Farmers harvest crops in flooded rice fields after heavy rains in Jiangxi province, China
Imaginechina Limited/Aramie
More frequent and intense rainfall extremes caused by climate change pose significant risks to China’s food security, according to a new study that predicts an 8% decline in rice yields by the end of the century.
China is the world’s largest rice producer, producing about 214 million tonnes annually. It is a staple food for the majority of the country’s 1.4 billion people.
Although studies warn that droughts, which are increasingly exacerbated by climate change, will cause yield declines over the next few decades, little research has been done on the potential impacts of extreme rainfall on crops. yeah.
Jin Fu and her colleagues at Peking University in China used data from nationwide observations and field experiments to model the impact of extreme rainfall on current and future rice yields across the country.
They found that extreme rainfall is already reducing rice yields by 8% compared to a world without anthropogenic warming.This is a reduction of magnitude comparable to the effects of extreme heat
Yields are projected to decline another 8% over the next few decades under a climate scenario of a 2-3°C increase in average temperatures by the end of the century.
“Extreme rainfall is usually an overlooked disaster for food security,” Fu says. But she says it “could cause a really big disaster” for food production in China and the world.
Heavy rains affect rice cultivation in two main ways. First, excess water in paddy fields dilutes nitrogen levels in the soil, leading to slower growth and lower yields. On the other hand, torrential rains can damage delicate flowers and inhibit the plant’s grain production.
Hu said the study’s findings are a conservative assessment. This is because the modeling does not consider the additional impact on yield of high winds, reduced sunshine, and cooler temperatures associated with wet weather.
The findings suggest that other countries in South East Asia, which are also high rice producers, may see even greater yield declines. Because climate models suggest it will suffer even more heavy rainfall than China.
Research is now needed to establish whether farmers can mitigate some of the negative effects of extreme rainfall by relocating paddy fields to less susceptible parts of China, Fu said. increase. He applies more nitrogen fertilizer to the fields to compensate for crop failures in rice, such as corn, or additional rainfall.
Allison Thomson of the Food and Agriculture Research Foundation, a US-based nonprofit, said: Adaptation is required. Knowing what the impact will be, how can farmers prepare to minimize the impact of these extreme rainfall events in the future?”
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