Despite pressing demand, China is unlikely to increase irrigated water supplies in the near future, considering the current water resources and the pace of social and economic development, industry officials said. The answer lies in conservation just to stay in place, they said.
China has promoted water-conserving irrigation technologies for many years. Substantial progress was made starting in the mid-1990s, when new technology from Israel and elsewhere was introduced.
Film-mulched drip irrigation, which uses a combination of agricultural film and trickle irrigation technologies, is particularly efficient.
Jia Xiwu, a villager in Tongyu County, Jilin Province, has used the technique on 15 mu of land since last year. He found it minimized the use of water by allowing the water to drip slowly to the roots of plants through a network of valves, pipes, tubing and emitters.
"The drip irrigation method I learned from county technicians saves 60 to 70 percent on water and increases corn output by 40 percent," he said.
China has promoted other water-saving irrigation methods. For instance, the sprinkler irrigation technique can cut water use by 50 percent and raise farm output by 20 to 30 percent.
With conservation efforts, nearly 14 billion cubic meters of water have been saved annually since the 1990s. About 23.3 million ha of farmland has been covered with water-efficient irrigation systems, said Chen.
The combination of financial savings and higher output achieved by the newer techniques has made water conservation attractive to China's farmers.
According to Yao Fucai, director of the Yaofu Town Water Conservation Association in Pingluo County, in northwest China's Ningxia, the town has managed to use the same amount of water to irrigate an extra 16,000 mu of land it has put under cultivation it expanded in recent years. It now has 83,000 mu of farmland.
Water-conserving irrigation methods and technologies also help expand the total amount of land that can be irrigated, as irrigation reduces the saline and alkaline content of soil.
Over the past decade, the Jiangdong irrigation area in Qiqiha'er City, in northeast China's Heilongjiang Province, has quadrupled the size of its rice fields to 120,000 mu.
"Water-saving irrigation plays the crucial role in turning wasteland into fertile farmland," said Wang Zizhang, a farmer with Zhalong Township, which is part of the irrigation area.
Despite the benefits of new irrigation techniques, obstacles remain.
"It's not easy to extend the use of irrigation technologies, because new technologies cost a lot more than most farmers can afford," said Yan Guanyu, an official with the department of irrigation, drainage and rural water supply, which is under the MWR.
The most popular drip and micro-sprinkling irrigation technologies cost farmers 2,000 yuan (about US$290) per mu to install, while rural per capita net income was just 4,140 yuan in 2007.
"Who will pay the bill?" said Yan. "Technology is expensive, but water is cheaper. If the money they save on water cannot cover their investment, farmers will not be interested."
(Xinhua News Agency December 3, 2008)