Productivity Impact of Integrating Soil Fertility Management Interventions (SFMIs) in Input Subsidy Programs (ISPs): Evidence from a Randomized Controlled Trial in Malawi

Last registered on September 08, 2022

Pre-Trial

Trial Information

General Information

Title
Productivity Impact of Integrating Soil Fertility Management Interventions (SFMIs) in Input Subsidy Programs (ISPs): Evidence from a Randomized Controlled Trial in Malawi
RCT ID
AEARCTR-0009804
Initial registration date
August 31, 2022

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
September 08, 2022, 12:34 PM EDT

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

Locations

Region

Primary Investigator

Affiliation
University of Malawi

Other Primary Investigator(s)

PI Affiliation
MwAPATA Institute
PI Affiliation
MwAPATA Institute
PI Affiliation
MwAPATA Institute
PI Affiliation
Ministry of Agriculture
PI Affiliation
Ministry of Agriculture
PI Affiliation
Ministry of Agriculture

Additional Trial Information

Status
In development
Start date
2022-09-12
End date
2024-03-20
Secondary IDs
PIERI-20620
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Against a 7 MT/Ha yield potential, smallholder farmers benefiting from the Affordable Input Program (AIP) in Malawi produce about 1.8 MT/Ha of maize. Low maize productivity in Malawi is partly caused by poor soil health, which can be addressed by supplementary soil fertility management interventions (SFMIs). We are implementing a randomised control trial (RCT) to evaluate the impact of integrating SFMIs in AIP on maize productivity and the demand for SFMIs. We will test the effect of adding agricultural lime and organic fertiliser to AIP inputs, i.e., improved maize seeds and inorganic fertiliser. The RCT is implemented in districts with acidic soils of Mzimba and Nkhoakota, which require liming. The findings from this trial will contribute to Malawi’s long-term development plan (MW2063) of increasing agricultural productivity. The findings stand a chance of being incorporated into the new national agricultural policy being developed.
External Link(s)

Registration Citation

Citation
Chiwaula, Levison et al. 2022. "Productivity Impact of Integrating Soil Fertility Management Interventions (SFMIs) in Input Subsidy Programs (ISPs): Evidence from a Randomized Controlled Trial in Malawi." AEA RCT Registry. September 08. https://doi.org/10.1257/rct.9804-1.0
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Experimental Details

Interventions

Intervention(s)
The intervention in this study aims to improve maise productivity through using SFMIs and study farmers' demand for these inputs. We will assign farmers into three arms - the control, the agricultural input subsidy (AIP) plus organic fertiliser, and the agricultural input subsidy plus organic fertiliser and agricultural lime. AIP is a national agricultural input subsidy that lowers the prices of inorganic fertiliser and improved maise seeds for smallholder farmers. We will train farmers through demonstration projects and provide some farmers with organic manure and other farmers with organic fertiliser and agricultural lime. The inputs will be delivered to the farmers through their extension workers.
Intervention (Hidden)
The intervention in this study aims to improve maize productivity by improving soil health through organic fertilizer and agricultural lime. Over 40% of soils in Malawi are low in nutrition and strongly acid (Munthali et al., 2017). Acidity in soils impairs agricultural productivity worldwide by 30 to 40% (Berihun, et al., 2017). The application of lime can lower the problem of soil acidity. Liming, either alone or in conjunction with mineral and organic fertilizer, is widely suggested for growing field crops on acid soils (Ayalew 2011). Acidic soils require liming to improve their productivity, while non-acidic soils do not require liming. We, therefore, decide to implement the study in districts that require lime application at 4000kg/Ha. The selected districts are Nkhotakota and Mzimba.
In districts with acidic soils, we can rehabilitate soils by applying organic fertilizer, agricultural lime, or both agricultural lime and organic fertilizer. All participants will be AIP beneficiaries. The treatments in the randomized control trial are therefore summarized below:

1. The control group – the control group will be allocated to farm households that are AIP beneficiaries, but we will not provide them with SFMIs. We will provide farmers in this group with agricultural extension services on good agricultural practices.
2. AIP plus organic fertilizer – We will provide these farmers with an organic fertilizer in addition to agricultural extension services.
3. AIP plus agricultural lime and organic fertilizer – This treatment arm will provide organic fertilizer and agricultural lime in addition to AIP inputs. The farmers in this group will also be offered agricultural extension services on how organic fertilizer and agricultural lime are applied.
Government agricultural extension officers will provide agricultural extension services through demonstration plots where either organic fertilizer or the combination of organic fertilizer and agricultural lime will be demonstrated based on the treatment arm.
Intervention Start Date
2022-10-03
Intervention End Date
2023-03-31

Primary Outcomes

Primary Outcomes (end points)
The primary outcome in this trial is maize yield measured as tons of maize per hectare (t/ha).
Primary Outcomes (explanation)
We will measure maize output from the experimental plot within each farm during the midline survey. Farmers will weigh the output from their experimental plots with the assistance of the extension officers. The maize output will be converted to output per hectare.

Secondary Outcomes

Secondary Outcomes (end points)
1. Crop revenue per unit area (MK/hectare)
2. Knowledge, Attitudes, and Practices
3. Household Food Insecurity and Access Scale (HFIAS)
4. Proportion of farmers using SFMIs
5. Household expenditure on SFMIs
Secondary Outcomes (explanation)
1. Crop revenue per unit area will be measured by multiplying crop outputs with the selling prices. Prices will be measured at the farm level. We will use village-level prices if the farmer did not participate in maize marketing.
2. Semi-structured questionnaire will be used to assess the level of knowledge, attitudes, and practices about SFMIs.
3. Household Food Insecurity and Access Scale (HFIAS) will be measured by the standard HFIAS measurement tool/questionnaire
4. Proportion of farmers using SFMIs will be measured through the reported use of SFMI
5. Household expenditure on SFMIs will be measured by asking farmers to recall how much they spent on SFMIs.

Experimental Design

Experimental Design
This is a cluster randomized control trial
Experimental Design Details
Agricultural sections will be our clusters. Malawi is divided into 187 Extension Planning Areas (EPA) to provide agricultural extension services. Each EPA is subdivided into agricultural sections that are comprised of five to 15 villages. One agricultural field assistant manages each agricultural section, and we will select one village within an agricultural section randomly. Selecting a single village per agricultural section will reduce the possibility of contamination. This will also reduce the distance the participants will walk to a demonstration project.
Randomization Method
Randomization will be done in the office using STATA
Randomization Unit
A cluster (an agricultural section) is our randomisation unit.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
108 agricultural sections
Sample size: planned number of observations
1,620 farming households.
Sample size (or number of clusters) by treatment arms
36 agricultural sections per treatment arm
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
0.24
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
University of Malawi Research Ethics Committee
IRB Approval Date
2022-08-31
IRB Approval Number
P.07/22/166
Analysis Plan

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Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials