Wisconsin produces the largest amount of cranberries in the U.S. In fact, half of the world's supply of the fruit comes from the state. It takes a lot of water to grow the tart red fruit, so in order to ensure the survival of their industry, cranberry producers have undergone technological upgrades to help conserve water.
Water is vital to every aspect of cranberry production. Most of it is used to irrigate the crop in the large, rectangular beds, called “bogs” or “marshes,” in which the fruit grows. When it's time for harvest, farmers flood the beds to float the bright red cranberries, making them easier to pick.
Cranberry producers flood the beds again in winter to encase the vines in ice for protection, and again in the spring to kill off any pests. Water is constantly cycling from the beds to the farm's retention ponds to natural rivers.
At Fred Prehn's farm outside of Tomah in southwest Wisconsin, harvest season is wrapping up. Water is draining from the beds back into the public waters. “Basically, this goes down to the Lemonweir River," Prehn explained. “It's our main water source.”
Prehn is like many producers in Wisconsin who are switching over to a more efficient farming operation. He says installing technology that monitors the temperature and moisture in the soil has made the biggest difference.
Prehn is also a dentist, but when he's not on his farm he can check on his cranberries from his office by a computer or smart phone app. “I sit between my patients in Wausau, when I'm not down here, and I can watch the soil monitor. I can see it go down and I make a phone call. Of course, my staff all has iPads and they're basically watching it, too.”
Prehn says the technology has drastically cut back on the amount of watering, since they know exactly how much moisture is in the soil. That also saves on fuel and energy used to pump water into the beds.
In fact, a University of Wisconsin study found that 57 percent of producers are now using soil-monitoring programs. That's up more than 20 percent from four years ago.
Prehn says his farm had its best cranberry yield ever this year. Perfect weather and good workers are a big part of that, “but I really think it's because we're putting on the right amount of water.”
Just a few miles away, third-generation cranberry grower Ed Grygleski drives his pickup truck around his cranberry beds.
He's also taken steps to reduce the amount of water used on his family's farm, but it's hard to tell how much water they've saved. That's because cranberry growers are regularly reusing water from nearby streams and retention ponds.
“We use a lot of water, but we are on watersheds and the water is there regardless if we're there or not and it flows through our marsh,” Grygleski said. "We use it to irrigate and flood, and return it back to the same water source.”
Grygleski says if nutrients are applied to the beds, producers hold the treated water in a reservoir until it's safe to return to the rivers.
Cranberry farmers have a pretty good deal with Wisconsin. A 140-year-old state law allows cranberry producers to use and dam the water for free on their property. Most growers say they don't want to abuse that, so they do their best to conserve their water sources.
They're also paying attention to how water supplies are running low in some parts of the country. Although dwindling water supplies are not a problem in most of Wisconsin, producers are doing what they can to make sure they always have water.
Nicole Hanson serves on a number of agriculture and sustainability boards and is the plant health manager at Cranberry Creek Cranberries, one of the largest producers in the state. “Because the nation is very concerned about water, as an industry, absolutely we want to be proactive," Hanson said. “One of the amazing things about the cranberry industry is the fact that the industry is very progressive, very involved in trying to stay ahead.”
And there’s one more way they’re looking ahead. Like many other producers, Hanson wants to make sure there's enough water so her children can work on the same cranberry farm.