IMAGINE: Integrated assessment of the determinants
of the MAize yield Gap in Sub-Saharan Africa: towards
farm INnovation and Enabling policies?
Introduction
The prospect and context for agricultural growth in low income countries (LICs) have changed
considerably over the last decade. An important question is how agricultural development, an
important contributor to economic growth, employment and food security, can be best promoted.
More specifically, insight is needed into how agricultural productivity can be raised at the level of
households, farms, crops and farming communities. Still significant yield gaps are observed in the
agricultural sector of LICs, which suggest possibilities for improving performance. An example is
maize, an important food crop in Sub-Saharan Africa, which accounts for 30% to -50% household
expenditure.
Objective
The objectives of the IMAGINE project is to contribute to Agriculture and growth (theme one of the
DFID-ESRC Growth research Programme, Call 2), and more specifically to the subtheme ‘ Raising
agricultural productivity in low-income countries’. IMAGINE specifically focuses on how to reduce
the yield gap of maize, a crop accounting for 30-50% of the low income household expenditure in
Sub-Saharan Africa. The main objectives of IMAGINE are:
 Identify the main bio-physical, management and socio-economic factors that explain the
observed yield gap in maize production in selected regions in Ghana and Ethiopia;
 Provide decision makers, farmers and other stakeholders with action and policy
recommendations on how to close the yield gap taking into account the complex
environment in which farmers in Ghana and Ethiopia operate;
 To elaborate and apply a generic framework that combines agronomic and economic
approaches to the assessment of yield gaps and agricultural productivity.
Approach
This project uses a framework that integrates agronomic and economic approaches to assess the
yield gap and analyse agricultural performance at the plot and farm level. Based on production
ecological concepts and economic production theory three different gaps are distinguished that
bridge four yield estimates. Figure 1 summarises the framework including a first list of factors
determining the yield gap.
Yield levels
Potential*
Gap 1
Highest
farmer’s
yield
Modelled
Gap 2
Economic ceiling
Gap 3
yield (given
Actual farmer
current markets
yield
and institutions)
Farm and plot level observations
*water-limited yield potential in case of rainfed systems
Figure 1. Yield gaps and key determining factors.
Factors determining the gap(s)

Access to technology

Socio-economic context: market conditions;
support programs; infrastructure.

Farm-specific factors: farm size, knowledge,
experience, crop and farm management and risk
aversion

Unexpected or random events: extreme
weather events, unanticipated seasonal events
but also price volatility and crisis.
In the project the yield gap is estimated and explained at two different
levels. Nationally representative farm level surveys are analysed with
econometric estimation techniques to assess the impact of economic and
infrastructural constraints at the national and sub-regional level. This is
deepened by means of an in-depth investigation of farm and plot level
production data that will be gathered via surveys in selected regions in
Ghana and Ethiopia. Based on this the project will identify promising technological improvements
and policy interventions, that will be assessed in on-farm experiments and policy and stakeholder
workshops.
Results
The research aims to generate results that are:
 relevant for policy makers by providing insights into drivers of agricultural performance and
how these are linked to policy and donor interventions.
 helping farmers and rural communities and provide them insights and education on how
productivity can be improved in the target region (using a model farm and active
dissemination and extension actions to share practical knowledge)
 contributing to capacity development at the level of socio-economic –agronomic research,
policy making level, and other stakeholders in the supply chain
 contributing to the wider research and stakeholder community.
The results of the research will be integrated in the Global Yield Atlas (www.yieldgap.org). Policy
makers and international donors can use the outcomes of the research to better target their
agricultural and food security initiatives.
This project is financed under the DFID-ESRC
This project is financed under the
DFID-ESRC Growth Research
Programme Call 2, project ES/L012294
Image project website: : http://imagine.pps.wur.nl
Contact
Project Coordinator: Prof.Dr. Martin van Ittersum, e-mail: [email protected]
Partners [represent by logo’s] Plant Production Systems, Wageningen
University, LEI WageningenUR, CYMMIT-Ethiopia, University of Ghana
( ISSER, IITA and FOHCREC School of Agriculture), EEPRI (Ethiopian
Economic Association)
Plant Production Systems,
Wageningen University &
LEI WageningenUR