Sixty years ago, the Aral Sea began drying up, leaving salty, barren soil in its wake. Lessons learned here will help other parts of the world experiencing climate change.
These days, the village of Karauzyak in western Uzbekistan is a dusty place. Surrounded by an arid landscape of dry scrub grasses and salt-crusted soils, it’s hard to believe the village was once along the banks of a swollen river, 30 miles from the shore of the world’s fourth-largest lake. Over the last 50 years, that lake, the Aral Sea, has dried up almost entirely, in what is often called the “world’s worst environmental disaster.” Now, it’s hard to farm much of anything in Karauzyak—except for atriplex, or saltbush.
In a 3.5-hectare plot of land near the village, a team of Japanese researchers is growing this salt-loving plant, known scientifically as a halophyte, to see if it can be a viable crop for farmers in the region and even nurture a small dairy industry. They’ve fed it to cows at a nearby farm and found that it helps lock scarce moisture into the thirsty soil, and it can be grown without extensive fertilizer use.
As she holds up a dusty green twig of atriplex, Kristina Toderich, a halophyte expert from Tottori University in Japan, explains why the salt-loving plant excites scientists like her: “This doesn’t need water. It doesn’t need anything.”
Toderich is one of the lead researchers on a project using the former seabed and nearby river delta as a living laboratory. It’s part of a larger Japanese foreign aid and scientific collaboration initiative called SATREPS. Working with Uzbekistan’s hydrometeorological service, UZGIP, the researchers are collecting real-time climate data and satellite imagery to better understand the conditions in the Aral Sea area: how much water is left, how fast it’s disappearing, and what kind of crops are being farmed there.
Based on the results, they’re drafting a model for sustainable agriculture in the region, recommending that farmers adopt new irrigation methods and plant crops that are more salt- and drought-tolerant, says Kenji Tanaka, a hydrologist who studies the effects of climate change on water resources and the head of the SATREPS project.
“Which areas are dry? Which areas have enough water?” By answering these questions, Tanaka said, “we can distribute the water actually where they need it.”
Their ultimate goal is to revitalize a region that has been devastated by intensive agriculture.
These environmental changes are not unique to the Aral Sea.
The United Nations Convention to Combat Desertification has warned that an area of land the size of Central Asia has become degraded from drought, salinization, and overuse since 2015. By learning what can grow in the Aral Sea, SATREPS could provide solutions for other parts of the world that are facing similar problems, from the Lake Chad basin in Western Africa to the Great Salt Lake in Utah.
Starting in the 1960s, Soviet officials diverted rivers flowing into the Aral Sea to produce cotton in nearby fields. Without rivers regularly replenishing the sea, the large lake began to evaporate, water levels plummeted, and the retreating sea left behind increasingly saline soil where regular crops could not grow. Today, cotton farming continues in an arid region that receives an average of just four inches of rain per year.
It's unclear whether the Uzbeki government will adopt the recommendations made by the SATREPS team. But so far, the country seems open to change; President Shavkat Mirziyoyev, who promised to loosen the rigid Soviet-era policies of his predecessor, Islam Karimov, ended the requirement that all Uzbek citizens pick cotton if called upon, and has spoken at the United Nations about the effects of desertification and land degradation on his country.
Climate change makes these adaptations even more urgent. Average temperatures in the Aral basin have increased by around 3.6 degrees Fahrenheit since 1968. And the shrinking of the Aral Sea itself has affected the climate; as the water disappeared, the air became drier and lost the cooling effect of the nearby lake, creating a feedback loop that resulted in hotter and drier weather. Sandstorms now spread dust and toxic heavy metals to nearby villages, while retreating water has caused a build-up of salts in the soil.
Tanaka’s project has several components. Aside from atriplex, SATREPS researchers are planting crops like sorghum, mung bean, and amaranth in test plots to learn which can best survive in dry, saline soil. So far, they’ve developed promising varieties of winter wheat and barley.
They’re also collecting satellite data to measure precipitation, solar radiation, and soil moisture in the Aral region, which can be used to help farmers decide which crops to plant or when to irrigate them. This kind of real-time analysis, known as precision agriculture, is already widely used in Japan. Tanaka hopes that by providing the data for free starting next year, the SATREPS project can help companies and government agencies develop tools for farmers to use when planning out their irrigation strategies.
SATREPS’ partners are also running their own experiments. The Karakalpak Institute of Agriculture and Agrotechnology has been testing different irrigation methods, such as drip systems that deliver water to specific plants, to see which technology uses water most efficiently. And the International Innovation Center for Aral Sea Basin, a government agency in the region, is growing hardy plants in soil collected from the former lakebed.
This data isn’t just useful for agriculture.
A devastating sandstorm in 2018, which destroyed crops and killed livestock on a scale not seen before, was a wakeup call for the region, said Bakhytzhan Khabibullaev, the center’s director. Uzbekistan’s government began a strategy to plant saxaul, a halophyte that is native to the area, in the dry lakebed to hold down the soil and combat dust and salt storms.
But researchers caution against the idea that the Aral Sea can ever be “saved,” or returned to its former state. Instead, scientists are focusing on new forms of agriculture and industries that can help local communities adapt to the changes that have taken place, as well as those still to come.
“It’s been 50 years” since the Aral Sea began to retreat, says Temur Khujanazarov, a researcher at Kyoto University who works with Toderich and Tanaka to study the potential of halophyte agriculture in the Aral Sea region. Rather than waiting for it to come back, he says, “we have to move on. We have to look toward the future.”