A new type of soil can pull water from the air and distribute it to plants and could potentially expand the map of farmable land around the globe to previously inhospitable places and reduce water use in agriculture at a time of growing droughts.
Researchers at Texas University have created a self-watering soil that looks set to provide plants with the on-demand hydration they need, even in dry climates.
The clever trick is to incorporate a moisture-absorbing gel in the soil that captures water from the air, then releases it when the soil is heated to a certain temperature, hydrating the plants.
Furthermore, when the soil releases moisture, some of it returns to the air, increasing humidity to repeat the cycle again. The technology essentially sucks up moisture at night and releases it for use during the hot hours of the day.
In testing, the researchers found that their soil retained about 40% of the water it started with compared to 20% in untreated sandy soils, over a four week period. When the team planted radishes in the treated soil, they survived for 14 days without any supplemental irrigation.
The team believes the technology could be used to reduce water use and irrigation costs in drier agricultural areas and even extend growing ranges into previously inhospitable areas.
“Enabling free-standing agriculture in areas where it’s hard to build up irrigation and power systems is crucial to liberating crop farming from the complex water supply chain as resources become increasingly scarce,” says Guihua Yu, associate professor of materials science at Texas University.
As our climate warms and demand for food increases, clever innovations like this will be essential if we are to be able to continue feeding a growing population. Although further ecological impact studies are required before this technology can be widely distributed, it's certainly an exciting prospect.