The production of rice on a grand scale has helped provide food for half of the world's human population, but the process has also led to increased levels of the greenhouse gas, methane, in the air.
This is what inspired scientists from three different countries to develop a method that could lessen the methane emission of rice paddies yet still retain its nourishing properties for food production.
In a study featured in the journal Nature, researchers from China's Hunan Agricultural University (HUNAU) and the Fujian Academy of Agricultural Sciences (FAAS), the Swedish University of Agricultural Sciences (SLU) and the Department of Energy (DOE) spent over a decade researching how to cultivate rice without emitting methane.
Studies have found that the warm, waterlogged soil needed for rice paddies produces as much as 17 percent of the total emission of methane in the world, which is equivalent to about 100 million tons every year.
While this figure may represent a smaller percentage to the overall greenhouse gases in the air compared to carbon dioxide, experts believe methane is 20 times more potent at trapping heat than other gases.
The researchers discovered that by adding another gene to that of rice, they can produce grains without emitting methane. The resulting new strain of rice, called SUSIBA2, is the first low-methane but high-starch rice that could provide a sustainable solution to lessening greenhouse gas emissions.
The SUSIBA2 rice strain is produced by adding a single gene extracted from barley to common rice. This results in a type of plant that can nourish its leaves, stems and grains better while preventing microbes that produce methane from feeding off of it.
Plant sciences director Christer Jansson of the DOE's Pacific Northwest National Laboratory explained that while the is a widely-recognized need to produce starch-rich rice content with low methane emissions, the key to the process has long eluded scientists.
Jansson said that as the population of the world continues to grow, the demand for more rice will continue to rise as well. The continued warming of the Earth will also lead to the warming of rice paddies, which will subsequently produce more emissions of methane. He pointed out that this is a concern that must be addressed.
To test the new rice strain, the researchers introduced the SUSIBA2 rice into a regular rice variety to find out how it will perform compared to a non-modified version of the rice strain.
Throughout the course of three years, field studies conducted by the researchers in China have shown that the SUSIBA2 rice was able to consistently produce more crops with virtually no emission of methane.
Jansson and his fellow researchers will now continue their study regarding the SUSIBA2 rice strain, particularly the mechanisms needed for the allocation of carbon in plant cultivation.
Photo: Jason Paris | Flickr
