Researchers Conduct Cultivation Studies to Solve Rice Climate Challenges
Rice is in jeopardy as the earth heats up, threatening billions of people’s food and livelihood. Sometimes there isn’t enough rain when seedlings need water, and other times there is too much rain when plants need to keep their heads above water. The salt in the sea destroys the produce. Yields decrease as the nights warm.
These risks are prompting nations worldwide to develop new methods of growing one of its most essential crops. Rice farmers are changing their planting schedules. Plant breeders are developing resistant seeds.
And, where water is scarce, as it is in so many parts of the world, farmers are intentionally letting their fields dry out, a method that also reduces methane, a potent greenhouse gas that rises from paddy fields.
The climate crisis is particularly distressing for small farmers with little land, which is the case for hundreds of millions of Asian farmers. “They have to adapt,” said Pham Tan Dao, irrigation chief for Soc Trang, a coastal province in Vietnam, one of the world’s largest rice producers. “Otherwise, they can’t live.”
A study in China discovered that excessive rainfall had lowered rice yields during the past 20 years. India limited rice exports due to concern for its own people’s food security. Heat and flooding destroyed harvests in Pakistan, while severe drought in California caused many farmers to fallow their fields. Rice production is projected to decline this year globally, partly because of the extreme weather.
The challenges we face now are not the same as they were 50 years ago. The globe needs to produce significantly more rice to avoid famine. Chemical fertilizers were used to cultivate high-yielding hybrid seeds. Farmers in the Mekong Delta went on to produce up to three harvests each year, feeding millions at home and abroad.
Today, that identical system of intensive production has caused new difficulties worldwide. It has depleted aquifers, increased fertilizer consumption, decreased the variety of rice breeds planted, and polluted the air with smoke from burning rice stubble. On top of that, climate change has disrupted the pattern of sunshine and rain on which rice depends.
Perhaps most concerning, because rice is consumed daily by some of the most impoverished individuals worldwide, rising carbon dioxide levels in the atmosphere deplete nutrients in each grain.
Rice is facing yet another climatic challenge. It accounts for an estimated 8% of global methane emissions. That is a small percentage of the emissions from coal, oil, and gas, which account for 35% of total methane emissions. But, fossil fuels are replaceable by other energy sources. Rice, on the other hand, not so much. Rice is the staple grain for three billion people. These dishes are a source of tradition and sustenance – biryani and pho, jollof, and jambalaya.
“We are in a fundamentally different moment,” said Lewis H. Ziska, a professor of environmental health sciences at Columbia University. “It’s a question of producing more with less. How do you do that in a way that’s sustainable? How do you do that in a changing climate?”
Struggling with starvation following the war, Vietnam resolved to grow more rice in 1975. It was a huge success, eventually becoming the world’s third-largest rice exporter after India and Thailand. The Mekong Delta’s green patchwork became its prized rice region.
At the same time, though, the Mekong River was reshaped by human hands in the same period. Beginning in southern China, the river flows through Myanmar, Laos, Thailand, and Cambodia, blocked by numerous dams. Today, by the time it reaches Vietnam, there is little fresh water available to clean off the seawater that has seeped inland.
Climate change brings other risks. The monsoon season no longer begins in May, as it once did. In dry years, farmers now sow rice 10 to 30 days earlier than usual, according to studies. Many people in coastal areas alternate between rice and shrimp, which prefer a little seawater. Shrimp have high earnings, but they also have huge risks. The disease spreads quickly. The land gets desolate.
Farmers may need to adjust their calendars for rice and other staple grains elsewhere, based on a recent paper. Scientists are attempting to help them.
The cabinet of wonders in Argelia Lorence’s laboratory is filled with seeds of rice — 310 different kinds of rice.
Many are centuries old and are rarely grown nowadays. But they hold genetic superpowers that Lorence, a plant scientist at Arkansas State University, is looking for, particularly those that allow rice plants to survive hot nights, one of the most acute hazards of climate change.
So far, she has discovered two such genes. These can be used to breed new hybrid varieties.
The new frontier of rice research involves Crispr, a gene-editing technology that US scientists use to create a seed that produces virtually no methane.
In Bangladesh, researchers have developed new types to address the climate pressures that farmers are already facing. Some can grow after a few days of being submerged in floodwaters.
No matter what happens with the climate, Bangladesh will need to produce more rice, according to Khandakar M Iftekharuddaula, chief scientific officer at the Bangladesh Rice Research Institute. Every meal includes rice. “Rice security is synonymous with food security,” he stated.
