EPTD Discussion Paper No. 115
ABSTRACT This case study explores the development, dissemination, adoption, and impact of improved tree fallows in rural western Kenya. The processes of technology development and dissemination throughout the region are described and analyzed. To analyze adoption and impact, the paper applies a variety of different data collection methods as well as samples from both pilot areas where researchers maintained a significant presence and non-pilot areas where farmers learned of the technologies through other channels. Sample sizes for the quantitative analysis ranged from almost 2,000 households for measuring the adoption process to just over 100 households for measuring impact indicators. Qualitative methods included long-term case studies for 40 households and focus group discussions involving 16 different groups. The paper describes the ways in which farmers used and modified improved fallow practices. Discussion also examines the types of households using fallows and benefiting from their use. Empirical results suggest that improved fallows almost always double on-farm maize yields. In addition, the data indicates that poor households use improved fallows at much greater rate (about 30 percent) than they do fertilizer (8 percent), though, on average, the size of fallow plots remains small, at 440m . As a result, despite these promising signs, the improved fallow systems were not found to be linked to improved household level food security or poverty indicators primarily, primarily because the size of the fields under the agroforestry systems was on average, quite small. Conclusion To conclude, improved fallows represent a technically effective and financially profitable technology that is attractive to poor households with little cash available for ...
- Agronomy Journal 89 (1997) 597-604. 01/1997;
- Washington : IFPRI, 2002. - Peer reviewed by Bebbington A., J. Behrman and R. Chambers. 01/2002;
- [Show abstract] [Hide abstract]
ABSTRACT: Two provenances of Sesbania sesban var. nubica (Kakamega and Chipata) were planted in fallows for 1, 2 and 3 years at 0.5 m × 0.5 m, 0.7 m × 0.7 and 1.0 m × 1.0 m spacing. Maize crop (MM604) was grown after fallow period at 0, 37, 74 and 112 kg N ha−1 to evaluate the effects of nitrogen (N) and fallow on grain yield. There were no significant differences between the two provenances of S. sesban. Wood biomass after 1, 2 and 3 years fallow at close spacing was 8.3, 17.6 and 21.4 t ha−1 for the Kakamega provenance and 10.8, 14.5 and 21.2 t ha−1 for the Chipata provenance. Litter fall in both provenances ranged from 0.6 t ha−1 in June to 0.01 t ha−1 in November. Stand mortality increased with plant density and fallow years: 27% in the first year and about 90% by the end of the third year. Weed biomass ranged from 6.8 t ha−1 to 6.0 t ha−1 at close and wide spacing respectively.Maize grain yield without N was 2.27, 5.59 and 6.02 t ha−1 after 1, 2 and 3 years fallow respectively compared with the control plots with 1.6, 1.2. 1.8 t ha−1 after 1, 2 and 3 years of continuous cropping. Even with addition of 112 kg N ha−1, yield in the control plots declined from 6.09 to 4.88 and 4.28 t ha−1 after 1, 2 and 3 years of continuous cropping. In the planted fallows at 112 kg N ha−1, maize yield increased from 6.75 to 7.16 and 7.57 t ha−1 following 1, 2 and 3 years fallow. It is concluded that short fallow rotations of 1–3 years using S. sesban have a potential in increasing maize yield even without fertilizers. Thus, increasing the fallow period decreases the effectiveness of inorganic fertilizers but increases grain yield for low fertilizer input.Forest Ecology and Management. 01/1994;
EPTD Discussion Paper No. 115
Environment and Production Technology Division
International Food Policy Research Institute
2033 K Street, N.W.
Washington, D.C. 20006 U.S.A.
International Center for Research in Agroforestry
United Nations Ave.
Gigiri, Nairobi, Kenya
Copyright © 2004: International Food Policy Research Institute
EPTD Discussion Papers contain preliminary material and research results, and are circulated prior to a full peer
review in order to stimulate discussion and critical comment. It is expected that most Discussion Papers will
eventually be published in some other form, and that their content may also be revised.
Improved Fallows in Kenya: History, Farmer Practice, and Impacts
Frank Place, Steve Franzel, Qureish Noordin, Bashir Jama
This case study explores the development, dissemination, adoption, and impact of improved tree
fallows in rural western Kenya. The processes of technology development and dissemination
throughout the region are described and analyzed. To analyze adoption and impact, the paper
applies a variety of different data collection methods as well as samples from both pilot areas
where researchers maintained a significant presence and non-pilot areas where farmers learned of
the technologies through other channels. Sample sizes for the quantitative analysis ranged from
almost 2,000 households for measuring the adoption process to just over 100 households for
measuring impact indicators. Qualitative methods included long-term case studies for 40
households and focus group discussions involving 16 different groups. The paper describes the
ways in which farmers used and modified improved fallow practices. Discussion also examines
the types of households using fallows and benefiting from their use.
Empirical results suggest that improved fallows almost always double on-farm maize yields. In
addition, the data indicates that poor households use improved fallows at much greater rate
(about 30 percent) than they do fertilizer (8 percent), though, on average, the size of fallow plots
remains small, at 440m2. As a result, despite these promising signs, the improved fallow systems
were not found to be linked to improved household level food security or poverty indicators
primarily, primarily because the size of the fields under the agroforestry systems was on average,
To conclude, improved fallows represent a technically effective and financially profitable
technology that is attractive to poor households with little cash available for investment. They
are being used and adopted by a significant proportion of households in areas of western Kenya
where they had been disseminated in the late 1990s. On the other hand, farm sizes are small and
the ability of farmers to set aside land, even for a season is limited. Hence, the average size
improved fallow is small among adopting farmers.
Looking to the future, it is best to view improved fallows as a component of a broader integrated
soil fertility management strategy for farmers. Farmers will also use manure, compost, and to
some degree, fertilizer. Improved fallows have a comparative advantage in that they are
relatively labor saving over manure or compost, they have a low risk of failure in supplying
nutrients on the farm (because of extensive rooting systems), and they offer some by-products.
Our evidence suggests that they may serve as an entry point for improved soil fertility
management for farmers who had previously not invested in soil fertility management.
Nonetheless, the scaling out of improved fallows to other areas will face challenges. It is not a
traditional practice and therefore must be learned. There are several stages involved in managing
fallows -- choice of species, fallow establishment, and cutting and incorporation. Technical
backstopping may be important for each of these stages. Yet ensuring that it is available is no
easy feat with scattered NGOs and sub-optimal extension services. These dissemination
problems affect the scaling out of most technologies, but particularly affect the more knowledge-
intensive technologies such as improved fallows. Making germplasm available is also a
challenge, though many fallow species are prolific seeders and farmers can in theory become
self-sufficient quite easily. Moving germplasm into new areas is more problematic. Markets for
seed may play a limited role in this because farmers need a high quantity of seed, but do not care
much about quality of these “input trees” and therefore are not willing to pay much, if anything
for the seed. These challenges are not minor. But neither are they insurmountable. Many other
tree species and other knowledge-intensive practices, such as integrated pest management (IPM),
have spread throughout pockets of smallholder Africa. It will require, however, considerably
more efforts to mainstream improved fallows – and indeed the concepts of integrated soil fertility
management -- into extension systems.
Keywords: agroforestry, soil fertility, Kenya, adoption, impact, technology
TABLE OF CONTENTS
1. Overview 1
2. Process 9
3. Impacts 16
4. Recommendation Domains 46
Improved Fallows in Kenya: History, Farmer Practice, and Impacts
Frank Place, Steve Franzel, Qureish Noordin, Bashir Jama
Many scientists consider declining soil fertility to be the fundamental root cause of
agricultural stagnation in Sub-Saharan Africa (Sanchez et al. 1997). With the highest fertility
rate in the world, Sub-Saharan Africa clearly faces increasing demographic pressure on its
natural resource base, the physical capital on which the continent’s agriculture depends.
Consequently, farmers across the continent and agencies working on their behalf have
experimented with a broad range of both soil and water conservation technologies (Reij, Scoones
and Toulmin 1996). Given the high cost of petroleum-based fertilizers imported into Africa,
many agencies and farm groups have focused on solutions using local resources and low external
inputs (Pretty and Hine 2001). Among these technologies, a recent survey of African
agriculturalists has pointed to recent work on improved fallow systems as a budding success
story in African agriculture (Gabre-Madhin and Haggblade 2001).
This paper explores ongoing work on improved fallows in Western Kenya. It describes
the process by which the technology is being developed, tested and scaled up. A companion
paper in this series focuses on related improved fallow technologies developed in the very
different ecological environment of Eastern Zambia, where a single rainy season and surplus
land lead to different technical solutions (Franzel et al. 2003). Using the same diagnostic
procedures and inventories of leguminous species, the roughly 40 partner institutions in Kenya
have developed different improved fallow systems appropriate to the high population density,
heavy land pressure, and dual rainy season of Western Kenya. This paper examines the process
by which the Kenyan collaborators developed their situation-specific improved fallow
technologies. It likewise reports early findings on the impact they have had on farm incomes and
SCOPE OF THE CASE STUDY
The research in western Kenya is focused largely on medium to high potential highland
areas. Rainfall is good, ranging from 1200 -1800mm/year with two cropping seasons annually:
the long rains from March to July, and the short rains from August to November. The short rainy
season is traditionally less reliable in terms of total rainfall and length of growing season, but the
rains have been good during the post 1998 period. The altitude is between 1250 and 1600 m
above sea level with rather moderate slopes. The topography is undulating with moderate slopes.
Soils are of generally good physical structure but are low in nutrient stocks. In many parts of the
region, phosphorus is the major limiting nutrient, but nitrogen and potassium limitations are also
prevalent (Shepherd et al. 1996; Jama et al. 1998a). Moreover, heavy infestation with Striga
hermontica, a parasitic weed that devastates the maize crops, is common (Oswald et al. 1996).
High population densities prevail, ranging from 500 - 1,200/km2 in Kakamega, Siaya, and
Vihiga Districts. The Luhya inhabit Kakamega and Vihiga Districts while the Luo reside in
Siaya. The farming system incorporates crops, livestock, and trees. Maize (local varieties) and
beans are the most common agricultural enterprise. The food situation was reported as deficient
by 89.5 percent of the households in Siaya and Vihiga, who had to buy food to supplement their
own harvest (Wangila et al. 1999). Only 8.9 percent of the households were food secure from
their own production. Average household income for western highland households was only
$1,014 and crop income a paltry $321 according to a recent study (Argwings-Kodhek et al.
1999). Average agricultural labor productivity (per year) was about $76 in western Kenya, only
one-fourth the level achieved by farmers in central Kenya.
In fact, many of the communities under study are among the poorest in all of Kenya and
clearly the poorest among the medium to high potential areas. For example, a recent national
study of poverty found Western Province (including Kakamega and Vihiga among its 4 districts)
to be one of the poorest in the country (Government of Kenya, 2000). It was estimated that 31.5
percent of households in western Kenya are among the hardcore poor, as opposed to 19.6 percent
for all rural areas. Western Province and Nyanza Province (including Siaya District) also had
high incidences of sickness which were twice as high as those reported in Central Kenya, an area
with similar farm sizes (median of about 1 hectare).
Following diagnostic studies revealing perceived poor soil fertility as being a major
constraint, ICRAF tried out the improved fallow technology in Western Kenya in 1991, both
under experimental circumstances and under farm circumstances. At that moment the only
species used was Sesbania sesban, an indigenous species that had proven its potential in
Southern Africa (Kwesiga and Coe 1994) and was a prolific biomass producer under West
Kenyan conditions (Onim et al. 1990). The agronomic performance and economic profitability of
Sesbania fallows were studied in detail (Hartemink et al. 1996; Swinkels et al. 1997; Jama et al.
1998b). At that time, testing of alley farming was also taking place and a major review of that
research raised questions as to its performance and viability in western Kenya. Thus, there was a
period of stagnation (1994-95) where there was little dissemination of soil fertility technologies
In 1996, new fallow species had been introduced with promising results and the directors
of ICRAF, KARI, and KEFRI decided to intensify efforts in research and dissemination of
improved fallows (and biomass transfer systems too). This was also catalyzed by recent success
in Zambia where yields and profits were found to increase substantially from improved fallows,
compared to the low-input farmer practice.1 Screening trials resulted in the selection of new
species that in most cases were shrubs and had a shorter life cycle than Sesbania sesban. Most
promising and widely used species are Crotalaria grahamiana and Tephrosia vogelii (Niang et
al. 1999). Other aspects and management options that were tested under research conditions are
planting densities (Niang et al. 1999), the addition of inorganic phosphorus fertilizer (Jama et al.
1997; Jama et al. 1998b), the effect on weeds (Niang et al. 1996), effect on nematodes (Desaeger
and Rao 1999) and minimum-tillage planting. Extensive on-farm experiments have been
conducted to assess the potential of fallows using these species, often in combination with
phosphorus fertilization during the years 1996 to 2001. Agronomic and economic performance
was studied within these trials.
Initial efforts at disseminating information on the fallows were focused in a pilot project
area involving 17 villages distributed mainly in the districts of Vihiga and Siaya at the beginning
of 1997. Village committees were established to help facilitate information flows between the
community and research staff. In addition, field technicians were made available to many of the
villages for a period of about two years. Wide-scale dissemination of improved fallows across
1 Many farmers had been using fertilizer in Zambia, but the government subsidization of fertilizer price and credit
halted after structural adjustment policies were adopted.
western Kenya started at the end of 1998, initiated by the research institutions that organized the
procurement of seed and trained extension and development organizations.
The research partners trained extension and development organization staff on the
establishment and management of improved fallows and provided them germplasm of species
new to the area. Many field days were conducted first at researcher managed sites and then later
at farmers’ own fields. Finally, extension materials were developed for use by development
BACKGROUND SOCIO-ECONOMIC STUDIES
ICRAF undertook several studies in the main pilot project area (and beyond, in some
cases) at the outset of the project. This includes a characterization census of all households in
the main 17 pilot villages, a participatory wealth ranking exercise in selected pilot villages, and a
survey of traditional fallowing practices in several locations in W. Kenya. The results of these
are summarized here. In addition, subsequent studies were undertaken to assess the performance
of improved fallows, farmers’ assessments, dissemination pathways, adoption behavior, and
impact. These results are discussed in the relevant sections below.
A wealth ranking exercise was conducted in five villages to determine indicators of
differences in endowments and assess how these differences can create opportunities and
constraints for adoption of agroforestry technologies among farmers of different economic status
within each village. Farmers identified indicators which make differences in their lives and
which can be used for impact assessment. These criteria included the ability to use fertilizer, hire
labor, and to acquire cattle. These criteria were then included in a census instrument given to all
pilot area households. The purpose of this was to be able to include wealth status as a sampling
stratification variable for trials and monitoring surveys.
Some of the results of the characterization survey are presented in order to describe the
rural economy of Siaya and Vihiga Districts (Wangila et al. 1999). Male headed monogamous
households were the dominant household type (63.6 percent), female headed widowed (17.8
percent), female headed with husband absent (7.7 percent), male headed polygamous (6.8
percent), single male headed households (3.7 percent), and male headed widowed (0.3 percent).
The distribution of education of the decision-makers were 39.5 percent with upper primary
school, 23.9 percent with lower primary education, 19.5 percent with no education and 17.0
percent with secondary education. High literacy levels mean that understanding of extension
messages should not be a problem, though formal education levels were lower for female adults
than for male adults. The average household size was 5.81 persons per household.
The average farm sizes are 1.75 acres for owned land and 0.11 for leased land, and per
capita land holdings were 0.42 acres of owned land and 0.43 acres for both owned and leased.
Landholdings were generally small with 95 percent of the population holding less than 5 acres
and only 0.6 percent of households having 10-31 acres of land.
Farm management -- especially land preparation, input use, hiring in and out labor and
use of hybrid seeds -- varies from farm to farm. Most of the households (88 percent) prepare
their land by hand, 11.5 percent use an ox-plow. Only 24.8 percent of the farmers used chemical
fertilizer compared to 68.9 percent who applied animal manure, and 38.3 percent compost. Most
farmers (78.6 percent) used local varieties of maize seed, 16.3 percent used a mixture of local
and hybrid seeds, and only 5.0 percent planted pure hybrid maize. A pattern emerging from this
description is that chemical fertilizer and hybrid maize seed, which are sourced from markets and
depend on farmers’ purchasing power, are used sparingly. This is despite significant efforts to
extend these modern practices and despite relatively favorable levels of market opportunities in
Maize was the most predominant crop in the villages with only 10 households not
growing any. Other common crops include local beans, bananas, cassava, sweet potatoes, and
kale/cabbages. The other food crops – sorghum, tomatoes, and groundnuts were found on less
than half of the farms. Sugarcane was grown by 31.2 percent of the households. Other crops not
listed on the questionnaire but known to be grown by farmers include yams, tobacco, millet,
onions, cow peas, groundnuts, finger millet, coffee, sisal, sesame, and soybeans. Some of these
crops are grown for home consumption and others for the market. All production is rainfed–
there is no irrigation used among the households.
Livestock production in western Kenya is mainly based on a semi-intensive dairy-meat-
draft-manure system. Western Province has 10 percent of the national indigenous herd and 3
percent of the dairy herd while Nyanza Province has 21 percent and 5 percent, respectively.
Because of land scarcity, confined grazing on farms or roadsides is dominant. Crops are fed to
cattle and manure used to fertilize crops. Livestock production in the area is based on local
cattle, sheep and goats (sheep & goats), pigs, and poultry. Almost three-quarters of households
had poultry and just over half had local cattle. On the other hand, only 4.3 percent of households
had an improved cow.
In addition to crops and livestock, trees are an important feature of the agricultural
landscape. In the Vihiga / Siaya sample, 80 percent of households reported to have woodlots,
mainly comprised of Eucalyptus. The trees are used for firewood and poles both on-farm and for
sale. About 70 percent of the households derived some income from off-farm activities. For the
poor households, the main off-farm source is through agricultural labor provided to other farms.
Households with members who sometimes worked on surrounding farms represented 24.4
percent of all households.
Farmers organize themselves in a large variety of ways. Village groups can vary from a
few members to an entire village and groups are formed around a large variety of issues or
themes. Organization diagrams were developed by the project in each village or group of
villages to identify the major organizations e.g. self-help groups, women and youth groups, and
church groups. Farmers social ties, complemented with wealth and soil fertility classes, can be
used to determine which type of social organization the poor or disadvantaged may belong to.
This information was used to develop a dissemination strategy that targeted such disadvantaged
people. Poor farmers belong to church groups and of course clan-based groups, but few others in
comparison to other wealthier farmers. It was found that the number of farmers not affiliated to
any group in five Luhya villages is higher (14 percent) than in three Luo villages. In one
particular Luo village (Luero), all the farmers were affiliated to at least one group. In Luo
villages, each farmer belonged on average to four groups, whereas in Luhya villages, each
farmer is a member of only two groups.
HOW DID THE IMPROVED FALLOW PRACTICE ARISE
Soil fertility was long recognized as a problem in the area, as noted in section 1.
Moreover, it was clearly recognized (and later confirmed by formal surveys) that most farmers
were not able to make cash investments in soil fertility management. Following up on this,
testing began on alley farming and improved fallow systems in W. Kenya.
This process is described in more detail above, but a key element in the process was a
survey to study the practice of traditional fallows in various agro-ecological zones of Western
Kenya (the following draws largely from De Wolf and Rommelse 2000). This was done mainly
to see if there was already an existing practice of fallowing in which a niche for improved
fallows could be found. The occurrence, duration, reasons and uses were inventoried.
The study zone was stratified according to rainfall, altitude, soils, population density,
and estimated land occupation by fallow. Five homogeneous but contrasting areas were
identified following this stratification. Within each area 36 farmers (total of 180) were randomly
selected and interviewed.
It was found that fallowing is a common and important practice in the area.
Depending on the location, between 22 and 61 percent of the farmers practice traditional
fallow. On these farms, the fallows occupy between 23 and 47 percent of the total farm size.
About two thirds of these fallows are kept for 2 to 4 seasons. This was confirmed with the
characterization census (n = 1,636) that found 35.2 percent of households reporting some fallow
land. In this case, about 60 percent of fallows lasted for at least 2 seasons. These results
surprised many who assumed that fallowing would be negligible in an area with such high
population density. The ages of traditional fallows are as shown in Table 1 below.
Table 1--Traditional fallows by age, characterization census from 17 villages in Siaya and
Age of fallow Frequency Percent
1 season 251 41.6
2 seasons 165 27.3
3 seasons 16 2.6
4 seasons 64 10.6
> 2 years 108 17.9
Total 604 100.0
Source: Wangila et al., 1999.
Although some farmers fallow because of lack of labor or seed for planting crops, it was
felt that a niche did indeed exist for improved fallows. The research partnership of ICRAF,
KARI, and KEFRI began some experiments initially based on technology design from Zambia.
This system was a Sesbania sesban multi-season fallowing system. This prototype was not
promising from a socio-economic view as the opportunity costs of foregone maize were too high
and the yield effects of the fallows by themselves were not always high due to widespread
phosphorus deficiency. Early cost-benefit analysis showed that improved fallows could however
be profitable if the fallow period could be trimmed to a single short rain season (Swinkels et al.
1997). Researchers began testing other systems and interactions with farmers led to a focus on
establishing a short fallow system within an existing crop relying on species that could be
directly seeded. The short rain, between October and December, is an ideal fallow niche because
of its increased riskiness for maize production.
HOW DID IMPROVED FALLOWS SPREAD
As noted earlier, within the pilot project area, information was actively spread through
the use of village committees. These turned out to have mixed effects. They certainly did help
to organize people and disseminate information fairly cheaply. But in some cases, individuals
used the committees to gain local power, posing as ‘agents’ for ICRAF, and this turned some
households against participating (Omosa 2002). In addition, the fact that some of these contact
farmers had been watchmen at the demonstration site somehow contradicted people’s
perceptions that a good technology should be brought in by knowledgeable and unique persons.
Since the fallows were a highly visible and new feature of the landscape there was also
considerable more informal dissemination of information, for example when relatives came to
visit or large groups gathered for a funeral. As noted earlier, there was considerable technical
backstopping support in many of pilot villages and this no doubt increased the rates of testing in
early years. The technical backstopping was reduced significantly from 1999 when there was a
more concerted effort to reach other locations in western Kenya.
Within the pilot villages several incentives were operating. Most farmers indeed began
testing fallows because of an interest to improve their crop yields. However, in 1997-98 when
there was some significant expansion in the number of farmers trying fallows in nearby villages,
the research project began purchasing tree seed from farmers. That also spawned interest from
another set of farmers. A final incentive that was apparent was a desire for some farmers to
participate in the agroforestry program in the hope that they would gain other benefits, such as
social status from the hosting of high-level visitors or access to benefits from other NGOs.
These other motivations were largely negligible in the non-pilot areas because ICRAF did not
have the resources to visit or backstop them.