Water-saving irrigation proves effective, calmly resolving the challenge of severe drought
In the face of a severe drought rarely seen in decades, crops in some areas of Henan and Liaoning provinces suffered serious damage, highlighting shortcomings in water conservancy facilities (see "In a Year of Severe Drought, a Test for Farmland Water Conservancy" in this section, August 19), but must a severe drought inevitably bring agricultural disaster? Not necessarily. Especially so today, on the road to modern agriculture. During visits, reporters found that although water shortages in some places were also very severe, the fields were a lush green, looking as though the weather had been favorable. What was the secret?
Water-saving irrigation shows clear results, increasing both yield and income in a year of severe drought
Although the drought was severe, reporters saw in the 500-mu high-efficiency water-saving irrigation demonstration area in Dongtianlong Village, Guqiao Township, Changge City, Henan Province, that corn taller than a person was lush and green, stretching as far as the eye could see. "The water-saving irrigation project built last year has been a great help this year, and higher yield and income are beyond doubt." Village Party secretary Gao Genshu was full of confidence. On both sides of the field roads, there was a motor-pumped well every 70 to 80 meters. The water pipes were all buried in the ground, and every 12 meters in each direction there was a sprinkler head protruding more than ten centimeters above the ground, irrigating the grain fields.
"We have already irrigated the fields three times." Li Huidong, director of the Agricultural Center of Guqiao Township, Changge City, said, "In the past, irrigating one mu of land required 50 to 60 cubic meters of water; now it takes only about 25 cubic meters. This year, in places where water-saving irrigation was not used, after one or two rounds of extensive irrigation, the water level in the motor-pumped wells dropped markedly, or they even dried up; but in the water-saving irrigation areas, even after three or four rounds of irrigation, there was still water available for irrigation."
"Henan now mainly adopts 4 water-saving irrigation methods, and sprinkler irrigation is one of the more water-saving among them. The most common is technical upgrading of canals to prevent seepage. Another is using pipelines instead of open canals, with water distributed directly from pipeline outlets into field furrows, or connecting a hose at the outlet to lead water into the furrows, improving water-use efficiency. Micro-irrigation technology saves even more water than sprinkler irrigation. Through a pipeline system, water is delivered to the irrigation area, and emitters installed on the final-stage pipelines deliver water directly to the soil near the crop roots." said Yang Biantong, flood control and drought relief inspector of Henan Province.
Tian Xiaoyu, a large-scale grower in Shajiatun, Daban Village, Mantanghong Town, Zhangwu County, Liaoning Province, used a similar method and was equally calm in the face of this year's drought. Old Tian planted more than 300 mu of corn, sorghum and peanuts this year. Although this is now the period of the most severe drought, he only goes to the fields to take a look each day. Old Tian tore open the plastic film in the cornfield to show reporters that a black soft plastic pipe ran close against the corn plants, and about every five centimeters there was a pinhole-sized water outlet on the plastic pipe. "The film can also prevent water evaporation," Old Tian said.
Both labor-saving and sustainable, China's agricultural water use has great water-saving potential
According to Wang Tie, deputy director of the Zhangwu County Water Conservancy Bureau in Liaoning Province, water-saving drip irrigation uses plastic pipes to send water through openings or emitters on capillary tubes about 10 millimeters in diameter to the crop roots for localized irrigation. "It is currently one of the most effective water-saving irrigation methods in arid and water-scarce areas, and water-use efficiency can reach 95%. Compared with flood irrigation, the water-saving rate of drip irrigation exceeds 40 percent, and the duration maintained by each irrigation is extended by 3 times. Drip irrigation can also deliver fertilizers and nutrients to farmland along with irrigation."
In Zhaojia Village, Xinglongshan Town, Zhangwu County, reporters happened to meet Ning Yuguang, Party secretary of the town, who was leading technicians from the town's agricultural technology extension station at a pumping station to help farmers install drought-resistance facilities. "In the past, many ordinary people still had concerns. After experiencing this drought, quite a few saw that water-saving facilities both save effort and preserve yields, and came one after another to ask the government for technical guidance."
"In 2013 we specifically conducted an experiment, and later the agricultural department measured the yield. Corn yield on plots using drip irrigation increased by 430 jin per mu compared with plots not using it. Calculated at the current corn price, after deducting the 200 yuan input, farmers could still increase net income by 230 yuan per mu, while each mu of land saved 80 cubic meters of water. Once a year of severe drought occurs, its role in ensuring stable production and increased income for farmers becomes even more prominent." Ning Yuguang said.
"Water-saving irrigation can not only reduce the burden on farmers in farming, but also save land occupied by canals and field ridges, expand the planted area, and promote China's agriculture's transformation from traditional agriculture to modern agriculture." said Cheng Chuanxing, Party secretary of Henan Agricultural University. "Using limited water to irrigate the most land is an important way forward for sustainable agricultural development."
Data show that China's agricultural water-use efficiency is 20 percentage points lower than that of developed countries, and the water-saving potential is huge. According to expert estimates, by promoting farmland water-saving technologies, there is a potential to save 36 billion cubic meters of water in wheat and rice production in irrigation districts, which would also increase a certain amount of irrigated area and thereby increase output; in arid areas, if the utilization rate of natural precipitation can be raised, there is also a certain potential for water resources.
Construction involves multi-department coordination, requiring greater government attention, assistance and investment
Are water-saving facilities expensive? "The disadvantage of water-saving irrigation projects is that they require large investment and a long construction period, and require coordinated construction by multiple departments such as electric power, municipal administration and agriculture." said Zhao Xuejun, section chief of the Engineering Section of the Changge City Water Conservancy Bureau in Henan Province.
Huang Xiliang, deputy director and senior engineer of the Henan Provincial Farmland Water Conservancy Technology Extension Station, said: "In the future, the focus of agricultural water saving should attach importance to developing pipeline water conveyance and low-pressure energy-saving sprinkler heads; seepage-prevention canals will gradually be replaced by pipelines; and drip irrigation, this new type of water-saving technology, compared with surface drip irrigation, shows broad prospects for development. The construction of these projects requires the joint completion of departments including land and resources, comprehensive agricultural development, development and reform, finance, poverty alleviation, agriculture and water conservancy." This also requires greater government attention, assistance and support.
Ning Yuguang said that the wells and pumps and other facilities of the local drip irrigation project were all funded by the state, and the money ordinary people had to pay was only the cost of laying plastic film and drip irrigation tape, about 200 yuan per mu. According to Wang Tie, since the provincial drip irrigation water-saving project began implementation in 2011, using a method in which the province, city and county put in the bulk of the investment and farmers put in a small part, the land in Zhangwu County with drip irrigation facilities has now reached 723,600 mu, accounting for more than 25% of the county's cultivated land area.
On the mechanism for encouraging the development of water-saving agriculture, Yu Fawen, a researcher at the Rural Development Institute of the Chinese Academy of Social Sciences and deputy director of the Ecological Economics and Environment Research Office, also reminded that water-saving agriculture needs to be applied more to grain production, thereby ensuring the country's food security.
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Since the founding of New China, China's farmland water conservancy undertakings have developed rapidly:
In the 1950s to 1960s, irrigation projects damaged by war were actively repaired, and the masses were vigorously mobilized to build a large number of ponds and small water diversion projects. After the late 1950s, a large number of medium- and large-sized reservoirs and irrigation districts were built. Most of China's medium- and large-sized reservoirs and large irrigation districts began construction during this period and gradually brought benefits into play afterwards.
In the 1970s to 1980s, affected by the "Cultural Revolution," water conservancy construction once came to a standstill. After 1991, China increased investment in agriculture and water conservancy, farmland irrigation projects were restored, the structure was adjusted, and management was reformed to some extent.
Modern agriculture cannot rely on the weather for its food.
Amid multiple tests such as drought and changes in the water environment, the shortcomings and weaknesses of farmland water conservancy in some places were exposed in a concentrated way, while the "water-saving irrigation" vigorously promoted on some farmland in Henan and Liaoning provinces stood out for its advantages. Whether in Changge in central Henan or Zhangwu in western Liaoning, reporters conducting field research exclaimed: "The crops on these farmlands show no shadow of drought."
Admittedly, water-saving irrigation requires large upfront investment, but compared with the marked drop in motor-pumped well water levels after only one or two rounds of extensive irrigation, water-saving irrigation lasts a long time. Having calculated the costs, the farmers with the most say "came one after another to the town to consult and ask the government to provide technical guidance."
In the final analysis, drought relief must mobilize farmers' enthusiasm. In addition to increasing investment, allocating water sources and promoting new policies, what the government especially must not overlook is forging "true skills" that can genuinely mobilize awareness of water saving and drought relief. And only "true skills" can pry open the hand gripping the throat of stable grain production and increased output, achieving little disaster in drought and harvest in sight.