on particular farms varied considerably, reflecting resource constraints and differing livelihood strategies. Farmers consistently adopted technologies to reduce associated risks. There are clear implications for agroforestry development policy, in selecting technological priorities and intervention strategies, accommodating household variability, and supporting farmer technical innovation.

(a) Designing interventions tofit regional economic patterns

Planning for agroforestry interventions calls for a broad assessment of constraints in the system linking production, inputs, consumption, processing and distribution of tree products and services and associated crops. Extension of information about agroforestry components and practices may not be sufficient to stimulate widespread adoption. It may be equally important to revise disincentives to agroforestry (e.g., distortions in reIative prices for inputs, outputs or substitutes), remove legal and regulatory constraints (e.g., tenure insecurities), improve marketing systems, or support local groups and institutions involved in agroforestry intensification (e.g., community work groups for nursery or tree establishment, local credit pools, marketing cooperatives) (Scherr, 1992). Selection of agroforestry components and technologies for extension should begin with systematic assessment of existing practices. To what extent and for what purposes have farmers begun to domesticate tree or shrubs species? To what extent does land pressure demand more intensive production systems? Can farmers still easily produce more tree products simply by improving management of naturally growing trees or by fitting more trees into the interstices of the farm, or are they faced with the need to increase productivity of intercropping systems? Do farmers have access to economically attractive substitutes for scarce tree products and services? What types of agroforestry innovations are being used by those farmers pursuing intensification (i.e., those with special interest, market access, or resource constraints)? In more extensive farming systems, the assumption that agroforestry programs should promote intensive seedling production of fast-growing improved tree

species for dense plantings of trees in cropland may be. questioned. Promotion of better protection for wildlings, denser planting of superior local seed of indigenous trees, or low-cost management systems for introduced species may be more appropriate.

(b) Accommodate variable livelihood strategies Extension strategies can recognize the high variability in farmer agroforestry options and preferences by promoting a “basket of choice” of species and systems. Farmers are likely to benefit from exposure to “models” which they are encouraged to adapt, rather than fixed “packages,” and by realistic information about expected costs and benefits under local economic conditions. The socioeconomic benefits of particular interventions need to be assessed relative to farmers’ real alternatives for obtaining the same products or services. For example, how do the costs and benefits of border plantings for poles compare to the options of collecting poles from natural woodlands, purchasing them in the market, bartering for them from neighbors, or substituting construction materials? How do cash returns to family labor and other scarce resources from producing tree crops compare to the cash income from allocating those resources to agriculture, artesanry, or off-farm income? Household-level economic analyses of these practices should explicitly evaluate the difference in returns for farmers with different strategies and access to land, labor, capitaI or tree resources, as these affect the structure of production costs and the appropriate selection of comparators, intrahousehold analysis may also be necessary, to distinguish incentives and constraints by gender, or age. Such analyses could guide extensionists in identifying likely adopters of particular interventions, and provide useful information to farmers in planning agroforestry investments.

(c) Reduce risks of agroforestry adoption Effective extension programs will respect farmers’ need to reduce the livelihood risks associated with agroforestry. Farmers’ need for a “trial period” with new species or technologies can be incorporated into efforts (Buck, 1990). agroforestry extension Extensionists can encourage farmers to try alternative designs (in terms of sites, species, spacing, management), combining technical information from the extensionist and their own experience. Projects can accelerate the process by setting up trials with farmer groups and individuals, for regular observation and assessment by the community, prior to large-scale planting.

FARMER ADOPTION OF AGROFORESTRY

A key role for the extensionist may be as a catalyst of local innovation and an information “broker” who can bring together local and externally derived knowledge in technology design, and document technology adaptations. He or she can bring in technical knowledge from outside the community, and provide a twoway link to formal research efforts on the effects of different factors on agroforestry performance, and selected tree germplasm. Costs and risks of agroforestry practices can be reduced by modifying species mix, layout, management and harvesting sequence. Farmers benefit particularly from incorporation of components or management systems which generate products, services or income in the early years of the production cycle, even if these involve some reduction in total output and income.

8. CONCLUSIONS The hypotheses on agroforestry adoption discussed in this paper are consistent with agricultural development theory, and are supported by some case study evidence. Overall, however, there has been little effort to empirically investigate the role of economic conditions and incentives in the development and management of agroforestry systems. Careful field survey and

803

archival research is needed, in different biophysical, social and economic environments, to understand historical trends in agroforestry practice, and to predict the likely effects of policy change at household and regional levels. We are still far from understanding the structute and function of markets for tree products grown on farms, and market changes in response to changing populations, economic integration, or ecological pressures. Nor do we understand the opportunities and constraints for disadvantaged groups of farmers to enjoy sustained economic benefits from agroforestry. Those promoting agroforestry development are seeking new strategies whose benefits are not limited to small areas of intensive project activity. Where current and prospective economic incentives for agroforestry are positive, one would expect to see widespread experimentation with more intensive practices. On the other hand, some regions and households will find that certain agroforestry systems cannot “compete” economically with alternative uses of labor, land or capital, or alternative, lower cost sources of product supply or methods of environmental protection. The research community is encouraged to undertake the detailed market and household economic studies, sensitive to social, cultural and ecological variables, which would allow us to characterize different settings and options.

NOTE 1.

Changes were statistically significant at the .05 level.

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