Drip Irrigation in the Tropics: Evidence from Southern India

Last registered on September 30, 2019

Pre-Trial

Trial Information

General Information

Title
Drip Irrigation in the Tropics: Evidence from Southern India
RCT ID
AEARCTR-0004504
Initial registration date
August 01, 2019

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
August 02, 2019, 3:36 PM EDT

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

Last updated
September 30, 2019, 2:50 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Region

Primary Investigator

Affiliation
World Bank

Other Primary Investigator(s)

PI Affiliation
World Bank
PI Affiliation
Tel Aviv University

Additional Trial Information

Status
On going
Start date
2016-01-01
End date
2020-12-31
Secondary IDs
Abstract
Water scarcity is one of the fundamental challenges facing developing country agriculture. In South Asia, millions of privately-owned borewells have sprung up in the last two decades, to the point where groundwater has become the largest irrigation source in India, especially vital for dry season cultivation. While groundwater exploitation has contributed significantly to poverty reduction in rural India, unregulated drilling has also raised concerns about the sustainability of this crucial resource. Widespread adoption of drip irrigation has been proposed as a promising water-saving solution to the problem of groundwater over-exploitation. However, there is little, if any, rigorous evidence on the benefits, both in terms of agricultural production and potential water savings, of drip irrigation.

We implement a randomized control trial, in which a treatment group of borewell owners was encouraged to participate in a government subsidy program to adopt drip irrigation against a control group that kept the status quo. The study will track agricultural production, farm income, and water use in both groups before and after drip adoption.
External Link(s)

Registration Citation

Citation
Fishman, Ram, Xavier Gine and Hanan Jacoby. 2019. "Drip Irrigation in the Tropics: Evidence from Southern India." AEA RCT Registry. September 30. https://doi.org/10.1257/rct.4504
Former Citation
Fishman, Ram, Xavier Gine and Hanan Jacoby. 2019. "Drip Irrigation in the Tropics: Evidence from Southern India." AEA RCT Registry. September 30. https://www.socialscienceregistry.org/trials/4504/history/54382
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
Subsidies on drip irrigation are distributed through a partnership of India’s central and state governments. The Centrally Sponsored Scheme, released in 2005-06, provides 40% of drip costs, contingent on an additional 10% or more being offered by state governments. There is considerable variation in both the level of subsidy and the delivery of drip subsidies across states. Andhra Pradesh, the state in which this IE will be carried out, has recently increased is subsidy share to 50%, making for a total subsidy of 90%. The overall amount a farmer can receive is capped at levels that depend on land holdings. For the smallest total land holding category (< 10 acres), the cap is 100,000 Rs. per farmer, which allows for a 2 acre drip system, depending on the crop in question and other technical parameters. Farmers who have availed themselves of the subsidy in the past are ineligible to receive additional subsidies for a period of 10 years.

Government certified commercial suppliers can sell drip equipment to farmers at regulated prices and be eligible for the subsidy. In particular, the farmer applies for the subsidy at a local government agency, a process that is often facilitated by the supplier, and involves the submission of documents establishing land ownership and a legal electricity connection for the pump. Once the farmer pays his share (10%) and the application is approved, the drip supplier installs the equipment. Finally, once the government verifies the installation, the remaining 90% of the costs are transferred directly to the supplier.

The intervention was implemented as follows. We offered to pay the farmer’s share of the cost of the drip system (i.e., the 10%, limited to 10,000 Rs. per farmer) and to connect them with a drip company. Jain Irrigation Inc., one of the world’s largest suppliers of drip systems and the one with the largest market share in India, agreed to handle the subsidy application process and the installation of all drip systems and to provide close technical support to participating farmers.
Intervention Start Date
2016-07-01
Intervention End Date
2017-07-01

Primary Outcomes

Primary Outcomes (end points)
utcome Name Definition Measurement Level
Total profit Total revenue – cost (Rs.) Borewell-plot
Cultivated area Acres Borewell-plot
Crop choice High water intensity (Wet) vs. low water intensity (Irrigated dry) Borewell-plot
Water Sales revenue Rs. Borewell
Irrigated area Acres Borewell
Well Use Frequency and duration Borewell
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Outcome Name Definition Measurement Level
Profit per acre for crop under drip Net revenue/Acre Borewell-plot
Yield for crop under drip Tons / Acre Borewell-plot
Labor Use Quantity (man-hours per acre) Borewell-plot
Water Use Frequency and duration Borewell-plot
Fertilizer Use Quantity (kg per acre) Borewell-plot
Water Transactions Any water transferred to Adjacency
neighboring parcels?
Amount (area under), price,
and nature of contract
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Sampling must account for the localized nature of groundwater markets; the vast majority of these transactions occur between adjacent plots. Thus, the highest level unit of analysis for the study is the adjacency of plots around a reference borewell. Our sampling frame will be drawn from the 2012 Groundwater Markets Survey (henceforth GMS; see Giné and Jacoby, 2019). As in that survey, the owner of the reference borewell will be surveyed with regards to his plot (reference plot), but he will also report on water transfers to any of the adjacent plots. Based on GMS data, inclusive of the reference borewell, there are typically 2-3 wells within an adjacency (mean = 2.5).

The experiment will consist of a treatment arms and a control group. The treatment will entail subsidized drip adoption on the reference borewell plot. As noted, this involves a total investment of around 100,000 Rs. (10% of which will be subsidized through the experimental intervention) that covers a drip system for around 2 acres.
Experimental Design Details
Randomization Method
Randomization done in office by a computer
Randomization Unit
Adjacency of all plots around a reference borewell belonging to a farmer
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
N/A
Sample size: planned number of observations
861 adjacencies
Sample size (or number of clusters) by treatment arms
471 control adjacencies and 390 treated adjacencies
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents

Drip_IE_PAP_all.pdf

MD5: 6ecd437953978b5c2e74e5dc39a8a977

SHA1: cb5ae25088bf635ce491490aa236b2a8b14023aa

Uploaded At: September 30, 2019

Drip_IE_PAP_all.pdf

MD5: 6ecd437953978b5c2e74e5dc39a8a977

SHA1: cb5ae25088bf635ce491490aa236b2a8b14023aa

Uploaded At: September 30, 2019

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