Society

Efficiency the key to irrigation

By Jin Zhu (China Daily)
Updated: 2011-01-31 07:21

BEIJING - China should focus more on water-efficient agriculture and improving the usage rate of water resources when it plans construction of new irrigation facilities in rural areas, experts have said.

A central policy document released on Saturday said the country will greatly increase its investment in water projects during the next 10 years and will require as much as 10 percent of local land transaction fees to go to farmland irrigation projects.

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With a new round of massive irrigation projects set to begin, a pilot program on water usage conservation, which is now under way in Northwest China's Gansu province, could provide valuable lessons, especially when the country is facing growing water shortages, said Wang Chunyan, a researcher at the Chinese Academy of Agricultural Sciences (CAAS).

Under the pilot program, farmers cover dry land with plastic sheeting, which collects rainwater that flows into the land and minimizes water loss.

"About 70 percent of planting areas in the province are dry land and cannot be irrigated due to water shortages. Under this technology, the efficiency of water usage has been improved greatly," Wang said.

At present, per hectare corn yields in Gansu have reached 8.9 tons, compared with the country's average of 5.2 tons.

In 2010, the Gansu provincial government invested 240 million yuan ($36.45 million) in spreading the technology over 702,000 hectares of dry land, increasing grain output in the province by 9.56 million tons compared with the previous year's output, official figures showed.

"It's a great achievement as Gansu, which is at a disadvantage due to the lack of water resources, now has shown great potential for growing grain," Wang said.

China built its huge rural water conservation project between 1949 and 1979 to prevent drought and flood.

"Most irrigation projects built during that period were based on large amounts of water consumption, which were mainly in irrigated areas such as the North China Plain and Northwest China's Guanzhong Plain," Lu Bu, a CAAS researcher on agricultural resources and regional planning, said.

"But future construction cannot follow that path as the country does not have enough water," he said.

At present, about 60 percent of the country's annual disposable water resources have been put into the agricultural sector, down from 80 percent in the 1980s, according to CAAS statistics.

"In these circumstances, a new round of construction should not focus on renovation or building similar projects but on new projects that can improve water-usage efficiency in rain-feed regions," he said.

Rain-feed regions are areas that are not rich in water resources and depend on rainfall for irrigation.

Many rain-feed regions, including Northeast China's Heilongjiang and Jilin provinces and Northwest China's Xinjiang Uygur autonomous region, will become potential areas for grain growth after their irrigation systems have been improved, Lu said.

"The government should also increase its subsidies for local farmers who spend their own money on improving irrigation facilities," he said.