Impact of small-package fertilizer sale on the adoption of micro-dose fertilization technology and the productivity of rice farming: Evidence from Madagascar

Last registered on July 29, 2024

Pre-Trial

Trial Information

General Information

Title
Impact of small-package fertilizer sale on the adoption of micro-dose fertilization technology and the productivity of rice farming: Evidence from Madagascar
RCT ID
AEARCTR-0010640
Initial registration date
July 21, 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
July 29, 2024, 4:32 PM EDT

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

Locations

Primary Investigator

Affiliation
Tohoku University

Other Primary Investigator(s)

PI Affiliation
Japan International Research Center for Agricultural Sciences (JIRCAS)
PI Affiliation
Japan International Research Center for Agricultural Sciences (JIRCAS)
PI Affiliation
Tsukuba University

Additional Trial Information

Status
On going
Start date
2021-04-01
End date
2025-03-01
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
In sub-Saharan Africa, where the population is rapidly increasing and arable land per capita is declining, enhancing agricultural productivity is critical for food security and poverty alleviation. One major challenge to crop production in the region is the very low use of chemical fertilizers. Addressing this issue, a rice cultivation technique known as P-dipping has been developed. This process involves submerging rice seedlings in a mud slurry mixed with a small amount of Triple Super Phosphate (TSP) fertilizer before transplanting them. P-dipping is particularly promising as it significantly boosts rice yields, even in tropical soils, with minimal fertilizer input, making it accessible for smallholder farmers with limited financial resources. However, the underdeveloped fertilizer market in Africa, characterized by the unavailability of small fertilizer packages, may hinder the widespread adoption of this technology. This research project aims to evaluate the effects of training on P-dipping technology and the availability of small-package fertilizers on farmers' adoption rates and rice productivity. In collaboration with a government extension agency and a private fertilizer company, we provided training on P-dipping and conducted an experiment on retailing fertilizers in small quantities. The study includes 600 randomly selected rice farmers from 25 communes in the Vakinankaratra Region.
External Link(s)

Registration Citation

Citation
Magezi, Eustadius et al. 2024. "Impact of small-package fertilizer sale on the adoption of micro-dose fertilization technology and the productivity of rice farming: Evidence from Madagascar." AEA RCT Registry. July 29. https://doi.org/10.1257/rct.10640-1.0
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Experimental Details

Interventions

Intervention(s)
In sub-Saharan Africa (SSA), where the population is rapidly increasing and arable land per capita is declining, enhancing agricultural productivity is critical for food security and poverty alleviation. One major challenge to crop production in the region is the very low use of chemical fertilizers. To address this challenge, a rice cultivation technique known as P-dipping has been gaining attention in recent years, as it requires minimal fertilizer application to significantly boosts rice yields, making it accessible for smallholder farmers with limited financial resources. P-dipping involves submerging rice seedlings in a mud slurry mixed with a small amount of Triple Super Phosphate (TSP) fertilizer before transplanting them. However, the underdeveloped fertilizer market in Africa, characterized by the unavailability of small fertilizer packages, may hinder the widespread adoption of this technology.

This study uses a randomized controlled trial (RCT) to evaluate: (1) the effectiveness of training in P-dipping, and (2) the impact of the sale of small packs of chemical fertilizer on the adoption of the P-dipping technique. The study was conducted in the Vakinankaratra region of Madagascar. This region is known for its soil phosphate deficiency, which makes P-dipping highly effective in this region. We partnered with one of country's largest agro-products distributors to produce and distribute small packs of TSP to retailers. Each pack, hereafter referred to as P-dipping bags, each containing 3 kg.

In designing our interventions, we consider that if the training is conducted in a given community, the training content are likely to be transferred from the training farmers to the non-training farmers, resulting in a phenomenon called information spillover. When spillover occurs, non-trained farmers also adopt the technology, and thus the effectiveness of training is likely to be underestimated when comparing trained and non-trained farmers within a training commune.

We also note that because P-Dipping is a newly developed technique, our evaluation is likely to face two challenges. First, an RCT design with two comparison groups (one trained and one control) may fail to assess the effectiveness of P-Dipping compared to other available yield-enhancing technology packages. In Madagascar, the most common technology packages are PAPRIZ techniques, which consist of the use of NPK, UREA, and crop establishment methods, and are being promoted in several regions, but have not yet achieved widespread adoption. Second, because fertilizer retailers are not familiar with the P-Dipping technique, they may find it difficult to explain the technique to farmers. If fertilizer retailers are not trained, it may limit the diffusion of P-Dipping after the training intervention.

Therefore, our interventions include:
1) To provide training on PAPRIZ techniques to rice farmers.
2) To provide training on P-Dipping techniques to rice farmers and selected fertilizer retailers.
3) To conduct sales experiment of small packs of TSP (P-Dipping packs).
Intervention Start Date
2021-10-01
Intervention End Date
2024-06-01

Primary Outcomes

Primary Outcomes (end points)
The primary outcomes of this intervention is to examine whether access to a small package of fertilizer can encourage farmers to adopt P-Dipping, and whether adoption would lead to improved rice productivity (measured as the amount of paddy harvested per hectare) and profitability (i.e., difference between revenue from rice cultivation and production cost per hectare). We will also examine the extent to which fertilizer demand changes when a technology such as P-dipping is introduced by comparing the fertilizer purchasing behavior of P-dipping training participants and non-training participants.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We design our experiment to have four treatment arms:

T0: Control group (farmers in this group do not receive any intervention).
T1: PAPRIZ training (receive training in PAPRIZ techniques).
T2: P-Dipping training for farmers only.
T3: P-Dipping training for farmers and fertilizer dealers.
Experimental Design Details
Not available
Randomization Method
Randomization done in office by a computer.
Randomization Unit
Commune
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
25 communes
Sample size: planned number of observations
The sample size is 600 households.
Sample size (or number of clusters) by treatment arms
T0: control group (6 communes, 144 sample households)
T1: PAPRIZ training (6 communes, 144 sample households)
T2: P-Dipping training for farmers only (7 communes, 168 sample households)
T3: P-Dipping training for farmers and fertilizer retailers (6 communes, 144 sample households).

In T2 and T3 communes, we worked with 19 fertilizer retailers who would sell TSP (P-Dipping bags) in their respective communes. The difference between the two is that the retailers in T3 received training on P-Dipping. This would help us to examine the impact of supply-side factors, such as retailers' technological know-how, on the adoption of P-Dipping.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Research Ethics Board, Faculty of Humanities and Social Sciences, University of Tsukuba
IRB Approval Date
2021-11-15
IRB Approval Number
2021-12