UT-Austin engineers develop self-watering soil

Arthur Yong

UT engineers have developed a gel that allows farmers to grow crops in areas that were once deemed agriculturally unsuitable.

The gel is a novel super moisture-absorbent gel, which extracts water from the air to be used in soil. Guihua Yu, material sciences associate professor and lead researcher, said the motivation to develop the gel arose from the need to address increasing global food shortages.

“As the global population continues to grow, I think the ability to grow crops on very low-quality or inhospitable land becomes increasingly important,” Yu said. “With our approach, you can chemically modify the soil with our … gel and increase production in those areas.”

According to the United Nations World Food Program’s 2020 global report on food crises, about 135 million people across 55 countries experienced food insecurity in 2019, which is the highest number recorded since the report’s inception in 2017. 

Yu said more countries are interested in providing their own food resources because of the COVID-19 pandemic. 

“Especially this year as the pandemic hit the world, the global food supply chain has been significantly disrupted, so many countries recognize that it's much better to rely on their own and to increase food production,” Yu said. 


Postdoctoral scholar Fei Zhao said the gel works through the combination of two chemical ingredients.

“It’s enabled by a highly hygroscopic component, meaning it can absorb water from the air very efficiently, and a thermally responsive polymer, so under certain temperatures, the gel becomes hydrophobic and releases the water,” Zhao said.

Graduate student Xingyi Zhou said agriculture is only one of many applications for the gel.

“(The gel) can provide clean, drinkable water for families,” Zhou said. “It can also be used to cool energy-related devices like solar cells or in buildings.”

Yu said the gel could also be used for environmental management and fighting land degradation to keep soil healthy for planting food crops.

“Land degradation adds a lot of difficulty to challenges in the future like food and the environment, which you want to preserve,” Yu said.

Yu said the application of the gel on a large scale is limited by high manufacturing costs.

“Some of the chemical ingredients, like the thermal responsive polymers, have never been produced on a commercial scale before,” Yu said. “Since we’re talking about agriculture, we need to produce a significant amount at a significantly low cost for it to be cost-effective.”