Dryland agriculture: from passive drought relief to active drought avoidance

In the cold winter months, farmers in Changcun, Shouyang County, Jinzhong City, Shanxi Province, are still busy pruning fruit branches. In the past, corn was grown mainly here, and winter was a leisure time for farmers.
, a villager in Changcun, said that today, more than 4,600 acres of dry land are planted with yulu pears. In 2019, Yulu pear sales revenue of 7 million yuan, this alone, let the village per capita income of more than 10,000 yuan.
selection of suitable crops for dryland agriculture is one of the results of the dry farming innovation team of the Chinese Academy of Agricultural Sciences (hereinafter referred to as the Chinese Academy of Agricultural Sciences).
recently held a report on the innovation and development of dryland agriculture, Mei Xurong, a researcher at the Chinese Academy of Agricultural Sciences and chief scientist of dryland agriculture, said that dryland agriculture is an important mode of production of agriculture in China. With China's demonstration and popularization of water-saving agriculture technology in drylands in arid and water-scarce areas such as Northwest, North china and Northeast China, dryland agriculture has gradually moved from passive drought resistance to active drought avoidance.China's northern dryland agricultural areas produced 58% of the country's grain (including irrigation) and more than 75% of the cattle and mutton, but also covered more than 70% of the ecologically fragile areas, strengthening scientific and technological innovation to promote dryland agricultural development to ensure the country's food security, ecological security is of great significance.
agriculture, which relies entirely on natural precipitation for production, is called dry farming, and its opposite concept is irrigated agriculture. Therefore, dry farming includes agricultural production that is not watered at all. Among them, in arid and semi-arid areas where precipitation is not enough, it is called dryland agriculture, that is, dry farming on arid, semi-arid arable land. Mei Xurong explains.
China is one of the countries in the world with severe drought and water shortage, dryland agriculture is mainly distributed in Qinling, Huaihe and Kunlun Mountain north of the vast northern region, involving 16 provinces (autonomous regions, municipalities directly under the Central Government), the land area and arable land area are more than half of the country, of which more than 65% of the cultivated land without irrigation conditions.
if a planting system can adapt to drought changes and match the corresponding drought-resistant water cultivation techniques, it can ensure that crops are not affected by changes in the weather and reduce production. Mei Xurong told China Science Daily that this is a difficult problem for dryland crops to achieve water-appropriate cultivation.
" to do a good job in dryland agriculture, first of all to understand it, to find out the law. Mei Xurong said, "What we are doing is to identify the use of natural precipitation in the drylands of the north, and to find out the extent to which the production potential of major crops can be exploited."
Yan Daozhi, a researcher at the Institute of Agricultural Environment and Sustainable Development of the Chinese Academy of Agricultural Sciences, said that the team has long been rooted in Shouyang dry agricultural test station in the eastern part of the Loess Plateau, and has been positioning observations to study the process of precipitation conversion dynamics and efficient control of farmland in the northern drylands.
Since 2001, the team has carried out a multi-point long-term positioning test of dryland agriculture in the north, figured out the drought occurrence law and water-appropriate planting priority of the main dryland crops, expounded the efficient conversion mechanism of carbon-nitrogen in drylands, and solved the scientific difficulties of soil carbon expansion, surface cover and steam suppression, water fertilizer synergy and other regulatory methods.Sun Dongbao, an associate researcher at the backbone of the
team, told China Science daily that the study found that the main crops in drylands in the north expanded from one to two latitudes to the west, and that crop precipitation satisfaction rate decreased by more than 5 percentage points due to the combination of crop cultivation, fertility change and precipitation reduction, and frequent drought re-development. Techniques such as dryland surface cover, straw return to field and deep pine tillage are closely related to precipitation, and the optimal precipitation range of the lift effect is 450 to 550 mm of annual precipitation in dry farming areas.
basis, they defined the priority of water-friendly planting of crops such as corn, wheat, grain, peanuts, soybeans and potatoes in different dryland types, and provided a scientific basis for the scientific layout of planting structure and matching appropriate water-saving cultivation techniques.villagers in Changcun have a water-appropriate crop of dryland agriculture, yulu pears, and have lived a well-off life ever since.
selection of drought-resistant crops is undoubtedly one of the basic work of agricultural technology innovation in drylands, Mei Xurong introduced, the Chinese Academy of Agricultural Sciences alone, selected more than 70 drought-resistant and abundant crop varieties.
addition to varieties, field management techniques are equally important. In view of the common problems of dryland agriculture in the north, the research and development team has innovated the key technologies such as rain-collecting cover drought relief, straw water return to the field, water-appropriate inter-working, etc., and developed products and equipment such as seed coating agent, soil structure conditioning agent and all-biodegradable film, intelligent irrigation fertilization system, and trench planting planter. These technologies have been applied in different typical dryland agricultural regions.
different from traditional planting methods, Guo Sanping, a farmer in Zhanghan village in Jingshan Township, Shouyang County, uses a variety of dryland agricultural techniques to grow corn. For example, wide mules, which are a water-tight planting technique, can cover 4 rows using a 1.6-meter-wide film, while ordinary film usually covers only 2 rows. The wide coating uses a degradation film, which is basically degraded at harvest time. Wide mules also help to increase planting density, each acre can be a variety of about 1000 plants, the yield increased by 100 to 200 kg.
model is one of the typical models created by the team. Different models have different dryland agricultural technology systems, adapted to different environments of dryland cultivation. Sun Dongbao introduced that China has developed five typical models of dryland agricultural regional development.
With Shanxi Shouyang model as the representative, aiming at the problems of single planting structure, seeding separation and low production efficiency in the hilly areas of North China, this paper puts forward the technical model of water-suitable water for dry farmland and deep fertilization of field, solves the problem of straw degradation and corn seedling growth and competition for water fertilizer, and can increase corn yield by 10% to 25%.
With the new model of Liaoning Province as the representative, in view of the lack of heat, water scarcity and degradation of cultivated land quality in the semi-arid areas of northeast Wind and Sand, a three-dimensional control technology system of above-ground-surface-underground has been constructed, which can improve the efficiency of water utilization of farmland by 14% to 19%, and effectively resist the occurrence of drought.
With Hebei Hengshui model as the representative, in view of the shortage of water resources and serious over-extraction of groundwater in North China, the supplementary irrigation of the critical period of water demand is carried out under the premise of efficient use of natural precipitation in the fields by dryland agricultural technology, and the three-water irrigation of the normal production of winter wheat is reduced to two-water irrigation, so as to maximize the wheat moisture productivity.
With the original model of Gansu town as the representative, the innovative water-saving planting technology, which covers water-saving planting in the semi-arid area of northwest China, can increase corn yield by 20% to 30% and winter wheat by 40%.
With the Wuchuan model of Inner Mongolia as the representative, in view of the shortage of drought and less rainwater resources in the dry areas of Inner Mongolia, the serious sand erosion of farmland, poor soil water retention and other outstanding problems, the formation of a semi-arid and dry areas of biological fence flexible wind protection, belt-shaped interminable and field micro-rainfall and other three technical systems, improve precipitation utilization rate of more than 8 percentage points, reduce soil erosion of more than 30%. The 13th Five-Year Plan period, with the development of agricultural science and technology in drylands, the coverage rate of drought-resistant water-saving wheat varieties in northern China increased to more than 40%, the precipitation utilization coefficient of dryland test demonstration fields increased to more than 0.70, and the water consumption of tons of grain fell from 844 cubic meters to 813 cubic meters.
Stressed that dryland agriculture does not have irrigation water sources and that improving the utilization rate of natural precipitation as much as possible is one of the key technologies.
2000, the utilization rate of natural precipitation in dryland agriculture in northern China was 56%. This figure will rise to 65% by 2020, equivalent to saving nearly 50 billion cubic meters of water. In typical demonstration areas of dryland agricultural technologies, this figure can even reach more than 70 per cent, far higher than the global average utilization rate of 50 per cent.
With Wang Hao and Kang Shaozhong as the group members of the Chinese Academy of Engineering, the evaluation team organized by the Chinese Agricultural Society concluded that the team's results systematically expounded the mechanism and approach of collaborative control of soil, surface and canopy in drylands;
future, dryland agriculture also urgently needs to carry out scientific research from the direction of deep water conservation and extreme water conservation. Mei Xurong, for example, said that the average water consumption of wheat in China is 900 to 1000 cubic meters, but the extreme water saving situation can be reduced to tons of grain water consumption 400 to 500 cubic meters.
, there is room for production potential to be tapped. Mei Xurong pointed out that at present, China's drought-resistant crops are 45% of the yield potential development, and feasible reasonable development is 65%, which still has a gap of 20 percentage points, each increase of one percentage point, it requires researchers to make great efforts.
" overall, our emphasis on dryland agriculture still needs to be strengthened. Mei Xurong said that while increasing yield and stabilizing total production capacity in the advantage areas of grain production, it is necessary to make room for the development of biodiversity in dry farming areas and protect the ecological environment of dry farming areas, which is a technical and regional problem that needs to be focused on in the whole dryland agriculture in the future.