How can dryland farming solve the water shortage problem?
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, coping with large-scale, prolonged droughts has become the norm in grain production development. The 2007 summer-to-dog-days drought in the Northeast region, the 2009 winter-spring consecutive drought in the northern winter wheat region and the summer-to-dog-days drought in the Northeast region, the 2011 consecutive drought in the northern winter wheat region and the severe spring drought in the middle and lower reaches of the Yangtze River…… The author believes that, beyond strengthening the construction of controllable water source projects and emergency drought-relief water source projects, developing dryland farming techniques is a major key to agricultural drought resistance in the future.
At present, effectively irrigated farmland nationwide 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, we must not only step up the construction of farmland water conservancy infrastructure, make up the shortfall in farmland water conservancy, accelerate the continued construction and supporting facilities of irrigation districts, build a batch of high-quality farmland in irrigation districts with good irrigation conditions, and create an effective drought-relief engineering system, but also develop dryland farming and rain-fed agriculture, pay attention to the promotion of advanced and applicable dryland farming techniques, and focus on improving the efficiency of natural precipitation use.
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 enhancement, as well as excellent new drought-resistant and drought-tolerant crop varieties and new machinery and new materials for agricultural drought resistance. In terms of philosophy, dryland farming follows the timing of nature 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, makes good use of rainwater, and focuses on water conservation, achieving a transition from confrontational agriculture to adaptive agriculture and from passive drought resistance to proactive disaster avoidance.
⟦NL> During interviews in this summer's drought-stricken areas, 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 a total crop failure. But in the nearby Qiaoling Town water-saving demonstration area, the corn grew well. This is because the corn in the demonstration area used drip irrigation under plastic film, which can save two-thirds of 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, we must also reduce crops' water demand through variety structure and water-saving techniques.
Many arid regions in China are typical dryland farming areas, most of which suffer drought nine years out of ten, and in these places the cost of irrigation is relatively high. Grain cultivation itself has relatively limited 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 advancing the application of drought-resistance techniques such as drip irrigation under plastic film, integrated water and fertilizer management, and deep plowing and deep loosening is key.
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 intensified, and the pressure on agricultural water resources has increased. Meanwhile, dryland farming areas have little rain and frequent drought, uneven temporal and spatial distribution, large areas of sloping farmland, severe soil erosion, fragile ecological environments, and weak infrastructure. In recent years, large-scale droughts have occurred frequently in China, and their scope and severity have shown an increasing trend. According to estimates, in dryland rain-fed agricultural areas, if the utilization rate of natural precipitation is raised by 10 percentage points, an additional 40 billion cubic meters of natural precipitation can be used. Practice has proven that by promoting efficient dryland farming techniques, the problem of mismatched light, temperature and water can be solved, and the comprehensive agricultural production capacity can be improved.
Accelerating the development of dryland farming has economic feasibility. For a long time, dryland farming was defined as low-efficiency agriculture. But according to estimates by the Ministry of Finance, in irrigation districts, every additional 1 jin of grain production capacity on average requires an investment of 4 to 6 yuan, while in dryland areas, promoting dryland farming techniques such as full-film double-ridge furrow sowing requires an average investment of only 2 yuan for every additional 1 jin of grain production capacity. Through the comprehensive promotion and application of dryland water-saving agricultural techniques and the development of regionally advantageous crops such as potatoes, plastic-film corn, sunflowers [-1.20% funds research report], and Chinese medicinal herbs according to local conditions, a number of agricultural product [-1.72% funds research report] industrial belts with strong competitive advantages can be formed.
Starting in 2010, the central government arranged special funds to support the demonstration and promotion of dryland farming techniques in the Northwest and North China regions. China's dryland farming areas follow the timing of nature 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 techniques, 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 long been relatively low. In recent years, the county has adopted full-film soil-covered hole sowing of wheat, and plastic-film use has increased from a single crop to 3 crops, with per-mu yield reaching 680 jin.
China's dryland area accounts for a considerable proportion. In a sense, the gap in grain production lies in dryland areas, and the potential for increasing production also lies in dryland areas. Against the background of frequent droughts, dryland farming techniques centered on improving precipitation use and water use efficiency are the key to future grain production.