System of Rice Intensification
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 to 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 million to 5 million farmers around the world, SRI yields are 50 to 100 percent higher than conventional rice production. Seed use drops by 80 to 90 percent and water inputs by 25 to 50 percent. Farm incomes can double, as methane emissions drop and soils sequester carbon.