Agriculture uses 85% of the world’s fresh water, and many irrigation methods are inefficient. “If you go to the fields, you see standing water”, says Ken Goldberg of the University of California–Berkeley (Berkeley, CA). “A lot of it is wasted.”
Many crops are overwatered, such as these furrow-irrigated grapevines in Australia.
But delivering the optimal amount of water is tricky, partly because each plant can have different needs. “Some get less light, some are in soil that doesn’t drain well”, Goldberg continues. Moreover, it can be a fine line between too much water and too little. This is particularly true for wine grapes, where judicious water stress can boost crop quality.
Scale is another challenge. “How do you make adjustments when you have a million plants, each with its own water emitter?” Goldberg asks. His team, which includes researchers from UC Davis and UC Merced, thinks they have an answer: “Our idea is that robots go through the field and make the adjustments.” The team was recently awarded a $1 million grant from the US Department of Agriculture (Washington, DC) to turn their idea into a reality.
Goldberg has devised a new emitter that requires a robot’s touch. Unlike conventional emitters that are turned on and off by pulling and pushing, the new ones have little screws that are turned to regulate the flow of water precisely. “The adjustments are as small as a quarter turn – people aren’t good at this”, Goldberg says. Emitter adjustments will be based on data from sources like soil water and weather sensors.
The system will not be entirely automated, however. “Fields have really bad conditions, and it’s a challenge for robots to travel reliably through them – but people are good at this”, he continues. The team’s solution combines the complementary strengths of people and robots: people will go to the right spots, and hand-held robotic grippers will fine-tune the emitters.
The new robotic irrigation system will be simple and affordable enough to be widely adopted. “Emitters can be retrofitted for a penny per plant”, Goldberg says. Lab trials will start this spring, and field trials in California vineyards could start as early as this summer.
By Robin Meadows
Originally published in Frontiers in Ecology and the Environment‘s March 2nd, 2017 issue titled Dispatches.