We had occasion to talk to Dr. William Padolina, former Science and Technology secretary, and now deputy director general for partnerships of the International Rice Research Institute (IRRI) based in Los Banos.
He was inviting us to Los Banos so we could be updated on the latest research developments in rice which he said are very exciting. Any example of such research development?
He mentioned the improvement of the photosynthetic pathway of rice, which is C3. Corn is much more efficient in utilizing the radiation from the sun to produce biomass and grains because it has a photosynthetic pathway of C4. The upgrade in the photosynthetic pathway of rice to C4 could mean more than 10 percent increase in yield. And that’s one of the strategies IRRI researchers have been pursuing.
The upgrade of the photosynthetic pathway is one of the new strategies to increase rice yields. The old strategy of using more and more nitrogen fertilizers to hike yields will only damage the environment. Dr. John Sheely, IRRI crop ecologist and modeller, explains it best in an IRRI publication that came out way back in 2001, titled “Rice Research: the Way Forward.” In the past, he said, higher yields have depended on increased use of organic and inorganic fertilizers to supply nitrogen to the plants. This no longer represents the way forward because the use of organic fertilizer often stimulates the emission of methane, and inorganic nitrogen fertilizers can stimulate the emission of nitrous oxide. Along with carbon dioxide, these are the two most damaging greenhouse gases and any proposal to boost rice production simply by increasing fertilizer use would risk making the world’s climate even worse.
The IRRI publication continues: “Converting a plant from C3 to C4 would involve a rearrangement of cellular structures within the leaves and more efficient expression of various enzymes related to the photosynthetic process.”
“All the components for C4 photosynthesis already exist in the rice plant,” Dr. Sheely says, “but they are just distributed differently and are not as active.”
Dr. Sheely adds that “plants with C4 photosynthetic pathway are better equipped to cope with the climate changes that are expected as a consequence of global warming. They operate well at high temperature, they’re extremely water-efficient, and they require less nitrogen.”
Posted on October 9th, 2008 under Special Report. Tags: N-Fertilization. Comments: None
