Integrated assessment of the determinants of the maize yield gap in Sub-Saharan Africa: towards farm innovation and enabling policies

Yield gaps estimations and explanations provide important information on the scope for production increases on existing agricultural land through better farming systems, farm management and enabling policies. The aim of this project is to develop and implement a framework that identifies the key bio-physical and management factors that influence the maize yield gap in SSA and how these are related to existing institutional, infrastructural, socio-economic and policy constraints. The research focuses on the major food crop in SSA, maize, mainly produced by small scale farmers. Maize is an important food crop in almost all Sub-Saharan African countries. Addressing yield performance in maize is therefore valuable from both a food security and poverty perspective. The project will focus on Ghana and Ethiopia as maize-growing case study countries where it builds on existing data and local partnerships. It is assumed that enhanced understanding for these two countries from West and East Africa will have wider meaning.

The innovative part of this project is the use of a framework that integrates agronomic and economic approaches to assess the yield gap and analyse agricultural performance at the farm and plot level. The analysis consists of three stages. In the first stage crop growth and economic production models are used to calculate potential, technical efficient ('best practice') and economic ceiling yields at the national and regional level, which are subsequently combined with actual yield data from surveys to compute the various yield gaps. In the second stage, econometric techniques are used to analyse variations in the observed yield gaps in space and relate them to plot-level, farm-level and context determining factors. In the third stage, a small number of local case studies are organised at the village level to deepen the analyses and to thoroughly understand the determinants of yield gaps to allow identification of farm and management innovations and policy interventions.

Information on yield potentials and actual yields will be taken from the Global Yield Gap Atlas (GYGA) that is currently being developed by University of Nebraska, Wageningen University and many partners from SSA. Farm/household level data and plot level information for Ethiopia and Ghana will be taken from the World Bank's Living Standards Measurement Study-Integrated Surveys on Agriculture (LSMS-ISA) and EGC-ISSER Ghana (expected to become available end of 2013). In addition, a survey in each of the case-study regions will be organised to collect additional and detailed information on plot-level crop production and management such as soil characteristics, cultivation history and agronomic management.

The results will be used to derive targeted policy and farming recommendations that account for the complex environments in which male and female farmers in the SSA-region operate and incorporate the basic mechanisms that link farm performance to the broader enabling environment. This process will be supported by initiating participatory on-farm demonstration trials on the one hand and a policy dialogue with stakeholders on the other hand.

The research will benefit:
(1) Local and national policymakers and planners in Ghana and Ethiopia that are responsible for agricultural policy formulation in the target countries.
(2) National agricultural research institutes that partner in the project.
(3) Farmers and national/regional farmers associations, in particular those that are active in the target regions and countries.
(4) International donors that support agricultural development in the target countries.
(5) International institutions and research organisations that are engaged in future assessments of food security, climate change and economic development.

How will they benefit from this research?
(1) The identification of major constraints and drivers of agricultural performance will provide policymakers with essential information to design targeted interventions at farm management and policy level that may narrow the yield gaps in the study regions and the wider economy. Yield gap estimations will also provide policymakers with information on the potential to increase maize production in the future and the implications for future food security in the region.
(2) Participating in the project will contribute to the capacity of national agricultural research institutes to combine socio-economic and bio-physical theories and approaches to analyse yield gaps and agricultural productivity.
(3) Through their engagement in village level demonstrations, farmers and extension agents will acquire useful information and knowledge on improved practices, leading to the adoption of these practices and ultimately higher agricultural productivity. farmers will benefit from enhance agricultural support policies.
(4) International donors can use the outcomes of the research to better target their agricultural and food security initiatives.
(5) It is expected that the framework to integrate bio-physical and economic approaches to yield gap analysis that will be applied and deepened in this project can also be applied to other regions and countries. It would be interesting to explore possibilities to combine this framework with existing integrated global and national models to assess future land use, climate change and food security (e.g. GTAP, IMPACT and IMAGE).

What will be done to ensure that they have the opportunity to benefit from this activity?
Information on promising options for improved farm management will be communicated to farmers and agricultural extension agents who are the primary actors operating at farm level in the case study sites. Joint learning by researchers, farmers and extension agents will be fostered through on-farm demonstration trials and field visits during which the trialled options are evaluated and discussed.
For policy makers, information on where yield gaps are large, potential areas where yield gaps can be narrowed relatively easily, and the necessary policy interventions and enabling institutions, are critical. The project will engage with policy makers by providing a platform for them to access this information and share and discuss it with other stakeholders such as farmer representatives, public and private sector agents, NGOs and local and international researchers. This will encourage mutual understanding, lead to better targeting of necessary policy interventions and ultimately to socio-economic-institutional environments that are more conducive to high agricultural productivity. In total two roundtables (each in one of the case-study countries) will be organised with policy makers and other stakeholders.
Besides the engagement activities, which form the core of our strategy to impact, farmers and extension agents will be informed through leaflets and radio broadcasts on good management practices. Furthermore, country-specific policy briefs in which the main findings and policy recommendations are summarised will be prepared.