Tiny Sensors Phone Home When Their Plant Needs Water

Wouldn’t it be nice if your plants could email you when they’re thirsty? Thanks to a NASA spinoff, they can!


This tiny sensor measures electrical pulses, creating a proxy for determining leaf rigidity and thus its general health and need for water. Originally developed for astronauts to take the guesswork out of watering (because yes, they, too, panic and overwater, drowning their first crop of lettuce!), the sensors adhere to individual leaves without damaging the plant or falling off when ruffled by wind or rain.

After getting initial support from NASA, inventor Hans Seelig partnered up with entrepreneur Richard Stoner to commercialize the product as a NASA spinoff.

First, they partnered with the Department of Agriculture to test if using the sensors to automatically trigger an irrigation system would actually work. It did, producing a viable crop while simultaneously reducing water use by 25% to 45% of normal. When checking over the data, Stoner realized that while traditional methods stuck to a fixed watering schedule, the sensors adapted to local conditions:

“In our test, we set four watering dates, but what we discovered by looking at the data is that some rain that fell before one of those dates made the irrigation unnecessary. The plants simply didn’t need to be watered—though we couldn’t have known that without the sensors in place.”


Next, they needed to scale up. The proof-of-concept hack involved running wires down the side of a road to attach to a sensor on each individual plant. Although a deeply inefficient setup, it worked: plants in the field were directly telling the farmers how much water they needed, and when they needed it.


Although the sensor is not yet in trials on the International Space Station, the spinoff is successful with a range of commercial products aimed at science and industry and a beta version of wireless sensors. You can also build your own version, or find similar sensors produced by other companies. Considering our ongoing concerns with drought in the west, even if the sensor never leaves the planet it’s contributions to reducing water waste are well-worth the investment.

[NASA | Irrigation control of cowpea plants using the measurement of leaf thickness under greenhouse conditions]


Image credits: AgriHouse Brands Ltd.

Contact the author at mika.mckinnon@io9.com or follow her at @MikaMcKinnon.


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