As China's demand for grain rises, its water tables drop
In 2006, China produced a surplus of grain, allowing it to export 10 million tons. Since then, the rising demand for meat has grown rapidly, and with it the demand for feed grain. This trend lead China to import 23 million tons of grain this year, according to the USDA. "China will be turning to the outside world for ever growing quantities of grain," Lester Brown said today in a teleconference. "Then the question is, can the world meet this demand?"
Brown is President of the Earth Policy Institute and is a guest contributor to TreeHugger. He has been studying world agricultural trends, and finds the trajectory in grain consumption, and the correlating water consumption, "rather disturbing."
That's because China has been tapping into its aquifers, underwater reservoirs deep underground, to irrigate its farm land. Brown said these ancient waters reserves are "like an oil field." When it's gone, it's gone. He said that the rate at which aquifers are being depleted varies from region to region, but Chinese researchers have reported aquifer levels in the North China plains to be dropping by as much as 10 feet per year.
Draining aquifers is also a problem in parts of U.S., such as northern Texas and Oklahoma. However, these regions only account for a small percentage of the country's grain production.
Continuing to increase China's imports may not be a possible solution. "We're seeing a lot of growth in grain demand because of rising affluence," said Brown. "But grain yields are starting to plateau." In the U.S., the corn crop hasn't increased in the last four years. In the biggest wheat producing countries in Europe, yield has plateaued for the last 10 years. Grain prices have steadily risen, even with a global bumper crop this year.
Brown said the availability of water is a major limiting factor to grain production, along with land. Growers have become skilled at increasing yield from a fixed amount of land, but now, Brown says we need policies that can "raise water productivity." One policy measure could be putting a higher price on water to avoid waste.
"It's taking us into a new area," said Brown. "Throughout our lifetimes irrigated areas were increasing, but now they're beginning to decline."