develop system for
tension in soil
By Mateusz Perkowski
Though agricultural sensors are becoming less expensive and more precise, plant physiologist Alan Campbell realized farmers still face a stiff challenge.
Installing sensors, collecting data and interpreting the information often isn’t intuitive, hindering growers from effectively applying the new technology.
“People can buy them but that just creates more problems,” Campbell said. “They don’t want to buy it and create a hundred new problems to solve.”
To simplify decision-making in a crucial realm of agriculture — irrigation — Campbell deploys sensors that measure the tension of water in the soil.
Greater water tension in the soil means that crops are using more suction to draw water from the ground, which stresses them. By monitoring soil water tension, farmers can then adjust irrigation to increase or decrease that plant stress.
For example, a vineyard manager may want to reduce plant stress during bloom to ensure healthy fruit set in the grape vines.
Once that’s accomplished, increasing stress can prevent the leaf canopy from growing too vigorously. Withdrawing irrigation can achieve this result more cheaply and efficiently than mechanical pruning.
“There are many things you want to control by applying stress,” Campbell said. “Depending on the preferences of the winemaker, you may apply more or less stress.”
SmartVineyards, a company co-founded by Campbell, sells sensors and related equipment that collect and transmit soil water tension data to the “cloud,” a network of computer servers, which relays the information to personal computers and cellular phones.
Relying on the concept of computer “machine-learning,” the startup’s software interprets data to guide irrigation decisions that influence various stages of the crop life cycle.
The hardware is outfitted with a miniature weather station as well as a solar panel to power the devices.
Soil water tension is measured at three depths — one foot, two feet and three feet — to better inform how hard the plant is working to draw water.
“There’s a very repeatable pattern here,” Campbell said, referring to the connection between water tension, plant stress and physiology. “We could teach a computer to manage irrigation.”
The system developed by SmartVineyards doesn’t automatically make irrigation decisions. That would take too much authority away from the grower, who can fine-tune water availability based on goals for the wine grapes.
Instead, the company makes it easier to analyze the dynamics of a crop’s water usage.
“We can help people manage complicated situations,” Campbell said.
The idea for SmartVineyards was hatched when Campbell was working as an adjunct professor at the Northwest Viticulture Center in Salem, Ore.
With his children flying the nest, he embarked on a new project in 2013 of comparing the water tension in grape vines to the water tension in soil.
Traditionally, measuring a plant’s water tension required a pressure chamber to gauge the strength of vacuum within the plant needed to suck water through its roots.
“Each measurement ends up costing you about $5, and that’s a very expensive data point,” Campbell said.
The experiment would ultimately cost more than $30,000 in hardware and analytical tools, but he was successful in demonstrating a strong correlation between water tension in the plant and the soil.
The next step involved developing a system that would rely on the more easily measured soil water tension to steer irrigation management.
Since his career was devoted to plant physiology, Campbell needed to recruit an engineer who understood the process of collecting and analyzing data with computers.
At a networking meeting of engineers, Campbell met his co-founder, Hector Dominguez, who specializes in mechanical engineering and robotics.
Dominguez, who has worked on many projects during his career, said he was intrigued by the dirt on Campbell’s jeans.
“This is actually someone going into the field. I can work with that,” he remembers thinking.
The company has since installed its systems in several vineyards in Oregon, California and Washington, and is applying the technology to hops, blueberries, onions, potatoes, cherries, apples and hazelnuts.
In 2017, SmartVineyards received a $250,000 grant from Oregon BEST, a nonprofit that invests in new technology, to team up with researchers from Oregon State University and Washington State University to validate and improve its system.
Smartvineyards is also seeking a $580,000 grant from the Oregon Innovation Council, a public-private partnership, which will facilitate the company’s expansion into other crops.
Occupation: Co-founder and chief executive officer of SmartVineyards
Hometown: Tualatin, Ore.
Family: Wife and two grown children
Education: Bachelor of science in botany from the University of Michigan in 1974, master’s degree in horticulture from Michigan State University in 1989, Ph.D. in plant physiology from the University of California-Davis in 1991
Occupation: Co-founder and chief technology officer of SmartVineyards
Hometown: Portland, Ore.
Family: Wife and young daughter
Education: Bachelor of science in electrical engineering in 1996, master’s degree in mechanical engineering design in 1999, both from the National Polytechnic Institute of Mexico City; master’s degree in mechanical engineering controls from the University of California-Berkeley in 2004. Ph.D. in mechanical engineering from the National Polytechnic Institute of Mexico City in 2011.