Expansion of Maize into the Northern Guinea Savanna


The high amount of radiation and
low night temperatures character-
istic of the northern Guinea sa-
vanna make this zone the most fa-
vorable ecology for maize in west-
ern and central Africa, provided
adverse soil conditions do not limit
production. Yet until the mid-
1970s, maize in the northern
Guinea savanna was a minor crop
valued primarily because, if har-
vested green, it was the earliest
food available after the "hungry pe-
riod." Families grew just enough
maize to sustain themselves until
the main cereal crops, sorghum
and millet, were harvested.

Today maize production appears to
be increasing substantially in this
zone. The effect is most striking in
Nigeria, where a recent study
shows that, in northern Kaduna
and southern Katsina States, maize
is the most important food crop in
over 50% of 15 randomly selected
villages and the top cash crop in
60%. The increased importance of
maize is also evident, though to a
lesser extent, in Bauchi and south-
eastern Sokoto States. Almost all
the maize grown in these areas
(with the exception of Sokoto)
appears to be improved varieties.

In the past, maize grain was
consumed mainly in southern
Nigeria. Although maize could be
produced in the north, demand
there was minimal, and poor
transportation made it uneconom-
ical to "export" maize from the
north to consumption centers in
the south. Beginning in the mid-
1970s, however, several factors
helped raise maize production in
the north. Oil revenues were used
to improve roads between the
urban south and rural areas of the
north, providing northern farmers
with better access to southern


markets. At the same time, subsi-
dized fertilizer and improved early
maturing maize varieties well
adapted to the ecology were made
available through World Bank-
assisted agricultural development
programs. Higher yields rather
than higher prices made maize
more profitable than competing
crops; the domestic price of maize
relative to competing crops such as
millet, sorghum, and groundnuts
either remained constant or de-
clined, although it remained high
relative to the world price of maize
(converted at official exchange
rates).

In addition to replacing other crops
on land already under cultivation,
maize also began to be cultivated on
land not previously used for crop
production. This expansion in area
was made possible by the adoption
of animal traction and by increased
use of fertilizer, which permitted
the elimination of fallow periods in
many areas. Also, fertilizer subsi-
dies favored maize because maize is
more responsive to fertilizer than
the sorghum and millet that it re-
placed. Eventually the greater
availability of maize in the north
led to its adoption as a staple food
in that area, further reinforcing its
attractiveness to small-scale
farmers.

The key question now is whether or
not expanded maize production is
sustainable. Three issues in par-
ticular will have to be resolved
before maize establishes itself as a
crop with long-term prospects in
the northern Guinea savanna.

The first issue relates to the future
cost and availability of inorganic
fertilizer. Maize production in the
northern Guinea savanna relies
heavily on added nutrients, espe-
cially nitrogen. In most countries of


western and central Africa, particu-
larly Nigeria, fertilizer has been
highly subsidized; when available
at official prices, it has generally
been cheap, although the quantities
available through official distribu-
tion channels have often varied. A
number of countries in the region
are now committed to removing
subsidies and privatizing fertilizer
distribution, which could lead to
improved availability, but at
substantially higher prices. The
likely impact of these policy
changes on future maize production
requires further investigation.

A second issue is the future profita-
bility of maize relative to export
crops such as cotton and ground-
nuts. In the past, overvalued
exchange rates reduced the profita-
bility of export crops. Now many
countries in the region have drasti-
cally devalued their currencies,
which would be expected to lead to
a resurgence in the production of
export crops, assuming domestic
producer prices reflect inter-
national prices. Whether increased
production of export crops would
occur at the expense of maize
remains unclear.

A third issue concerns the impact of
continuous maize cultivation on
savanna soils. Farmers once relied
on a combination of fallowing,
manuring, and crop rotation to
maintain soil organic matter and
preserve soil fertility. As continu-
ous cropping of maize for cash
receives greater emphasis, tradi-
tional soil conservation practices
are being replaced by increased use
of fertilizer. It will be important to
investigate whether this strategy is
sustainable over the long run.