Front Cover
 Title Page
 Table of Contents
 List of Tables
 Executive summary
 Inorganic fertilizer use
 Factors influencing farmers' adoption...
 Demand factors
 Supply factors
 New papers
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Group Title: Paper - Natural Resources Group - 96-05
Title: Losw use of fertilizers and low productivity in Sub-Saharan Africa
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Permanent Link: http://ufdc.ufl.edu/UF00077521/00001
 Material Information
Title: Losw use of fertilizers and low productivity in Sub-Saharan Africa
Series Title: Paper - Natural Resources Group - 96-05
Physical Description: Book
Language: English
Creator: Mwangi, Wilfred
Publisher: International Maize and Wheat Improvement Center (CIMMYT)
Publication Date: 1996
Subject: Africa   ( lcsh )
Farming   ( lcsh )
Spatial Coverage: Africa
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Bibliographic ID: UF00077521
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: African Studies Collections in the Department of Special Collections and Area Studies, George A. Smathers Libraries, University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: issn - 1405-2830


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Table of Contents
    Front Cover
        Front cover
    Title Page
        Page i
        Page ii
    Table of Contents
        Page iii
    List of Tables
        Page iv
        Page iv
    Executive summary
        Page v
        Page 1
    Inorganic fertilizer use
        Page 2
        Page 3
        Page 4
        Page 5
    Factors influencing farmers' adoption and intensity of fertilizer use
        Page 6
    Demand factors
        Page 7
        Page 8
        Page 9
        Page 10
    Supply factors
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
    New papers
        Page 19
    Back Cover
        Back cover
Full Text



Low Use of Fertilizers

and Low Productivity

in Sub-Saharan Africa*

Wilfred Mwangi **

Natural Resources Group
Paper 96-05

* An earlier version of this paper was presented at the IFPRI/FAO workshop on Plant Nutrition Management, Food
Security and Sustainable Agriculture, and Poverty Alleviation in Developing Countries, May 16-17, 1995, in Viterbo,
** Wilfred Mwangi is a CIMMYT economist who can be reached at P.O. Box 5689, Addis Ababa, Ethiopia. The views
expressed in this paper are the author's and may not necessarily reflect CIMMYT policy.

CIMMYT is an internationally funded, nonprofit scientific research and training organization.
Headquartered in Mexico, the Center is engaged in a research program for maize, wheat, and triticale, with
emphasis on improving the productivity of agricultural resources in developing countries. It is one of
several nonprofit international agricultural research and training centers supported by the Consultative
Group on International Agricultural Research (CGIAR), which is sponsored by the Food and Agriculture
Organization (FAO) of the United Nations, the International Bank for Reconstruction and Development
(World Bank), and the United Nations Development Programme (UNDP). The CGIAR consists of some 40
donor countries, international and regional organizations, and private foundations.

CIMMYT receives core support through the CGIAR from a number of sources, including the international
aid agencies of Australia, Austria, Belgium, Brazil, Canada, China, Denmark, Finland, France, India,
Germany, Italy, Japan, Mexico, the Netherlands, Norway, the Philippines, Spain, Switzerland, the United
Kingdom, and the USA, and from the European Union, Ford Foundation, Inter-American Development
Bank, OPEC Fund for International Development, UNDP, and World Bank. CIMMYT also receives non-
CGIAR extra-core support from the International Development Research Centre (IDRC) of Canada, the
Rockefeller Foundation, and many of the core donors listed above.

Responsibility for this publication rests solely with CIMMYT.

Printed in Mexico.

Correct citation: W. Mwangi. 1996. Low Use of Fertilizers and Low Productivity in Sub-Saharan Africa. NRG
Paper 96-05. Mexico, D.F.: CIMMYT.

Abstract: Factors related to the low use of fertilizers and the resulting low agricultural productivity in
sub-Saharan Africa are reviewed. The importance of inorganic fertilizers and agricultural research to
improving soil fertility and increasing agricultural productivity are outlined. Particular attention is
devoted to the following factors that influence farmers' adoption and intensity of fertilizer use: the
economics of fertilizer use, the availability of fertilizer, price policies and credit, pricing environment
and distribution costs, the privatization of supply, and infrastructural development.

Additional information on CIMMYT activities is available on the World Wide Web at:
http:/ /www.cimmyt.mx or http:/ /www.cgiar.org

ISSN: 1405-2830
AGROVOC descriptors: Africa south of Sahara; food production; food supply; Zea mays; fertilizers;
fertilizer application; innovation adoption; economic environment; economic policies; price policies; credit
AGRIS category codes: E14; E16
Dewey decimal classification: 338.16



iv Tables
iv Acknowledgments
v Executive Summary

1 Introduction

2 Inorganic Fertilizer Use
2 Improving soil fertility
5 Agricultural research

6 Factors Influencing Farmers' Adoption and Intensity of Fertilizer Use
7 Demand factors
7 Economics of fertilizer use
8 Availability
9 Price policies and credit
11 Supply factors
11 Pricing environment and distribution costs
12 Privatization of supply
13 Infrastructural development

13 Conclusions

15 References



3 Table 1. Fertilizer consumption in sub-Saharan Africa

8 Table 2. Effect of price policy on the profitability of alternative maize technologies in 110 on-
farm demonstrations, Lilongwe, Malawi, 1990 and 1991

11 Table 3. Ratio of farm-level prices of nitrogen fertilizer to maize grain prices in sub-Saharan
Africa and other regions, 1989


Helpful comments on earlier drafts of this paper were received from H. Ade Freeman, P. Heisey,
W. Ongaro, A.J.S. Sodhi, Ann Stroud and S. Waddington. Anne Nyamu provided editorial
assistance. Responsibility for statements of fact and interpretation rests solely with the author.



3 Table 1. Fertilizer consumption in sub-Saharan Africa

8 Table 2. Effect of price policy on the profitability of alternative maize technologies in 110 on-
farm demonstrations, Lilongwe, Malawi, 1990 and 1991

11 Table 3. Ratio of farm-level prices of nitrogen fertilizer to maize grain prices in sub-Saharan
Africa and other regions, 1989


Helpful comments on earlier drafts of this paper were received from H. Ade Freeman, P. Heisey,
W. Ongaro, A.J.S. Sodhi, Ann Stroud and S. Waddington. Anne Nyamu provided editorial
assistance. Responsibility for statements of fact and interpretation rests solely with the author.

Executive Summary

Up to the year 2000 and beyond, the population of sub-Saharan Africa (SSA) is expected to grow
at a rate of more than 3% per year, while food production is likely to grow at a rate of 2% or less
per year. Closing this gap and increasing food production will require intensive agriculture based
on modern technologies, including fertilizers. Such changes are particularly crucial because many
regions of SSA are no longer land abundant.

Land scarcity is compounded by low soil fertility, resulting from the shortening or elimination of
the fallow period without concurrent efforts to increase soil nutrients through fertilizer application
or other soil management practices. Output per hectare will need to grow by raising the
productivity of land and labor. Increased use of fertilizer has a key role to play in this process.
Because of the high labor intensity and low quality of organic fertilizer, restoration of soil fertility
increasingly requires the use of inorganic fertilizer. SSA's consumption of this critical input is very
low. In 1990, farmers in SSA used 8.4 kilograms per hectare of plant nutrients, far short of what is
needed to compensate for the harvested nutrients.

A stable policy environment conducive to change is absolutely critical for promoting growth in
fertilizer use. Such growth is especially important if small-scale farmers are to increase production,
ensure food security, and protect the environment. Policy particularly needs to address the issue
of subsidies. Although they will inevitably be removed in the long run, in the short and medium
run they should be retained while policies address other important issues such as credit and the
need to support appropriate agricultural research, to develop and maintain infrastructure, and to
foster the development of a viable private sector-all of which will lead to increased fertilizer use.

Low Use of Fertilizers and Low Productivity
in Sub-Saharan Africa

Wilfred Mwangi


In sub-Saharan Africa (SSA), population
growth will continue to outstrip growth in food
production for a long time to come unless
serious action is taken to accelerate agricultural
productivity. Between now and the year 2000,
population in SSA is expected to grow at a rate
of more than 3% per year, while food
production is likely to grow at a rate of 2% or
less per year. By the year 2000, the production
shortfall in SSA is estimated to increase to
about 50 million tons of grain equivalent-up
from the current level of about 14 million tons
(von Braun and Paulino 1990). The World Bank
(1989) estimates that by the year 2020, Africa
will have a food shortage of 250 million tons.
Furthermore, the region will not have the
necessary foreign exchange to import such
large amounts of food, nor will the African
governments be able to count on enough food
aid to make up the difference. Even if
importing food were financially viable, most
countries in SSA lack the infrastructure (ports,
roads, trucks, distribution networks, and so on)
to handle it efficiently.

In general, low-input systems are characterized
by relatively low land productivity. In terms of
long-term sustainability and returns to land
and labor, however, extensive low-input
systems tend to be highly efficient. To grow
enough food to feed an increasing population
from these systems, farmers have to expand
cultivated area, moving onto marginal lands of

lower quality; these lands tend to be easily
degraded (Matlon and Spencer 1984). Also,
many parts of Africa are extremely land-scarce,
despite the appearance of land-abundance
(Binswanger 1986; Matlon 1987b; Binswanger
and Pingali 1988). Intensification would reduce
the need to cultivate marginal lands. Moreover,
high-input systems would restore fertility via
fertilizer (Matlon 1987a; Wong et al. 1991),
especially in areas where nutrient depletion is
the major soil degradation problem.

Population increases and land scarcity indicate
that SSA's food needs cannot be met through
the low-input systems that are based largely on
traditional practices; instead, much more will
be required from farmers in terms of labor,
knowledge, and skill (Borlaug and Dowswell
1994). Furthermore, for the world as a whole, a
shift from the currently known best practice for
completely organic sources of nutrients would
result in a food shortfall of about 40% (Smil 1991).

This paper examines the factors related to the
low use of fertilizer and the resulting low
agricultural productivity in SSA. The
importance of fertilizer and of improving soil
fertility and agricultural research are outlined
first. Next, demand factors that influence
adoption decisions and the intensity of
fertilizer use are summarized. The subsequent
section focuses on supply constraints to
fertilizer use and the privatization of supply.
Infrastructure development and conclusions
are discussed in the final sections.

Inorganic Fertilizer Use

Fertilizer is a critical input for improving
production technologies and increasing crop
yields. Over the past 25 years, chemical
fertilizers have been the primary means of
enhancing soil fertility in small-farm
agriculture (Byerlee et al. 1994). Estimates
suggest that in Asia and Latin America,
chemical fertilizers are responsible for 50-75%
of the increase in the food crop yield over the
past two decades (Viyas 1983; Narayana and
Parikh 1987). Also, given present knowledge,
the rapid rate at which food production must
increase in developing countries, and severe
soil degradation, farmers probably have little
choice but to depend heavily on external
sources of nutrients in the foreseeable future
(Desai 1990).

Researchers and policy makers widely
recognize the importance of fertilizers in
accelerating the growth of food production in
SSA (Bumb 1988). Mellor et al. (1987) give
fertilizers the first functional priority for
accelerating food production in the region.
They suggest that, even with existing
technologies, a 15% annual growth rate in
fertilizer consumption is both possible and of
great potential significance. However, given
much of the evidence presented elsewhere in
this paper, such increases do not seem feasible
without large changes in infrastructure,
institutions, and policies. Furthermore, based
on the experience of other developing world
countries, where aggregate fertilizer
consumption has increased far more rapidly
than in SSA, such expansion rates will not be
easy to achieve in an economically efficient
fashion (Heisey and Mwangi, forthcoming).

Farmers in SSA use very low levels of fertilizer
(Table 1). Average use in 1990 was 8.4 kg of
fertilizer nutrients per ha of arable land and

land under permanent crops. In that same year,
the world average was 93 kg; for developing
countries, the average was 81 kg (Gerner and
Harris 1993). Fertilizer use in SSA does not
come close to compensating for harvested
nutrients (Vlek 1993).

Slightly more than half of the fertilizer is used
on cereals, particularly maize. Although the
area of the other two important cereals (millet
and sorghum) is also large, very little of this
area is fertilized, and when it is, application
rates are low (Gerner and Harris 1993). In
general, fertilizer use has shifted from cash
crops to cereals, particularly maize, over the
past 20 years (Heisey and Mwangi,

Improving soil fertility

Shifting cultivation and fallowing have been
the traditional method of maintaining soil
fertility and replenishing nutrients in SSA
(Blackie and Jones 1993; Blackie 1994a; Spencer
1994). However, due to increased population
pressure in most areas, fallowing has
disappeared from the system in some areas and
is declining in others. The shortening of fallow
cycles-without adequate replenishment of soil
nutrients through the use of organic and
inorganic inputs-has caused yields to decline
over time (Ehui et al. 1994).

In SSA, grain yields average about a third of
those in East Asia. Differences in land quality
are part of the reason, but so too is SSA's low
fertilizer use-less than one-fifth of East Asia's
average (World Development Report 1992).
Given the low levels of fertilizer use in SSA and
the demonstrated contribution of fertilizers to
increasing crop yields and land productivity,
the increased use of fertilizers has great
regional potential for boosting food production
and promoting agricultural development.

Table 1. Fertilizer consumption in sub-
Saharan Africa (kg/ha)a

Country 1979/80 1991/92

Benin 1 6
Botswana 1 1
Burkina Faso 3 7
Burundi 1 <1
Cameroon 5 3
Central African Republic <1 <1
Chad 3
Congo 1 1
Cote d'lvoire 17 10
Ethiopia 3 7
Gabon <1 1
Ghana 7 3
Guinea 3 3
Guinea Bissau 1 2
Kenya 17 39
Lesotho 14 17
Madagascar 3 3
Malawi 19 45
Mali 7 7
Mauritania 11 7
Mauritius 56 60
Mozambique 8 2
Namibia -
Niger 1 <1
Nigeria 4 13
Rwanda <1 1
Senegal 12 7
Sierra Leone 5 1
Somalia <1 -
Sudan 3 7
Tanzania 9 15
Togo 5 9
Uganda <1
Zambia 11 12
Zimbabwe 44 53
Sub-Saharan Africa 12 14
a Application rates per actual cropped area may be higher.
Source: World Development Report (1994).

Furthermore, increased and efficient fertilizer
use can help reverse the declining trends in per
capital cereal production experienced in many
SSA countries, without having adverse
environmental consequences (Bumb 1991). But
this potential can only be realized through
sound government policies and investments

that will promote the adoption and increased
use of fertilizers by small-scale farmers
(Baanante and Thompson 1988).

Low fertilizer use results in declining soil
fertility; it also increases soil degradation
through nutrient mining (Byerlee et al. 1994;
World Development Report 1992). For the
foreseeable future, "the environmental
consequences of continued low use of
fertilizers" through nutrient mining and
increased use of marginal lands "are more
inevitable and devastating than those
anticipated from increased fertilizer use"
(Dudal and Brynes 1993; Matlon and Spencer
1984; World Development Report 1992).

In general, soil fertility is on a downward
spiral, with inputs of nutrients (from organic
and inorganic sources) into sedentary
agriculture insufficient to reverse the trend.
Estimated rates of net nutrient depletion are
high, exceeding 30 kg of nitrogen (N) and 20 kg
of potassium (K) per hectare of arable land per
year in Ethiopia, Kenya, Malawi, Nigeria,
Rwanda, and Zimbabwe (Stoorvogel et al.

From 1988 to 1990, fertilizer use in Ghana
averaged about 11,000 nutrients tons; 90,000
nutrient tons were removed by various crops.
The implications for Ghana are clear: depletion
of soil nutrients is becoming a serious
constraint to soil fertility and crop productivity.
Moreover, the level of depletion suggests that
large amounts of fertilizers are needed to
maintain soil fertility (Bumb et al. 1994).

Declining soil fertility has been identified as
one of the most significant constraints to
increasing food production in SSA. This is true
even in the highlands of eastern Africa

1 Although these are probably the best available estimates of net nutrient depletion, they are still not highly reliable.

(traditionally the region's most productive
and fertile lands) due to human population
pressure and intensification in land use
(Waddington and Ransom 1995). Adequate
and timely fertilizer applications will not only
supply necessary nutrients and improve crop
yields, but will also provide relatively higher
amounts of crop residue, which can be used as
organic matter to improve soil health and
prevent soil degradation (Bumb 1991). Wong
et al. (1991) have also urged the promotion of
judicious fertilizer use in West Africa, use
which, they contend, will enhance agricultural
production while protecting the fragile

Byerlee et al. (1994) contrast the relatively high
adoption of improved maize by farmers
(improved varieties and hybrids now cover
33-50% of the maize area in Africa) with the
lack of resource management technologies for
maintaining soil fertility and increasing labor
productivity. But when fertilizer is not
applied, adoption of improved maize is often
associated with only marginal gains in
productivity under smallholder conditions.
For example, in an extensive program of on-
farm demonstrations in Malawi, hybrid maize
grown without fertilizer gave grain yields of
only around 1.6 t/ha in seasons of near
normal rainfall (Jones and Wendt 1994;
Conroy and Kumwenda 1994), and on some
depleted communal lands in Zimbabwe,
hybrid maize will yield nothing without
fertilizer (Waddington and Ransom 1995).

In some ecologies, continuous cropping of
maize has led to degraded soil structure and
micronutrient deficiencies, which, in turn,
have led to a long-term decline in yields even
where chemical fertilizer is used at relatively
high levels (IITA 1991). Thus, it is important to
seek a balanced approach to improving soil
fertility, an approach that combines both

organic and inorganic source of nutrients
(Byerlee et al. 1994).

The efficiency of chemical fertilizers and the
long-term sustainability of yields can often be
increased by adding organic matter from
internal nutrient sources (e.g., green manures
and farmyard manures), by employing reduced
tillage techniques, and by alley crops (Spencer
and Polson 1991; Matlon 1990; Low and
Waddington 1991; Borlaug and Dowswell
1994). The review of the considerable literature
on long-term fertility trials conducted in SSA
has indicated the long-term yield benefits of
combining organic and inorganic soil
amendments (McIntire et al. 1992). Successful
intensification will need to combine such soil
management with greater use of inorganic
fertilizers, which provide about 40% of the
nutrients for the world's crops (World
Development Report 1992). This is particularly
critical in arid areas where, in most cases,
organic material has virtually disappeared
from the soil due to extraction and
decomposition. The use of fertilizers in
combination with organic materials and soil
conservation measures can increase the low
yields of food grains common in these areas.

However, as observed earlier, SSA lacks
resource management technologies for
maintaining soil fertility and increasing labor
productivity. And even where research and
extension systems have recommended
improved soil and crop management
technologies, adoption by small farmers has
been virtually nil (Spencer 1994; Ehui et al.
1994). In general, low producer prices for crops
and livestock in SSA have discouraged farmers
from investing in natural resource conservation
measures (Larson and Bromley 1993).

As Vlek (1993) has rightly observed, however,
". failing to enhance fertilizer use in SSA

might actually lead to an environmental
disaster, as it will cause stagnation in economic
development with millions of farmers trading
their exhausted and irreversibly degraded
lands for still remaining problem lands, leaving
behind a denuded landscape."

Farm-level studies show that technologies
which employ green manure crops,
composting, and animal manures to increase
soil fertility in smallholder agriculture have
largely been rejected because of the high labor
demands and the variable quality of the
product. There are also problems in producing
the quantity of manures and composts needed
to have a noticeable affect on soil fertility
(Blackie 1994; Jones and Wendt 1994).

Ehui et al. (1994) report that the benefits in
improved soil quality, fertility, and crop yields
are limited by the low output response of
inputs such as manure, crop residues, and
animal power. These inputs are also
insufficient to replace the major nutrients
mined from the soil by crop production.

Although it is acknowledged that improved
organic techniques of nutrient supply will
contribute to soil health and productivity
(Kumwenda et al., forthcoming), relying only
on the efficient recycling of nutrients available
in depleted soils will not generate the food
production increases required in SSA
(Janssen 1993).

Agricultural research

Future increases in food production must come
primarily from higher yields per unit of land
rather than from land expansion. Agricultural
research must therefore continue to develop

yield-enhancing production technologies
targeted to specific agroecologies, especially on
food crops. Research must also build tolerance
of, or resistance to, pests and adverse climatic

However, despite recent studies showing high
rates of return to research that has produced
new technologies (Oehmke and Crawford 1993)
and to the extension systems that helped
introduce such technologies to farmers
(Bindlish and Evenson 1993), investment in
research is declining. This trend must be
reversed if SSA is to meet its food needs. A
long-term research strategy will require
substantial public-sector involvement, which in
turn will require higher, not lower, investments
in agricultural research (Heisey and Mwangi,

In most areas of SSA, declining soil fertility is a
major limiting factor to food production.
Policies that support long-term agricultural
research are crucial to developing a fertilizer
sector capable of overcoming this problem.
Implicit in the often-repeated injunction that
"the right fertilizer be available at the right
time in the right place" is the assumption that
the "right fertilizer" is known. Agricultural
research is the foundation upon which such
determinations are made.

Soil fertility and fertilizer research should
receive high priority and research on organic
sources of nutrients must be encouraged and
strengthened. Some have argued that
continued research investment should be
directed toward the low-potential and problem
areas of SSA in order to arrest soil degradation
and promote efficient types of extensive
farming; however, fertilizer should probably

2 The high returns to research referred to are for varietal improvement research, not research on fertilizer or, more
broadly, resource management. Returns to these are generally much lower.

not play a major role in strategies for low-
potential areas, particularly those for which
increasing soil organic matter would be
problematic under any circumstances
(Vleck 1993).

In Malawi, research into alley cropping maize
with Leucaena leucocephalla has demonstrated
that organic fertilizers can increase maize
yields, although the biggest yield increase was
obtained when both inorganic and organic
fertilizers were applied together (Jones and
Wendt 1994). Experiments conducted by IFDC
and ICRISAT at Sadore and Gobey in Niger
have demonstrated that the addition of up to
20 t/ha of manure could result in as much
millet production as when chemical fertilizers
are used. However, managing such quantities
of organic materials is labor-intensive and
requires tools not now possessed by the
peasant farmer (Bationo and Mokwunye 1991).
Bationo and Mokwunye have also
demonstrated that the addition of crop residue
plus fertilizer increased millet yields 15-fold
over the control.3

Lynam and Blackie (1991) underlined the
importance of crop and resource management
research to overcome seasonal labor
constraints, while conserving the soil base and
enhancing soil fertility over the long run. They
contend that this type of research will assume a
major role in increasing the productivity and
sustainability of maize-based cropping
systems. However, such research is very site-
specific and more detailed micro-level research
will be needed to define appropriate strategies
for each location (Lele et al. 1989). More
research is also needed on the efficiency of

fertilizer use. So far, limited research has
shown that by using better agronomic and
management practices and improved fertilizer
products, many farmers can achieve
significantly higher crop output from the same
level of nutrient use (Bumb 1991).

It is important to emphasize that the process of
developing research recommendations, making
them consistent with policy, and turning them
into more effective (and often more
complicated) extension advice is far from
satisfactory for most countries in SSA (Heisey
and Mwangi, forthcoming).

Factors Influencing Farmers'
Adoption and Intensity
of Fertilizer Use

Demand and supply factors are hard to
separate when evaluating farmers' decisions to
adopt fertilizer and their subsequent decisions
about application rates. For example, many of
the key influences discussed in the adoption
literature (farm size, access to credit,
membership of cooperatives, contact with
extension, access to outside information,
availability of inputs, distance to markets) may
be related at least as much to supply side
constraints as to farmer demand (Mwangi
1995). Furthermore, in Kenya and some other
nations, fertilizer consumption tends to be
higher where input supply networks are well
developed. In some cases, however, it is
difficult to establish whether poorly developed
input supply channels are demand-driven
(arising from factors such as unattractive
returns, lack of credit, and poor technical
knowledge) or supply-driven. In this

3 The real problem is the wide performance gap between station-based and on-farm trials of new technologies. The
figure of 20 tons per hectare, for instance, is well beyond the capacity of most small farmers to produce and/or

subsection, we focus on factors influencing
demand for fertilizer; in the next subsection, we
turn to supply factors.

Demand factors

The demand for fertilizers is derived from the
demand for agricultural products. The factors
that affect and determine agricultural
production and the demand for fertilizers may
be classified as (1) climatic variables, (2) soil
characteristics, and (3) economic and social
variables. In conjunction with the knowledge
and experience of farmers, these factors affect
decisions about the use of resources for
agricultural production (crops and cropping
systems) and the use and management of
fertilizers and other variable inputs (Baanante
and Thompson 1988).

Low use of fertilizer has been partly attributed
to weak or nonexistent crop responses,
partially because of variable rainfall, poor soil
quality, an absence of irrigation, and a lack of
improved crop cultivars (McIntire et al. 1992).
Under rainfed conditions, maize in Africa tends
to be more fertilizer responsive than other
cereals, with the possible exception of rice
(Heisey and Mwangi, forthcoming). This is
undoubtedly one of the reasons maize
production appears positively linked with
fertilizer consumption.4 The agronomicc
efficiency" (fertilizer use efficiency) for maize
ranges from 5 to 25 kg grain or more per 1 kg
nutrient. A cursory examination of response
data for maize in other developing countries
(India, Mesoamerica) reveals no marked
difference from African response data (Heisey
and Mwangi, forthcoming).

Economics of fertilizer use The economics
of using chemical fertilizer on maize is highly
site-specific, depending on land pressure,
agroclimatic variables, fertilizer costs, and
farm gate maize prices (Byerlee et al. 1994).
Anderson (1992) has hypothesized that most of
the recommended technologies, including
chemical fertilizer use, are not more profitable
than existing practices, given the constrained
resources of affected farmers.

In Malawi, a recent program of 110 on-farm
demonstrations over two years in one district
found that it is economical for food-deficit
households to use fertilizer on local maize,
although fertilizer use on hybrid maize at
recommended doses provided even higher
returns (Table 2); Malawi has the highest
N:grain price ratio in Table 3. If the fertilizer
subsidy were removed, however, fertilizing
local maize varieties would not be
economically efficient.5 Even for hybrid maize,
returns to fertilizer use are less than the 100%
rate of return usually assumed to be the
minimum required for small-scale farmers to
adopt this type of technology widely (Table 2).
A similar situation has been observed for maize
in Tanzania, where for farmers the profitability
of fertilizer use is low, especially in interior
locations where the high cost of transport
reduces effective maize prices and increases the
price of chemical fertilizers (Lele 1992).

An important consideration for those with
small farms and little cash is the possible risk of
using fertilizer. But in favorable growing
conditions like those of Malawi, risk is not an
important factor in many farmers' decisions to
accept or reject the seed-fertilizer technology

4 That relative responsiveness is not the only factor determining fertilizer consumption is well illustrated by Ethiopia,
where teff-the cereal least responsive to fertilizer-receives the highest aggregate amount of fertilizer, partially
because it is a relatively high-value crop with a somewhat more stable market (Makken 1993).
5 The fertilizer subsidy has been removed, and for 1995/96, fertilizer cost has gone up 300%.

(Smale et al. 1991). However, in marginal
production areas with a high yield risk of
drought, the yield risk of fertilizer use increases
substantially. Results from marginal maize-
growing areas of Kenya, where soils are highly
degraded, indicate that rainfall risk is probably
a key factor in the low rate of fertilizer
adoption (McCown et al. 1992).

Price instability and input supply problems
often pose a greater risk for fertilizer users than
yield risk per se (Byerlee et al. 1994). In general,
price instability leads to lower investment in
new technologies such as those that employ
fertilizer (Timmer 1993). It has also been
observed that uncertainty in the profitability of
fertilizer represents a serious disincentive to
fertilizer adoption and use on staple crops
(Vlek 1990).6

Availability Although the factors affecting
fertilizer availability are often referred to as non-
price factors, they can be accommodated within
a pricing framework by noting that in effect they
raise the shadow price of fertilizers to farmers. A
major constraint to technology adoption in
much of Africa is the physical unavailability or
untimeliness of inputs. On whether fertilizer use
is limited more by supply or demand, Pinstrup-
Andersen (1993) notes that in most cases
farmers' limited access to the right kind of
fertilizer at the right time was probably just as
important a constraint as price. One study of
farmers' reasons for not following the extension
recommendations developed through adaptive
on-farm research in Zambia found that in 44% of
the cases inputs simply were not available (Low
and Waddington 1991).

Table 2. Effect of price policy on the profitability of alternative maize technologies in 110
on-farm demonstrations, Lilongwe, Malawi, 1990 and 1991

Local maize
with fertilizer

Fertilizer applied (kg nutrient/ha)

Yield increase observed over
unfertilized local maize (kg/ha)

Hybrid maize
with fertilizer


Marginal rate of return (%)C0

Subsidized input pricesa
Maize-deficit households 133 237
Maize-surplus households 64 136

Unsubsidized input prices
Maize-deficit households 79 145
Maize-surplus households 27 72

Source: P. Heisey (personal communication), based on data provided by the FAO/Ministry of Agriculture Fertilizer
Program. Reported in Byerlee et al. (1994).

a Subsidy of 25% on fertilizer and about 40% on hybrid seed.
b The price of maize in households that purchase maize is about 40% above the farm gate selling price.
c Marginal rate of return on input expenditures. A return above 100% is usually assumed to be necessary for
widespread farmer adoption.

6 But despite this problem, fertilizer use on cereals has increased, particularly for maize.

Price policies and credit Many countries in
SSA have promoted fertilizer use through price
and/or credit subsidies. The high cost of
fertilizer in SSA is the main justification for
maintaining subsidies. Other reasons include
compensating for low output prices,
uncertainty about the profitability of fertilizer,
promoting adoption, making fertilizer more
readily available to small farmers (thus
fulfilling an equity goal), and the high cost of
capital in informal markets (Byerlee et al. 1994;
Pinstrup-Andersen 1994; Vlek 1990).

Shalit and Binswanger (1985) have outlined
three theoretical cases for fertilizer subsidies.
The best theoretical case is to promote the
learning of a new technology that will in time
be socially profitable. Compensation for an
export tax (more likely to apply to cash crops)
is another theoretical argument. Yet another is
that if there is a policy goal of food self-
sufficiency, fertilizer subsidies may be more
effective than output price subsidies; given
other policy goals, fertilizer subsidies might
seem somewhat less attractive.

Some policy analysts would contend that other
arguments, such as compensating for the high
cost of capital, are best addressed by improving
financial intermediation, not by subsidizing
fertilizer. It is also debatable whether high
prices are best countered by subsidies or by
trying to address the underlying causes of the
high prices. Perhaps a middle ground would be
to look at both alternatives as important, with
their relative roles changing over time. Other
arguments might also be geographically
specific. For example, temporary fertilizer
subsidies would seem more justifiable for
Malawi than for Nigeria.

In recent years, governments in SSA have been
pressured by the World Bank, IMF, and other
donors through structural adjustment

programs (SAPs) to remove fertilizer subsidies.
In countries where such actions have been
taken, overall national demand for fertilizers
has been substantially weakened, at least in the
short run (Vlek 1990).

Waddington and Ransom (1995) indicate that
for most countries in the region, SAPs have
eliminated price subsidies and reduced the
availability of credit for inorganic fertilizer
inputs and seed. This creates a great deal of
uncertainty for farmers and for the research
and extension services that support them.
However, it also creates new opportunities
(such as potential availability of a wider range
of micronutrient fertilizers). Nevertheless, the
short- to medium-term consequences of SAPs
are that smallholder farmers will apply even
less N and phosphorus (P) fertilizers and will
use less hybrid maize seed because of real price
increases at the farm gate.

In Nigeria, Smith et al. (1994) indicate that
removing the fertilizer subsidy is expected to
reduce the profitability of maize, while reduced
fertilizer use levels will necessitate major
changes in soil maintenance practices in a
production system that relies heavily on
fertilizer for maintaining soil fertility. In
Senegal the reduction in fertilizer subsidies has
led to declining demand for fertilizer
(Shepherd 1989). In Malawi and Cameroon,
some contend that removing the subsidy will
reduce fertilizer use by women farmers, whose
use of fertilizers is already low (Gladwin 1992).

In Ghana, removing fertilizer subsidies in the
absence of credit and remunerative output
prices has resulted in falling demand for the
input (Kwandwo Asenso-Okyere 1994). A
study from Nigeria, where fertilizer is
subsidized heavily, showed that chaotic and
untimely supply was one of the most salient
reasons for non-adoption (Daramola 1989). In

this case, continuing the fertilizer subsidy
appears unjustified on either efficiency or
equity grounds. However, others have argued
that despite the supply problems, the fertilizer
subsidy undoubtedly assisted the adoption and
expansion of maize (Smith et al. 1994).

A strong case can be made for fertilizer
subsidies-especially for phosphate
fertilizers-to restore and sustain soil fertility.
But although SSA has plenty of phosphate rock
reserves, these have not been exploited due to
high investment costs, low phosphate prices,
foreign exchange shortages, and limited skilled
manpower (Bumb and Baanante 1995).

Given the very low levels of fertilizer use, the
high prices, and the fact that most countries in
SSA are pursuing the policy of food self-
sufficiency, there will be theoretical arguments
for continued fertilizer subsidies in the short
and medium terms. Furthermore, we have seen
that, in most cases, removing the subsidy
significantly reduces fertilizer use.

Besides subsidies, government-sponsored
credit programs have commonly been used to
promote input adoption, often by providing
inputs in kind at low or negative real interest
rates (Byerlee et al. 1994). While such programs
have sometimes stimulated input adoption by a
significant proportion of farmers (Kimuyu et al.
1991), adoption has usually been achieved at a
high cost, and the programs have not been
sustainable over the long term (Adams et al.
1984; Eicher and Rukuni 1992). Moreover,
credit programs have tended to be
monopolized by more powerful rural political
groups and male farmers (Gladwin 1992) and
are difficult to administer. In 1994, Malawi's
fertilizer use decreased to less than 70,000 tons,
compared to 180,000 tons in 1992/93. This
reduction was caused by the collapse of the
smallholder credit system (Conroy and

Kumwenda 1994). It should be noted, however,
that this system was, prior to its collapse, a
relatively efficient one (as indicated by high
repayment rates and other measures).

Government-sponsored credit schemes
featuring group lending, credit extended by
traders, and effective rural financial
intermediation based on small community
savings and credit schemes have all been
proposed as solutions to farmers' liquidity
problems. But experience with government
schemes has been disappointing (Eicher and
Kupfuma, forthcoming). To date, however,
experience with and analysis of other ways to
provide smallholders with credit have been

Other important elements in an environment
conducive to technology transfer are producer
price incentives and stability (Byerlee et al.
1994). In some cases, distortions in producer
prices are the major factor limiting technology
adoption. In Ethiopia, fertilizer use on maize
was uneconomic at any level under prevailing
maize prices. If maize prices were to reflect
import prices at a realistic exchange rate,
however, fertilizer would become an attractive
investment (Legesse Dadi et al. 1992).

In Ethiopia, consumption of chemical fertilizers
averaged 50,000 tons during the 1980s. Major
growth in fertilizer use occurred after 1991:
consumption doubled (to 113,000 tons) and
then rose to 160,000 tons in 1992 due to
liberalization of the grain market (World Bank
1994). But in Kenya, liberalization has been less
encouraging: fertilizer use peaked at 271,000
tons of various products in 1988-1989 and
declined steadily to 225,000 tons in 1991-1992.
This decline occurred mainly because the
government liberalized the fertilizer market but
did not liberalize the grain market, especially
that of maize (Sodhi 1993).

Supply factors

SSA imports about 85% of the fertilizer it
consumes (Vlek 1990). Fertilizer supply
constraints are thus associated with
importation, distribution, and pricing. Policies
that affect these areas, along with a lack of
infrastructure, are the main source of potential
constraints to fertilizer supply.

Pricing environment and distribution costs -
Farmers in SSA face very high fertilizer prices
(Table 3). The price they pay for fertilizer,
relative to the price they receive for their
output, is thus much higher than in Asia. Some
of the reasons for this high price result from
SSA's dependence on fertilizer imports.

Differences between world f.o.b. prices and
landed cost tend to be twice as high in many
sub-Saharan countries as compared to Asian
countries (Shepherd and Coster 1987). Bumb
(1988) indicates that this large difference is the
result of the small volume of fertilizer that most
African countries import; small volumes
increase transportation costs and weaken the
nations' position in negotiating for lower
prices. Also, transportation costs are high
because of poor physical infrastructure. Almost
half of the 40 countries Bumb analyzed
imported less than 5,000 tons of nutrients
annually in the mid-1980s; only Nigeria
imported more than 100,000 tons.

In 1990, almost one-third of all fertilizer
imports in SSA were financed by aid. For 21
countries, all fertilizer was financed through
donor programs.7 Donors impose conditions
(such as limitations on origin, transporters, and
fertilizer type) that can lead to excessive
marketing costs and margins (Gerner and

Harris 1993), which ultimately translate into
high fertilizer prices.

Another reason for high fertilizer prices in SSA
is the high cost of distribution. These costs are
higher by several fold than costs in Asia. For
instance, in Sri Lanka, the distribution costs for
urea averaged about US$ 45/ton, as against
US$ 92/ton in Zambia and US$ 246/ton in
Tanzania (Bumb 1988). Higher prices in SSA
are the result of high transportation costs,
which in turn are a consequence of poor
physical infrastructure and the small volumes
to be distributed. The cost of transport and
marketing can increase the real farm-level price
of imported fertilizer by up to 50% in a
landlocked country such as Malawi, compared
with the real farm-level price in a country like

Table 3. Ratio of farm-level prices of
nitrogen fertilizer to maize grain prices in
sub-Saharan Africa and other regions, 1989

Price ratio



Latin America
Brazil 6.0
Colombia 1.4
Mexico 1.6

Source: CIMMYT (1990); Byerlee et al. (1994);
Lele et al. (1989).

7 Countries with relatively large fertilizer consumption levels-like Ethiopia, Kenya, Ghana, Malawi, and Tanzania-
depend primarily on aid-financed fertilizer (Gerner and Harris 1993).

Kenya, which has relatively good infrastructrue
and ready access to a port.

In Zimbabwe, Conroy (1990) reports that
fertilizer use in communal lands has not kept
pace with population growth since 1985-
although fertilizers, in terms of nutrient/crop
price ratios, are cheaper in Zimbabwe than in
other countries in the region (except Zambia).
Moreover, the price of fertilizer relative to
maize, cotton, and wheat prices has been
falling over the last five years (Conroy 1990).
The reasons for the limited use of inorganic
fertilizer by communal farmers include
problems of supply, the lack of an effective
distribution network, and the absence of
appropriate fertilizer recommendations.
Consequently, one can conclude that fertilizer
will remain a scarce and expensive commodity
for communal farmers in Zimbabwe until
distribution problems are resolved (Blackie

The inability of the public sector to operate
fertilizer distribution systems efficiently and
the absence of competition within the
distribution network are additional reasons for
high fertilizer prices (Pinstrup-Andersen 1993).

Privatization of supply The current
response to fertilizer supply problems has been
to urge the rapid privatization of the
distribution system and the liberalization of
fertilizer imports. The argument is based on
experience in other parts of the world, which
has shown that private enterprise is more
effective in delivering improved technology to
farmers and in developing marketing and
credit institutions (Borlaug and Dowswell
1994). However, Vlek (1990) observes that
although private enterprise appears better
suited to handling fertilizer procurement,
distribution, and marketing, dealers must be
afforded a sufficient margin to cover

investment and operating costs and to make
profits if a nation is to have a dynamic private
fertilizer distribution and marketing network.

So far, experience with privatization has been
mixed. In Ghana, fertilizer marketing channels
have functioned poorly even after the
privatization of supply and distribution. The
scant participation of the private sector in the
retailing, wholesaling, and importation of
fertilizer has been attributed to the relative
profitability of the enterprise from the narrow
margins allowed by the Ministry of Agriculture
(Kwandwo Asenso-Okyere 1994). Experience
from Cameroon shows that once a market is
developed, the private sector can import and
deliver inputs at a lower cost, provided that the
public sector provides market information and
other appropriate supports (Truong and
Walker 1990).

Experience with privatizing the fertilizer trade
underlines the importance of government in
creating a favorable environment (i.e.,
eliminating constraints from government
involvement). If mutual trust and confidence
are to develop, both the short- and long-term
roles of government and the private sector
must be clearly spelled out (Sodhi 1993).
Initially, fertilizer distributors may need to be
trained. This is an important issue: governments
consider fertilizer a strategic and politically
sensitive commodity; thus, completely
divesting their fertilizer interests to the private
sector may prove politically sensitive (e.g.,
fertilizer shortages could affect national food
security, which, in turn, could lead to political
and social instability).

Sodhi (1993) in his review of fertilizer sectors in
Ethiopia, Kenya, and Uganda indicates that
government's role includes setting and
enforcing standards and controlling quality;
estimating fertilizer demand in consultation

with the private sector; monitoring and
evaluating sector performance; setting up
mechanisms for consultations between the
private sector and government; providing
incentives and creating a conducive
environment; supporting research and
extension, especially on soil fertility and
fertilizer issues; and developing infrastructure,
especially rural/feeder roads and
transportation facilities.

For the fertilizer sector to be effective, the
government, in consultation with the private
sector and donors, will need to develop what
most countries in SSA lack: a detailed national
fertilizer-sector policy and plan that is carefully
integrated with a comprehensive agricultural

Infrastructural development Fertilizer
transportation accounts for the largest share of
the difference in marketing margins between
Asia and Africa. Reducing transportation and
storage for a bulky input like fertilizer is
essential if long-run consumption is ever to
approach the social optimum. Investments in
rural and agricultural institutions and rural
infrastructure, especially rural/feeder roads
should therefore be accelerated. Furthermore,
public provision of legal and social
infrastructure may also help to reduce the risks
of fertilizer distribution (Ndayisenga and
Schuh 1995). In Ghana, some have argued that
reducing post-harvest losses, increasing the
availability of effective storage structures, and
improving transport infrastructure can increase
the profitability of many crops, especially
cereals, and serve as an incentive for increasing
fertilizer use (Kwandwo Asenso-Okyere 1994).
Such increases would reduce the price of
fertilizer and eliminate the need for subsidies.

The need for investments in roads is
underscored by the fact that SSA has only 5 km

of roads per 100 km2 compared to 45 and 95
km of roads for the same area in Asia and
industrialized economies, respectively (Vlek
1990). In Tanzania, poor feeder roads make
primary marketing less efficient than
secondary marketing because both private
traders and cooperative societies refrain from
trading in remote areas (Amani et al. 1992). In
Iringa, Coulter and Golob (1991) have observed
that, for villages 15-45 kilometers off the main
highway, the cost of primary marketing
(wholesale assembly) ranges from 9 to 40 times
the cost of secondary marketing. Private
traders do not go to such areas to buy farm
produce. Poor roads thus prevent fertilizer
from coming in and produce from going out.
Similar experiences have been observed
elsewhere in SSA (Makken 1991; Ehui et al.


In SSA, farmers use low levels of fertilizer.
Given that fact and the current state of
knowledge, low-input systems are unlikely to
increase food production rapidly, reverse the
decline in rural incomes, and slow
environmental degradation. Increases in food
production must now come primarily from
higher yields per unit of land rather than from
land expansion. Historically, inorganic
fertilizer has been a major component in
achieving such increases.

The profitability of applying inorganic
fertilizers often varies due to the variations in
crop response and the high and variable cost of
fertilizer in relation to product prices. Fertilizer
use is strongly affected by various policies,
especially those that affect input supply and
prices. In many areas of SSA, fertilizer adoption
has been slowed by the absence of appropriate
institutional structures to supply inputs, credit,
and information.

Public research and extension investments will
also play an important role in increasing the
profitability of fertilizer use for farmers in SSA.
Even though research investments have
generated high rates of return, support for
research is declining. This trend must be
reversed, and investments must be accelerated,
if research is to continue developing input-
responsive and yield-stabilizing varieties while
improving crop and resource management
strategies. Research and extension investments
offer an assured way to satisfy increased
demands for food at reasonable prices, while
avoiding irreversible degradation of the natural
resource base.

Without subsidies, farmers in SSA pay a very
high price for fertilizer. Such prices occur in
part because most of the fertilizers used in SSA
are imported, and transportation costs are high.
In the short and medium terms, fertilizer
subsidies can help to compensate for these cost-
increasing factors.

In the long-term, however, SSA must find other
ways to make the right type of fertilizer
available at the right time, place, and price.
Research can help to clarify what fertilizers
work best in particular situations. In addition,
regional cooperation in international fertilizer
procurement (Vlek 1990; Pinstrup-Andersen
1993) would help offset problems associated
with the small volume of fertilizer purchased
by countries in SSA, volumes that do not take
advantage of scale economies for purchasing
and shipment. Governments in SSA consider
fertilizer a strategic and politically sensitive
commodity, however, and given their
experience with regional cooperation, this kind
of cooperation may not be feasible.

The donor community (spearheaded by the
World Bank and IMF) is encouraging
governments to promote private enterprise and
competition with respect to fertilizer imports
and distribution. Thus far, the experience has
been mixed. Future strategies should include a
greater mix of public- and private-sector
initiatives involving organizations throughout
SSA's fertilizer sector. The roles of each
partner, especially that of government, will
have to be clearly spelled out. Governments
must make national fertilizer policies and plans
a part of the overall agricultural development
strategy. Such efforts should produce more
predictable policies and more stable
institutions so that the private sector can
develop the confidence necessary to invest in
the fertilizer trade. The policies should ensure
that sufficient price incentives exist to make
fertilizer use profitable for farmers and
suppliers. Credit, for instance, must be
extended not only to farmers but to private
traders as well.

Poor rural infrastructure-especially rural/
feeder roads- is a major cause of high
fertilizer prices. Governments must increase
their investments in infrastructure if they are to
increase agricultural productivity.
Infrastructure development should be treated
as a social cost and charged to a social
overhead account in the national budget (Bumb
and Baanate 1995).

For fertilizer use to increase over the long term,
political commitment to agriculture must be
translated into investments that develop
institutions and infrastructure. Such support
will enable agriculture to play its crucial role in
SSA's overall economic development.


Adams, D., D. Graham, and J. von Pischke. 1984.
Undermining Rural Development with Cheap
Credit. Boulder, Colorado: Westview Press.

Amani, H.K.R., R. van den Brink, and W.E. Maro. 1992.
Tolerating the Private Sector: Grain Trade in
Tanzania after Adjustment. Working Paper 32,
Cornell Food and Nutrition Policy Program.
Ithaca, New York: Cornell University.

Anderson, J.R. 1992. Difficulties in African agricultural
systems enhancement? Ten hypotheses.
Agricultural Systems: 387-409.

Baanante, C.A., and T.P. Thompson. 1988. Micro-
socioeconomic research on constraints to
fertilizer use in sub-Saharan Africa for policy
development. In Tshikala, B. Tshibaka and
C.A. Baanante (eds.), Fertilizer Policy in Tropical
Africa. Workshop Proceedings, Lome, Togo:
International Fertilizer Development Center
and International Food Policy Research

Bationo, A., and A.U. Mokwunye. 1991. Role of
manures and crop residue in alleviating soil
fertility constraints to crop production with
special reference to the Sahelian and Sudanian
zones of West Africa. Fertilizer Research 29:117-

Bindlish, V., and R. Evenson. 1993. Evaluation of the
Performance ofT & V Extension in Kenya.
Agriculture and Rural Development Series
No. 7, Technical Department. Washington,
D.C.: The World Bank.

Binswanger, H.P. 1986. Evaluating research system
performance and targeting research in land-
abundant areas of sub-Saharan Africa. World
Development 14(4): 469-476.

Binswanger, H.P., and P. Pingali. 1988. Technological
priorities for farming in sub-Saharan Africa.
World Bank Research Observer 3(1) 81-98.

Blackie, M.J., and R.B. Jones. 1993. Agronomy and
increased maize productivity in eastern and
southern Africa. Biological Agriculture and
Horticulture 9: 147-160.

Blackie, M.J. 1994a. Maize productivity for the 21st
Century: The African challenge. Outlook on
Agriculture 23: 189-195.

Blackie, M.J. 1994b. Realizing smallholder agricultural
potential. In Mandivamba Rukuni and Carl
Eicher (eds.), Zimbabwe's Agricultural
Revolution. Harare, Zimbabwe: University of
Zimbabwe Publications. Pp. 335-347.

Borlaug, N.E., and C.R. Dowswell. 1994. Mobilizing
science and technology to get agriculture
moving in Africa. Plenary Lecture, The Second
Roundtable of Science Advisors for Science-
led Development in Africa, 20 July, Maputo,

Bumb, B.L. 1988. Fertilizer supply in sub-Saharan
Africa-an analysis. In Tshikala, B. Tshibaka
and C.A. Baanante (eds.), Fertilizer Policy in
Tropical Africa. Workshop Proceedings, Lome,
Togo: International Fertilizer Development
Center and International Food Policy Research

Bumb, B.L. 1991. Trends in fertilizer use and
production in sub-Saharan Africa, 1970-95: An
overview. Fertilizer Research 28: 41-48.

Bumb, B.L., J.F Teboh, J.K. Atta, and W.K. Asenso-
Okyere. 1994. Ghana Policy Environment and
Fertilizer Sector Development. Muscle Shoals,
Alabama: International Fertilizer
Development Center.

Bumb, B.L., and C.A. Baanante. 1995. The Role of
Fertilizers in Sustaining Food Security and
Protecting the Environment: Trends to 2020.
Paper prepared for IFPRI's 2020 Vision for
Food, Agricultural and the Environment.
Washington, D.C.: IFPRI.

Byerlee, D., with P. Anandajayasekeram, A. Diallo, B.
Gelaw, P.W. Heisey, M. Lopez-Pereira, W.
Mwangi, M. Smale, R. Tripp, and S.
Waddington. 1994. Maize Research in Sub-
Saharan Africa: An Overview of Past Impacts and
Future Prospects. CIMMYT Economics Working
Paper 94-03. Mexico, D.F.: CIMMYT.

CIMMYT. 1990.1989/90 CIMMYT World Maize Facts
and Trends: Realizing the Potential of Maize in
Sub-Saharan Africa. Mexico, D.F: CIMMYT.

Conroy, A. 1990. Fertilizer Use and Distribution in
Zimbabwe. Paper prepared for the World Bank
Agriculture Sector Study. Harare, Zimbabwe:
The World Bank.

Conroy, A.C., and J.D.T. Kumwenda. 1994. Risks
associated with the adoption of hybrid seed
and fertilizer by smallholders in Malawi.
Paper presented at the Fourth Eastern and
Southern Africa Regional Maize Conference:
Maize Research for Stress Environments, 28
March to 1 April, Harare, Zimbabwe.

Coulter, J., and P. Golob. 1991. Liberalizing of cereals
marketing in sub-Saharan Africa:
Implementing issues. In Report No. 2:
Tanzania-A Case Study. Kent, United
Kingdom: Natural Resource Institute.

Daramola, B. 1989. The study of socioeconomic factors
influencing fertilizer adoption decisions in
Nigeria: A survey of Oyo State farmers.
Fertilizer Research 20: 143-151.

Desai, G.M. 1990. Fertilizer policy issues and
sustainable agricultural growth in developing
countries. In T..,. ...1, .. Policy for Sustainable
Agricultural Growth. Policy Brief No. 7.
Washington, D.C.: International Food Policy
Research Institute.

Dudal, R., and B.H. Byrnes. 1993. The effects of
fertilizer use on environment. In H. van Reuler
and W.H. Prins (eds.), The Role of Plant
Nutrients for Sustainable Food Crop Production in
Sub-Saharan Africa. Leidschendam, The
Netherlands: VPK (Dutch Association of
Fertilizer Producers).

Ehui, S., T. Williams, and B. Swallow. 1994. Economic
factors and policies encouraging
environmentally detrimental land use
practices in sub-Saharan Africa. Invited paper,
XXII International Conference of Agricultural
Economists, 22-29 August, Harare, Zimbabwe.

Eicher, C.K., and M. Rukuni. 1992. Zimbabwe's
experience in restructuring institutions to
support communal farmers: Lessons from
Namibia. In C. Csaki, T. Dams, D. Mezger, and
J. van Zyl (eds.), Agricultural Restructuring in
Southern Africa. Sqkopmund, Namibia:
International Association of Agricultural
Economists and Association of Agricultural

Eicher, C.K., and B. Kupfuma. Forthcoming.
Zimbabwe's maize-based green revolution:
Economic and institutional preconditions for
replication. In D. Byerlee and C.K. Eicher
(eds.), The Emerging Maize-Based Revolution in
Sub-Saharan Africa: Technologies, Institutions,
and Policies.

Gerner, H., and G. Harris. 1993. The use and supply of
fertilizers in sub-Saharan Africa. In H. van
Reuler and W.H. Prins (eds.), The Role of Plant
Nutrientsfor Sustainable Food Production in Sub-
Saharan Africa. Leidschendam: Vereniging van
Kunstmest Producenten.

Gladwin, C.H. 1992. Gendered impacts of fertilizer
subsidy removal programs in Malawi and
Cameroon. Agricultural Economics 7: 141-153.

Heisey, P.W., and W. Mwangi. Forthcoming. Fertilizer
use and maize production in sub-Saharan
Africa. In D. Byerlee and C.K. Eicher (eds.),
The Emerging Maize-Based Revolution in Sub-
Saharan Africa: Technologies, Institutions, and

IITA. 1991. Annual Report 1989/90. Ibadan Nigeria:
International Institute of Tropical Agriculture.

Janssen, B.H. 1993. Integrated nutrient management:
The use of organic and mineral fertilizers. In
H. van Reuler and W.H. Prins (eds.), The Role
of Plant Nutrientsfor Sustainable Food Crop
Production in Sub-Saharan Africa. Leidschedam,
The Netherlands: VKP (Dutch Association of
Fertilizer Producers).

Jones, R.B., and J.W. Wendt. 1994. Contribution of soil
fertility research to improved maize
production by smallholders in eastern and
southern Africa. Paper presented at the Fourth
Eastern and Southern Africa Regional Maize
Conference: Maize Research for Stress
Environments, 28 March to 1 April, Harare,

Kimuyu, P.K., M.A. Jama, W.M. Muturi. 1991.
Determinants of fertilizer use on smallholder
coffee and maize in Muranga District, Kenya.
East Africa Economic Review 7(1): 45-49.

Kumwenda, J.D.T., S.R. Waddington, S.S. Snapp, R.B.
Jones, and M.J. Blackie. Forthcoming. Soil
fertility management in the smallholder
maize-based cropping systems of Africa. In D.
Byerlee and C.K. Eicher (eds.), The Emerging
Maize-Based Revolution in Sub-Saharan Africa:
Technologies, Institutions, and Policies.

Kwandwo Asenso-Okyere, W. 1994. Fertilizer pricing
and distribution policy in Ghana. In Issues in
African Rural Development. Arkansas, U.S.:
Winrock International Institute for
Agricultural Development.

Larson, B.A., and D.W. Bromley. 1993. Natural
resources prices, export prices, and
deforestation: The case of Sudan. World
Development 19: 1289-1297.

Legesse Dadi, W. Mwangi, and S. Franzel. 1992.
Socioeconomic constraints to increasing maize
production. In Steven Franzel and Helen van
Houten (eds.), Research With Farmers: Lessons
from Ethiopia. CAB International, Wallingford.

Lele, U., R.E. Christiansen, and K. Kadiresan. 1989.
Issues in Fertilizer Policy in Africa: Lessons from
Development and Adjustment Lending. MADIA
Paper No. 5. Washington, D.C.: The World

Lele, U. 1992. Can technology transfer and
macroeconomic adjustment sustain Africa's
agricultural revolution without an agricultural
sector strategy? Sasakawa-Global 2000 Draft
Paper. Minneapolis: Mimeo.

Low, A., and S. Waddington. 1991. Farming systems
adaptive research: Achievements and
prospects in southern Africa. Experimental
Agriculture 27: 115-125.

Lynam, J.K., and M.J. Blackie. 1991. Building effective
agricultural research capacity: The African
challenge. Paper presented at the Conference
on Agricultural Technology for Sustainable
Economic Development in the New Century:
Policy Issues for the International Community,
October, Airlie House, Virginia, U.S.

Makken, F 1991. Alleviating fertilizer policy
constraints to increased fertilizer use and
increased food production in West Africa.
Fertilizer Research 29: 1-7.

Matlon, P., and D.S. Spencer. 1984. Increasing Food
Production in sub-Saharan Africa:
Environmental problems and inadequate
technological solutions. American Journal of
Agricultural Economics 66: 671-676.

Matlon, P. 1987a. The West African semi-arid tropics. In
J.W. Mellor, C.L. Delgado, and M.J. Blackie
(eds.), Accelerating Food Production in Africa.
Baltimore, Maryland: Johns Hopkins
University Press, 1987.

Matlon, P. 1987b. Prospects for sorghum and millet
production in the West African semi-arid
tropics. Paper presented at IFPRI/ISRA
Conference in Dakar, Senegal, July.

Matlon, P. 1990. Improving productivity in sorghum
and pearl millet in semi-arid Africa. Food
Research Institute Studies 22(1): 1-43.

McCown, R.L., B.A. Keating, R.E. Robert, and R.K.
Jones. 1992. Strategies for sustainable crop
production in semi-arid Africa. Outlook on
Agriculture 21(1): 21-31.

McIntire, J., D. Bourzat, and P. Pingali. 1992. Crop-
livestock Interaction in sub-Saharan Africa.
Washington, D.C.: The World Bank.

Mellor, J.W., C.L. Delgado, and M.J. Blackie (eds.).
1987. Accelerating Food Production in sub-Saharn
Africa. Baltimore, Maryland: Johns Hopkins
University Press.

Mwangi, W. 1995. Low use of fertilizers and low
productivity in sub-Saharan Africa. Paper
presented at the IFPRI/FAO workshop: Plant
Nutrition Management, Food Security and
Sustainable Agriculture, and Poverty
Alleviation in Developing Countries, Viterbo,
Italy, 16-17 May.

Narayana, N.S.S., and K.S. Parikh. 1987. Estimation of
yield functions for major cereals in India.
Journal of Quantitative Economics (2): 287-312.

Ndayisenga, F., and G.E. Schuh. 1995. Fertilizer policy
in sub-Saharan Africa: Recurring Issues and
Recommendations. Sasakawa-Global 2000
Draft Paper. Minneapolis: Mimeo.

Oehmke, J.F., and E.W. Crawford. 1993. The Impact of
Agricultural TI.. ,I1,,.. in sub-Saharan Africa.
Washington, D.C.: ARTS Technical Paper No. 3.

Per Pinstrup-Andersen. 1993. Fertilizer subsidies:
Balancing short-term responses with long-
term imperatives. In N.C. Russell and C.R.
Dowswell (eds.), Policy Options for Agricultural
Development in Sub-Saharan Africa. Mexico,
D.F: CASIN/SAA/Global 2000.

Shepherd, A., and R. Coster. 1987. Fertilizer Marketing
Costs and Margins in Developing Countries.
Rome, Italy: FAO/FIAC.

Shepherd, A. 1989. Approaches to the privatization of
fertilizer marketing in Africa. Food Policy 14(2):

Smale, M., with Z.H.W. Kaunda, H.L. Makina,
M.M.M.K. Mkandawire, M.N.S. Msowoya,
D.J.E.K. Mwale, and P.W. Heisey. 1991.
Chimanga Cha Makolo, Hybrids, and
Composites: An Analysis of Farmers' Adoption of
Maize T,. ,-h,,, ,, in Malawi, 1989-91. CIMMYT
Economics Program Working Paper 91-04.
Mexico, D.F: CIMMYT.

Smil, V. 1991. Population growth and nitrogen: An
exploration of a critical existential link.
Population and Development Review 17(4): 569-

Smith J., A.D. Barau, A. Goldman, and J.H. Mareck.
1994. The role of technology in agricultural
intensification: The evolution of maize
production in the northern Guinea savanna of
Nigeria. Economic Development and Cultural
C0;.,,0. 42(3): 537-554.

Sodhi, A.J.S. 1993. Reforming the agribusiness markets:
The case of fertilizers from East Africa. Paper
presented at International Training Workshop
on Deregulation and Privatization Policies to
Reform Agribusiness Markets, 19-30 April,
Muscle Shoals, Alabama, and Washington,

Spencer, D., and R.A. Poison. 1991. Agricultural
growth and sustainability: Conditions for their
compatibility in the humid and sub-humid
tropics of Africa. In Agricultural Sustainability
Growth, and Poverty Alleviation: Issues and
Policies. Feldafing, Germany: DSE/
International Food Policy Research Institute.

Spencer, D.S.C. 1994. Infrastructure and T,.1., 1, ..
Constraints to Agricultural Development in the
Humid and Sub-humid Tropics of Africa. EPTD
Discussion Paper No. 3. Washington, D.C.:

Stoorvogel, J.J., E.M.A. Smaling, and B.H. Janssen.
1993. Calculating soil nutrient balances in
Africa at different scales: 1. Supranational
scale. Fertilizer Research 35: 227-235.

Timmer, C.P. 1993. Food price stabilization: The
relevance of the Asian experience to Africa. In
N.C. Russell and C.R. Dowswell (eds.), Policy
Options for Agricultural Development in Sub-
Saharan Africa. Mexico, D.F.: CASIN/SAA/
Global 2000.

Truong, T.V., and S.T. Walker. 1990. Policy reform as
institutional change: Privatizing the fertilizer
subsector in Cameroon. In D. Brinkerhoff and
A. Goldsmith (eds.), Institutional Sustainability
in Agriculture and Rural Development: Global
Perspective. New York, N.Y: Praeger.

Viyas, V.S. 1983. Asian agriculture: Achievements and
challenges. Asian Development Review 1: 27-44.

Vlek, P.L.G. 1990. The role of fertilizers in sustaining
agriculture in sub-Saharan Africa. Fertilizer
Research 26: 327-339.

Vlek, P.L.G. 1993. Strategies for sustaining agriculture
in sub-Saharan Africa: The fertilizer
technology issue. In T.1,, ii,.1, ,. for Sustainable
Agriculture in the Tropics: American Society for
A ,, ,", ,. Special Publication 56:265-277.

von Braun, J., and L. Paulino. 1990 Food in sub-
Saharan Africa: Trends and Policy Challenges
for the 1990s. Food Policy 15: 505-517.

Waddington, S.R., and J.K. Ransom. 1995. Linking
soils, agronomy, and crops research for maize:
CIMMYT initiatives in southern and eastern
Africa. Paper prepared for the meeting on
Soils Management in Eastern and Southern
Africa, 30 January to 2 February, Bellagio,

Wong, M.T.F., A. Wild, and A.U. Mokwunye. 1991.
Overcoming soil nutrient constraints to crop
production in West Africa: Importance of
fertilizers and priorities in soil fertility
research. Fertilizer Research 29: 45-54.

World Bank. 1989. Sub-Saharan Africa: From Crisis to
Sustainable Growth. Washington, D.C.: The
World Bank.

World Bank. 1992. World Development Report:
Development and the Environment. New York,
New York: Oxford University Press.

World Bank. 1994. Ethiopia: Public Expenditure Policy for
Transition. Washington, D.C.: The World Bank.

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