Drought, high temperature, rainstorm, floods, extreme weather is threatening global wheat

For wheat with a global seeding area of ​​more than 3 billion acres, 2022 is an unusual year. From March, the world's second -largest wheat producer India has soared to a hundred years since it has never been there. In the key growing wheat, a heat wave was attacked. By April, high temperatures invaded European wheat in Europe, France, Britain and other European wheat. The Americas have not escaped high temperatures. Two major wheat produced in Kansas and Oklahoma suffered severe spring drought. Local experts expect that wheat production will reduce the production rate of 7%-8%.

Studies have shown that every time the global temperature rises a degree of Celsius, wheat production is reduced by about 6%. "Food is facing a variety of factors, and climate change is one of them." At the "Second International Wheat Conference" held recently, Senthold Asseng, a professor at the University of Munich University of Technology, said in his speech.

Professor Senthold Asseng, a professor at Munich University of Munich. Chinese Academy of Agricultural Sciences

The abnormal summer difficult wheat

In August 2022, the Ministry of Agriculture of the Indian Ministry of Agriculture issued the estimated report of wheat output. The report shows that in 2022, India harvested 1068.4 million tons of wheat, higher than the previously estimated 106.4 million tons, but below the estimated 111 million tons in February.

High temperature and drought obviously affected the output of Indian wheat, and then pushed up the price of wheat. Since April, the inflation rate of wheat consumption has remained above 9%, soaring in July to 11.7%. At the same time, wheat wholesale prices in July rose 13.6%.

The impact of high temperature and drought is far more than India. According to the "World Agricultural Production Report" issued by the US Department of Agriculture, the EU 2022/2023 wheat output is estimated to be 132.1 million tons, a decrease of 1%month -on -month, a year -on -year decrease of 4%, below five years, less than five years. Average.

Data from the US Department of Agriculture also show that US wheat is expected to reduce production by 8%. Among them, Winter wheat productions decreased by 4.6%compared to last year. Spring wheat was affected by drought and sowing area decreased significantly, only about half of the reservation area.

At the same time as high temperature attacks, in other places, in the threat of lenients and waterlogging, in the United States, Blizzard came in April, and then after the melting of ice and snow caused floods. Until late May, the end of the spring wheat sowing. The sowing area of ​​American spring wheat accounts for only 49%of the planned sowing area. At the same time, at the same time, the area of ​​spring wheat sowing was only 27%of the expected.

In 2021, the autumn flood in northern China caused 110 million acres of winter wheat to broadcast late. The warm spring in 2022 reduced the impact of late broadcasting, but in southern China, the winter wheat districts in the middle and upper reaches of the Yangtze River, such as some places in Hubei and Jiangsu, continuous rainfall soaked a large amount of wheat fields in 5 cm deep water.

In the world, one -third of people are mainly wheat, but the severe climate change is making the uncertainty of wheat production stronger. "Climate change is affecting 10%of the world's population," SENTHOLD Asseng said.

Large mature wheat fields. Data Map/Beijing News reporter Wang Wei

Under the influence of high temperature, is the wheat reduced production?

How to judge the impact of extreme climate on wheat production is becoming an increasingly important issue in scientists in the global wheat field.

SENTHOLD Asseng introduced that they used a new model to simulate the changes in wheat production. "Experiments have found that changes in temperature have a great impact on the maturity of wheat. We simulate the data of 30 different locations around the world and 30 years. As a result, the result It shows that every time the global temperature increases, wheat output will be reduced by about 6%. This data is not constant. In tropical and subtropical, the temperature changes have greater impact, and the uncertainty is smaller. "

Global climate change, the most significant feature is the global warming brought by the greenhouse effect. Zhao Chuang, a professor at the School of Resources and Environment of China Agricultural University, said, "The historical data of the integration of long -term observations shows that compared with the industrial revolution, the average global temperature has increased by the world's average temperature rising. 1.2 Celsius. The temperature rise is mainly caused by the greenhouse gases discharged from human activities to the atmosphere. "

The rise of temperature has produced a chain effect in the ecosystem. Taking global wheat as an example, regardless of other factors, the temperature can cause about 6%to reduce yields for every 1 degree Celsius, but at the same time, other factors are also affecting the output of wheat, including human measures. In China, after the flood in the autumn of 2021, the huge and perfect agricultural technology promotion and plant protection system followed. At the same time, the national agricultural scientific researchers went deep into the field to guide the disaster reduction technology on the spot. , Ensure the production of wheat.

According to the forecast of the Food and Agriculture Organization of the United Nations, in 2022, the global wheat production reduction was 1%. "From a specific level, the heating worldwide does not necessarily cause production all places to reduce production," said Zhao Chuang. "For example, in the south and north of China, the influence of heating is different. Effects, in the southern part of North China with sufficient water and relatively low temperature, such as Anhui, Jiangsu and other places, the heating up brings a production increase effect. "

The harvester galloped in the wheat field. Data Map/Beijing News reporter Wang Wei

Not only high temperature and drought, but also flood disasters

High temperatures are often accompanied by drought, which makes response measures more complicated and difficult. But extreme weather is not only high temperature and drought, but also heavy rain and waterlogging. In Australia, Dr. Liu Ke at the University of Tasmania conducted an experiment on the impact of waterlogging on wheat output. The same experiment was also conducting in the middle and lower reaches of the Yangtze River in China.

In the spring of 2022, Australia suffered a rare rainstorm. In March, heavy rain and strong winds attacked many regions such as Queensland and New South Wales in the east. Local wheat and rapeseed were seriously damaged.

In July 2022, Pakistan suffered a rare rainstorm and flood attack. By September, one -third of Pakistan was affected by floods.

"In the influence of extreme climate on agricultural production, the attention of drought and high temperature is far greater than the disasters of waterlogging," Liu Ke said. "In fact, the stain disaster is equally common in the world, and the randomness is more complicated. "

Waterlogging disasters may occur in any agricultural area around the world. Whether it is Europe or the Americas, or China, it is a common agricultural disaster. The critical period, "Liu Ke said.

A study by the International Climate Scientist Group shows that in the future, as global temperatures continue to rise, similar heavy rainfall may become more.

In the Yangtze River Basin in my country, it also encountered continuous heavy rainfall in March and April this year. The rare continuous rainstorm fell in the rice wheel wheel area. Due to the end of the field soil plate, the underwater underwater was too slow, which caused local wheat and rapeseed to soak in the water for a long time in the water. Essence

"In the world, the losses caused by flood disasters to wheat each year are far greater than expected," Liu Ke said. "From the data of the field test, the conventional waterlogging disaster may be given without taking remedial measures. More than 30 % of the wheat output causes more than 30 % of the losses. This does not include some devastating flood disasters. "

To protect the wheat, we are protecting the ecology at all

Scientists are considering developing more technologies in response to the impact of extreme climate on wheat.

Among them, the cultivation of drought -resistant wheat is undoubtedly one of the most important ways. China is a large country of wheat breeding. The wheat varieties are 100%autonomous, and they have become a variety of drought -resistant wheat varieties. For example, the Zhongmai 895 raised by the Chinese Academy of Agricultural Sciences has excellent grouting rate and heat resistance. Essence Sun Qixin, a professor at the Agricultural University of China, presided over the "wheat heat -resistant gene excavation and gear innovation technology and breeding utilization" project, and won the second prize of the National Technology Invention in 2021.

The Zhongmai 895 raised by the Chinese Academy of Agricultural Sciences has excellent grouting rate and heat resistance. Chinese Academy of Agricultural Sciences

With the development of molecular genome, research on the heat -resistant and drought -resistant genes of wheat has also been made in breakthroughs. According to data from the Chinese Academy of Agricultural Sciences, scientists of the institute have screened more than 110 wheat quality resources with outstanding drought resistance and heat resistance. Essence In addition, in July 2022, the Institute of Wheat Anti -Adjustle Breeding Innovation Research Group of the Institute of Crop Science of the Chinese Academy of Agricultural Sciences found a negative regulatory mechanism that helped wheat balance drought coercion response and normal plant growth and development.

In terms of response to stain disasters, Liu Ke told reporters that he has now positioned the relevant genes of wheat, and found in the experiment that the production loss of the control group can be reduced by 17%-25%under the condition of continuous extreme waterlogging. This is of great significance for future breeding related resistance.

More methods are developed by scientists, such as vertical agriculture produced in factory. SENTHOLD Asseng introduced at the International Wheat Conference that they found through experiments that factory production in facilities may be one of the ways to respond to the food crisis in the future. "We have calculated the production potential of vertical agriculture. In ordinary farmland, 1 hectares of land can be produced by three to four tons of wheat per year, while moving to indoor production, the output can reach 5 times. Agriculture, if in a building, plant 100 floors, theoretically output can reach 6,000 times. Of course, such limit production is extremely high and does not have the value of promotion. But it is undeniable that when you really encounter the food crisis, At the time, the cost is secondary. "

However, compared with the passive adaptation of environmental changes, the sustainable development of the ecological environment is the fundamental way to solve the extreme climate crisis. In 2015, the Paris Agreement stipulated that the global average heating up the world was higher than the higher level before the industrial revolution. Within 2 degrees Celsius, it is limited to 1.5 degrees Celsius. In 2021, the G20 summit reached an agreement again, promising to take "meaningful and effective" measures to achieve the goal of limiting global warming to 1.5 degrees Celsius.

"In the future, if we take extremely strict measures, this goal is possible," Zhao Chuang said. "On the one hand, we must consider how to cope with the impact of climate change on wheat and agricultural production. On the other hand Taking ecological development as the basic principle, truly protect our place of survival. "

Source: Beijing News

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