A newly engineered type of soil can capture water out of thin air to keep plants hydrated and manage controlled release of fertiliser for a constant supply of nutrients.

Underpinning the innovative smart soil system is a hydrogel material developed by researchers at the University of Texas in Austin, USA. In experiments, the hydrogel-infused soil led to the growth of larger, healthier plants, compared to regular soil, all while using less water and fertiliser.

“This new gel technology can reduce the burden on farmers by decreasing the need for frequent irrigation and fertilisation,” said Jungjoon Park, a graduate student in the Walker Department of Mechanical Engineering who led the research.

“The technology is also versatile enough to be adopted across a wide range of climates, from arid regions to temperate areas.”

Agriculture today accounts for 70% of global freshwater withdrawals and up to 95% in some developing countries as our global population continues to rise.

The UN Food & Agriculture Organisation emphasises the importance of improving irrigation efficiency, adopting water-saving technologies and promoting crops with lower water footprints to ensure sustainable food production and water resource management.

Meanwhile, traditional farming methods, especially irrigation and fertilising, face significant challenges, including inefficient water usage and environmental land degradation.

As climate change intensifies and water resources become increasingly scarce, the need for more efficient and sustainable irrigation practices has never been more urgent.

Additionally, conventional fertilisation techniques often result in excessive nutrient exposure, reducing nutrient uptake efficiency and causing environmental pollution, and farmable land degradation.

"The global water scarcity coupled with a growing population has an immediate impact on food security," said Professor Guihua Yu, of the university's Cockrell School of Engineering.

"This new class of hydrogels offers a promising solution to meet the pressing needs of water scarcity and efficient nutrient uptake in modern sustainable agriculture."

In experiments, plants rooted in the hydrogel soil saw a 138% increase in stem length, compared to a control group in regular soil. And the modified soil can achieve approximately 40% water savings, significantly reducing the need for frequent irrigation and ensuring robust crop development. ​

This research builds on previous discoveries involving hydrogels that can pull water from the atmosphere and make farming more efficient. It is part of Yu’s overall mission that dates back to his childhood: to expand access to clean water to people around the globe.

This work mainly focused on calcium-based fertilisers. The project will continue, and the researchers’ next moves involve integrating different types of fertilisers and longer field tests.