US: Math comes to the aid of local berry growers
As groundwater levels throughout the Salinas and Pajaro valleys continue to fall due to the absence of rain to recharge them, any edge these growers can get, they’re taking with an open mind. According to the U.S. Geological Survey, in 119 years of recorded history, 2013 was the driest calendar year for the state of California. To be sure, California, and specifically coastal Central California, is never overflowing with water in any year, but recent, yearly water-supply needs caused serious concern.
Drought conditions like these are prompting policymakers, conservationists, geologists, hydrologists, farmers and business owners to creatively address the state’s water problems. And, in an interesting turn, mathematicians entered into this mix with a unique perspective.
The math is extremely complex and factors in variables such as soil properties, precipitation data, topography and run-off measurements, all with the purpose of minimizing aquifer impact and to find ways to recharge it naturally.
John Eiskamp, owner and president of JE Farms, a Watsonville berry grower, described why it is so critical to find sustainable irrigation methods in the region.
“This is an agricultural area,” he said. “It’s the driver of the economy. It provides the majority of the jobs. It provides the majority of the support industries that are here for agriculture – the companies that sell the product, the supplies, and the inputs that we growers use to produce the crops.”
Eiskamp estimates that agriculture represents 85 percent of the Pajaro Valley’s water usage, while in the Salinas Valley that figure jumps to just over 90 percent, according to the Monterey County Water Resources Agency. Because of that amount, Eiskamp said growers are well aware that they must be good stewards of the limited water supply.
So, in 2011, a National Science Foundation-funded math institute, the American Institute of Mathematics in Palo Alto, got involved with a consortium of university mathematicians to solve the problem of gaining the greatest efficiency of a varying water supply.
“I’m not sure that a lot of the public actually realize the risks involved,” said Estelle Basor, deputy director of the Math Institute. “So, if we [mathematicians] can just help smooth out some of the decision-making process and help solve a few of the problems that growers might have, I think it’s a really good step forward.”
Basor approached Watsonville-based Driscoll’s and invited them to participate in an institute workshop that brought together 30 mathematicians from around the world to discuss sustainability problems. Nine of the participants worked on the berry problem and, along with three industry representatives, got the ball rolling. These collaborators then formed a smaller group to focus on the water supply’s confined aquifer and its chronic overdraft of water that has persisted over many years.
“This problem is about math,” said Dan Balbas, vice president of operations for Reiter Affiliated Companies, a grower for Driscoll’s. “You’ have a given resource, so how do you maximize it to maintain sustainability and do the right thing from an economic and environmental standpoint, marrying the two.”
The results of the modeling – still a work in progress – has affected the way at least one grower executes his business plan.
“We found that raspberries – from a per-unit-of-water standpoint – were a better crop, so we’ve grown the raspberry program a little bit,” said Balbas, who attended the 2011 workshop said. “Of course, that changed the economics. In fact, we have so many more raspberries now, it would be good to do the analysis again. It’s a moving target. There are a lot more raspberries in the valley, partly because of water, but partly because it was just good business.”
Source: thecalifornian.com