Researchers at The University of Texas at Austin have engineered a new type of soil infused with a hydrogel material that can capture water from the air and provide a controlled release of fertilizer. This innovative “smart soil” significantly enhances plant growth and reduces water and fertilizer usage.

“This new gel technology can reduce the burden on farmers by decreasing the need for frequent irrigation and fertilization,” 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.” The research was recently published in ACS Materials Letters.

Agriculture today accounts for 70% of global freshwater withdrawals and up to 95% in some developing countries. As the global population rises, the U.N. Food and Agriculture Organization emphasizes 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. Traditional farming methods, especially irrigation and fertilization, face significant challenges, including inefficient water usage and environmental degradation. As climate change intensifies and water resources become scarcer, efficient and sustainable irrigation practices are urgently needed. Additionally, conventional fertilization techniques often result in excessive nutrient exposure, reducing nutrient uptake efficiency and causing environmental pollution and land degradation.

“The global water scarcity coupled with a growing population has an immediate impact on food security,” said Guihua Yu, a professor of materials science in the Cockrell School of Engineering’s Walker Department of Mechanical Engineering and Texas Materials Institute. “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 grown in the hydrogel-infused soil exhibited a 138% increase in stem length compared to plants in regular soil. The modified soil also achieved 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, making farming more efficient. It is part of Professor Yu’s mission, which dates back to his childhood, to expand access to clean water globally.

This study mainly focused on calcium-based fertilizers. The researchers plan to integrate different types of fertilizers and conduct longer field tests in future studies.

Joining Yu and Park on the project are Weixin Guan and Chuxin Lei, graduate students in the materials science and engineering program and Texas Materials Institute.

By Impact Lab