System of Rice Intensification
Reduced / Sequestered
(2020–2050)
(To Implement Solution)
Operational Savings
Net Profit
Solution Summary*
Rice is the staple food of 3 billion people, providing one-fifth of calories consumed worldwide. Its cultivation is responsible for at least 10 percent of agricultural greenhouse gas emissions and 9–19 percent of global methane emissions. That is because flooded rice paddies are ideal anaerobic environments for methane-producing microbes that feed on decomposing organic matter, a process known as methanogenesis.
The System of Rice Intensification (SRI), developed on Madagascar in the 1980s, is a holistic approach for sustainable rice cultivation. It calls for:
- Planting single seedlings with more space between them, rather than by the handful and bunched closely together.
- Watering intermittently and allowing for dry spells, rather than using continuous flooding.
- Tending plots with a rotating hoe to address weeds and aerate soil, and applying compost.
These methods benefit soil and root systems, while lowering the inputs required for production and increasing crop yields. Now practiced by 4–5 million farmers around the world, SRI yields 50–100 percent more than conventional rice production. Seed use drops 80–90 percent and water inputs, 25–50 percent. Farm incomes can double as methane emissions drop and soils sequester carbon.
System of Rice Intensification (SRI) has been adopted largely by smallholder farmers and has much higher yield benefits than improved rice production. We calculate that SRI can expand from 6.7 million hectares to 40–52 million hectares by 2050, both sequestering carbon and avoiding methane emissions that together total 2.8–4.3 gigatons of carbon dioxide or its equivalent over 30 years. With increased yields, 333–510 million additional tons of rice could be produced, earning farmers an additional $574–817 billion in profit in the lifetime and lifetime operational savings of US$14–21 billion.
