SalFar: Let's talk about salt

Farmers in arid and coastal zones around the world are facing a growing problem. Their soils are increasingly salt-infested due to drought brought on by climate change.

This threatens food production due to reduced yields or crop failure. Soil salinisation currently leads to a global loss of 1.5 million hectares of farmland per year and decreases the productivity of another 46 million hectares.  

This raises some questions: How big is this problem in the North Sea Region? And what can be done about it? The project Saline Farming (SalFar) made some hopeful discoveries. 

One might worry how saline farming affects the taste of food crops. Are they too salty, for example? The SalFar team found that the answer is 'it depends'.

“Saline soil affects plants differently than sweet water,” explains Van Noordenburg. “Strawberry, for example, will start tasting really bad. A tomato reacts completely differently. It does not absorb the salt. Instead, the salt triggers it to make a lot more sugar, so you will get a unique product that restaurants really like.” 

To their delight, the team found a range of salt-tolerant crops that are very appetizing.  

From bladderwreck fertiliser to saline-grown spices, SalFar catalysed innovation in the food value chains. In total, the project led to the development of 106 new products. SalFar even developed a brand label for saline farmed produce. 

The partners also realised that salt-tolerant crops might possess a secret power. “We identified polyphenols as an interesting research topic within saline farming,” says Van Noordenburg. Polyphenols are complex compounds found in plants and associated with a range of health benefits. “When you stress plants, for example by growing them in saline soils, they will typically produce more polyphenols."

SalFar's inspiration catalogue captures many of the new ideas for using salt-tolerant veggies and the current state of knowledge about the health aspects.

As it turned out, saline farming not only allows farmers to produce food crops on saline soils. It also saves precious fresh water. 

The SalFar trials reduced freshwater usage by on average 55%. While the potential for freshwater savings depends on local factors such as soil type, it is clear that the scope is significant. 

Freshwater scarcity is expected to become more pronounced in the future and is seen as one of the main future threats to human wellbeing. 

In addition, Salfar showed that saline farming will save energy compared to pumping out seawater and desalinising water for irrigation.

Armed with new insights and demonstration sites, the SalFar partners put soil salinisation on the radar of farmers, policymakers, food producers, and citizens.

“SalFar contributed a lot to normalising the topic,” says Van Noordenburg. “We organised 40 farmers’ cafés for farmers to meet water and agricultural experts and discuss salinisation. The farmers brought water samples from their canals for analysis and it was almost always saltier than they knew. In the dry summer of 2019, the salinity of the water was close to seawater in around 50% of the samples.”  

New policies are needed to face a more saline future, he adds. Carrying on as usual won't make the cut in the future.

"The policy in the Netherlands always was, just flush out the salt! This is what we have done in the last 600 years or so."

“In the summer, meltwater from the Alps flows through Germany into the Netherlands. Much of this fresh water ends up in the Ijsselmeer lake and is essentially used to flush out the salt in farm soils. We expect this won’t be possible anymore in the future as the Alpine glaciers are shrinking.”

Before SalFar, salinisation was largely ignored in policymaking. This changed during the project as SalFar brought the topic on the agenda. Van Noordenburg notes that salinisation is now covered in some policy papers and by many international and national funding schemes available in the region. The project is also featured at the European Environmental Agency's Climate-ADAPT platform.

As SalFar closes, its legacy has already been picked up and the next steps are being taken at full speed. 

The project has led to several spinoffs, including the research project SALAD scaling up SalFar's work through research in Belgium, Germany, Italy, the Netherlands, Egypt and Morocco. Also, the Norwegian University of Life Sciences' work on soil microbes' salt tolerance in the SalFar project has led to a new project funded by the European Joint Programme. Several additional projects based on SalFar's work are under way.

SalFar's pilots have been instrumental in sparking conversations with farmers who are likely to be affected by salinisation in the future or are already grappling with its effects, explains Van Noordenburg. In the Netherlands, the platform Zoet-Zout knooppunt  now enables farmers, scientists, and water boards to share knowledge on salinisation and related topics. And some Dutch farmers are now delivering saline-grown food crops to exclusive restaurants in the Netherlands and Belgium. 

"The SalFar pilots have also been critical in understanding the impacts of salinisation, but continuing the research is vital", says Van Noordenburg. “Scientists require more than two to four years of data due to fluctuating rainfall. Long-term data is necessary to predict the effects of salinisation.” While some pilots were set up to raise initial awareness and foster dialogue, he expects 8-10 pilots will continue after project end. 

Last but not least, the project gave rise to the formation of the international “Knowledge Cluster Salinisation” initiated by the Province of Fryslan at SalFar’s final conference.

The project was a first mover in the North Sea Region but according to Van Noordenburg, it is none too soon to act.

“In Groningen, for example, we are planning what our landscape should look like in the future. A lot of that has to do with water management and how we can hold on to sweet water. Also, we have a large export of seed potatoes. The best lands for this crop are precisely the areas that will be most impacted by salinisation, so we need to plan ahead.”   
 

We started just in time to plan for the future. Saline farming is a good example of futureproof, climate-adaptive, regional food production.

SalFar's discoveries show how much interdisciplinary cooperation across borders matters in the face of climate change. This speeds up the innovation needed for people to live and thrive in a more saline future, with enough food to go around. 

Van Noordenburg: “By building and sharing knowledge, we can help not only the North Sea Region but also the rest of the world.”

Or check out these key resources:

Online Resources Centre including plenty of video explainers and tutorials 

SalFar's book "Future of Sustainable Agriculture in Saline Environments"  

Inspiration Catalogue of salt-tolerant plants

You can contact the author and project leader Douwe van Noordenburg at d.van.noordenburg@provinciegroningen.nl.

Sofie Forfang is a communications advisor at the Interreg North Sea Programme secretariat.