Saline solutions: As Europe's sea levels rise, farmers adapt

As climate change and rising sea levels make Europe’s farmland increasingly salty and barren, can saline agriculture offer growers a way forward?
Illustration by Adrià Voltà

By Gabriela Galindo

Gabriela is an agriculture and EU affairs reporter currently based in Brussels.

08 Sep 2023

Europe’s changing climate is putting farmers face to face with an unlikely foe: salt. Along European coasts, salty water has begun encroaching on the land, pressuring farm communities in coastal areas and at times even wiping out their harvests. 

With global temperatures only projected to keep climbing, so long as polluting human activity continues, some in the affected communities are leading a push to stop fighting against the advent of a much saltier new normal and begin adapting to it instead. 

In countries such as Hungary and Greece, warmer and drier climates are making naturally sodic or arid soils saltier, while inappropriate irrigation practices in Spain are causing soil-drying minerals to accumulate in the soil.  

In northern Italy, recurrent droughts have dried up the Po river so badly that seawater has begun seeping into a freshwater source that is crucial for farmers. And along the Mediterranean and North Sea coastlines, the rising sea level is pushing seawater inland – a phenomenon known as seepage. 

Further inland, drier winters coupled with increasingly common summer droughts mean entire swathes of land are turning coarse and barren, as salt and other minerals accumulate in the soil. This means farmers have a much harder time cultivating it. 

Saline farming “is a possible solution for many different scenarios”, says Jeroen De Waegemaeker, a senior researcher at the Flemish Research Institute for Agriculture, Fisheries and Food (ILVO) in Belgium. He adds that while the causes and manifestations of salinisation vary largely throughout Europe, across many countries, both climate change and resource mismanagement are making the problem worse.  

According to a 2021 report by the United Nations’ Food and Agriculture Organisation, more than 833 million hectares of soil worldwide are affected by salinisation, a number which grows by an additional 1.5 million hectares each year. The report estimates that growing salinisation, which severely impacts crops’ growth by impeding their ability to take up and retain water, and depletes the soil of crucial plant nutrients, means that some 1.5 billion people around the world already face significant challenges to grow food. 

A spokesperson for the EU Commission’s agricultural department did not reply to our questions on salinisation and saline farming. But in a 2020 report, a Commission expert group on salinisation said the extent of salt-degraded surface or underground soil in the EU was still uncertain, largely because of a lack of standardised measuring methods and tools. The expert group warned that this phenomenon could only be expected to worsen, as the world continues to warm up in the coming years. 

De Waegemaeker and Kate Negacz, a researcher at the Vrije Universiteit Amsterdam and a project co-ordinator for SALAD, a Horizon Europe project focusing on scaling-up saline farming, are part of a growing community of experts looking into the potential of saline farming to offer ways to address this problem on a global scale.  
For Negacz, using saline farming, which consists of cultivating crops by using brackish water or salt-affected soils, or a combination of both, to tackle the issue of salinisation is a perfect example of how “a major challenge can be turned into an opportunity”.  

While many EU policies and strategies mention salinisation of agricultural land and seawater incursion as a major problem, Negacz says, the EU still has “no one single integrated saline agriculture policy”, even as freshwater resources continue to dwindle. 

“A lot of policies are still favouring freshwater [use] and mitigation techniques instead of adaptation,” she says. “However, in the future, if climate predictions turn out to be right, we will also need to adapt and we will have to learn to work with salinity and see just how we can manage it.” 

Across the world, salt-degraded land is often abandoned. By embracing saline agriculture, a good portion of this land could be restored and put back into production. “We could avoid deforestation and avoid land use change in other places,” she says. 

Yet, as with many current environmental challenges, EU policymakers are lagging behind science, and still largely favour techniques to mitigate and avoid salinisation. 

A wealth of EU countries pull on Brussels’ purse strings to unlock crisis funds when drought begins to parch the fields; this helps farmers to compensate for financial losses but does not address the root of the problem. 

To combat soil degradation, including from drought, authorities in Spain and Portugal resort to implementing water use restrictions – something which, in Spain, has been coupled with a push to deploy so-called smart irrigation infrastructure. While proponents say the goal of this is to make watering systems more efficient and less wasteful, opponents and environmentalists argue their impact on water preservation is marginal

In France and Italy, projects to build large water reservoirs to ensure ongoing agricultural irrigation are progressing, a move that has sparked major opposition from small-scale farmers and environmentalists, who argue these reservoirs will not only see already-limited freshwater resources captured by large industrial farmers but also fail to curb irresponsible irrigation practices that worsen or at times cause salinisation. 

In the wake of massive protests in France, several UN human rights experts wrote to the government to raise concerns about the project. And, in Spain, according to WWF, the little water that has been saved by the deployment of smart irrigation techniques has been diverted to intensive farming holdings rather than used to replenish reservoirs. 

Meanwhile, saline agriculture is well under way in several countries with historically more arid climates, such as Bangladesh, Pakistan, Egypt and Morocco, which could offer lessons on saline farming to Europe. But a context-specific strategy remains crucial for Europe, De Waegemaeker says, not only because its deployment here remains “very much in the experimental phase” but also because “salinisation is not going to be the same in Egypt as in Germany”. 

For farmers in the United Kingdom, saline farming can be a cheaper alternative than building and maintaining ever-higher dykes, while for farmers in Nordic countries, such as Norway, it can provide a solution to storm surges that hit coastal areas in the spring, showering freshly-budding crops with abrasive seawater. It can also offer an alternative to droughts or floods in the Mediterranean, where both desertification and rising sea levels are major issues. 

For residents of the Frisian Islands, an archipelago which crowns the northernmost part of the Netherlands, sea level rise has been a long time coming. Salinisation and rising tides are causing the islands’ land to sink as it becomes saltier and marsh-like. And while the Dutch have spent millennia perfecting the art of keeping the sea at bay, residents along the 13km coastline of Terschelling, one of the archipelago’s biggest islands, are embracing saline farming to learn how to reap from the tide, rather than fight against it.  

Gert Noordhoff, an agricultural policy adviser in the Dutch province of Groningen, to which a number of the west Frisian islands belong, says in an emailed statement that Groningen – which, like most of the Netherlands, lies largely below sea level – expects salinisation to pose an increasing challenge in the near future.  

And while mitigation strategies – such as draining coastal farmlands of seawater or flooding them with freshwater – have been one of the main ways to allow farmers to work land affected by salinisation and  seawater incursion, their underlying logic rests on the assumption that humans would invariably be capable of taming the sea’s advance. 

“There will come a time when that too will become increasingly difficult, and we will have to anticipate how to deal with food production in a completely different, much saltier, context,” Noordhoff says. “For the long term, it is good to anticipate a situation in which freshwater is no longer available in sufficient quantities.” 

Arjan Berkhuysen, a veteran nature conservation expert living on Terschelling, says the issue of salinisation there has worsened over the past 20 years, raising the question of just how much longer the island can keep fighting the tide. 

“It’s getting more and more expensive to do this and, ultimately, maybe we are just fighting against something which is unavoidable,” he says via video link.  

Berkhuysen, who has worked with NGOs such as the World Wildlife Fund (WWF and the World Fish Migration Foundation, was one of several islanders who launched a saline farming initiative in 2017 called De Zilte Smaak which, in English, translates to ‘The Salty Taste’. 

Today, the small organisation farms several types of crops known as halophytes – salt-loving plants that grow and taste better if they are cultivated in salty soil.  

Salicornia – a salty-tasting succulent which grows in small bushes and is similar in appearance to asparagus – is one of its main offerings and part of a handful of halophytes that have begun to make tentative appearances on supermarket shelves, including some in Belgium. 

But several more kinds of halophytes with intriguing names have begun taking root in De Zilte Smaak’s small plot of land, such as beach bananas, sea fennel, and the herb starflower, also known as borage. “Sea lavender and sea aster are also very, very nice,” Berkhuysen says, as he continues listing the organisation’s offering of marine greens, including ice plant, a type of succulent that looks like it has frozen water drops on its tips and is described by Berkhuysen as fresh and crunchy.  

Around a dozen hotels and restaurants in Terschelling and on the wider Frisian archipelago have worked De Zilte Smaak’s salty crops into their menus, proudly offering guests a taste of the local flavours.  

While De Zilte Smaak started off as a small farming project mostly fuelled by the work of volunteer islanders, it became a non-profit after it joined an EU research programme called SalFar, for which the province of Groningen was the leading project partner. Running from 2014 to 2021, SalFar, which received €2.7m from the European Regional Development Fund, aimed to explore the viability of saline farming in seven countries of the North Sea region – Denmark, Sweden, Norway, the UK, Belgium, the Netherlands and Germany – grappling with the impacts of sea level rise and salinisation on their agricultural production by exploring not only halophyte farming but also the salt tolerance of other crops. 

Terschelling’s farmers have managed to cultivate salty potatoes and beets, which Berkhuysen says are “very nice and tasty” but have a long way to go before being market-ready. 

And for its advocates, the extent to which saline agriculture can offer a solution to farmers struggling with growing salinisation will depend on the ability of science to find ways to use it to grow a wider array of crops. 

“Salicornia on top of your sushi is fantastic,” De Waegemaeker, who was ILVO’s lead for SalFar, says. “But if we really unlock the potential of saline farming, we have to look at the salt-tolerant varieties of conventional crops – the ones that the agricultural communities are growing now.” 

That’s a main focus for SALAD, which will run until 2024 in four EU countries (Italy, Germany, Belgium and the Netherlands) and in two African ones (Morocco and Egypt). SALAD project co-ordinator Negacz says that, using conventional plant breeding techniques, researchers have so far developed salt-tolerant varieties of tomatoes, potatoes, onions, carrots, beets and cabbages, using conventional breeding methods. But other crops pose a greater challenge: such as all kinds of berries or crops such as cucumbers and aubergines, which struggle with salt. 

Contrary to what might be expected, Negacz says, the salt-tolerant varieties of some crops, including tomatoes, potatoes and beets, actually taste “a tiny bit sweeter than their conventional varieties, since they react by trying to push out the salt”. When it came to grains, she says quinoa is a “very promising crop” on which research is well advanced. “We should go further, since we know that [quinoa] is a crop that is salt-tolerant and can also be introduced into our diets,” she says, citing its growing consumer appeal. 

The ever-present threat of the rising seas for farming means the Netherlands (which, after the United States, is the world’s second-largest agricultural exporter) is pouring significant resources into saline farming. Authorities at several levels of government support a range of research initiatives and experimental farm plots aiming to discover salt-tolerant varieties of crucial crops such as onions or potatoes. 

Dutch agricultural firms, such as The Salt Doctors and the Salt Farm Foundation, have also been spearheading research and upscaling efforts for saline farming, and have been crucial in jump-starting these efforts in Europe. The Salt Farm Foundation, which did not reply to a request for comment, has tested some 1,600 crops for salt-tolerance, including onions, millet, potatoes and strawberries. In 2018, it launched a platform to boost research into saline farming with the support of the Dutch Ministry of Agriculture. 

But for Andrés Parra Gonzáles, a saline agroecology consultant for The Salt Doctors, this farming method could also help countries further south, such as his native Spain, where an increasing number of farmers are struggling with salinisation as climate-driven droughts turn southern Europe’s climate increasingly arid. 

Parra Gonzáles says that Almería, a coastal province in Spain’s deep south which is among the driest areas in Europe, would be an ideal testing ground for saline agriculture. “Our location, our climate and the large number of agricultural holdings located here could be perfect for further developing this type of farming, which could in addition be transferable to many other arid areas with a Mediterranean climate.”

He says that, in a small, family-run farm producing citrus and other fruits, he and his family have begun experimenting with growing oranges, mandarins, and two peach varieties in parts of their farm badly affected by salinisation. The resulting fruit, he says, is similar to conventionally-grown varieties, but with one major problem – reduced yield; something which he says could be an acceptable trade-off for the added market value that comes with slightly sweeter fruit. 

Yet, before saline farming products hit supermarket shelves, researchers including Negacz and De Waegemaeker say it is crucial for policymakers to rethink the current approach to salinisation – which consists mainly of fighting it – in order to provide farmers with the knowledge and techniques they need to continue working in a rapidly changing environment. 

De Waegemaeker also points out that while, one day, saline farming could be a cheaper solution to managing coastal farms than, for example, building and maintaining a dyke, natural resource exhaustion might mean that, in the future, there could be little choice left. “At some point, if there is no more fresh water available, we will also have to think of other ways,” he says. 

The crucial part, he adds, will be for the EU and its Member States to be able to connect the dots as the science of saline farming progresses across and beyond Europe. “This will be about regional authorities of the Netherlands, Belgium, Germany, Spain, Portugal, Greece – those local regional authorities where the salinisation occurs – working together with a higher level, the European Union, to avoid seeing each member country go at it alone, reinventing the wheel on saline farming.”

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