Agricultural Economics at the
International Institute of Tropical Agriculture
When examining the activities of the Agricultural Economists at the
International Institute of Tropical Agriculture, it is useful to first
consider the framework in which the Sub-Program operates as this largely
dictates its priorities, and for comparative purposes such a review is
appropriate as the economists at the various Centers seem to have somewhat
different modes of operation. Hence, before reviewing the activities of
the Economics Sub-Program, the structure of the Institute is briefly described.
2. The Programs at IITA
IITA is an agricultural research and training Institute established to help
accelerate the production of food crops and so increase the standards of
living of peoples in the humid tropics. It is one of ten Centers which come
under the overall direction of the Consultative Group on International
IITA's Board of Trustees has set the Institute the following objectives:
(a) accept responsibility for finding solutions to the problems related
to replacing shifting cultivation with more productive forms of land
use in the humid tropics.
(b) develop crop improvement research with international responsibility
for cowpeas, yams and sweet potatoes-
(c) develop crop improvement research with regional responsibility for
rice, maize, soybeans, pigeon peas and cassava;
(d) conduct exploratory studies with crops potentially useful in the humid
(e) limit work with animals, forages, and tree crops to their role as
components of farming systems,
To achieve these objectives, IITA is divided into three Crop Improvement
Programs and the Farming Systems Program. The crops of major concern in the
* Agricultural Economist, IITA, Ibadan, Nigeria, Background notes to
supplement slide presentation at Center Economists' Meeting, Washington
D.C. 21-23 June. 1976.
Cereals, Roots and Tuber, and Grain Legume Improvement Programs are listed
in Table 1L the task of the Farming Systems Program is to synthesise the
superior materials developed in the Crop Improvement Programs into Productive
farming systems which are economically and socially acceptable to both the
farmer and society at large. In addition to these four production Programs
the Institute has a Training Program and a Cooperative Program with the
capacity to undertake collaborative research, extension and planning in food
crop production as and when invited by national governments. At present,
the Institute has collaborative programs in five countries (Sierra Leone,
Liberia, Nigeria, Zaire and Tanzania). The International Genetics
Resources Board also has a Germplasm Collection Unit located at IITA, with
a major responsibility to collect the genetic resources of food legumes,
roots and tubers in Sub Saharan Africa.
Table 1. Crops of major importance in the Crop Improvement Programs at IITA
Cereals Roots and Tuber Grain Legume (a)
Improvement Program Improvement Program Improvement Program
Maize Cassava Cowpea
Rice (dry land) Yams Pigeon pea
Rice (wet foot) Sweet potato Soybean
Aroids Lima bean
(a) Exploratory work is being undertaken with species which appear to be
well adapted to the humid tropics such as yambean, winged bean
jackbean and rice bean.
3. The Farming Systems Program
The objective of the Farming Systems Program is to "develop crop production
systems which will enable good yields and improved crop varieties to be
produced in various ecological zones of the humid tropics on a sustained
basis The broad areas of priority of the Program are:
(a) determining appropriate crop combinations for obtaining high yields
and minimizing inputs of fertilizers, herbicides and insecticides for
the important cereal, root and tuber and grain legume crops of the
(b) developing land preparation, planting and weef control methods that
will ensure good seeding and plant growth conditions, effective weed
and erosion control at minimal cost:
(c) establishing methods for ensuring optimal plant nutrient supplies by
appropriate selection of fertilizers in terms of nutrient content and
formulation, development of methods that take full advantage of potential
biological nitrogen fixation and utilization of mycorrhiza for enhancing
phosphate nutrition with control and avoidance of problems associated
with excessive soil acidity;
(d) designing appropriate tools and machinery and developing techniques
for their economic use in crop production and land development systems:
(e) conducting agro economic surveys and analyses to ensure that the
advantages and disadvantages of existing production systems are fully
recognized and that the methods developed for their improvement are
acceptable and represent an economically viable proposition.
To achieve its objectives, the Farming Systems Program is divided into seven
Sub Programs as follows:
Subl Prp!!am1 No. of Scientists
Cropping Systems 3
Soil Chemistry and Fertility 3
Agricultural Engineering and Land Development 2
Agricultural Physics and Soil Conservation 2
Crop Protection 5
Agricultural Economics 3
Regional Analysis 1
The present division of FSP into seven functional units is currently under
4. The Agricultural economics Sub-Program
The objectives of the Economics Sub-Program are to:
(a) help identify factors (technical, economic an' social) which limit, or
potentially limit, the production of commodities included in IITA's
(b) assess the economic and social implications of alternative means of
eliminating or reducing production and income constraints with the view
(i) help guide priorities for the Institute's and cooperating
agencies' problem oriented research and
(ii) help specify food crop technologies which are technically and
economically more attractive to the small farmer than his
(c) assess the infrastructural, input and marketing requirements necessary
for sustained increases in food crop production to become a reality: and
(d) assist in the development of the skills of r*:..r~nal so as to maximize
their effectiveness as agricultural economists working in the tropics.
The research responsibilities are tackled largely through cooperative
research with Institute scientists, officials and scholars from National
Governments and Universities. An emerging and time consuming responsibility,
of rather an applied nature,. is in the economists' -,.articipation in the
Institute's Coonerative Programs. The Sub-Program s training function is
principally related to teaching at Crop Production Courses organized by the
Institute, the supervision of graduatee students, and assisting indigenous
economists (when requested) in the design, analysis and interpretation of
4.1 The Resource Base of the Sub-Program.
1976 is the first occasion that the Economics Sub-Program has been fully staffed.
As of June 1976, the staff consists of-
(a) Professional Staff Anpointed
J.C. Flinn, Sub-Program Coordinator April 73
L.B. Uilliams, Planning Economist, NAFPF October 74
F.E. Winch, Agricultural Economist December 75
Vacant, Economist in Tanzania Project Late 76
R..G. Dums?-ay, Visiting Scientist To July 76.
(b) Graduate students No.
Ph.D students 3
M.Sc. students 2
Ph.D students expected later this year 1 (2?)
(c) Staff Hired Locally
Graduate (vacant) 1
Field supervisors/clerks 3
Enumerators (temporary) 6
For the past two years the one agricultural economist attempted to service
the majority of the Institute's demands on the Sub-Program as the planning
economist was committed full time to the Ni !-.riait National Accelerated Food
Production Project. As a result. the resources oF the Sub Proaram were spread
far too thinly -- individual projects were not covered at the appropriate
depth- new projects could not be professionally responded to -- which in total
led to frustration in attempts to increase cooperative work between the
economists and other Institute scientists. Honpefully, with the doubling of
the Sub Program's capacity this problem has been partly overcome moreover,
it is timely that the activities of the expanded Economics Sub-Program be
re evaluated, focuses and priorities narrowed.
The major constraints to the Sub-Program increasing its productivity are:
(a) difficulty in delegating professional responsibility due to lack of
(b) a lack of logistical s~,port which makes it extremely difficult to
conduct and supervise field work in a timely manner; and
(c) delays in data preparation prior to analysis.
Fortunately, the Sub-Program has been able to obtain field staff (supervisors,
enumerators) through the Institute's budgetary resources and on secondment
from the staff of cooperating agencies (e.... Agricultural Assistants from the
Departments of Agriculture).
5. Sub-Proaram Activities
The emphasis of the Sub- Program over the past three years has been
(a) Cooperative Research:
(i) the development and testing of agronomic practices:
(ii) rural (farm management) surveys;
(iii) modelling of crop and farming systems'
(iv) planning for increased food production at the regional to
(i) production training courses'
(ii) supervision of graduate students.
(c) Evaluating/Assisting in the Preparation of Food Crop Research and
To provide an insight into the Sub-Program's past activities, T.prln-lir A
contains a bibliography of materials prepared by members associated with the
group over the past three years. Research currently in progress, or planned
to commence in 1976 is listed in Anrennfix B, by project area. Sections 5.1
to 5.3 below provide examples of the procedures being adopted, and the type
of results being obtained by the Sub-Program. The interested reader should
refer to materials listed in Appendixes A and B for more details or reference
of the work.
5.1 Research Into The Development and Testing of Improved Practices
Research aimed at developing and testing improved crop production practices
is carried out in cooperation with Institute scientists and trainees. The
work involves a continuum from research station experiments, through adaptive
trials on farmers' fields to the farmer testing what are thought to be
improved production practices. This type of work has progressed furthest
with maize and cowpea maize is the example used in this paper, all the results
are drawn from experiences in Nigeria.
The cooperative on-station research with maize has been directed at
evaluating the profitability of alternative levels and forms of technical
inputs (e.g. fertilizers, plant protection materials) and are conducted as
multi-factor trials (factorials, central composite and continuous function
designs) to identify the important sub-set of variables, and their levels,
which should be studied further in farmers fields. By way of example of
research station results while plant protection against stem borers appears
to be economic in second season maize, it is not so in the first (due to a lower
incidence of borers in the first season). Further, plant protection in
the second season increases the responsiveness of the maize to fertilizer,
and reduces the variability of second season maize yields. (These findings
are at present being tested on farmers' fields.)
The most interesting sub-set of management variables identified from research
station experiments are then tested in experiments and adaptive trials on
farmer's fields. For example, in 1975, six sites were used in one region
(Alfisols, derived savannah), and three in another (Ultisols, high forest) for
cooperative off-site testing of maize technology. These experiments were
2n factorials (2 reps) based partly on the argument that the objective is
not to identify marginal levels of input use, but rather whether it is
economic to use a combination of inputs where individual input levels have
been arrived at with a concern for the resource base and environment in which
the farmer operates.1
Results from these on farm experiments, in the derived savannah zone of
Western Nigeria at least, are largely consistent with those reported
elsewhere, i.e., that without improved management practices (weeding and plant
population) improved varieties and fertilizers are not clearly profitable,
and that potential yield and the profitability of the practice may vary
markedly due to soil type and the number of years that the plot had previously
been in crop and bush fallow. However, our results suggest that with moderate
input levels that maize populations lower than those previously recommended
to small farmers as components of a package of improved technology (e.g.
25 30,000 v 40-50,000 plants/ha), planted three plants per stand (as opposed
to single plant spacing at higher density intra-row) are economic. Economic
yields seem to be much the same with the lower density but have the advantage
of having fewer but larger cobs, and requiring loss labor for planting, early
weeding and harvest.
From the adaptive trials a combination of practices is selected to form a
package to be tested by a number of cooperating farmers. Information is
recorded during the crops' growth and obtained from the cooperating farmer to
(a) factors influencing yields;
(b) the "success" rate of the technology;
1. The author is aware of the limitations of this design and procedure from
an economic viewpoint. However, he also operates in a constrained
(c) problems of storing and disposing of the crop; and
(d) farmer's reaction to the technology and maize variety
to be assessed.
For example, in 1975, 69 farmers in South Eastern Nigeria in a region of
similar soil type cooperated in the testing of a proposed maize package.
(The farmers were provided with the necessary inputs (which other than
variety were available locally),extension advice and demonstration on how
to manage the maize.) The base saturation (Ca + Mg) and level of organic
carbon -- which are related to the previous crop and fallow history of the
farm -- were found to be the most important soil factors influencing the
maize yield on these coarse textured Ultisols. From a crop management
viewpoint, planting early, thinning the crop early, weeding the crop twice
and maintaining stand density to harvest also importantly contributed to
higher maize yields.
The economic relevance of the maize technology was assessed by estimating
whether the farmer would have been "better-off- by usina the proposed technology
(assuming he had to pay for all inputs) than by using traditional low-cost
technology. On this basis, some 80 per cent of the participating farmers in
the two villages with the more fertile soils (5 to 6 years of bush fallow)
and 25 per cent of the farmers in the village with the impoverished soils
(1 to 2 years of bush fallow) were judged as being 'better off" by adopting
the technology. The agro climatic circumstances (soils, previous land-use,
weather) are critical factors in determining the relevance of a production
It is unlikely that the market in the region studied would have the capacity
to absorb large quantities of wet maize were production to increase without
severely depressing maize prices at harvest time. Thus the relevance of
maize cribs, developed at ITTA were tested by the cooperating farmers
for drying and storing maize. The cribs were effective in allowing the maize
to dry without loss from mold, but grain loss from weavils and rats resulted
in storage being of questionable profitability. Thus, a low cost method
of controlling rats and weavils, which would keep storage losses below some
10 per cent is necessary before the storage technology could be judged as
clearly profitable, given current price relationships in the region.
The most important modification the farmers' planned to make (and made) to
the suggested maize package in 1976 was to grow the variety as an intercrop
with cassava and melon or goundnuts. This coupled with results from other
experiments designed to provide information on the circumstances in which
sole cropping is more profitable than intercropping (consistent with the
findings of others) show that in general sole cropping on upland soils is only
more profitable than intercropping under high levels of inputs. As this is
likely to be an unrealistic situation for sone time to come in West Africa, the
Sub-oProgram is redirecting its cooperative bio-economic work to crops grown
in combinations and sequences, with low to moderate levels of technical inputs.
5,2 Rural Survey Work
The rural survey work conducted by the Sub-Program is of two types-
(a) baseline surveys of specific crops?
(b) indepth village level studies.
Baseline surveys have been conducted to provide information to planners
involved with the Nigerian National Accelerated Food Production Project. To
date, baseline surveys have been completed for cassava in South Eastern Nigeria,
and for wheat, millet and sorghum in Kano State and are planned to commence
with two of the Institute's Cooperative Programs later this year.
The objective of the detailed village level studies is to provide quantitative
information on resource use and production, management objectives, income
and consumption patterns of smallholders in the humid tropics. The results
are used with the purpose of understanding what the farmer does and why he
does it- identify important areas where agricultural research or policies
could be directed to make it possible and attractive for the smallfarmer to
increase his marketed surplus of food crops; and to provide a framework in
which to judge the likely consequences, requirements and problems (at the farm
level) of alternative packages of technology being developed by Institute
scientists and cooperating agencies.
The first indepth village level study by the Institute was that of Paul
Zuckerman2 who collected farm level data in Yorubaland in 1970/1971.
Zuckerman used his data to construct a simulation model of a small farmer's
decision making process. He found four factors, in addition to the traditional
ones which importantly influence the farmer's allocation of his resources to
farming to be;
(a) the manner in which the farmer managed his cash resources;
(b) the influence of time on his decision making;
(c) the use to which the small farmer put different cropsr and
(d) the effect of uncertainty on his decision to invest resources in his
A second village level study was completed by the Institute in 1975. South
Eastern Nigeria was chosen for study as it has soils (Ultisols) and climate
typical of large areas of the humid tropics and has among the highest
population densities in rural tropical Africa. Twenty five farmers were
selected in each of three survey villages to provide information on resource
use, production and management at the farm level. The three villages were
chosen as they differed markedly in population densities, but were similar
in terms of soil type, climate, access to markets and ethnic group, to quantify
2. Zuckerman, P.S. Yoruba Smallholders' Farming Systems. A report prepared
for the IITA,Department of Agricultural Economics and Management, University
of Reading, July, 1973. A number of papers by Zuckerman on his work are
currently in Press at IITA.
(a) farming systems, resource use and production;
(b) the productivity of land and labor, and
(c) soil properties and plant climaxes;
in response to increasing intensity of use of agricultural land and to
(d) assess possibilities for increasing the profitability of food crop.
production in the region through improved practices.
Analysis of the survey shows that with increasing population density (and
as a result, reduced periods of bush fallow) that the fertility of the soil
diminishes, as does the productivity of the farmers' land and labor. For
example, output per hectare per year in terms of dry matter, calories or
value terms fell (e.c,. $986 to $472/ha/year) from the low to the high density
village as did the average productivity per man day of family labor ($2.56 to
$1.28), and as a result so did the total value of production, the proportion
of output sold, and the cash income from farming (Table 2).
Table 2. Average values of total farm production and sales, E.C.S. 1974-75.
Village/Population Density High Medium Low
Total Farm Production $* 391 514 768
of which food crops % 48 45 56
tree crops % 40 43 35
livestock % 12 21 9
Cash Income (Sales) $* 122 277 491
of which food crops % 10 21 47
tree crops %77 71 49
livestock % 13 8 4
Official exchange rate M1.00 = $1.61
Farmers were found to intensify their compound farming, which involved the
import of mulch, and the use of household refuse (in an attempt to augment
the falling soil fertility of their farms) as population pressure increased.
Also the number of crops grown in a mixture and the range of crops grown by
the farmers was found to increase with population density.
An important result derived from the survey was the somewhat neglected (in
IITA's research) value and role of a range of shrubs and tree species in the
farming systems. A wide range of indigenous species provided food during
food deficit periods of the year, inputs for farming and for the household,
in addition to a major source of income. whilee tree crops contributed less
than 50 per cent of the total value of output, in the high population
areas they contributed in the order of three quarters of cash farm income
(Table 2). It is not surprising then, that farmers are unwilling to adopt
food crop technologies which require the removal of economic or potentially
economic trees (in this case mainly wild oil-palm). However, while the
farmers' recognized the importance of tree crops as a source of cash income,
their priorities result in labor being allocated first to food crops and
second to the cash (tree) crops during periods of labor scarcity -- even
if this results in foregoing harvest and so cash income of the tree crops.
Two points emerge from the study of food crop/tree crop associations in the
forest zone. First, it would seem that research aimed at developing food
crop technology for these zones should be carried out in a more realistic
environment than in an open field, i.e., within a food crop/tree crop
complex. Second, if the output of tree crops is to be increased by
smallfarmers (which is an objective of many governments) then it will probably
be necessary to increase labor productivity during periods of labor scarcity
on the food crops first.
Details of other surveys conducted by the Sub-Program and those scheduled to
commence later this year are listed in the Appendixes.
5.3 Models of Crop and Farming Systems
Simulation and regression models are being developed to examine the economics
of fertilizer practices and soil conservation strategies for both small and
large scale maize production in the humid tropics. The models take account of
soil-plant atmosphere relationships, topography, cropping systems and prices.
Data from IITA experiments, weather records, and from market price information
have been used to quantify:
(a) growth (dry matter production) curves for maize;
(b) potential (i.e., non stressed) maize yields;
(c) relationships between weather variables, time of planting and maize
(d) relationships between soil loss and storm erositivity; and
(e) seasonal maize prices indices
for inclusion as relationships within the simulation models. (The long-term
fertility data to be included in the models is at present being analysed.)
The linked simulation models (an erosion model, a fertilizer model, and a
soil-plant-atmosphere model) are adapted versions of ones developed for
sub-tropical Australia. The models are designed to accommodate both seasonal
and long-term production effects and provide bio-physical data which permit
comparison of discounted income streams for alternative management systems.
The immediate objective of the crop modelling work is to assess the long-run
economic consequences of traditional versus minimum tillage practices, and
the economic possibilities of substituting fertilizer for bush fallow.
Although confined to sole-crop maize production as a first step, the model
has the potential of being expanded to encompass mixed cropping systems.
Two models of faring systems have been developed. The first is a growth
model (multi-period linear program) of the development and management of
hydromorphic bottomlands and associated uplands by a farm family. The second
is an integer programming model designed to evaluate optimal machinery
systems (from land preparation through threshing and drying) for irrigated
rice production. Not surprisingly, both models highlight the sensitivity of
the optimal plans to land/labor/capital ratios and the availability of short
and long term credit.
5.4 Planning For Increased Foodcrop Production.
The planning economist had the responsibility of initiating and coordinating
a series of studies (see Appendix A2) used as background material to prepare
a national plan for infrastructaral and policy requirements to support an
increase in food crop production in Nigerialto be made possible by agricultural
research and training. This Wrk has culminated in an agro-service center
concept for an input delivery $sstem being proposed together with associated
national agricultural policy to the Federal Government. The concept has been
accepted' the pilot phase of the acro- service centers is being initiated.
5.5 Future Research Focus
A glance at Appendix B shows that the Sub-Program is committing a large
proportion of its resources to describing existing farming systems, formulating
and testing hypothesis as to the causes and factors which importantly
influence farmer's decision. making, agricultural productivity and land use.
In future, more emphasis (In thZ writer's view) should be directed towards
constructing normative models' to evaluate the short and long run implications,
and resource requirements, of modified farming systems emanating from
agricultural research. Such a shift in emphasis should logically lead to an
increased effort by the Sub-Program to examine how recommended changes in
farming system could or should be brought about; and what will be the
infrastructural (input Supply, marketing, policy) requirements necessary
for the new technology' to become reality in different situations.
6. The Impact of Agricultural Economics at IITA
In the writer's view, it would be unrealistic to suggest that the present
group of agricultural economists at the Institute have, in themselves,
greatly influenced the current direction or emphasis of IITA's research.
(This is partly a result of the biological programs being firmly established
before the arrival of the current group of economists, partly a result of the
Sub-Program's limited capacity- and partly that economic criteria are not of
immediate relevance to the research programs of some scientists.) However,
the opinion of the economists is sought as an input when research policies
are being reviewed, and through cooperative research with IITA biologists,
economists principles are keing incorporated ir the design, analysis and
interpretation of an increasingly larger number of biological experiments.
Cooperative work is strongest with the agronomists, soil scientists and
Historically, the economists have been most successful in developing
cooperative off-site projects. This work is of a dual nature:
(a) studies of farming systems:
(b) adaptive trials aimed at identifying feasible cropping systems
incorporating more productive technology than is now the case,
and is undertaken both with scientists located at IITA and those associated
with the Cooperative Programs.
As far as the eventual client of the Institute, i.e. the farmer, is concerned,
no identifiable contribution by the Agricultural Economics Sub-Program is
yet apparent. This is not surprising due to the laq between research,
testing and technology transfer, and to the fact that IITA is in the early
stages of demonstrating the relevance of its emerging research endeavors
(e.g. tillage systems and improved crop varieties). However, IITA economists
are hopefully contributing to the future welfare of the farmer in the sense
that they provide an input to policy makers on what other preconditions must
exist and what may be the consequences of various options -- for increasing
food crop production on a sustained basis.
If the demand for the economists' resources by scientists (which has increased
more rapidly than our capacity to resnonc to then) is taken as a proxy of the
usefulness of economists in the Institute's program, it would seem that
scientists are increasingly of the opinion that our input is valuable.
PHowever, only time will tell whether biologists do see us contributing
substantially to the relevance of their work or whether they are merely
responding to the directives of donors and senior Institute policy makers.
Bob Dumsday, Lew Williams and Fred Winch have contributed to the attitudes
expressed in this paper. However, it must he stressed that the views
expressed are mine and need not reflect those of the Institute.