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Saltwater Saviors

Saltwater Saviors

By Emily Cadei

Sea Kale, Crambe maritima, is a halophytic perennial plant. A halophyte is a plant that grows in waters of high salinity.
SourceRobert Pickett/Corbis


If farmers don’t figure out how to produce more with less, the Earth will face a major food crisis by 2050. Saltwater farming could be one answer.

By Emily Cadei

What if someone told you that in the next 10 to 20 years we could solve the planet’s most vexing environmental challenges — burgeoning water, food and energy shortages and climate change — all in one fell swoop?

Dennis Bushnell, the chief scientist at NASA’s Langley Research Center, says it’s possible, and that the solution lies in something as simple and affordable as a small, succulent plant.

Not just any plant, though. What Bushnell is talking about is growing a class of plant that can tolerate high levels of salt in both soil and water — “halophytes” in scientific terms — something our main food crops can’t do. It would open huge swathes of land for farming, given that just over 10 percent of the world’s land is considered “arable” (fertile and suitable for traditional forms of farming), and roughly half of our land is considered marginal or arid (consisting of deserts, salt basins, coastal lowlands), where halophytes can grow.

 Bushnell, NASA Langley's Chief Scientist.

Dennis Bushnell, NASA Langley’s Chief Scientist.

The upside when it comes to water could be even higher — just 2.5 percent of the world’s water is fresh water and just 1 percent of that fresh water is readily accessible to humans. And what do humans do when we get our hands on that teeny bit of fresh water? Nearly 60 percent goes to irrigate the crops that provide food for ourselves and our livestock or get turned into products like textiles and fuel (like corn-based ethanol).

Salt-tolerant plants can thrive in water with varying levels of salinity — up to pure seawater.

Salt-tolerant plants, however, can thrive in water with varying levels of salinity — up to pure seawater, depending on the type of plant.

With the U.N.’s Food and Agriculture Organization (FAO) predicting that we’ll need to increase food production by 70 percent to feed the 9.1 billion people projected to be populating the Earth by 2050, finding new places and ways to grow crops is more pressing than ever. The buzzword is “food security” — using technology, infrastructure and policy to ensure the world produces the food to feed its growing number of mouths — and it’s gaining increased attention from government officials, academics and agriculture companies. The FAO predicts that, thanks to underused farmland in Africa and Latin America, the world has the resources to grow the food it needs — if production levels continue to advance.

A mighty big “if.” But proponents of saltwater agriculture are confident that halophyte crops can help, particularly in places like the Middle East and parts of Asia where land and water are already growing scarce.

There’s another argument for these salt-tolerant plants, thousands of which exist in nature: They’ve been found to absorb and store carbon dioxide at a rate on par with or even higher than your average tree. And certain halophytes produce oils that have proven particularly promising for making fuel that could some day replace the fossil fuels generating the carbon that’s heating the planet.

Sea kale.

Sea kale.

Saltwater agriculture is hardly a new concept. People in Israel and India and other arid climates have been cultivating saltwater crops on a small scale for hundreds and even thousands of years, Bushnell points out. But interest and research into the practice have picked up significantly in the last two decades as a result of two global developments: water shortages and a growing interest in plant-based “biofuels.”

The latter is how Bushnell and his colleagues at NASA’s research lab first came across the concept of saltwater agriculture. They’ve been running tests on biofuels made from saltwater plants for the last five or six years.

The private sector is also ramping up its research. A consortium that includes Boeing, Honeywell and the United Arab Emirates’ Etihad airline has been working on a five-year project to cultivate the plants in Abu Dhabi’s highly salinated desert soil, watered with seawater from the Gulf of Arabia. The aim is to turn the oils from the plants into jet fuel for commercial use.

The commercialization of saltwater food crops, however, doesn’t seem to be attracting the same sort of interest as saltwater plant biofuels, where companies have a greater economic incentive to invest. 

One exception is the salt marsh plant salicornia, among the most promising crops for biofuel, which has become something of a delicacy in England, where it is known as glasswort or samphire. But so far it appears to be an outlier.

Seafresh fishmongers at St Peter Port, Guernsey, UK

Seafresh fishmongers at St Peter Port, Guernsey, UK

Dr. Ismahane Elouafi, the director general of the Dubai-based International Center for Biosaline Agriculture, and her team are working to increase the salinity tolerance of types of hardier traditional crops — such as date palms, sorghum and millet. They’re not halophytes but they can be grown in more marginal environments, unlike major staple crops like wheat and rice. The center is partnering with farmers in parts of the Middle East and Africa to distribute and cultivate their seeds, but Elouafi says cracking international agriculture markets is a whole different ballgame.

“The technologies that make a big impact are the ones championed by the multinationals,” Elouafi says. ”We’re not using the biodiversity, not because it doesn’t exist, but because the global market is very competitive and only the mega-production systems can survive it.”

Bushnell concedes that for now, ”there’s no handle on this” — patents, for example — ”that companies can use to make money.” And in presenting a potential alternative to staple crops like wheat, rice and corn, the commercial expansion of saltwater agriculture ”gores many, many bulls and sacred cows” he says. 

But as countries and regions start to exhaust traditional farmland, the drive to invest in saltwater food crops could pick up speed. ”The problem will become acute in the next 20 to 30 years, as human beings continue to degrade land and waste fresh water,” says Elouafi. ”We are pushing the boundaries.”

Pass the salicornia? 

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