The project tackles challenges of food production, water scarcity and renewable energy (Credit: Credit: Amanda Ruggeri)

How to use seawater to grow food – in the desert

An ambitious project plans to use seawater and solar power for agriculture. But is it technically feasible?

Inside the greenhouse, tiny leaves of wild rocket, iceberg lettuce and pak choi poke through the dirt, each as small as a fingernail. Planters hold calla lilies and dragonfruit, sea samphire and gerberas. Bright strawberries dot buttery green leaves. And there are row after row of vines, draped over wires, leaves as big as dinner plates: snack cucumbers and fragrant basil and nine varieties of tomatoes.

“My basil’s a bit straggly,” head grower Blaise Jowett says, apologetically. “But I’m keeping them for pesto.”

He shouldn’t be too apologetic. Outside of the greenhouse, a camel grazes. Pale pink sand extends to the rocky mountains in the distance. Only the hardiest tufts of green thrust up through the ground. There is no water. There are no trees.

This spot in the Jordanian desert, just a kilometre from the Israeli border and 15km inland of the Red Sea, may be one of the most surprising places on Earth to start a farm. It’s also one that, in some ways, makes perfect sense.

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By 2050, the Food and Agricultural Organisation (FAO) has said, food production needs to be increased by 50% to match the projected increase in population. That won’t be easy. “The challenge is to produce this amount of food within the boundaries of this planet, with a limited number of hectares of arable land – while knowing that a lot of the land and the soil is getting degraded,” says FAO emergency and rehabilitation officer Sylvie Wabbes-Candotti.

We’re facing other global challenges, too. Climate change, for one. And in many countries, including Jordan, a lack of water. And to make matters thornier, each of these issues impacts on the other. Currently, food production consumes about 70% of global freshwater consumption and emits 25% of greenhouse gases. Simply upping how much food we’re producing – without changing how it’s done – will make emissions and water usage worse. Meanwhile, as climate change and water shortages get more severe, the more difficult it will be to produce food with the same methods we use today.

“You can’t see climate change as an isolated challenge; it is connected to water and food production,” says Joakim Hauge, president of the Sahara Forest Project Foundation, the organisation behind the Wadi Araba project. “You need to progress those issues together with tackling climate change. Our response to that was, well, let’s take what we have enough of to produce what we need more of.”

Triple axle

One resource Jordan needs more of is water. The second most water-poor nation in the world, it has less than 150 cubic meters of water per person, per year. (The US has more than 9,000). Part of the problem is that the country is three-quarters desert. Another problem is agriculture. Farming sucks up half of Jordan’s water supply, but contributes only 3% to the country’s GDP. (Read more about one surprising solution Jordan is using to solve its water crisis).

What Jordan does have is sunshine – and plenty of it. On average, the country gets an average of between 5 and 7kWh of solar energy per square meter. That's enough to power 14 traditional light bulbs for eight hours, 14 washing machines to each do a load of laundry or, perhaps most relevant for Jordan, one air conditioner for four hours. It’s one reason why the US government’s International Trade Administration calls renewable energy one of Jordan’s best-prospect industries.

Jordan also has seawater… sort of. Though mostly landlocked, with its access to the Mediterranean separated by Israel and Lebanon, 26km of the country borders the Red Sea. That isn’t much coastline – but with the approach being taken by the Sahara Forest Project, that may be all it needs.

The project’s concept is elegant in its simplicity: Jordan’s solar energy desalinates the seawater, the desalinated water grows the crops (and the run-off cools the greenhouse) and the crops help plough carbon from the atmosphere back into the soil. Three tentpole challenges, tackled at once.

And along with being a sustainable use of resources, the project could bring another benefit. Once scaled up and commercialised – and especially if its methods are adopted by other farms in the country – it could give Jordan another list of valuable exports. Currently, the country imports 98% of its food.

“Jordan is dependent on food imports,” says Wabbes-Candotti, who works across the region but isn’t involved with the Sahara project. “Water is really the shortage. If you cannot depend on the rain, but have a reliable water supply with this desalinated water, then if you have adequate funding, and master the techniques… you can go produce food and even become an exporter of food.”

Arriving at that point will be a little more complicated. The project is only a year old, having launched in September 2017. The greenhouse and its surroundings, where Jowett is experimenting with growing other plants, currently adds up to an area of about four football fields in size. This is just the pilot stage. The total land they own is 200 hectares. Once they’ve proven that the concept works, the idea is to scale up to 10 hectares by 2020, then to 20 hectares.

No-one doubts there will be a number of challenges ahead.

But even now, the team has already started tackling the difficulties of just how you use desalinated water to grow crops in the inhospitable desert.

Hot house

On the spring morning when I visit, the outside temperature is around 30C. Managing that heat is one of the crucial aspects that the project has had to master. Inside the greenhouse, where three young men plant cucumber seedlings in neat rows, the temperature hovers around 25C. Even so, Jowett points out the plants growing nearest to the greenhouse walls: those too close got too hot and died and the next round of plants will have to be moved further away.

With Jowett and facility manager Frank Utsola, I walk around the back of the greenhouse to the separate cooling room. The system is switched on: within what feels like moments, the air feels markedly more comfortable. The system can lower the temperature in the greenhouse by about 15C. In a region where summer days can get to 45C, unmanageable for even the heartiest of vegetables, this is key.

How it works “is very easy to explain”, says Utsola. Salt water is pumped into a pipe that runs along the top of the wind-facing wall. The wall is covered with a sort of ‘blanket’ that draws the water down; when the wind blows through, the water evaporates, cooling the air. (It works the same way as hanging a damp towel in your house on a hot day). At the same time, the heavier salt is left behind.

Although they can turn on solar-powered fans instead of relying on the wind, they normally don’t have to; most of the time, the wind sweeps through the valley from the north – a direction the cooling room has been built to take full advantage of.

The team is the first to admit that none of this is an innovation on its own. Utsola points to the ‘blanket’ that lines the cooling room: Bedouins have used carpets like this to cool their tents for centuries, he says. Of course, solar power and desalinisation techniques aren’t new, either.

“A lot of these are well tested environmental technologies,” says Hauge. “The new thing about this project is how we combine them.”

Heat isn’t the only thing the plants have to contend with. At night, it can get down to 7C. When that happens, the pipes in the ceiling hold water which is warmed by the sun during the day. When it is piped into the plants at night, it gives them a warm bath.

Meanwhile, the plants inside the greenhouse are given more water than the roots can absorb; the extra run-off collects in tanks at the end of the greenhouse. Jowett is using it to experiment on the plants outside, where he has divided the soil into plots for varying levels of salinity to see how much, if any, is okay. This is a work in progress, too. Of 864 plants outside, 49 have died. Some he’s growing just to help nourish the soil. “Here I’m trialling this, which is called a field bean. And this is clover, so green manure,” he says. “I just want to let it grow – they’re legumes, they fix nitrogen into the soil. Further on, we dig them in and incorporate them into the sand. They’ll decompose and improve the soil and the water holding capacity and add a bit of nutrients.”

Further on, he picks a piece of wild rocket for me to taste. “It’s pretty peppery,” he says. I pop it in my mouth. It’s extremely peppery – though some of the shock of the taste is owed to the surprise of knowing where it was grown.

Pipe dream

Even if the team is mastering how to grow crops in a desert, there’s one stumbling block they haven’t yet overcome: how to carry the seawater 15km from the Red Sea to the site. At the moment, it’s being brought in by lorries every two days. That’s not exactly a carbon-neutral approach, and it won’t be sustainable when the project expands.

“To scale up ops, we will need a pipeline from the sea pumping in the seawater. That is what we are now working to finance,” says Hauge. The problem isn’t digging a trench. It’s getting access to the land to do so. One option is for the pipe to take the same route as the long-planned $10 billion conduit planned to siphon water from the Red Sea to the Dead Sea, though the project has been mired in difficulties for years. Or it could go beneath the main road close to the greenhouse, the Jordan Valley Highway, but that cuts through areas owned by a variety of stakeholders, from government to private citizens.

Still, the team is optimistic. They’re currently preparing studies to show how a pipeline could create value not only for a commercial-scale Sahara Forest Project, but for the rest of the community, such as by creating job and business opportunities. The level of support for the project – including, crucially, endorsements from the royal family and royal courts of Jordan – mean they have reason to think it may move forward, perhaps with a pipeline beginning as soon as the end of 2018.

Even putting aside the political and bureaucratic challenges that pertain to the pipeline alone, the idea of turning this swath of desert into a 20ha collection of greenhouses and gardens is more than a little bit surreal. But as the team says, the technologies here are all proven – and already being used in tandem here in the desert. Most persuasive of all, though, are the cucumbers that Utsola gives me as a parting snack, grown from the vines in the solar-powered greenhouse: they are crisp, delicious and very much real.

Correction: An earlier version of this story misstated calculations for Jordan's solar energy. This has been fixed. We regret the error.

Amanda Ruggeri is BBC Future's senior editor. She can be found at @amanda_ruggeri on Twitter.

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