Dryland farming breaks the water dilemma; nationally, the share of effectively irrigated area is limited

Right now, the drought in China's Huang-Huai region has been effectively alleviated, but the drought in the Northeast region is still ongoing. In recent years, responding to large-scale, prolonged droughts has become the norm in grain production development. In 2007, the Northeast region suffered a summer-to-dog-days drought; in 2009, the northern winter wheat region suffered a winter-spring continuous drought and the Northeast region suffered a summer-to-dog-days drought; in 2011, the northern winter wheat region suffered a continuous drought and the middle and lower reaches of the Yangtze River suffered a severe spring drought…… The author believes that, in addition to strengthening the construction of controlling water source projects and emergency drought-relief water source projects, developing dryland farming technology is a major key to agricultural drought resistance in the future.

At present, the country's effective irrigated farmland area accounts for only 51.5%, and nearly half of the cultivated land is still “rain-fed land” lacking basic irrigation conditions. To cope with severe droughts, it is necessary to grasp the basic construction of farmland water conservancy, make up the arrears in farmland water conservancy, accelerate the continuation and supporting construction of irrigation districts, build a batch of good farmland in irrigation districts with good irrigation conditions, and create an effective drought-relief engineering system. At the same time, it is also necessary to develop dryland farming and rain-fed agriculture, pay attention to the promotion of advanced and applicable dryland farming technology, and focus on improving the use efficiency of natural precipitation.

Why vigorously develop dryland farming? Technically, dryland farming includes dryland cultivation and tillage techniques such as efficient use of natural precipitation and promoting soil moisture conservation and moisture increase, as well as excellent new drought-resistant and drought-tolerant crop varieties and new agricultural drought-relief machinery and new materials. Conceptually, dryland farming follows the timing of heaven and the laws of crop growth. It does not simply increase the amount of irrigation, but strives to synchronize precipitation with the crop water demand period, make good use of rainwater, and pay attention to water conservation, realizing the transformation from confrontational agriculture to adaptive agriculture and from passive drought resistance to proactive disaster avoidance.

⟦NL> In interviews in the drought-stricken areas this summer, the author found that the land of Sun Gongli, a villager in Xiangliu Village, Pucheng County, Shaanxi, did not get watered, and the corn was almost completely lost. But not far away in the Qiaoling Town water-saving demonstration area, the corn was growing well. This is because the corn in the demonstration area used under-film drip irrigation technology, which can save two-thirds of the water. Even with this year's drought, drip irrigation could still use limited water sources to meet growth needs. It can be seen that while drilling more drought-relief wells in the short term and improving irrigation capacity in the long term, it is also necessary to reduce crops' water demand through variety structure and water-saving technology.

⟦NL> Many arid areas in China are typical dryland farming areas, most of which suffer drought nine years out of ten. In these places, the cost of irrigation is relatively high. Grain planting itself has limited comparative returns, so farmers will naturally compare the costs and benefits of irrigation facilities and water use, and local governments will also comprehensively consider economic, ecological, and social benefits. Therefore, vigorously promoting the application of drought-relief technologies such as under-film drip irrigation, integrated water and fertilizer, and deep plowing and deep loosening is key.

⟦NL> Accelerating the development of dryland farming has practical necessity. With the acceleration of industrialization and urbanization, the contradiction in water use between industry and agriculture and between urban and rural areas has increased, and the pressure on agricultural water resources has increased. Dryland farming areas have little rain and drought, uneven spatial and temporal distribution, large sloping farmland areas, severe soil erosion, fragile ecological environments, and weak infrastructure. In recent years, large-scale droughts have occurred frequently in China, and the scope and degree of occurrence have shown an increasing trend. According to estimates, in dryland rain-fed agricultural areas, if the utilization rate of natural precipitation is increased by 10 percentage points, an additional 40 billion cubic meters of natural precipitation can be used. Practice has proved that by promoting efficient dryland farming technology, the problem of mismatched light, temperature, and water can be solved, and the comprehensive agricultural production capacity can be improved.

⟦NL> Accelerating the development of dryland farming has economic feasibility. For a long time, dryland farming has been defined as low-efficiency agriculture. But according to estimates by the Ministry of Finance, in irrigation districts, an average investment of 4 to 6 yuan is needed to increase grain production capacity by 1 jin, while in dry areas, promoting dryland farming technologies such as full-film double-ridge furrow sowing requires an average investment of only 2 yuan to increase grain production capacity by 1 jin. Through the comprehensive promotion and application of dryland water-saving agricultural technology and the development of regionally advantageous crops such as potatoes, plastic-film corn, sunflower, and Chinese medicinal materials according to local conditions, a number of agricultural product industrial belts with strong competitive advantages can be formed.

⟦NL> Starting in 2010, the central finance arranged special funds to support the demonstration and promotion of dryland farming technology in Northwest and North China. China's dryland farming areas follow the timing of heaven and the laws of crop growth, adjust the planting structure, and focus on alleviating the impact of drought on agricultural production. Corn in the north is mainly distributed in areas with rainfall above 450 mm and altitude below 1,800 m. By promoting plastic-film mulching technology, the corn planting range has expanded to areas with rainfall above 300 mm and altitude below 2,350 m. Gangu County in Gansu Province is a major dryland farming county, with annual rainfall of only 400 mm, and wheat yields have always been relatively low. In recent years, the county has adopted full-film soil-covered hole-sowing wheat, and plastic-film use has increased from a single crop to 3 crops, with a per-mu yield reaching 680 jin.

⟦NL> China's dryland area accounts for a considerable proportion. In a certain sense, the gap in grain production lies in dry areas, and the potential for increasing production also lies in dry areas. Against the background of frequent droughts, dryland farming technology, with improving precipitation use and water use efficiency at its core, is the key to future grain production.