Number 3, June 1995 

 

 

The material that follows has been provided by 

Overseas Development Institute

  

 

Alley farming: have resource-poor farmers 
benefited? 

Jane Carter 

Over the past two decades, there has been much scientific interest in the potential of 
agroforestry for small-scale farming. One form of agroforestry that has received 
particular attention is alley farming, intended as a sustainable, intensive system that 
would radically improve the long-term prospects of resource-poor farmers. Although 
impossible to estimate precisely, total global expenditure on alley farming research, 
development and promotion to date runs to tens of millions of US dollars. It is now 
widely recognised that the technology has far less potential than originally 
anticipated, major limitations having emerged in both its technical and socio-
economic characteristics. This paper reviews the documented on-farm performance of 
alley farming to date, identifying niche areas with some prospects for successful 
adoption, and suggesting specific areas for further research.[1]

 

 

Alley farming 

was conceived in the late 1970s by researchers at the International 

Institute for Tropical Agriculture (IITA) in Ibadan, Nigeria. Their aim was to create a 
system of farming rainfed lands in the humid and semi-humid tropics that would 
eliminate the need for a fallow period to replenish soil fertility. This was achieved in 
alley farming by combining trees and crops in a systematic manner, and utilising the 
deeper rooting trees as pumps to bring up nutrients from lower soil horizons. The 
originally selected tree species could also fix atmospheric nitrogen, thus further 
contributing to soil enhancement. 

The spread of alley farming 

Research

 

Following promising early on-station results at IITA, alley farming trials were 
adopted and promoted by a number of other international research centres within the 
Consultative Group for International Agricultural Research (CGIAR), most notably 
ILCA[2](the International Livestock Centre for Africa) and ICRAF (the International 

Centre for Research in Agroforestry).[3] Subsequently, research trials by national 

agricultural research stations 

were also supported, particularly through two 

internationally funded networks AFNETA (Alley Farming Network for Tropical 
Africa) and AFRENA (the Agroforestry Research Network for Eastern and Central 
Africa). AFNETA commenced operations in 1989 with a strong West African base 
(the network was coordinated through IITA), and by 1992 linked alley farming trials 
in 20 African countries. Since then, the network has reduced operations due to limited 
funding. AFRENA is coordinated by ICRAF in Kenya and has a remit that extends to 
all agroforestry technologies. Until recently, alley farming formed a key feature of its 
research programme. 

It is significant that much early alley farming research, particularly in 

West Africa

, 

took place on-station. In the on-farm trials which 

were 

established, the level of 

researcher involvement was often high, even where trials were designated as farmer-
managed trials. Many scientists argued that the technology had to be developed on-
station before it was introduced to farmers. However, the long testing period implied 
lengthy delays before results could be tried on farms. There is also the danger of 
inadequately capturing on-station many of the factors relevant to farmers adoption (or 
non-adoption) decisions. Where early on-farm trials did indicate certain problems 
with Alley farming , research institutions appear to have been initially reluctant to act 
on such findings when designing further research. 

Extension projects 

Such was the enthusiasm over the perceived potential of alley farming in the 1980s 
that it was taken up and promoted by many government and NGO extension 
programmes, often with donor support.  

NGOs appear to have been particularly active in alley farming projects both large 
international NGOs such as CARE and World Neighbors, and much smaller local 
ones. In West Africa, church groups have demonstrated a particular interest in 
promoting the technology. Government extension agencies active in promoting alley 
farming include those of Nigeria (through its ADPs Agricultural Development 
Projects), Ghana, Sri Lanka, and Indonesia. In some countries, alley farming 
continues to be promoted by agricultural extension projects, whilst researchers have 
begun to advocate caution: in Malawi, for instance, ICRAF researchers are now 
advocating a greater focus on agroforestry technologies other than alley farming. This 
review focuses on the experience of alley farming in sub-Saharan Africa (SSA), 
where the technology was developed and has been most widely tested. Ironically, it 
has met with greater success elsewhere in the world although in a modified form as is 
discussed in the penultimate section. 

Alley farming adoption by farmers  

Data on the number of farmers who have adopted alley farming on a long-term basis, 
or on the total area now farmed using the technology, remain imprecise. Some 
research (in Nigeria and Benin) has indicated that even amongst farmers who have 
tried alley farming, the majority abandoned it after several years (Whittome, 1994). It 
is clear that the technology has been less widely and rapidly adopted by farmers than 
anticipated, particularly in Africa. The full reasons for this are yet to be elucidated, 

but key issues common across many geographical areas and farming communities are 
becoming apparent. Far more is known about 

problems

 with alley farming adoption 

than about where and why the technology has been popular with farmers. 

A simple reason for the more limited popularity of alley farming than researchers had 
expected is that, despite many apparent benefits, it did not address their particular 
needs. Another overall reason for low alley farming adoption is poorer performance 
on-farm than on-station. The factors behind this are complex. They may be broadly 
categorised into predominately technical or predominately socio-economic in 
character, although in some cases there are close links between categories. 

Technical aspects affecting adoptability  

Some aspects of poor technical performance in farmers fields are intrinsic to the 
technology itself; others are specific to local farming contexts. Key issues are outlined 
below. 

Tree component 

 

There is no single tree species ideally suited for alley farming. Early research focused 
almost exclusively on two leguminous nitrogen-fixing trees native to Central 
America,

 Leucaena leucocephala

 and

 Gliricidia sepium

. These were often promoted 

on farm as wonder trees , regardless of their suitability to the given site conditions. 
Particular problems experienced by farmers include the intolerance of these species to 
acid soils; low drought resistance; limited availability of quality seed; susceptibility to 
pests (notably in the case of 

L. leucocephala

); and a tendency to spread rapidly, 

becoming weeds. Attempts are now being made to identify a wider range of suitable 
tree species for use under different site conditions. However, progress in introducing 
new material to field-based projects has so far been very limited. 
Successful alley farming requires good uniform hedgerow establishment. This has 
commonly proved difficult to achieve on-farm for a number of reasons other than 
species suitability. For example, certain activities related to the tree component 
require intensive labour input, and many clash with crop (and other) labour demands. 
This may result in tree nurseries being established late; in hedgerows not being 
planted at the optimal time of year; and in inadequate weeding during establishment. 
Other contributing factors may include damage by domestic animals, and by burning. 

Crop component 

 

Crop yields on farms have rarely been as promising as predicted from on-station 
work. This may partly be explained by more recent research, which indicates that 
hedgerow root competition is far greater than originally thought, resulting in lower 
than expected crop yields. Despite original claims of sustainable crop yields without 
artificial fertiliser, research indicates that this was over-optimistic. Small applications 
of fertiliser are therefore now recommended. 

The most successful examples of on-farm alley farming are when maize is grown as 
the sole crop. However, multiple cropping in which crops are grown as mixed stands, 
and/or in relays is traditionally practised in many farming systems, and some of the 
crops other than maize are adversely affected by alley hedgerows. Cassava, in 
particular, responds badly to alley farming rendering the system unsuitable for many 
parts of the humid tropics. 

Socio-economic factors affecting adoptability 

Farmers have multiple criteria for assessing new technologies, including economic 
profitability, risk, contribution to food security, time taken to see a return on 
investment, and labour requirement. To be widely adopted, alley farming should 
perform better in meeting these criteria than existing technologies.  
In the policy context, questions of who gains and who loses from the introduction of a 
new technology are important. Pertinent questions include: Who acquires rights to 
income flows? On whom do additional labour demands fall? Whose rights to land are 
threatened? 

Economic analyses of alley farming are highly complex, but a number have been 
attempted. Broadly speaking, they indicate that alley farming is most likely to be 
profitable where maize is the main crop and hedgerows are regularly pruned. Labour 
supply is highlighted as a factor of key importance. 

Labour demands 

 

Alley farming is a labour intensive technology, and is unlikely to be adopted where 
labour is already a limiting factor of production. Further, alley farming is highly 
inflexible in the 

timing 

of its labour requirements. Maintenance work, notably 

hedgerow pruning and the weeding of volunteer hedgerow seedlings, must be 
conducted on time. Crop yields will be jeopardised if these operations are delayed, yet 
farmers cannot always respond as necessary. Conflicting on-farm operations, off-farm 
commitments, and sickness may all contribute to delayed maintenance work. 

Returns on investment 

 

Alley farming has the disadvantage of providing limited early returns on investment. 
Farmers usually have to wait for 3-4 years before increased yields due to soil 
improvement are obtained. Unless short-term benefits such as fuel, fodder and stake 
provision are of high value, or (as has frequently happened) other direct incentives are 
offered, farmers are unlikely to be willing to adopt the technology.  

Security of tenure and usufruct rights

  

Tenure concerns both land and trees. Secure land tenure does not necessarily 
guarantee secure rights over trees. Security of land tenure is almost invariably 
necessary for farmers to establish alley farms. Even if permitted by their landlords, 
tenants may hesitate to establish trees on rented land. In much of Africa, land is not 
owned in the western sense, but is governed by customary tenure. How this influences 
the adoptability of alley farming will vary according to circumstances. As a broad 
generalisation, alley farming is most likely to be adopted where land has been divided 
between heirs. Where plots are cultivated by the extended family, or the land remains 
completely undivided and is allocated on a rotational basis, alley farming is less likely 
to be adopted. 

Tree tenure and usufruct rights may be determined by a variety of factors other than 
the tenure of the land on which the tree is growing. These include whether or not the 
tree was planted (and if so, by whom); the use of the tree (particularly whether 
commercial or non-commercial); and the species. For alley farming, the main 
implications appear to be gender-related, as outlined below. 

Who is likely to gain or lose from the technology?

 

This question has been addressed only to a limited extent by research. However, it 
appears that those most unlikely to adopt alley farming are tenants, other farmers with 
primary access to very little land, and women. Reasons for the gender bias include a 
bar in many societies on women owning land or planting trees, and the male 
orientation of many extension programmes. Women and men also commonly value 
different tree products in different ways, and this needs to be addressed in extension 
messages. Where extension has been appropriately tailored, women 

have

 adopted 

alley farming. Widows may be particularly likely to do so, as they often have greater 
independence in making farming decisions. 

Overall, it appears that although alley farming was intended for resource-poor 
farmers, it is not appropriate for those who are poorest in resources. 

An important feature in alley farming adoption is 

incentives

. The literature indicates 

that where farmers have established alley farms, they have usually been offered some 
form of encouragement to do so. Incentives have variously taken the form of: seed of 
improved crop varieties; free fertiliser; food aid; farm implements; labour (in the case 
of on-farm trials); livestock (goats), and free vaccinations for goats (Leach and 
Marslan, 1994; Versteeg and Koudokpon, 1993; Whittome, 1994). In addition, there 
may be the expectation amongst farmers of other benefits arising from their 
association with apparently wealthy research institutes or projects. Many workers 
argue that incentives are necessary when introducing a new technology that does not 
provide immediate benefits, and that they can be phased out once the technology is 
proven. Unfortunately, incentives are rarely phased out, and by providing them in the 
first place projects have often masked some of the real reasons behind farmers 
hesitation to adopt the technology which have thus only slowly become apparent.  

In what circumstances might alley farming be an appropriate 
intervention? 

It is now possible to define on a broad basis the bio-physical and socio-economic 
circumstances under which alley farming is most likely to succeed. If the bio-physical 
criteria are considered alone, it is clear that the geographical areas in which alley 
farming can be recommended are far more limited than originally claimed by IITA 
scientists. Superimposing the socio-economic criteria inevitably further reduces the 
potential client population, as indicated in Box 3. The experience of ICRAF in East 
Africa confirms these parameters, and suggests the addition of two more (K. 
Shepherd, 

pers. comm

). These are: 

•

  cultivated, moderately sloping land; and 

•

  fertile subsoils. 

One of the main clear benefits of hedgerows is soil and water conservation. This is 
particularly significant on moderately sloping land; on flat land such benefits are 
minimal, and on very steep land (over 30%), hedgerows tend to break down. Further 
to this, greatest benefits are likely where soil erosion results in large decreases in plant 
productivity. With acid infertile subsoils, there are very low levels of nutrients to 
recycle and it is more difficult to find species that can grow rapidly without being 
very competitive with crops in the topsoil. 

If work on alley farming is to continue in the future, it is logical to target activities in 
areas within the recommendation domain , where both bio-physical and socio-
economic criteria are met. 

Adaptations of alley farming that show promise 

Modified alley farming systems have been adopted by farmers in certain 
circumstances. They include the following: 

•

  alley farming on sloping land, in the form of contour hedgerows; 

•

  the use of pigeon pea (

Cajanus cajan

) as the hedgerow species; 

•

  widening alley spacing to allow more mechanised cultivation; 

•

  a form of alley grazing, in which widely-spaced hedgerows are grazed directly. 

Where forms of alley farming have met with success amongst farmers, there has been 
a common feature to the approach adopted. This is an adaptation of the system to the 
particular needs of the farmers concerned, building as far as possible on their existing 
knowledge. 

Contour hedgerows are widely used in the intensive cultivation of slopes, and are one 
of the components of SALT (Sloping Agricultural Land Technology), developed in 
the Philippines over a decade ago. In other countries of South East Asia, such as 
Indonesia, contour hedgerows on sloping lands are a common innovation, despite a 
temporary setback in the late 1980s caused by the widespread loss of 

Leucaena 

leucocephala 

to pest (

psyllid

) attack. An important feature facilitating the adoption of 

contour hedgerows in Indonesia is that it builds on indigenous management systems, 
and is thus not a completely new technology. 

Pigeon pea is a leguminous, nitrogen-fixing species widely recognised by farmers to 
improve soil fertility. Further, it produces edible leaves and seeds suitable for human 
consumption, whilst perennial varieties can also be used for fuel. Researchers have 
considered the plant to have limited potential for alley farming due to its short life (3-
4) years, especially if repeatedly pruned). However, in view of its apparent popularity 
with farmers, further investigation is justified. 

Many farmers perceive the need for regular pruning of hedgerows as one of the main 
disadvantages of alley farming. Some have therefore used wider spacing, both to 
reduce the amount of pruning necessary as well as facilitating ploughing within the 
crop alleys. The extent to which this modification enhances soil fertility is uncertain, 
but would merit research. 

Alley grazing was tested and abandoned by ILCA in early trials in Nigeria because of 
poor hedgerow performance. However, the use of fodder alleys is reported to have 
met with success in a different farming context, in Bolivia. Here hedgerows of fodder 
species such as 

Flemingia

 spp. between pasture have been used for grazing dairy 

cattle. In temperate parts of Australia and South Africa, a system of wide alleys, with 
hedgerows spaced 20 to 80 m apart or more, has been developed by farmers for sheep 
grazing. However, this is an extensive range management situation which bears little 
relation to small-scale farming in the tropics. 

Conclusion 

It is clear that alley farming is likely to be adopted on a much more limited scale than 
was originally supposed. Its adoption faces a number of constraints, among them its 
unsuitability for the crops (and crop combinations) used by many farmers in SSA, its 
high and inflexible labour requirements, and its inappropriateness for farmers who do 
not have secure, long-term access to land. Some modifications to the original concept 
are gaining ground in certain areas. The success of such niche adoption is often 
attributable at least in part to farmers own inventiveness in modifying traditional 
farming practices or to locally specific research. If future research and extension 
focuses on where and how niche adoption is possible, more resource-poor farmers 
might yet benefit from the experience gained to date. 

 

References 

Kang, B.T.

(1993) Alley cropping: past achievements and future directions. 

Agroforestry Systems,

 23 

(2-3): 141-156. 

Leach, M. and Marslan, N.

 (1994) ADDFOOD 

Beneficiary Assessment Study 1994 using 

participatory rural appraisal methods. 

Planning Division, Ministry of Agriculture and Livestock 

Development, Lilongwe, Malawi, 151p. 

Versteeg, M.N. and Koudokpon, V.

 (1993) Participative farmer testing of four low external input 

technologies, to address soil fertility decline in Mono Province (Benin). 

Agricultural Systems,

 42: 265-

276. 

Whittome, M. 

(1994) The Adoption of Alley Farming in Nigeria and Benin: The on-farm experience 

of IITA and ILCA. PhD Thesis, Department of Geography, University of Cambridge, UK.

 

Acronyms used in the text 

ADP 

- Agricultural Development Project (Nigeria) 

AFNETA

- Alley Farming Network for Tropical Africa 

AFRENA

- Agroforestry Research Network for Eastern and Central Africa 

CGIAR

- Consultative Group for International Agricultural Research 

FPR

- Farmer Participatory Research 

FSR

- Farming Systems Research 

ICRAF

- International Centre for Research in Agroforestry 

ILCA

- International Livestock Centre for Africa 

IITA

- International Institute for Tropical Africa 

NGO

- Non-governmental organisation 

SALT

- Sloping Agricultural Land Technology 

SSA

- Sub-Saharan Africa 

Notes 

1. For readers interested in more detail, supplementary information sheets are available from the author 
on its technical performance and on socio-economic factors influencing alley-farming adoption. The 
supplement (Supplement A) on socio-economic factors also contains an extended list of references. 
2. Since 1995 merged with the International Laboratory for Research on Animal Diseases to create the 
International Livestock Research Institute (ILRI). 
3. ICRAF joined the CGIAR system only in 1991.

 

 

Acknowledgements 

The author is grateful to those people, in particular Mike Whittome, who made available various 
documents that were otherwise unobtainable. She would also like to thank Jim Sumberg and Annie 
Hillyer (University of East Anglia), Keith Shepherd (ICRAF); John Farrington, Gill Shepherd and 
Hugh Turral (ODI) for their helpful comments on an early draft of this paper. The views stated are 
nevertheless her own.

 

 

©Copyright:Overseas Development Institute 1995 ISSN: 1356 9228 

Natural Resource Perspectives present accessible information on important 
development issues. Readers are encouraged to quote from them for their own 
purposes, but as copyright holder, ODI requests due acknowledgement and a copy of 
the publication.  

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Administrative Editor: Alison Saxby  
Series Editor: John Farrington 

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