Alleviating Soil Fertility Constraints to Increased Crop Production in West Africa

243 Pages·1991·6.431 MB·English

by  F. Makken (auth.), A. Uzo Mokwunye (eds.)

ALLEVIATING SOIL FERTILITY CONSTRAINTS TO INCREASED
CROP PRODUCTION IN WEST AFRICA
Developments in Plant and Soil Sciences
VOLUME 47
The titles published in this series are listed at the end a/this volume.
Alleviating Soil Fertility Constraints to
Increased Crop Production in West Africa
Edited by
A. UZO MOKWUNYE
International Fertilizer Development Center
Lome, Togo
Partly reprinted from Fertilizer Research, Volume 29 (I) 1991
Kluwer Academic Publishers
DORDRECHT/BOSTON/LONDON
Library of Congress Cataloging in Publication Data
Alleviating soil fertility constraints to increased crop production in
West Africa / edited by A. Uzo Mokwunye.
p. cm. -- iOevelopments in plant and soi 1 sciences; v. 47)
English and French.
ISBN 0-7923-1221-X
1. Fertl1izers--Africa. West. 2. Soil fertillty--Afrlca. West.
3. Crops and sOils--Africa. West. 4. Crop ylelds--Africa. West.
I. Mokwunye. A. Uzo. II. Series.
S633.5.A358A44 1991
632.8·0966--dc20 91-12857
ISBN 0-7923-1221-x
Published by Kluwer Academic Publishers,
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v
Contents
Preface by A.U. Mokwunye VII
General papers
F. Makken, Alleviating fertilizer policy constraints to increased fertilizer use and increased food production
in West Africa
R. Coster, Alleviating fertilizer supply constraints in West Africa 9
M. Connolly and T. Arokoyo, Alleviating fertilizer technology transfer constraints 19
T. L. Lawson and M. V. K. Sivakumar, Climatic constraints to crop production and fertilizer use 33
C. B. Christianson and P. L. G. Vlek, Alleviating soil fertility constraints to food production in West
Africa: Efficiency of nitrogen fertilizers applied to food crops 45
D. K. Friesen, Fate and efficiency of sulfur fertilizer applied to food crops in West Africa 59
K. G. Steiner, Overcoming soil fertility constraints to crop production in West Africa: Impact of traditional
and improved cropping systems on soil fertility 69
J. Henao, Management of fertilizer research data: General concepts 93
M. T. F. Wong, A. Wild and A. U. Mokwunye, Overcoming soil nutrient constraints to crop production in
West Africa: Importance of fertilizers and priorities in soil fertility research 105
Country papers
P. M. Sedogo, B. V. Bado, V. Hien and F. Lompo, Utilisation efficace des engrais azotes pour une
augmentation de la production vivriere: L'experience du Burkina Faso 115
S. Traore and J. Gigou, Utilisation efficace des engrais azotes pour une augmentation de la production
vivriere: L'experience de la Cote d'Ivoire 125
T. Senghore, Efficient fertilizer use for increased crop production: The Gambian experience 131
A. T. Halm and K. Dartey, Efficient fertilizer use for increased crop production: The Ghana experience 139
VI
E. Owusu-Bennoah, D. K. Acquaye and M. Abekoe, Efficient fertilizer use for increased crop production:
Use of phosphorus fertilizers in concretional soils of northern Ghana 149
J. K. Jal1ah, C. K. Mulbah, J. S. Kiazolu, K. Frank and M. Z. Morris, Efficient fertilizer use for increased
crop production: The Liberia experience 155
H. O. Maduakor, Efficient fertilizer use for increased crop production: The humid Nigeria experience 165
E. O. Oyovbisere and G. Lombim, Efficient fertilizer use for increased crop production: The sub-humid
Nigeria experience 181
A. Bationo and A. U. Mokwunye, Alleviating soil fertility constraints to increased crop production in West
Africa: The experience in the Sahel 195
A. Bationo and A. U. Mokwunye, 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 217
F. Ganry and A. Badiane, Utilisation efficace des engrais pour accroitre la production vegetale: Efficience
de l'uree apportee sur mais (Senegal) 227
A. U. Mokwunye and A. K. Pinto Toyi, Efficient fertilizer use for increased crop production: The IFDC-
Africa experience in Togo 235
VII
Preface
Tropical Africa escaped from the glaciers that covered the temperate parts of the world during the Ice Age. The
legacy is that most of the parent materials of the soils of tropical Africa are old, highly weathered and devoid of
bases and phosphate-bearing minerals. Traditional farming systems which were relatively stable and sustainable
relied on long fallow periods after one to two years of cropping to maintain the productive capacity of the soils.
In recent times and especially in densely populated areas, a sizeable class of 'landless' farmers have begun to
cultivate marginal lands or to invade the 'forest reserves' thereby exacerbating the problems of land and environ
mental degradation.
Maintaining a level of soil fertility that will facilitate the production of adequate quantities of the principle
staples has become a major challenge to agricultural scientists in tropical Africa. To increase the nutrient
supplying power of soils requires the inputs of fertilizers. These can be organic or inorganic. The efficiency with
which these externally supplied inputs can increase agricultural production and reduce soil and environmental
deterioration is dependent on the ability of scientists to determine the right types and quantities of the products to
apply to each soil, crop and cropping system as well as the ability of farmers to acquire requisite farm manage
ment skills.
In these pages, scientists have attempted to review soil fertility research that has been done in the past fifty
years in several West African countries. Attempts have also been made to interprete present-day data in light of
past information. Finally the physical and the socio-economic climate as well as the policy environment under
which the West African farmer operates are reviewed in order to demonstrate how these factors affect agricultural
production in general and fertilizer use in particular.
A. Uzo Mokwunye
Lome, Togo
A. U. Mokwunye (Ed.), Alleviating Soil Fertility Constraints to Increased Crop Production in West Africa, 1-7.
© 1991 Kluwer Academic Publishers. 1
Alleviating fertilizer policy constraints to increased fertilizer use and
increased food production in West Africa
F. Makken
Agricultural Economics Research Institute (LEI), The Hague, The Netherlands
Key words: Fertilizer policy, West Africa, fertilizer supply and demand constraints
Abstract
In sub-Saharan Africa, sustainable economic growth and development, food security, and fair income
distribution are possible only if there is sustained growth in agricultural production. The influx of
commercially imported or donated foodgrains has helped many governments to maintain a policy of low
food prices, usually for the benefit of the vocal urban dwellers. Such practices tend to kill the incentive
for increased local production of foodgrains or for the increase in the use of inputs needed to improve
the productivity of the farming systems.
High degree of state control in the handling of fertilizers, existence of subsidies which put undue
strain on national treasuries, lack of good infrastructures, relatively small markets and poorly developed
research and extension systems are some of the constraints that prevent the optimal use of fertilizers in
West Africa.
Overcoming the constraints requires total commitment by governments, collaboration with the
private sector as well as with the donor community and the development of carefully thought-out
fertilizer policy instruments. The various measures needed for an effective policy are interrelated and
must be undertaken simultaneously to ensure success.
Introduction most countries have a growing structural food
import requirement [5]. Their market require
The economies of most Sub-Saharan countries ments are relatively small, which creates a strong
largely depend on their agricultural sectors. Sus import dependency with their attendant con
tainable economic growth and development, suf sequences such as: price uncertainty, foreign ex
ficient food for all, fair income distribution; all change uncertainty and high costs [1].
can to be achieved only through equitable The influx of commercially imported and do
growth of the agricultural sector. In the past nated foodgrains has aided many governments to
decades however, agriculture has not received maintain a policy of low food prices, usually for
the interest and funds from governments and the benefit of urban dwellers. This has killed
donors alike, to establish and maintain a stable incentives to grow food for the domestic market
economic growth. and reduced the demand for agricultural inputs
The fast growing population has by far out such as fertilizer. In order to stimulate the use of
paced the growth in food production and the fertilizer, while keeping output prices low, gov
agricultural sector as a whole is performing poor ernments have often resorted to large fertilizer
ly as a result of the low priority it has been given subsidy schemes.
over the years. The per capita food production The low productivity of the agricultural sector,
has actually declined in many countries [3,5] and the heavily subsidized foodgrains and fertilizers,
2
the growing dependency on imported foodgrains the production of foodcrops since evidence
(and a host of other factors) have caused a crisis shows that private small-holder farms are among
situation in many Sub-Saharan countries. Struc the first to suffer from a sudden drop in supply
tural adjustment is necessary to bring the nation [11]. Local projects and influential heads of ex
al economies in line with the prevailing condi tended families (usually in the cash crop sector)
tions, both domestic and international, in order are in the best position to secure sufficient fertil
to avoid a total collapse [6]. izer when the supplies are tight.
The adjustment measures are directed at the There is a variety of reasons for West African
imbalances in the domestic economies that have governments' preoccupation with the handling of
led to the current crisis situation. This means, fertilizers. Governments consider fertilizer to be
among other things, creating incentives to stimu a 'strategic' commodity for agricultural produc
late agricultural production, particularly through tion, which justifies their involvement. There is
the use of more inputs such as fertilizer. moreover, a deep-rooted fear that if the supply
Stimulating the use of fertilizer for increased of fertilizers were left to be determined by mar
food production is one of the main concerns for ket forces, the private traders would exploit the
most governments. poor farmers.
This paper will briefly discuss the policy con A direct result of a high degree of government
straints that prevent an optimal use of fertilizers involvement in the fertilizer sector is the exist
and how these constraints relate to macro food ence of price controls. Most governments control
policy. Indications will be given as to how these the prices of fertilizer, mainly as a protective
constraints could be alleviated through adjust measure for the poor farmers against exploita
ments in macro food and fertilizer policies. tion by traders. However, prices are usually
controlled through so-called pan-territorial pric
ing systems, i.e., a uniform pricing throughout
the country [4]. These prices are normally low
Fertilizer policy constraints and unattractive for private traders. Traders are
thus allowed only small margins, which means
One of the most striking factors that limits opti they will service only areas with the best infra
mal use of fertilizers is the degree of state con structure. This leaves the government to supply
trol in this sector. In most West African and the least profitable areas through mostly
other Sub-Saharan countries the procurement, inadequate retail outlets.
importation, transportation and distribution of Another common feature of government in
fertilizers is in the hands of state monopolies or volvement is the existence of fertilizer subsidies.
parastatals. In West Africa it could be said that These subsidies, aimed at keeping the input and
these parastatals have been operating quite effi output prices low, could be beneficial to food
ciently for the growers of export crops, but their crop growers. However, more often than not
performance has been far from satisfactory for these subsidies apply only to the fertilizers sup
small individual farmers, in particular the small plied by parastatals to growers of cashcrop or to
and remote growers of food crops [4]. the large food producers. Private traders without
When it comes to foodcrops, the operations of any margin of profit cannot supply the small
these parastatals are marked by excessive foodgrowers in the more remote areas.
bureaucracy, bad planning and forecasting, lack Administrative controls represent another con
of accountability for performance and as a result, straint resulting from government intervention.
lack of business expertise. This, combined with These controls are usually in the form of alloca
such factors as enforced use of state facilities and tion of imports, foreign exchange and licenses.
foreign exchange problems, leads to very cum Due to the aforementioned bureaucratic delays,
bersome procedures and delays in the supply of allocations are often effected too late which
fertilizers. These delays (or even non-importa hampers private and government traders alike,
tion in some years) are particularly damaging for resulting in late deliveries. Import allocations
3
may also prevent importers from procuring the able response rates of local cereal varieties to
right type of fertilizer for their customers. fertilizer.
The constraints summed up so far are the
direct result of government interference in the
fertilizer sector. These issues can be addressed Macro food policy
directly through changes in government policies.
There are, however, other constraints which are Food and fertilizer policies have to be seen in the
not the direct results of government interference context of international and macro policy. A
but require nevertheless its attention in the form good understanding of macro economic variables
of policy adjustments that facilitate a better and is necessary when discussing ways to overcome
more widespread use of fertilizers. the constraints discussed in the preceding
The lack of good infrastructure is an important section.
bottleneck in the distribution of fertilizers. Rural The West African countries are all net impor
feeder roads are often grossly inadequate, par ters of foodgrains and fertilizers. Their relative
ticularly in the rainy, (and consequently, the market shares for both commodities range from
growing) season. This leads inevitably to high or small to very small. Thus their economies are
very high marketing costs, as compared to, for totally dependent on the vagaries of the world
example the Asian countries. Government market. Governments always try to shield their
owned storage and transport capacity are some domestic economies from extreme fluctuations of
times in poor state of repair and are highly world market supplies and prices, sometimes at
inadequate to service the remote areas where very high costs (e.g., bufferstocks). These pro
access is difficult. Improvements in infrastructure tective measures disconnect, to a certain degree,
require large sums of money. Private entrep the domestic economy from the international
reneurs who may want to invest in, for example, economy. In the long run, calamities such as
storage capacity may find the cost of capital sudden drops in export prices, steep price rises
prohibitive. Particularly traders operating at re on the world market for energy, foodgrains or
tail level in rural areas encounter problems in agricultural inputs may force the country never
raising sufficient capital for investments. They theless into structural adjustments to prevent an
also lack access to credit facilities which heavily economic and social disaster.
impedes the trade in fertilizers at all levels, since Macro food policy is concerned with matters
large amounts of money have to be tied up for such as income growth, fair income distribution
several months. The small foodcrop growers suf and food security for all. Food policies are being
fer from insufficient liquidity at the farm level designed to defend the interests of producers and
and depend on loans from traders, provided the consumers alike, i.e. coping with the so-called
latter can obtain a credit from the wholesaler, food price dilemma. This is the constant struggle
etc. of maintaining low food prices for consumers on
The typical fertilizer market in West African the one hand and securing sufficient domestic
countries is relatively small and it is difficult to supplies through incentives to farmers on the
attain economies of scale. The use of fertilizer is other hand. In most countries this dilemma is
low and, particularly in West Africa, there is a being solved in the short run through a price
rather specialized demand for sophisticated NPK fixing and a great variety of subsidies. The pro
compounds which can only be supplied by cess of food production, processing and market
specialized producers in small shipments [1]. ing is further conditioned by foreign exchange
Finally it should be mentioned that extension rates, inflation rates and real interest rates.
systems are poorly developed, particularly in These matters are briefly discussed below.
areas with small foodcrop growers. First of all there is the question of realistic
Research on foodcrops is inadequate and is exchange rates. The currencies of most West
badly in need of strengthening since another African countries are generally overvalued. The
major bottleneck is formed by the low and vari- case of the CFA franc, for example, is currently