Low-carbon rice cultivation: Foundation for fulfilling Net Zero commitment

Water management: 'Key' to reducing methane emissions

In the context of increasingly complex climate change, mounting pest and disease pressure, and growing requirements to cut greenhouse gas emissions, the long-standing practice of keeping paddy fields continuously flooded by Vietnamese farmers is revealing troubling consequences for both rice health and the environment.

Scientific studies indicate that prolonged waterlogging in rice fields creates the anaerobic environment that stimulates the activity of methane-producing bacteria during the decomposition of organic matter. The methane gas (CH₄) generated through this process is one of the greenhouse gases with a global warming potential many times greater than that of CO₂. Therefore, in Viet Nam's roadmap to achieving net-zero emissions by 2050, rice production must adopt new cultivation practices that are more emission-reducing and sustainable.

In Thanh Hoa province, rice is a key crop and also a significant source of methane emissions. In recent years, the province's agricultural sector has stepped up the synchronous application of solutions to reform production practices, aiming to both enhance productivity and reduce emissions from rice cultivation.

On this basis, the Center for Crop Research, Testing, and Services under the Thanh Hoa Agriculture Institute, in collaboration with Faeger Viet Nam Co., Ltd., implemented an experimental model to verify greenhouse gas emissions in rice cultivation using the alternate wetting and drying (AWD) method during the spring and summer–autumn crops of 2025.

The model was carried out on a total area of 8,000 m² over the two crops, with both experimental fields and control fields established. The experimental fields adopted the AWD method, while the control plots maintained continuous flooding in line with traditional farming practices.

Mr. Le Viet Dong, Deputy Director of the Center for Crop Research, Testing, and Services, said that emissions in rice production currently stem from three main sources: excessive application of inorganic fertilizers leading to nitrous oxide emissions, burning of rice straw releasing CO₂, and methane emissions generated by continuously flooded paddy soils. Among these, reducing methane emissions is the most challenging, as it requires the application of the AWD method. 

Monitoring results showed that rice plants in the AWD fields grew normally and were even more vigorous than those in the control plots. They experienced lower pest and disease pressure and had sturdier leaves and a stronger root system. Rice yields in the AWD fields reached an average of 6.4 tons/ha in the spring crop and 5.5 tons/ha in the summer–autumn crop.

Emission reduction opens the potential for carbon credits

The most notable outcome of the model was its effectiveness in reducing greenhouse gas emissions. Gas analysis results indicated that methane emissions from the AWD fields were significantly lower than those from the control plots in both crops. In particular, under controlled conditions with two drainage times, emissions during the summer–autumn crop declined sharply, equivalent to an estimated 5–12 tons of carbon credits/ha.

According to Dr. Nguyen Thi Thu Thuy, Deputy Chief Executive Officer of Faeger Viet Nam Co., Ltd., these results clearly demonstrate the effectiveness of the AWD method in reducing methane emissions while maintaining yields.

"Building on these positive outcomes, in the coming period, Faeger Company and the Thanh Hoa Agriculture Institute will continue to cooperate to scale up the AWD model, aiming to generate carbon credits and contribute to the national Net Zero target while increasing farmers' incomes and protecting the rural environment sustainably," Ms. Thuy emphasized.