Rice is a key food source for more than half of the people in the world. Asia grows 90 percent of the world's rice, though more than 600 million people in the region are malnourished, the U.N.'s humanitarian news agency IRIN reports.
Asian rice farms typically use nearly 400 gallons of water to produce about 1 pound of rice. Less than half of the water, however, is used by the plant.
Robert Zeigler, the director general of International Rice Research Institute, told the news agency on the sidelines of a rice conference in Hanoi that irrigation problems and water scarcity issues were affecting rice crop yields in Asia.
"The food security of hundreds of millions of people will be adversely affected," he warned.
As much as 30 percent of the world's fresh water is used to irrigate rice while about 2 billion people don't have adequate access to fresh drinking water supplies.
Officials said rice yields need to grow at least 1.5 percent per year to keep up with global demand, though yields have increased by only 1 percent in the last 20 years.