In the face of climate change, Maine's wild blueberry growers see a bit of hope
For wild blueberry growers, climate change presents a challenge — but also an opportunity.
A few pipes and hoses are still scattered around Courtney Hammond's wild blueberry fields in Harrington, the last remaining sign of a three-to-four week drought that frustrated wild blueberry farmers this summer.
For the first time ever, Hammond turned to the pond that he typically draws from to flood his cranberry beds, and used it to irrigate his wild blueberries.
"We irrigated the top of the hill and harvested this first, and then moved down to the north side of the ridge that doesn't get the direct sunlight," said Hammond, a third-generation wild blueberry grower who who runs Lynch Hill Farm with his family. "The berries were in better condition."
The dry spell came at the worst time, right as the berries were developing their size.
Irrigation helped. But Hammond estimates that he still lost about half of his crop to drought.
Hammond spent the summer developing a makeshift irrigation system, using sprinkler heads and hoses that he found around his farm, a scrapyard and a local fire department. He connected the hoses to two pumps inside a shed.
"Two pumps running all the time, trying to maintain what we had for our crop," Hammond said. "It was... it was a long season. At least until it rained."
Scientists say earlier harvests and more frequent droughts could soon become the norm as temperatures rise on the blueberry fields. University of Maine research shows those fields are warming at a faster rate compared to the rest of the state as a whole.
It's not all bad news, said YongJiang "John" Zhang, an assistant professor of plant physiology at the University of Maine. Warmer temperatures will extend the berries' growing season.
"They have more time to accumulate carbohydrates or sugars, and they have more time to grow," he said.
That means the berries will be heavier, generating a better yield for farmers, as long as steps are taken to address the drier conditions.
"If we provide them enough resources, maybe we can turn the warming or climate change into a good thing for the crops, if we can mitigate those negative impacts," Zhang said.
About 12 miles away from Hammond's fields is the university's research farm in Jonesboro, where Zhang and his team are studying how the berries respond to warmer temperatures.
They're using about a half dozen climate chambers, small, six-sided structures made of plexi-glass. They're just about two feet tall and surround the berries planted in the soil. They're open at the top.
"It's just like a small greenhouse," Zhang said. "It will warm up the atmosphere inside just like a greenhouse, and to further raise the temperature we are using these heating tapes."
The berries are warmed by 3 to 5 degrees Celsius, the temperature that researchers project the region will experience by the end of the century.
They're also testing techniques that the university hopes Hammond and other growers will eventually use to mitigate the impacts of climate change.
In one of the chambers., the has been covered with a material designed to retain moisture, known as biochar. It's a byproduct of sawmills, that when burned at the right conditions, resembles a "fancy charcoal," Zhang said.
"We just apply the bio-char on the surface," he said. "But for example during the rain events they will get into the soil, mix with the soil. And they can change the soil properties, increase the water holding of the soils, to mitigate the drought impacts."
The initial results are promising, Zhang said. Researchers will test the material on a larger field next year, to find the proper mix of biochar to soil.
The goal, Zhang said, is to use enough biochar to increase soil moisture for the plants, without making the practice too expensive for blueberry growers. There are relatively few biochar producers in Maine today, though both the university and a company called Standard Biocarbon are trying to start up operations.
In the meantime, studies are also underway to test other growing practices.
"There's definitely a lot of room in the wild blueberry industry to invest in irrigation," said Rachel Schattman, an assistant professor of sustainable agriculture at the University of Maine. "But the other part of that that doesn't get talked about nearly enough is water source development. So can people get the water to put it on their fields to begin with? It can be quite expensive. Most people dig deep wells, which can be very expensive to drill."
Schattman is studying whether a new type of shallow well can be used to irrigate wild blueberries that's less expensive to dig than traditional wells.
The university is also researching the effects of invasive pests on wild blueberries, and it's planning other precipitation and pollination studies. Zhang, Schattman and others will place their studies on a soon-to-be-built research farm closer the main Orono campus. Wyman's, one of the largest producers of frozen wild blueberries, is a partner.
Grower Courtney Hammond said he's eager to see what solutions the university comes up with. He'd like to find a way to hold more moisture in the porous, gravelly soil, so that when he does irrigate the barrens, he doesn't have to use as much water.
"Some of us have come to the realization that some water is better than no water," Hammond said. "For these short-term droughts that we might have — if we were able to irrigate sometimes maybe just three or four times — it would be enough to maintain that fruit, so that we could get it harvested and still have a high quality product."
As for next season, Hammond said he's purchased enough hoses and sprinklers to irrigate an entire field at once.