Advancing salinity adaptation through hydroponics in Egypt

Salinity threatens agricultural productivity and water security worldwide. In response, the Dutch organisation The Salt Doctors, together with consortium partners Delphy and Plug ‘n’ Grow, is piloting a practical and scalable solution in Egypt’s Nile Delta. Supported by Partners for Water, the team has been testing low-cost hydroponic systems that allow farmers to grow crops even when soil and groundwater are too saline for traditional cultivation. Bas Bruning from The Salt Doctors shares the ins and outs of the ProSal-Hydro project.

A simple idea for a complex challenge

In Egypt’s Nile Delta, around 40% of farmland is severely affected by salinity. Rising sea levels, inefficient irrigation, and poor drainage is gradually turning soils more saline. “People directly affected by salinity are often small-scale farmers,” explains Bas Bruning, Saline Agriculture Specialist at The Salt Doctors. “They work on marginal land, often with poor soil quality and saline water. On top of that, they often have few resources to adapt. To accommodate them, we wanted to design something that is simple, robust and affordable.”

The project’s approach bypasses saline soils entirely: crops grow in nutrient-rich water rather than in the ground. “We developed an open hydroponic system that grows vegetables in floating trays. It can be used in the harsh conditions of the warm and saline Nile Delta,” says Bruning. “By keeping the design minimal we can ensure it works even in remote areas. And to make it affordable, we use locally available materials wherever possible.”

On top of that, the system uses around 80% less water compared to conventional irrigation. Bruning explains: “Water loss through evaporation is almost eliminated because the surface is fully covered by floating trays. Plants still transpire, but the absence of open water drastically reduces overall water use.”

At five pilot sites across the delta region, the team has now succeeded in cultivating vegetables year-round. “Initially, trials faced predictable challenges,” shares Bruning. “The first crops included pak choi. However, this variety was unfamiliar to local consumers. We soon realised that even the most salt-tolerant crop is useless if no one wants to buy it. So we switched to local lettuce and cabbage varieties that locals already know and that the farmers could sell at the market.”

From scepticism to success

Convincing farmers to experiment with a new growing method took time. For many, the idea of producing vegetables in floating trays rather than soil seemed counterintuitive. “At first, the local farmers didn’t trust our solution. But as results improved, perceptions shifted,” says Bruning.

“Through a combination of technical training, field visits, and peer-to-peer learning, farmers began to see consistent quality and reliable yields.” A real turning point came when they received positive feedback from the market about their hydroponically grown cabbages. “Though smaller in size, they were denser, tastier, and fetched better prices,” says Bruning. “This convinced the farmers that the new cultivation system could be profitable and give their incomes a real boost.”

The project also benefited from collaboration with two Master’s students from the Vrije Universiteit Amsterdam. These students conducted social and technical research on farmer engagement. Their findings confirmed what the field experience showed: alignment between local practices, perceptions and new technology is key to adoption. “It’s not just about the technology,” Bruning emphasises, “it’s also about building trust”.

Technology shaped by experience

“Earlier systems in the Netherlands, Tunisia and Vietnam performed well with brackish water and salt tolerant crops. They demonstrated that this approach can support food production in saline environments. In Egypt, depending on the location, we use brackish or fresh water.”

The system in Egypt has evolved through hands-on experimentation. Early prototypes used different types of pumps, pots and rafts until the team found the right combination. The focus remained on ensuring durability and reducing costs without compromising quality. “Some components – like one key pump – are still imported from the Netherlands to guarantee quality,” says Bruning. “But most parts are now sourced locally.”

“Affordability is our biggest design constraint,” Bruning notes. “We’re still looking for ways to lower the return-on-investment time for smallholders. That means further simplifying the system while maintaining stable performance.”

Scaling salinity solutions

As the project approaches its final stages, the focus turns to consolidating lessons learned and preparing for broader application. The next phase focuses on scaling up – both technically and socially. Two new farmers have already joined the project, and they requested pilot hydroponic systems that were recently added. “In the long run, we hope to see a network of small hydroponic farms across the delta,” Bruning explains. “If we can support a hundred farmers in one area, providing weekly monitoring and training, this will make a promising impact on food security at the local level.