Friday, October 12, 2012

on reducing rice's carbon footprint

I interrupt regular personal blog posting to give way to some insights from the Global Rice Science Partnership Asia review. Let's shift towards more scientific stuff, sort of...


Rice is one of the most important food items in the world. It is eaten by the majority of the human population. The sheer size of land dedicated to rice production is said to be a major contributor to global warming.

When I first learned that rice farms -- a traditional sight in Asia -- is a source of the greenhouse gas methane, I was nothing short of shocked. As a grade schooler, I had thought that the involvement of plants in agriculture surely made it an Earth-friendly endeavor.

But no. The rice farm, particularly the irrigated type, produces a lot of methane due to the decomposition of plant matter thanks to anaerobic bacteria (the ones that thrive where there's no oxygen... like under the water in irrigated rice paddies). Because of methane emission, the rice paddies are considered to have relatively high carbon footprints.

How then do rice scientists reduce rice fields' (and grains') carbon footprint?

In the 2012 Global Rice Science Partnership Asia Review, scientists from different fields of study at the International Rice Research Institute highlighted some technologies that could help mitigate methane emissions in the rice fields. Here are three of them:

Alternate wetting and drying. In this technique, the soil is irrigated and allowed to soak for several days before it is dried to a certain level (as indicated by a pipe inserted in the ground which monitors the groundwater level). Then it is flooded again. According to the talks I listened in on, the shorter time spent in flooded conditions, the less methane should be generated by the field. But another greenhouse gas, nitrous oxide (aka laughing gas) is released once the flooded fields dry up. One of the speakers assured the audience, however, that the way fertilizer is applied can help reduce the emission of laughing gas.

Dry-seeded rice. Another way of reducing methane emissions is to not flood the land for so long. Actually, by using the dry-seeded rice technology, scientists aim to hit two birds with one stone: (1) reduce methane emissions and (2) address the water shortage issues (since the fields will depend more on rainfall, right?).

Green Super Rice. No, the rice grains aren't green. The 'green' in this super rice is in it's ability to thrive in the toughest landscapes. That means that it will live healthily with minimal fertilizer and pesticide application and can easily compete with weeds! It can live in drought conditions too. Varieties that are considered green super rice have been developed through conventional rice breeding.

So, will these three Earth-friendly technologies actually stop greenhouse gases from giving rice a bad name? Only the future can tell. In the meantime, what ways can we, rice eaters, do to reduce rice's carbon footprint?