Digital Extension Platforms and Farmer Behaviour Change in South West Nigeria: A Randomised Evaluation

This study provides a randomised evaluation of digital agricultural extension platforms and their effect on farmer behaviour change and productivity in South West Nigeria. Digital extension technologies including WhatsApp-based advisory services, interactive voice response agronomy hotlines, and SMS weather and market alerts have proliferated rapidly in Nigeria's agricultural sector, driven by high mobile phone penetration. However, rigorous experimental evidence on which digital extension formats generate sustainable behaviour change and productivity improvements is limited. This study uses a three-arm randomised controlled trial design with 540 farmers randomly assigned to a WhatsApp advisory group, an IVR agronomy hotline group, and a control group in Ogun, Ondo, and Osun States. Technology adoption, agronomic practice improvement, and crop yield are measured at baseline and 12-month endline. Intention-to-treat and local average treatment effect estimates are computed. Findings reveal that both digital extension modalities generate significant improvements in agronomic knowledge scores relative to the control group. WhatsApp advisory services produce stronger behaviour change effects for educated farmers, while IVR services show superior reach among low-literacy farmers. Combined exposure to both platforms produces the largest yield gains, averaging 18 percent above control group yields. Cost-effectiveness analysis shows IVR as the more cost-efficient modality per farmer reached. The study contributes original experimental evidence on digital extension effectiveness and recommends modality-targeted digital extension design based on farmer literacy and connectivity profiles.

Keywords: digital extension, randomised evaluation, behaviour change, South West Nigeria, agricultural technology.