Uc Science Today

There’s good ozone, and there’s bad ozone. The good is high up in the stratosphere and the bad, a mixture of sunlight and nitrous oxide, is near the surface of the Earth. This pollution affects not only human health, but also plant growth. A research team led by Colin Carter of the University of California, Davis, has made a key discovery about how surface ozone impacts rice production. "There’s a critical period during the growing season where you have a day of extremely high ozone, that it can reduce the yield up to 1 percent, just one day. So we measured across the country that yields could be reduced by two percent or more, which doesn’t sound like a large number, but it is when you consider the fact that China is the world’s largest producer of rice and the world’s largest importer. By identifying this critical stage of development, Carter hopes their data can inform better regulatory policies in China to alleviate the damaging effects of ozone pollution on rice yields and ultimately, the global market