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As climate change continues, the increasingly humid climate in Northwest China brings both pros and cons to local agricultural production

By Huo Siyi Updated Jan.1

Crops are destroyed by a hailstorm, Xinjiang Uygur Autonomous Region, July 1, 2004 (Photo by IC)

Farm workers harvest maize, Mingyong Town, Zhangye, Gansu Province, September 14, 2021 (Photo by VCG)

Du Minchao owns an apple orchard of some 18,000 trees. A thin netting system hangs above all of them. Du said he installed it in June to protect his trees from the increasingly common hailstorms battering Aksu Prefecture, Xinjiang Uygur Autonomous Region. “Even a mild hailstorm could destroy my entire harvest and cause losses of up to 8,000 yuan (US$1,095) per mu for me,” Du explained. His orchard covers 600 mu (40 hectares).  

With its rich farmland and abundant sunlight, Northwest China is a major producer of cotton and fruit. Varieties such as the Aksu apple, Korla pear and Hami melon are widely sold in China and grown for export.  

But increasingly warmer and wetter weather in Northwest China has profoundly impacted agriculture production since the 1980s. While crop and fruit planting has expanded northward into historically arid areas, with extended growing seasons and improved yield and quality, extreme weather poses more and challenges to agriculture.  

Growing Expansion 
According to statistics from the China Apple Industry Association, Xinjiang has 72,000 hectares of apple orchards producing a total of 1.253 million tons. Aksu alone has 31,866 hectares of apple orchards.  

Thanks to Aksu’s abundant sunlight and significant temperature fluctuations, which is conducive to the accumulation of sugar in apples, Aksu apples are sweeter than other varieties. 
Apple growing in Aksu began to expand rapidly in the early 2000s. Du Minchao, chairman for Fengqing Garden Fruit Farmers Cooperative in Aksu, moved from Henan Province to Xinjiang in 2000 to grow apples on Hongqipo Farm. Du said Aksu only had 14,133 hectares of apple orchards in 2014. Within four years, that area doubled.  

Ji Chunrong, a senior engineer at Xinjiang Agricultural Meteorological Observatory, told NewsChina that Hongqipo was originally barren land. But with the development of human-induced oasis expansion, afforestation projects have improved the microclimate. Coupled with climate change and improved regional hydrothermal conditions, the area became ideal for apple cultivation.  

As Northwest China turns warmer and wetter, planting areas of fruits such as apples, grapes and fragrant pears in Xinjiang have changed in unique ways. According to a study the Observatory conducted in 2018, areas in northern Xinjiang suited for apple growing have expanded northward slightly since 2017, but decreased in southern Xinjiang over the same period as average summer temperatures rise.  

Cotton planting has also expanded. Ji Chunrong said in major cotton farming areas in northern Xinjiang, the average elevation has risen to about 560 meters, while planting has increased overall. In the 1960s, cotton only accounted for 7.8 percent of the total cultivated land in northern Xinjiang, increasing to 14.9 percent in the 1990s. By the 2020s, the proportion reached 21 percent. As global climate change continues, areas suited for cotton will expand to higher latitudes and altitudes, Ji said.  

Ji cautioned that planting areas should not be adjusted only according to climate, but also consider factors such as regional water resources, soil conditions and cultivation technologies. “Water resources are one of the most important constraints. In some areas, cultivation and management methods are not mature, so whenever extreme weather events occur, the impact on agriculture is devastating,” Ji said.  

As cotton cultivation in Xinjiang expanded in the 1990s, some ignored the suitability of climate conditions, resulting in a low and unstable yield and quality decline, which further affected overall production and local economies.  

Extreme Weather 
On May 28, a severe hailstorm struck parts of Aksu including Shaya, Kuqa and Wushi counties, the golf ball-sized ice devastating over 6,667 hectares of cotton. “The hailstones crushed all the flowers and leaves, leaving nothing,” said Dai Lu, station master at Aksu agricultural technology center.  

The hailstorm season in Northwest China has been getting longer. Luo Ji, deputy director of the Aksu regional meteorological bureau, said storms typically began in April to early May and lasted until late summer. But now, they start as early as March and continue into mid-October.  

Experts say hotter and more humid weather is to blame. Luo Ji explained that increasing ground temperatures from solar radiation heat the atmosphere like “boiling water in a pot,” causing the intense updrafts that force raindrops into extremely cold areas of the atmosphere, where they freeze.  

Luo Ji said the number and intensity of hailstorms in Aksu has increased in recent years, concentrating in the spring and autumn.  

Between 2009 to 2020, there were up to 17.6 hailstorms annually. In 2019, hailstorm events reached historical highs for spring, summer and autumn. Seven occurred during autumn, a season that historically rarely saw hail.  

The longer the hail period and the later the hail falls, the greater the impact on cotton production. In April, as cotton sprouts, damage caused by hailstorms can be mitigated with replanting. But if a hailstorm strikes in September when the cotton blooms, the destruction can be devastating.  

Compared to concentrated hailstorms, the volatility and instability of temperature and precipitation can negatively affect agriculture over wider regions.  

Many of the farmers NewsChina interviewed said that the number of extremely high and very low temperature days is increasing, while drought and flooding occur more frequently.  

This year, Aksu experienced severe spring frost and extreme summer heat. Data from the local meteorological bureau showed cold snaps in mid-April and early May destroyed crops in most parts of Aksu. From May 6 to 7, Wushi, Baicheng and Kuqa counties saw their all-time latest recorded annual frost, forcing farmers in many areas to replant their cotton. “The spring frost this year was a very extreme phenomenon,” Ji said.  

For cotton growth, according to Dai Lu, distribution of temperature during the growing period is more important. Over the last decade, extreme high temperature weather has become more frequent. Previously, the number of days above 35 C annually was generally no more than 10 days, but prior to August 2023, there had already been 20 days where temperatures reached over 35 C. “When the temperature gets very high, it adversely affects cotton pollination and makes the cotton flower buds fall off. For example, from mid-July to early August 2015, there were about 20 days of extreme high temperatures, which caused an average production loss of over 50 kilograms per mu,” Dai said.  

Winter freezes also pose threats to agriculture in Xinjiang. Prolonged low temperatures can be fatal to orchards. Yang Junjie, senior engineer of Wensu County forestry technology promotion service center, told NewsChina that in December 2022, temperatures in Wensu County dropped to - 22 C for 25 consecutive days, freezing many trees to death and completely devastating walnut orchards. “It takes a long time for surviving trees to recover, and the negative effects will last for seven or eight years, resulting in declining production,” Yang added.  

Pest Outbreaks
There are other problems. Corn spider mites are tiny arachnids that feed on the underside of corn leaves. They thrive in hotter weather – the higher the temperatures, the faster they reproduce. At the outset of summer, many parts of China saw corn spider mite outbreaks.  

Zhangye in Gansu Province is known as the “golden base” of corn seed production in China. Among the world’s top-10 corn seed production companies, five are based in Zhangye, where seed production covers 73,333 hectares.  

Zhang Yang, a manager of a seed company in Zhangye’s Ganzhou District, told NewsChina that the rate of corn spider mite damage in Ganzhou has increased by about 15 percent in area in recent years, reducing the company’s seed output by up to 20 percent.  

According to statistics from Zhangye Agricultural Science Research Institute, in 2005 only 16,333 hectares in Zhangye were affected by bollworm, an invasive pest that feeds on crops such as corn, cotton and small grains. Fifteen years later, that area had expanded to 59,620 hectares. The total number of pest species in the area has increased from 18 in the 1980s to 73 today.  

Addressing challenges posed by climate change in Northwest China, Li Xinjian, deputy director for Xinjiang Agricultural Meteorological Station, highlighted the importance of enhancing monitoring, forecasts and early-warning systems for extreme weather. Xinjiang is vast, with significantly different climates in its north and south.  

Many counties only have one monitoring station but grow a range of crops, which results in incomplete agricultural meteorological monitoring. Therefore, more observation stations are crucial to understanding climate change in Xinjiang. According to Li, Xinjiang plans to add about 100 stations by 2025. “It was proposed to build observation stations in farmland to monitor each local crop,” Li said. “We will also integrate ground monitoring with drone and satellite remote sensing monitoring,” Li said.  

Ji Chunrong said that while timely and accurate monitoring is an important part of managing risk, it is not enough. Along with meteorological forecasts, regions can also be graded according to potential disaster risk. This way farmers can take targeted measures in advance to mitigate losses.  

To address potential future losses, Ji suggests that farmers take targeted measures in advance. “For example, if the forecast says there will be frost on March 21, cotton farmers can adjust their sprouting or planting times to avoid potential disaster, such as having their cotton sprout earlier on March 10 and then using plant growth regulators, which could help them survive the frost. They can also opt to have the plants sprout later after the frost, of course,” Ji said.  

She stressed that in the future, with the increasing uncertainty of extreme weather, it is necessary to promote crop risk management and improve risk management countermeasures throughout the planting and production process. “It’s just like managing chronic disease. Crops should also enjoy health management,” Ji said.  

‘Boiling Frog’
Zhang Qiang, chief engineer of Gansu Meteorological Bureau, cautioned that it is necessary to scientifically manage both the “opportunities and challenges” brought by warmer and wetter climate to local agriculture.  

“We need to ensure we keep up with these warming and wetter trends, make timely refinements to agricultural climate zoning, take the initiative to adjust the agricultural industry layout, optimize the agricultural industrial structure, and improve agricultural yield and quality,” Zhang said. “But we should also increase awareness of disasters and prevention, strengthen the construction of comprehensive disaster reduction and prevention capacity, and improve the early warning, forecast and field management systems.”  

Zhang told NewsChina it is high time to raise people’s scientific understanding of the effects of warmer and wetter climates, and to take precautions to deal with climate change. “Some local governments are unaware of how to address climate change. Without being aware of the changes and potential dangers, it is like the metaphor of slowly boiling a frog in increasingly warmer water. By the time climate change already makes a serious impact, it will be too late to take action,” Zhang said. 

People fsh in Helan County, Yinchuan City, Ningxia Hui Autonomous Region, September 25, 2019 (Photo by VCG)