Rwanda Soil Health Trial 2020
RWA -19 -1390Last modified on October 29th, 2025 at 12:04 pm
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Abstract
One Acre Fund (OAF) is an agricultural service provider that provides support for smallholder farmers in Africa to access agricultural inputs, training, and markets, to help the farmers increase their harvests and income. PAD and OAF began collaborating in 2016 on efforts to increase adoption of agricultural inputs and improve OAF operations in Kenya and Rwanda.
This trial tested whether variation in SMS messages within farmer groups affected the adoption of recommended soil health inputs, including agricultural lime and fertilizer, by OAF farmers in Rwanda. Farmers from diverse-message groups received messages that were different from the messages received by their group members; farmers from same-message groups received the same messages as their group members did. We find that farmers from diverse-message groups were marginally less likely than farmers in same-message groups to order lime, although the difference was very small and only marginally significant after we accounted for multiple hypothesis testing. Groups that received diverse messages were no more likely to adopt fertilizer. We do not find differences in outcomes across the four message framings that we tested. These findings offer a counterpoint to earlier suggestive evidence from similar SMS trials in Rwanda (for example, the "2018 Rwanda Lime Trial"), which showed positive effects of message diversity within farmer groups. -
Status
Completed
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Start date
Q2 May 2019
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End date
Q2 May 2019
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Experiment Location
Rwanda
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Partner Organization
One Acre Fund (OAF)
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Agricultural season
Season B
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Experiment type
A/B test
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Sample frame / target population
OAF farmers
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Sample size
280,202
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Outcome type
Input adoption
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Mode of data collection
Partner administrative data
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Research question(s)/hypotheses
Does sending OAF group members different messages increase lime and fertilizer adoption?
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Research theme
Communication technology, Message framing
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Research design notes
This experiment was designed as a follow-up to the 2018 Rwanda Lime Trial. The tentative finding from that trial was that the diverse-message groups were more likely to adopt lime than the same-message groups. In this follow-up experiment, we aimed to validate the 2018 result with greater statistical power. To do this, we randomized all OAF farmer groups for all the farmers in a group either to receive the same message (same-message group), or to receive different messages (diverse-message group). The randomization was stratified by district, and by whether the group had any 2019 lime adopters. In diverse-message groups, we randomized individuals to receive different messages, which were stratified by farmer group to ensure maximum diversity in each group. The messages were taken from the 2019 Rwanda Soil Health Trial, since these messages had been more thoroughly field tested than the 2018 messages had been. The messages were as follows:
M1: Basic message
M2: Feed your family
M3: Social comparison
M4: House metaphor -
Results
Farmers in diverse-message groups were marginally less likely than farmers in same-message groups to order lime, although the difference was very small (only 0.4 pp less, compared to the same-message group mean of 7.4%) and only marginally significant after we accounted for multiple hypothesis testing.
We do not find differences in outcomes across the four message framings that we tested. We examined heterogeneity across groups, and find slightly better outcomes for newer farmers, although the differences are not significant. We also see slightly larger effects among farmers assigned to treatments in the previous year; again, this is not statistically significant.