Assessing the impact of Leaf Color Charts among paddy farmers in India

2025-12-01

2026-01-15

a. Leaf Color Chart panel reading.
b. Chlorophyll meter reading.
c. Self-reported urea use (kg/acre).
d. Self-reported timing of urea use
E. Self-reported frequency of urea use

Self-reported paddy yield (kg/acre).
Self-reported LCC use.

This study usesa randomized controlled trial with paddy farmers in Odisha, India to test how varying the timing and conditionality of monetary incentives and social image concerns affects the adoption and impact of an agricultural advisory service, comprising training, a Leaf Color Chart (LCC) decision-support tool, and ongoing guidance via IVR, designed to optimize nitrogen (urea) fertilizer application timing, frequency, and quantity.

Using a random-walk sampling method, we are recruiting up to 1,440 paddy farmers in Odisha for this study. We stratified recruited farmers by farmer’s block of residence and randomly assigned them to one of the following four experimental arms:

-Control / T0 (up to 480 farmers). No agricultural advisory service.

-Treatment 1 / T1: agricultural advisory service+ upfront conditional payment + public recognition framing (up to 480 farmers). Farmers receive access to agricultural advisory service, in person training, and an incentive contract with a conditional upfront payment by bank transfer within one week of receiving training. The contract states that PxD reserves the right to request a refund if advisory is not followed. The contract adds light-touch social image framing, stating that monitoring visits are in open fields therefore likely visible to other community members and that a public list of compliant farmers will be posted at the Gram Panchayat office at season end.

-Treatment 2 / T2: agricultural advisory service+delayed conditional payment (promissory note) + confidentiality reminder (up to 480 farmers). Farmers receive access to agricultural advisory service and a promissory note/debt acknowledgement guaranteeing payment only if advisory is followed, with payment by bank transfer on May 15, 2026 (after the fertilizer window closes). The note states PxD may void the note and cancel payment for non-compliance. Farmers are reminded that their participation and compliance will be kept confidential and the surveyor signs this commitment in front of the farmer again.

-Treatment 3 / T3: agricultural advisory service+ upfront conditional payment + confidentiality reminder (up to 480 farmers). Farmers receive access to agricultural advisory service and an incentive contract with an upfront payment by bank transfer within one week of receiving training. As in T1, the contract states PxD reserves the right to request a refund if advisory is not followed. Farmers are reminded that their participation and compliance will be kept confidential and the surveyor signs this commitment in front of the farmer again.

The incentive is ₹1,000 × monitored plot area (acres), capped at ₹200 minimum and ₹1,000 maximum total. LCC use is verified via two monitoring visits (Jan–Apr 2026) using a chlorophyll meter as an objective indicator of compliance.

Not available

We randomized individual farmers using a computer with Stata's ‘randtreat’ command, stratified by the farmers’ block of residence.

Individual (farmer) level randomization for the full sample.

No

N/A

1,440 farmers

-Control / T0 (up to 480 farmers). No agricultural advisory service.
-Treatment 1 / T1: agricultural advisory service+ upfront conditional payment + public recognition framing (up to 480 farmers). Farmers receive access to agricultural advisory service, in person training, and an incentive contract with a conditional upfront payment by bank transfer within one week of receiving training. The contract states that PxD reserves the right to request a refund if advisory is not followed. The contract adds light-touch social image framing: monitoring visits are in open fields therefore likely visible to other community members and a public list of compliant farmers will be posted at the Gram Panchayat office at season end.
-Treatment 2 / T2: agricultural advisory service+delayed conditional payment (promissory note) + confidentiality reminder (up to 480 farmers). Farmers receive access to agricultural advisory service and a promissory note/debt acknowledgement guaranteeing payment only if advisory is followed, with payment by bank transfer on May 15, 2026 (after the fertilizer window closes). The note states PxD may void the note and cancel payment for non-compliance. Farmers are reminded that their participation and compliance will be kept confidential and the surveyor signs this commitment in front of the farmer again.
-Treatment 3 / T3: agricultural advisory service+ upfront conditional payment + confidentiality reminder (up to 480 farmers). Farmers receive access to agricultural advisory service and an incentive contract with an upfront payment by bank transfer within one week of receiving training. As in T1, the contract states PxD reserves the right to request a refund if advisory is not followed. Farmers are reminded that their participation and compliance will be kept confidential and the surveyor signs this commitment in front of the farmer again.

The incentive is ₹1,000 × monitored plot area (acres), capped at ₹200 minimum and ₹1,000 maximum total. LCC use is verified via two monitoring visits (Jan–Apr 2026) using a chlorophyll meter as an objective indicator of compliance.