Rice cultivation is responsible for significant methane emissions, making it a major contributor to greenhouse gas emissions. However, there are techniques that farmers can employ to reduce methane emissions and make rice production more climate-friendly.
One solution is to drain the fields a few times during the growing season to allow the soil to replenish its oxygen. This helps to suppress methane-producing bacteria and allows more climate-friendly bacteria to take over. This technique, known as alternate wetting and drying (AWD), has been shown to reduce methane emissions by at least 50%. However, it is not effective during the rainy season in Southeast Asia, where rice is grown in countries like Vietnam, Thailand, and Cambodia.
Another technique that can be used is furrow irrigation, where rice is planted in rows of mounds and the channels between them are flooded. This allows oxygen into the soil and reduces methane emissions.
In addition to water management techniques, removing the leftover straw from the previous harvest can also help to reduce methane production. This removes the food source for methane-producing microbes.
Switching from cheaper urea fertilizers to more expensive ammonium sulphate fertilizers can also contribute to reducing methane emissions. However, this may not be feasible for all farmers due to the higher cost of the fertilizers.
Some projects have been created to sell emissions losses from reduced methane emissions as carbon credits to companies that want to offset their own emissions. For example, a Gold Standard certified project in India has farmers using AWD techniques and generates carbon credits. This project not only helps to reduce methane emissions but also reduces water consumption and adapts to future climate change risks.
Overall, addressing methane emissions from rice cultivation is crucial in meeting climate commitments. Implementing techniques such as AWD, furrow irrigation, and managing leftover straw can contribute to significant reductions in methane emissions and make rice production more sustainable.