Rice-duck farming can mitigate global warming - study

CEBU CITY , Philippines —The Integrated Rice-Duck Technology in organic farming can help mitigate global warming, said one scientist of a leading university in Mindanao.

Dr. Rachel Polestico, executive director of the Appropriate Technology Center (ATC or AproTech) of Cagayan de Oro City’s Xavier University (XU), said that ducks in the rice paddies effectively reduced the emission of the greenhouse gas methane.

Methane, which is produced when bacteria decomposes organic matter, is the second most important greenhouse gas after carbon dioxide.

According to studies on global warming, about one quarter of global methane emissions from human activities comes from livestock and the decomposition of animal manure.

But Polestico, a physicist and lecturer at XU’s South East Asia Rural  Leadership Institute (SEARSOLIN), pointed out that various scientific studies on the effect of the Integrated Rice-Duck Technology have proven that ducks effectively suppressed methane emission from rice paddies because of the ducks constant paddling.

Citing a study on the amount of methanogens in the rice-duck agro-ecosystem done by the Chinese scientist Tsing Hua, Polestico stressed that “methane emission is proportional to the amount of methanogens in the soil.”

The Chinese research “showed that the seasonal law of variation of the amount of methanogens in paddy field was consistent with methane emission from paddy field. It also confirmed that the amount of methanogens was one of the main factors affecting the amount of methane emission from paddy field. This research shows that rice-duck system has suppressed the production of methanagens through breeding duck in paddy field and also achieved the goal of mitigating methane emission from paddy field,” she added.

Chinese scientists such as Chengfang Li, Cougi Cao, Jingping Wang, Ming Zhan, Weiling Yuan and Shahrear Ahmad who did a research on the “Nitrous Oxide Emissions from Wetland Rice-Duck Cultivation System in Southern China” found out that integrated rice-ducks farming “will contribute to alleviating global warming.”

The Chinese research team evaluated the integrated global warming potentials (GWPs) of a rice–duck cultivation system based on methane (CH4) and N2O emission and they found out that integrated rice-ducks farming “could suppress the total amount of CH4 (methane) and N2O (nitrous oxide) emissions from rice paddies.”

“Moreover, because the decrease of CH4 emissions from rice-ducks compared to traditional rice farming was far more than the increase of N2O emissions from rice-ducks compared to traditional rice farming, rice-ducks farming greatly reduced integrated GWPs (CH4 + N2O) compared to traditional rice farming. So, the rice–duck cultivation system is an effective strategy for reducing integrated GWPs of the rice–duck cultivation systems based on CH4 and N2O in southern China and will contribute to alleviating global warming,” the Chinese research team said in their report.

Polestico also said that farmers can really help mitigate or alleviate global warming by planting trees to reduce carbon dioxide; by practicing organic farming to reduce nitrous oxide; and by practicing the integrated rice-duck technology to reduce methane emissions.                – Bong Fabe