More from the article...

... It's been estimated that around 70% of the world's freshwater usage goes towards agriculture. That of course means that in areas where water is more scarce it can be hard to grow crops and feed populations, so scientists are investigating ways to boost efficiency.

Building on earlier work, the new study marks a good step in that direction.

The soil gets its "smart" moniker thanks to the addition of a specially formulated hydrogel, which works to absorb more water vapor from the air overnight, then releasing it to the plants' roots during the day. Incorporating calcium chloride into the hydrogel also provides a slow release of this vital nutrient. ...