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The Effects of Decentralized and Video-based Extension on the Adoption of Integrated Soil Fertility Management – Experimental Evidence from Ethiopia
Last registered on July 04, 2019


Trial Information
General Information
The Effects of Decentralized and Video-based Extension on the Adoption of Integrated Soil Fertility Management – Experimental Evidence from Ethiopia
Initial registration date
July 02, 2019
Last updated
July 04, 2019 3:51 AM EDT
Primary Investigator
University of Göttingen
Other Primary Investigator(s)
PI Affiliation
University of Göttingen
PI Affiliation
University of Mannheim and Center for Evaluation and Development (C4ED) and J-PAL Affiliate
PI Affiliation
University of California, Berkeley
Additional Trial Information
On going
Start date
End date
Secondary IDs
The slow adoption of new agricultural technologies is an important factor in explaining persistent productivity deficits among smallholders in Sub-Saharan Africa (SSA). Farmers delay in particular the joint uptake of technology packages consisting of several practices. Since knowledge constraints are an important barrier to adoption, effective extension approaches are key to overcoming technology deficits. In recent decades, extension systems in many SSA countries have moved away from “top-down” towards decentralized “bottom-up” models that involve farmers as active stakeholders.
In this study we assess the effects of a decentralized extension program and an additional video intervention on the adoption of integrated soil fertility management (ISFM) among 2,382 small-scale farmers in Ethiopia using a randomized controlled trial, in cooperation with the German Agency for International Cooperation and Development (GIZ). ISFM should enhance soil fertility and productivity and ultimately combat land degradation by using organic and inorganic soil amendments simultaneously. We find that both extension-only and extension combined with video induce ISFM adoption as well as gains in knowledge. We further find evidence for increased adoption of ISFM practices at the household level among farmers in extension communities that do not actively participate in the extension activities. The additional video intervention shows a significant complementary effect for these non-actively involved farmers, in particular when it comes to the integrated use of the practices on the same plot, and thus, appears especially beneficial for this group. A causal mediation analysis further reveals that increases in knowledge explain part of the treatment effects on adoption.
External Link(s)
Registration Citation
Hörner, Denise et al. 2019. "The Effects of Decentralized and Video-based Extension on the Adoption of Integrated Soil Fertility Management – Experimental Evidence from Ethiopia ." AEA RCT Registry. July 04. https://doi.org/10.1257/rct.4406-2.0.
Former Citation
Hörner, Denise et al. 2019. "The Effects of Decentralized and Video-based Extension on the Adoption of Integrated Soil Fertility Management – Experimental Evidence from Ethiopia ." AEA RCT Registry. July 04. http://www.socialscienceregistry.org/trials/4406/history/49326.
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Experimental Details
The extension intervention has been implemented by the German Agency for International Cooperation and Development (GIZ) with its national partners from the agricultural ministry and offices at different administrative levels.
The core of the extension treatment consists of the (non-random) selection of model farmers, who are trained by public extension agents and provided with inputs to maintain ISFM demonstration plots on their farms. Model farmers lead and train so-called "Farmer Research and Extension Groups" (FREG) consisting of 50 farmers in each mws. In addition, two farmer field days per cropping cycle are conducted. During these field days, model farmers share and discuss their experience with FREG members regarding the implementation of ISFM and its results. Field day activities are mainly targeted to FREG members, although in some communities other farmers do also participate. The extension treatment mainly aims at creating awareness and know-how about ISFM through a knowledge sharing process from development agents to model farmers, and from model farmers to FREG members. Through that entry point, information should diffuse to the broader population of farmers in the communities.

The additional video intervention should serve to provide an additional stimulus to adoption by exposing farmers to information about the ISFM concept with all its individual components, in order to overcome potential incomplete information diffusion between farmers and resulting knowledge gaps. The movie is composed of two parts: A narrative and documentary part which presents the example of a farmer couple who has already successfully implemented the ISFM technologies and visibly increased yields, serving as (potential) role models for treated farmers. The second component of the film consists of animations that visualize processes taking place in the soil – such as hydrological cycles, the “work” of roots, soil organic matter, microorganisms and nutrients. Complex soil processes and the relationship between the individual ISFM components, soil fertility and improved yields are presented in a simplified way.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
- The number of adopted ISFM practices
- The likelihood of integrated ISFM adoption (all practices jointly on one plot)
- ISFM knowledge
Primary Outcomes (explanation)
- Adoption variables rely on self-reported data
- Knowledge variables are constructred based on an ISFM knowledge exam made with farmers; we calculate knowledge scores ranging from 0 to 1 based on the number of correct answers a respondent gave relative to the total number of questions
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
The study builds on an RCT design with two treatment arms and a control group. We used microwatersheds (mws) as units of randomization, which are common implementation units for natural-resource-related interventions in Ethiopia. One group of treatment mws (T1) receives the decentralized extension treatment only, while the second group of treatment mws (T2) receives the extension treatment plus the additional video intervention. The extension intervention is implemented at the level of mws as an an-going process since 2016, all activities are regionally aligned with the course of the main harvest cycle. The video screenings were conducted in T2 communities in early 2017, around six weeks prior to the start of the main growing season. Typically, the video was shown in public spaces such as farmer training centers, health posts or schools, and followed by group discussions that were facilitated by extension agents. In each microwatershed, the 15 households from our sample were invited by village heads a few days prior to the screenings orally and with written invitation cards. In the case of double-headed households we invited both spouses, otherwise only household heads.

Experimental Design Details
Randomization Method
Randomization Unit
Cluster randomization at the level of micrwatersheds; within microwatersheds, random selection of households
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
161 microwatersheds
Sample size: planned number of observations
2,416 households
Sample size (or number of clusters) by treatment arms
36 microwatersheds extension (only)
36 microwatersheds extension + video
89 microwatersheds control
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Minimum detectable effect size: 20% of a standard deviation, with 161 clusters and 15 households per cluster, assuming 10% intra-cluster correlation; for the number of adopted practices (0-5) with a mean of 2.5 and SD of 1.4, this would be 0.28
IRB Name
IRB Approval Date
IRB Approval Number
Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)