Researchers at the University of Texas at Austin have engineered a new kind of “smart soil” that can hydrate plants and deliver them nutrients more efficiently, potentially making for a game-changing advance in agriculture. This new kind of soil has been developed using a specially formulated hydrogel, which showed striking results in laboratory experiments, hugely boosting crop growth while simultaneously limiting water usage.
A team led by Jungjoon Park, a graduate student in the Walker Department of Mechanical Engineering, developed this smart soil system based on a hydrogel material. What’s special about this hydrogel is that it captures the water vapor from the air at night and then, during the day, releases the captured water into plant roots. This controlled hydration ensures that the plants indeed get enough water even in arid conditions. Besides, hydrogel contains calcium chloride that creates very slow releases of key elements as nutrients.
“This new gel technology can reduce the burden on farmers by decreasing the need for frequent irrigation and fertilization,” Park said. This versatility also means that the technology could be adopted across a wide variety of climates, from arid to temperate regions.
This research has huge implications since about 70% of the world’s freshwater withdrawal is used in agriculture and up to 95% in some developing countries. As the rise in global population escalates, the significance of requiring low-impact, high-productive food systems and efficient management of water resources will increase immensely. With most of its activities having low water-use efficiency and many even leading to environmental degradation, in some cases, for instance, by irrigation and fertilization, conventional agriculture is under severe pressure from various directions.
The challenges are pressing, said Guihua Yu, a professor of materials science in the Cockrell School of Engineering. “The global water scarcity coupled with a growing population has an immediate impact on food security,” Yu said. “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.”
Plants nurtured in hydrogel-enhanced soil in controlled experiments showcased a 138% growth in stem length compared to plants grown in regular soil. The modified soil saved water by approximately 40% by reducing the frequency of irrigation and providing better crop growth.
This work grew from earlier revelations in which hydrogels that somehow managed to draw water from the atmosphere were prepared and thus farmed more effectively. The next steps will be the integration of different fertilizer types and prolonged field tests, which will be required to finally validate this technology.
The research was published in the journal ACS Materials Letters, thus marking a reputed step toward sustainable agricultural practices. With advances like smart soil, some hope begins to light up the grim picture of a world reeling under challenges related to water scarcity and food security.