Dry farming to solve the "water trap" only accounts for the effective irrigation area in the country.

At present, the drought in Huang-Huai region of China has been effectively alleviated, but the drought in Northeast China is still continuing. In recent years, dealing with large-scale and long-term drought has become the norm in the development of grain production. Summer drought in Northeast China in 2007, continuous winter and spring drought in North China and summer drought in Northeast China in 2009, continuous drought in North China and severe spring drought in the middle and lower reaches of the Yangtze River in 2011. The author believes that in addition to strengthening the construction of controlled water source projects and drought emergency water source projects, the development of dry farming agricultural technology is a key to agricultural drought resistance in the future.

At present, the effective irrigation area of farmland in the country accounts for only 51.5%, and nearly half of the cultivated land is "Wangtian", which is lack of basic irrigation conditions. To deal with the severe drought, we should pay close attention to the basic construction of irrigation and water conservancy, make up for the debts of irrigation and water conservancy, speed up the construction of irrigation areas, build a number of good irrigation areas with good irrigation conditions, and create an effective drought-resistant engineering system. at the same time, we should also develop dry farming and rain-fed agriculture, pay attention to the promotion of advanced and applicable dry farming techniques, and strive to improve the utilization efficiency of natural precipitation.

Why should we vigorously develop dry farming? Technically, dry farming includes dry cultivation techniques such as efficient use of natural precipitation, promoting soil moisture conservation and increasing soil moisture, new drought-resistant and drought-resistant varieties of crops, new agricultural drought-resistant machines and new materials, and so on. Conceptually, dry farming conforms to the laws of weather and crop growth, not blindly increasing irrigation, but striving to synchronize precipitation with crop water demand, make good use of Rain Water, pay attention to water saving, and realize the transformation from antagonistic agriculture to adaptive agriculture. from passive drought resistance to active disaster avoidance.

In an interview in the arid area this summer, the author found that the land of Sun Gongli, a villager in Xiang Liu Village, Pucheng County, Shaanxi Province, had not been watered, and the corn was almost completely harvested. However, in the water-saving demonstration area of Qiaoling Town not far away, corn is growing well. This is because the corn in the demonstration area uses drip irrigation under plastic film, which can save water by 2/3. Even if it is so dry this year, the limited water source can still be used to meet the growth demand through drip irrigation. It can be seen that at the same time of drilling more drought-resistant wells in the short term and improving irrigation capacity in the long term, it is necessary to reduce crop water demand in terms of variety structure and water-saving technology.

Many arid areas in China are typical dry farming areas, most of which have been dry for ten years, and the cost of irrigation is relatively high in these areas. The comparative benefits of grain cultivation are limited, 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 promote the application of drought resistance technologies such as drip irrigation under plastic film, integration of water and fertilizer, deep ploughing and deep loosening is the key.

It is necessary to speed up the development of dry farming. With the acceleration of industrialization and urbanization, the contradiction of water use between workers and farmers and between urban and rural areas is increasing, and the pressure of agricultural water resources is increasing. On the other hand, in the dry farming area, there is little rain, uneven temporal and spatial distribution, large area of sloping farmland, serious soil erosion, fragile ecological environment and weak infrastructure. In recent years, large-scale droughts occur frequently in China, and the scope and degree of occurrence are increasing. It is estimated that in dry farming rain-fed agricultural areas, if the utilization rate of natural precipitation is increased by 10 percentage points, 40 billion cubic meters of natural precipitation can be used more. Practice has proved that the problem of mismatch of light, temperature and water can be solved and the comprehensive production capacity of agriculture can be improved by popularizing high-efficiency dry farming technology.

It is economically feasible to speed up the development of dry farming. For a long time, dry farming has been defined as inefficient agriculture. According to the estimation of the Ministry of Finance, an average increase of 1 jin of grain production capacity in irrigated areas requires an investment of 4 to 6 yuan, and to popularize dry farming techniques such as full-film double-ridge and furrow sowing in arid areas, an average increase of 1 jin of grain production capacity requires only 2 yuan. Through the popularization and application of comprehensive dry farming and water-saving agricultural technology, the development of regional superior crops such as potato, plastic film corn, sunflower and traditional Chinese medicine according to local conditions can form a number of agricultural product industrial belts with strong competitive advantages.

Since 2010, the central government has allocated special funds to support the demonstration and popularization of dry farming techniques in Northwest and North China. China's dry farming areas comply with the weather and the law of crop growth, adjust the planting structure, and strive to alleviate the impact of drought on agricultural production. Northern corn is mainly distributed in areas with rainfall above 450mm and below 1800 meters above sea level. Through the promotion of plastic film mulching technology, the planting scope of corn has been expanded to areas with rainfall of more than 300mm and elevation below 2350 meters. Gangu County, Gansu Province is a major dry farming county, the annual rainfall is only 400 mm, wheat yield has been low. In recent years, the whole film mulching soil is used to sow wheat in the county, and the application of plastic film is increased from single stubble to 3 stubble, and the yield per mu can reach 680 jin.

The proportion of dry land area in China is quite large, in a sense, the gap in grain production is in the arid area, and the potential to increase production is also in the arid area. Under the background of frequent drought, dry farming technology with improving precipitation use and water use efficiency as the core is the key to food production in the future.