Crossbow's eKo system has triggered an agricultural revolution in the world of precision agriculture and environmental monitoring. This cutting edge system was recently featured in the San Francisco Chronicle and the story can be viewed here.
(08-31) 15:50 PDT -- On a rolling hillside planted with row upon row of Cabernet grapes, viticulturist Jason Cole waxes eloquent about the elusive notion of 'terroir,' a term French farmers use to describe the 'je ne sais quoi' of crops harvested in any given locale.
"Grapes, chocolates, coffee, these are all incredibly good at soaking up their environments and spitting them out in their fruits," said Cole, who oversees the preening and pampering of more than 500 acres of vines planted at the Stagecoach Vineyard in Napa County.
That vineyard is a test bed for a new wireless sensing technology that measures soil wetness, wind speed, temperature and humidity to take the statistical pulse of the vineyard's microclimates to help determine how often and how much to irrigate.
The system being tested at Stagecoach was developed by Crossbow Technology, a privately held, 90-person San Jose company that has created inertial guidance sensors for the aviation industry and researched the use of wireless sensor networks for the federal Defense Advanced Research Projects Agency.
Other manufacturers of microclimate sensing systems include the Austrian company Adcon Telemetry, as well as Ranch Systems of Novato and Grape Networks of San Ramon.
The sensors that Cole is using at Stagecoach Vineyard represent one manifestation of a broader phenomenon called precision agriculture - the attempt to tailor the cultivation of large stretches of land so that the smallest possible subsection of a farm gets special but automated attention.
In the Midwest, with its amber waves of grain, precision agriculture has been synonymous with huge tractors equipped with global positioning systems to keep the rows straight, for instance. But in California, the land of fruits, nuts and other specialty crops, precision agriculture has been expressed in technologies such as Cole's efforts to use wireless sensors to compute 'terroir.'
"The way that growers for many years decided whether it was time to water was they stuck their thumb in the ground," said Robert Robinson, vice president for Crossbow's wireless sensor division.
The basic field kit that Crossbow released earlier this year, priced at $3,359, consists of three sensing nodes that feed data collected in the field through an electronic gateway into what is essentially a Web page that can be viewed from any Internet-connected device. Crossbow says that basic configuration can divine the microclimate of sites as varied as a 4-acre plot of land in hilly and varied terrains such as Napa and 20 acres in the flatter, homogeneous Central Valley. Additional kits can extend the sensing network, wirelessly and indefinitely, over hill and dale.
Moisture sensors
Kneeling alongside a vine at Stagecoach Vineyard, Cole explained how the system, in addition to measuring temperature and humidity with above-ground sensors, sticks a virtual thumb deep into the soil in the form of two moisture sensors, one at a depth of 1 foot and the other at 3 feet.
"The whole point is to monitor what the roots are experiencing," Cole said. "Watering grapes is one of the most important factors to wine quality. You want to stress the vines in order to condense the flavor into smaller berries."
UC Davis Professor Stu Pettygrove, a soil specialist who has tracked precision agriculture in California, said the water-sensitivity of wine grapes, coupled with their high value relative to other agriculture products, make them a good candidate for this high-tech approach. But how many other California crops fit that description? Pistachios were the only other example Pettygrove offered. He said water-stinginess at just the right point helps burst the shells, making pistachios easy to eat.
Tree crops experiment
Professor Michael Delwiche, chairman of biological and cultural engineering at UC Davis, has experimented with wireless sensing systems that precisely apply water - sometimes mixed with chemical fertilizers in a process called fertigation - to tree crops like nectarines. So far, however, the cost benefit is not there in production orchards, he said.
Delwiche said wireless sensing systems and precision watering might find a home in commercial nurseries and flower-growing greenhouses, where the impetus is not purely economic - as measured by greater crop value - so much as it is regulatory. "They are under environmental regulation not to have runoff from the nursery location," Delwiche said.
Eventually, manufacturers will try to improve the performance and bring down costs to encourage broader adoption of wireless sensing systems, he said. Meanwhile, the technology remains economical in niche markets - or exceptionally arid locales.
"In Israel, where water is so dear and they have the technological infrastructure, they're doing a lot of work in this area," Delwiche said.
But at Stagecoach Vineyard, where cachet is central to the business plan, the cost of wireless sensing technology is hardly a barrier to the pursuit of quality.
"We're trying to grasp the 'terroir', but you'll always be grasping, you'll never have it all," Cole said.
For more information on the eKo system, visit the eKo site here.
