Source: The Indian Express | Author: Harish Damodaran

0.1 Why rice farming is linked to methane emissions

0.1.1 Rice is usually grown in flooded fields, where water remains standing for long periods.
0.1.2 When soil stays submerged, it loses oxygen and becomes anaerobic, meaning conditions without oxygen.
0.1.3 Under anaerobic conditions, soil microbes break down organic matter and release methane, a potent greenhouse gas.
0.1.4 Methane has a global warming potential about 28 times higher than carbon dioxide over a 100-year period.

0.2 Traditional rice cultivation practice

0.2.1 Farmers typically raise seedlings in nurseries and transplant them into fields after 25–30 days.
0.2.2 After transplantation, fields are kept continuously flooded with about 4–5 cm of water mainly to suppress weeds.
0.2.3 This flooding usually continues for nearly 65 days of the crop cycle.
0.2.4 Rice crops generally take 90–100 days to mature after transplantation.
0.2.5 Continuous flooding prevents oxygen from entering the soil, which directly increases rice methane emissions.

0.3 Why changing farming practices is difficult

0.3.1 Methods aimed at reducing methane often require new machinery, new techniques, or changes in timing.
0.3.2 Over 86% of Indian farmers are small or marginal, owning less than 2 hectares of land.
0.3.3 Such farmers are highly risk-averse and avoid practices that could increase costs or reduce yields.
0.3.4 Any climate-friendly solution must therefore work without affecting production or raising expenses.

0.4 What is Alternate Wetting and Drying (AWD)

0.4.1 Alternate Wetting and Drying (AWD) is a rice cultivation method that avoids continuous flooding.
0.4.2 Instead of keeping fields submerged, water is periodically drained and reintroduced.
0.4.3 This drying phase allows oxygen to enter the soil, breaking the anaerobic conditions that generate methane.
0.4.4 As a result, methane-producing microbes become inactive for part of the crop cycle.

0.5 How AWD is actually practiced in fields

0.5.1 Fields are kept flooded for the first 20 days after transplantation, which is critical for early plant establishment.
0.5.2 During the next 45 days, fields are allowed to dry for a total of about 12 days, split into two cycles.
0.5.3 Water is drained until it falls 10–15 cm below the soil surface, after which fields are reflooded.
0.5.4 This controlled drying does not stress the crop and does not affect grain formation.
0.5.5 Studies show that yields remain stable under AWD when practiced correctly.

0.6 Evidence from field studies in India

0.6.1 Field studies were conducted during the 2024 kharif season in Telangana.
0.6.2 Acrylic chambers were installed in rice fields to directly capture and measure methane emissions.
0.6.3 Fields using AWD recorded lower methane emissions, significant water savings, and no yield loss.
0.6.4 The study covered 30 farmers across three villages, ensuring real-world farming conditions.

0.7 Scaling up AWD adoption

0.7.1 Farmers enrolled under AWD increased from 11,300 in 2024 to a projected 69,000 in 2025–26.
0.7.2 Adoption has expanded across Telangana, Andhra Pradesh, Odisha, Tamil Nadu, and Karnataka.
0.7.3 Both kharif and rabi rice-growing seasons are now included under the programme.

0.8 How farmers can earn money from emission reduction

0.8.1 Reduced rice methane emissions are quantified and converted into carbon credits.
0.8.2 One carbon credit represents the reduction of one tonne of carbon dioxide equivalent (CO₂e).
0.8.3 These credits can be sold in domestic as well as international carbon markets.

0.9 Value of carbon credits for farmers

0.9.1 Methane-reduction credits are currently priced at around $15–25 per tonne of CO₂e.
0.9.2 A single rice crop can generate roughly $37.5 per hectare in carbon credit value.
0.9.3 This translates to over ₹3,300 per hectare as additional income for farmers.

1.0 Who buys these carbon credits

1.0.1 Buyers include airlines, data centres, and energy-intensive industries.
1.0.2 These entities purchase credits to offset unavoidable emissions.
1.0.3 Carbon credits help companies meet net-zero and climate commitments.

1.1 Institutional support and alliances

1.1.1 Organisations such as Mitti Labs and the Good Rice Alliance are promoting AWD adoption.
1.1.2 The alliance includes global corporations supporting climate-smart agriculture.
1.1.3 More than 12,000 farmers across 13 states are already part of these initiatives.

1.2 Why this matters for India

1.2.1 India is the world’s largest rice producer and exporter, making its farming practices globally significant.
1.2.2 Even small changes in rice cultivation can lead to large reductions in methane emissions.
1.2.3 AWD offers a rare win-win solution, combining climate action with higher farmer income.