UAE researchers develop plant-waste gel that cuts irrigation water use by 30%

Tiny green leaves were beginning to emerge from pots treated with a new soil additive, while the pots lined up beside them, planted on the same day but without the material, had no green leaves showing.

The difference was visible in a greenhouse at the Technology Innovation Institute (TII), where researchers are testing a plant-waste gel designed to help crops grow with less water in the UAE’s harsh climate.

All the pots in this particular comparison had been planted the previous Friday. While the untreated pots showed little or no growth, small green shoots were already peeking out of the soil treated with the material, known as agrigel.

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In another comparison, spinach grown with the gel was about twice the size of spinach grown without it. Corn plants treated with the material were also about twice as long as those in the untreated comparison.

The observations are early indications rather than a formal measurement of increased crop yields. But greenhouse trials have shown an average reduction of about 30 per cent in water use, according to Professor Phil Hart, Chief Researcher and Head of TII’s Renewable and Sustainable Energy Research Centre.

“More crops, less water,” Hart said, describing the goal of the project.

The challenge is to grow more food in a country where farming is constrained by a harsh climate and limited suitable land, without increasing pressure on water and energy supplies.

“If we did that by using much more water, then that would be much more energy,” Hart said. “Where are we going to get all this energy and this water from?”

The agrigel is made from natural waste products, including date palm and other plant waste. Researchers process the material, rebuild it into a porous substance and combine it with other components before mixing it into the soil.

Hart described each grain of the material as “its own little reservoir”. It absorbs water quickly and holds it near the roots rather than allowing it to drain away, releasing moisture slowly according to the plant’s needs.

The material also breaks down over the growing season. Components mixed into it release fertiliser gradually, potentially reducing the need for farmers to apply fertiliser separately.

“It grabs hold really quickly, it releases very slowly, under the demand of the plant,” Hart said.

Unlike conventional materials that can resemble dust and be blown away, the agrigel is designed to remain in the soil while it releases water and nutrients, he explained.

Turning humidity to water

A similar material is also being developed to harvest water from humidity in the air. 

Unlike the soil-based agrigel, the material is shaped to absorb atmospheric moisture and hold it until the water is needed.

“You can think of it as harvesting humidity,” Hart said. “If it's sufficiently humid, it will grab hold of that and lock it in. It becomes like a sponge.”

The water can then be extracted by heating the material or squeezing it, offering a potential way to collect small quantities of water from the atmosphere.

Hart said it was not intended as an alternative to conventional water supplies, but could be useful in situations where a limited amount of water is needed. “It's the same principle,” he said, describing a material designed to absorb water quickly and release it only when required.

From greenhouse to UAE farms

The team is moving towards field trials to establish whether the results can be replicated outside controlled greenhouse conditions.

Trials are due to begin next week at three farms: one in Al Ain, one north of Yas Island and another in Al Barsha. Two sites were to host indoor and outdoor trials, while the third was planned as a full outdoor trial.

“Our question to answer is: great in a greenhouse, can we get this to work in an open field?” Hart said.

The researchers have tested the material on different crops, including spinach, corn, sunflowers, chillies and lettuce. During the greenhouse tour, a researcher said sunflowers treated with the gel had flowered about two weeks earlier than those grown without it.

The team is targeting commercialisation in 2027, subject to the results of the field trials.

For Hart, the measure of success is whether research translates into a practical benefit beyond the laboratory. “If it wasn't going to make a difference on the ground, we wouldn't be doing it.”

AI searches for a sunblock for solar panels

In a separate project, TII researchers are using artificial intelligence to identify molecules that could protect solar panels from ultraviolet (UV) radiation.

The concept is similar to sunblock: the molecules are designed to absorb UV light before it degrades panel materials, then re-emit the energy as visible light that solar cells can use to generate electricity.

Hart said the team’s testing indicated that modern solar panels could degrade by up to 20 per cent over roughly their first two years of operation. Such a loss could have a significant impact when multiplied across a large solar farm, he said.

The researchers are looking to address the problem by developing molecules that block UV radiation while making some of that energy useful.

Traditionally, researchers might design a candidate molecule, synthesise it in a laboratory and spend months testing it, only to discover that it does not work. AI has changed the early stages of that process, Hart said.

The team used AI to screen about 40,000 combinations of elements and narrowed the candidates to 10 molecules that showed potential. The molecules are designed to absorb UV light and convert the energy into visible photons.

The main aim is to protect the panels, with any additional electricity generation a secondary benefit. Hart cautioned that the extra power would not be dramatic, but said even small gains could matter if the technology also helped prevent degradation.

“If you stop that 20 per cent degradation and keep it up at the original rated power of the panel, you're already quite ahead,” he said.

The team is now assessing which of the 10 candidates performs best, with Hart saying two had emerged as particularly promising. The research has not yet established a quantified improvement in panel lifespan or power output.