As published in ACS Materials Letters , the equipment's atmospheric water irrigation system uses super moisture-absorbing gels to capture water from the air. When the soil is heated to a certain temperature, the gels release the water and make it available to the plants. When the soil distributes water, some of it returns to the air, which increases humidity and facilitates the continuation of the harvesting cycle.

“Permitir la agricultura autónoma en áreas donde es difícil construir sistemas de irrigación y energía es crucial para liberar la agricultura de la compleja cadena de suministro de agua a medida que los recursos se vuelven cada vez más escasos”, dijo Guihua Yu, profesor asociado de ciencia de materiales en el Departamento de Walker. de Ingeniería Mecánica.

Each gram of soil can extract approximately 3-4 grams of water. Depending on the crops, approximately 0,1 to 1 kilogram of soil can provide enough water to irrigate about one square meter of farmland.

Soil gels draw water out of the air during the cooler and wetter periods of the night. Solar heat during the day activates the gels that contain water to release their content into the soil.

The team conducted experiments on the roof of the Cockrell School Engineering Teaching Center building at UT Austin to test the soil. They found that hydrogel soil was able to hold water better than sandy soils found in dry areas, and needed much less water to grow plants.

During a four-week experiment, the team found that their soil retained about 40% of the amount of water it started with. In contrast, the sandy soil only had 20% of its water left after just one week.

In another experiment, the team planted radishes in both types of soil. All radishes in the hydrogel soil survived a 14-day period without any watering beyond an initial round to make sure the plants took hold. The radishes on the sandy soil were watered several times during the first four days of the experiment. None of the radishes on the sandy soil survived more than two days after the initial irrigation period.

“La mayor parte del suelo es lo suficientemente bueno para soportar el crecimiento de las plantas”, dijo Fei Zhao, investigador postdoctoral en el grupo de investigación de Yu que dirigió el estudio con Xingyi Zhou y Panpan Zhang. “El agua es la principal limitación, por eso queríamos desarrollar un suelo que pudiera recolectar agua del aire ambiental”.

El suelo recolector de agua es la primera gran aplicación de tecnología en la que el grupo de Yu ha estado trabajando durante más de dos años. El año pasado, el equipo desarrolló la capacidad de utilizar materiales híbridos gel-polímero que funcionan como “super esponjas”, extrayendo grandes cantidades de agua del aire ambiental, limpiándolo y liberándolo rápidamente utilizando energía solar.

The researchers envision several other applications of the technology. It could potentially be used to cool solar panels and data centers. It could expand access to clean water, either through individual systems for households or larger systems for large groups such as workers or soldiers.