Soil health extension approaches and intra-household behavior: a randomized evaluation in Zambia

Last registered on January 02, 2025

Pre-Trial

Trial Information

General Information

Title
Soil health extension approaches and intra-household behavior: a randomized evaluation in Zambia
RCT ID
AEARCTR-0015093
Initial registration date
December 31, 2024

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
January 02, 2025, 7:36 AM EST

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Region

Primary Investigator

Affiliation
CIMMYT

Other Primary Investigator(s)

Additional Trial Information

Status
On going
Start date
2024-08-01
End date
2025-12-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study tests whether tailored extension approaches with and without the use of a digital advisory tool 'reflectometer' for plot-specific decision support can improve intrahousehold learning outcomes.
External Link(s)

Registration Citation

Citation
Oyinbo, Oyakhilomen. 2025. "Soil health extension approaches and intra-household behavior: a randomized evaluation in Zambia." AEA RCT Registry. January 02. https://doi.org/10.1257/rct.15093-1.0
Experimental Details

Interventions

Intervention(s)
Farmer-tailored soil health extension with the use of a reflectometer tool: this entails the use of a low-cost, handheld digital advisory tool ‘reflectometer’ with the capacity to provide a real-time diagnosis of soil organic carbon, which informs the delivery of plot-specific advice and associated learning spaces for in-depth extension officer-farmer interactions on soil health

Farmer-tailored soil health extension without the use of a reflectometer tool: this entails one-on-one in-depth interactions between an extension agent and a farmer focused on soil health without the use of a reflectometer
Intervention Start Date
2024-10-25
Intervention End Date
2024-11-25

Primary Outcomes

Primary Outcomes (end points)
Knowledge of soil health, farmer agency and adoption of soil health-improving practices
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Crop yield, gross and net farm revenues
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experimental design is a cluster randomized controlled trial with two treatment groups (T1 and T2) and a control group (C). Households randomly assigned to T1 are exposed to reflectometer-enabled plot-specific extension advice on soil health. Specifically, this includes reflectometer advice based on a real-time diagnosis of soil organic carbon and in-depth extension officer-farmer conversation about soil health based on the reflectometer advice. Households assigned to T2 are exposed to only in-depth extension officer-farmer conversations about soil health. For both T1 and T2 groups, the interventions are tailored to plots managed solely by a male (husband) and a female (wife) plot manager in each selected household. The T1 and T2 groups received extension interventions through their agricultural camp extension officers. The agricultural extension camp officers are well-trained by the research team on how to use the reflectometer and implement the one-on-one in-depth interactions between an extension agent and a farmer focusing on soil health. The control group is not exposed to any soil health extension intervention tailored to the T1 and T2 groups.
Experimental Design Details
Not available
Randomization Method
Randomization done in office by a computer
Randomization Unit
Agricultural extension camp
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
77 agricultural extension camps
Sample size: planned number of observations
1386 spousal-couple households and 2772 respondents (1386 husbands and 1386 wives)
Sample size (or number of clusters) by treatment arms
25 agricultural extension camps in C (450 households), 26 agricultural extension camps in T1 (468 households) and 26 agricultural extension camps in T2 (468 households)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
CIMMYT Internal Research Ethics Committee
IRB Approval Date
2024-02-23
IRB Approval Number
IREC.2024.003