A robot gardener outperformed human horticulturalists in one vital area

UC Berkeley researchers claim their robotic farmer passes the green thumb Turing Test.
Gardener harvesting beets from ground.
AlphaGarden used as much as 44 percent less water than its human counterparts. Deposit Photos

Even after all that quarantine hobby honing, gardening can still be an uphill battle for those lacking a green thumb—but a little help from robotic friends apparently goes a long way. Recently, UC Berkeley unveiled AlphaGarden, a high-tech, AI-assisted plant ecosystem reportedly capable of cultivating a polycultural garden at least as well as its human counterparts. And in one particular, consequential metric, AlphaGarden actually excelled.

As detailed by IEEE Spectrum over the weekend, UC Berkeley’s gardening plot combined a commercial robotic gantry farming setup with AlphaGardenSim, an AI program developed in-house by utilizing a high-resolution camera alongside soil moisture sensors. Additionally, the developers included automated drip irrigation, pruning, and even seed planting. AlphaGarden (unfortunately) doesn’t feature a fleet of cute, tiny farm bots scuttling around its produce; instead, the system resembles a small crane installation capable of moving above and tending to the garden bed.

[Related: How to keep your houseplants from dying this summer.]

As an added challenge, AlphaGarden was a polyculture creation, meaning it contained a variety of crops like turnips, arugula, lettuce, cilantro, kale, and other plants. Polyculture gardens reflect nature much more accurately, and benefit from better soil health, pest resilience, and fewer fertilization requirements. At the same time, they are often much more labor-intensive given the myriad plant needs, growth rates, and other such issues when compared to a monoculture yield.

To test out AlphaGarden’s capabilities compared with humans, researchers simply built two plots and planted the same seeds in both of them. Over the next 60 days, AlphaGarden was largely left to its own literal and figurative devices, while professional horticulturalists did the same. Afterwards, UC Berkeley repeated the same growth cycle, but this time allowed AlphaGarden to give its slower-growing plants an earlier start.

According to researchers, the results from the two cycles  “suggest that the automated AlphaGarden performs comparably to professional horticulturalists in terms of coverage and diversity.” While that might not be too surprising given all the recent, impressive AI advancements, there was one aspect that AlphaGarden unequivocally outperformed its human farmer controls—over the two test periods, the robotic system reduced water consumption by as much as a whopping 44 percent. As IEEE Spectrum explained, that translates to several hundred liters less after the two month period.

[Related: Quick and dirty tips to make sure your plants love the soil they’re in.]

Although researchers claim “AlphaGarden has thus passed the Turing Test for gardening,” referencing the much-debated marker for robotic intelligence and sentience, there are a few caveats here. For one, these commercial gantry systems remain cost prohibitive for most people (the cheapest one looks to be about $3,000), and more research is needed to further optimize its artificial light sources and water usage. There’s also the question of scalability and customization, as different gardens have different shapes, sizes, and needs.

Still, in an era of increasingly dire water worries, it’s nice to see developers creating novel ways to reduce water consumption for one of the planet’s thirstiest industries.