Impact of farmer field school on maize yield and adoption in sub-Saharan smallholders

Thesis Abstract

Smallholder maize production in sub-Saharan Africa remains constrained by limited access to agricultural information, low adoption of improved practices, and variable yields. Farmer Field School (FFS) approaches have been promoted as participatory learning platforms that enhance agronomic knowledge, experimentation, and peer-to-peer diffusion of innovations; however, empirical evidence on their impact in maize yield and technology adoption under sub-Saharan conditions is mixed. This study aims to evaluate the impact of FFS participation on maize yield and the adoption of improved agronomic practices among smallholders in sub-Saharan Africa. The specific objectives are to (i) assess the effect of FFS attendance on maize grain yield, controlling for soil quality, rainfall, input use, and farm household characteristics; (ii) measure the extent of adoption of improved maize varieties, fertilizer practices, pest and disease management, and timely planting among FFS participants versus non-participants; (iii) identify channels through which FFS influences adoption, including knowledge gains, farmer experimentation, and social networks; and (iv) examine the heterogeneity of effects across household size, gender of the household head, and farm size. A cross-sectional, mixed-methods design was employed. The study sampled 400 maize-producing smallholders from four districts in two sub-Saharan countries, with 200 FFS participants and 200 non-participants selected through a multi-stage sampling strategy. Data collection combined structured household surveys, agronomic field measurements, and key informant interviews. Survey instruments captured household demographics, asset endowments, input usage, extension contact, and production outcomes, while field measurements provided plot-level yield data and soil fertility indicators. The study applied propensity score matching to address selection bias and estimate the average treatment effect on the treated (ATT) for yield and adoption outcomes. Multivariate regression analyses (ordinary least squares and generalized linear models) were used to test relationships between FFS participation, yield, and adoption, incorporating fixed effects at the district level. A mediation analysis examined whether knowledge gains and trial-and-error experimentation mediated the adoption of improved practices. Qualitative data from interviews were analyzed thematically to triangulate quantitative findings and elucidate the mechanisms of change, guided by the knowledge diffusion and social learning theories, particularly Bandura’s social cognitive theory and Rogers’ diffusion of innovations framework. Expected findings include a statistically significant positive impact of FFS participation on maize grain yield after controlling for agronomic and socio-economic covariates, with ATT improvements estimated in the range of 8–15 percent relative to non-participants. Adoption rates for improved varieties, phosphorus- and nitrogen-based fertilization, integrated pest management, and timely planting are anticipated to be higher among FFS participants, with effect sizes greatest for fertilizer use and pest management. Mediation analysis is expected to reveal knowledge gains and farmer-led experiments as key channels linking FFS to adoption decisions. Heterogeneity analyses may reveal stronger yield and adoption benefits among larger households and female-headed households where women actively participate in field activities, highlighting the role of inclusive participation. The study contributes to knowledge by providing robust, context-specific evidence on the effectiveness of FFS as a pathway to yield gains and technology uptake among sub-Saharan maize smallholders, informing policy debates on scaling participatory extension models. It advances methodological rigor through the integration of propensity score matching, regression analysis, mediation modeling, and qualitative triangulation, offering a replicable approach for similar evaluations in comparable agro-ecological zones. Based on findings, recommendations include strengthening gender-inclusive FFS curricula, enhancing capacity-building for local extension agents to facilitate farmer experimentation, and ensuring access to improved seed and balanced fertilizer packages to amplify the impact of FFS on productivity and climate resilience. The study underscores the importance of aligning FFS activities with market incentives and supportive agribusiness linkages to sustain adoption and yield improvements beyond the training period.