UO ecologists secure $2 million to boost soil health of Oregon hazelnut farms
A mix of native wildflowers and volcanic rock dust can offer climate resilience for filbert orchards
What started as a dozen trees on a family farm is growing to 20 partner farms across the state through a $2 million federal investment to set a new standard for sustainable agriculture.
Ecologists from the University of Oregon have designed a soil health management system to strengthen the long-term vitality of the state’s hazelnut industry. Oregon produces 99 percent of the nation’s hazelnuts, but the escalation of global extreme heat, which brings dry soil and scalded plants, threatens the agricultural productivity of the region.
A promising solution: carpeting the orchard floor with native wildflowers and basalt dust.
Native cover crops bloom in a hazelnut orchard. (Photos courtesy of Lily Robbins)
“To be resilient to climate change and to minimize climate change, you need healthy soil,” said Lauren Hallett, an associate professor of environmental studies and biology at the UO’s College of Arts and Sciences.
For the past five years, Hallett and her colleague Marissa Lane-Massee, a research assistant at the UO and fourth-generation hazelnut farmer, have worked together to create cover crop seed mixes that keep agricultural soils cooler during increasingly hotter seasons without interfering with the harvest. Compared to bare soil, a blanket of cover crops can better regulate soil temperature and enhance water retention and soil microbiology.
To test and demonstrate the soil management system at scale, the research pair was recently awarded $2 million in federal funds from the U.S. Department of Agriculture to partner with 20 Oregon hazelnut farms. U.S. Sen. Ron Wyden of Oregon established the USDA program through his work on the Inflation Reduction Act. The effort built on his earlier work on the 2018 Farm Bill to promote soil health and climate resilience.
“Oregon is great at both growing things and adding value to them, but we need to make sure we do both in a sustainable way,” Wyden said. “I am always eager to support programs that tackle challenges farmers face while helping address the climate crisis.”
The research team additionally consists of Lucas Silva, a professor of environmental studies and biology, and Nik Wiman, an associate professor of horticulture at Oregon State University.
Despite its whispered potential, cover cropping historically has had a negative stigma among hazelnut farmers, Lane-Massee said. The orchard ground is conventionally left bare because of concerns that adding vegetation would tangle up fallen nuts and mess with harvesting, she said. A clean orchard floor is considered a good orchard floor.
“My grandma always said you got to keep the orchard like a golf course, so that when you go to harvest, the nuts roll right across the ground and into the machine,” Lane-Massee said. “But there's also cultural and aesthetic reasons, like wanting an aesthetically pleasing understory with smooth floors and rows that are neat and tidy."
Marissa Lane-Massee checks to see if the cover crops make it difficult for equipment to pick up hazelnuts on her family’s farm.
Unlike tangle-prone grasses or weeds, the research pair’s cover crop mix includes native wildflowers, including camas, checkermallow and phacelia, that harmoniously follow the hazelnut lifecycle. The cover crops sprout in late fall, grow to a small ground cover in winter and bloom taller during spring and summer. They improve soil integrity by acting as a shield from the sun, retaining soil moisture and preventing erosion.
By autumn when trees drop their hazelnuts, the wildflowers have already died back, allowing for easy, untangled picking. To validate this, Lane-Massee checks how many hazelnuts remain unpicked in each plot after the harvesting machines plow through as part of their data collection process. The ideal is two nuts or fewer to avoid profit losses, she said.
As perennials, the cover crops grow back once the fall rains begin.
“You never have to reseed. It’s a one-time input,” Lane-Massee said.
Some regrowth of the cover crops a week after a rainy day in the fall
The cover crop mix will be used alongside basalt dust amendments, which can potentially help mitigate climate change. When basalt gets weathered down by rain or wind, a chemical reaction occurs that removes carbon dioxide from the atmosphere and converts it into stable minerals. These wash into local streams and rivers and eventually flow into oceans where they stay trapped on the seafloor for thousands of years — a tactic to address carbon pollution.
Spreading the dust can also increase the pH of the soil, serving as a carbon-sequestering alternative to conventional lime. The process has the potential to scale up quickly because basalt powder, a byproduct of mining, isn’t in short supply with Oregon’s Columbia Plateau as a local source, Hallett said.
Basalt dust may be a climate-mitigating alternative to lime.
The Lane-Massee Farm is the first hazelnut orchard to use basalt dust amendments and plans to investigate how it can be scaled up to commercial farming. Measuring how much carbon gets stored and the amount of powder to apply for the best results is hard to ascertain, Hallett added, but basalt dust is a very compelling source of permanent carbon removal.
“This is potentially one of the most promising natural climate solutions but also one with the biggest range of uncertainty,” she said.
Stop and smell the wildflowers
The work started from Lane-Massee's undergraduate senior thesis in 2019. She and Hallett were initially working on the restoration of Oregon’s oak tree ecosystems but identified a shared problem in hazelnut orchards: the frequency of pesticides and labor needed to maintain a clean understory from unwanted bugs and plants.
Native wildflowers from the Willamette Valley, on the other hand, naturally suppress weed invasions and only need to be mowed annually and sprayed with herbicides once. Their low maintenance comes from the fact that they have co-evolved with Indigenous burning practices over thousands of years, Lane-Massee said. Unlike conventional cover crops, the native plants have adapted to fire disturbances, and because burning functionally translates to mowing, she said the cover crops survive, even thrive, after being trimmed down.
A hazelnut tree marked in a plot with cover crops. The letters on the tag represent, from top to bottom, a seed mix of cover crops (S), sprayed with herbicide prior to seeding (S), no fertilizer (NF) and the fifth iteration of the plot (5).
Lane-Massee asked her parents if she could use part of their hazelnut farm in Salem to test the cover crop mix. They gave her three small plots of 12 trees, but that was more than enough to show promise.
“If it can handle the flailing, the scraping and the ‘beat-down-to-the-dirt’ attitude of a hazelnut farmer, it can go far,” Lane-Masse said. “Our pilot was from 2019 through 2021, and those plants were so resilient. I mowed it down every year and they kept coming back and flourishing. They survived ice storms and 115-degree weather, outperformed the weeds that would otherwise interfere with harvesting and expanded their range out of these tiny plots.”
Lane-Massee continued this work through her graduate studies and is now a research associate at the UO. Her research plots have grown to 10 acres, a scale at which it has become clear they’re compatible with productive orchard management.
In addition to supporting his daughter’s education, Paul Massee wanted to give back to both the hazelnut industry as a third-generation farmer and the UO as an alumnus. He said he didn’t expect the service to be through a research-driven endeavor, but the experience of co-creating with scientists and farmers has opened his eyes to the larger world beyond his shed and orchard.
“If this is the kind of legacy of our farm, all the better,” Massee said.
But what works on one orchard may not work for another.
“Every farm you go to has a different story,” Lane-Masse said.
To expand, apply and personalize this system at scale to hazelnut farms across the state, the U.S. Department of Agriculture awarded $2 million in federal funds to the research team as part of its Conservation and Innovation Grants program. They will partner with 20 farms across the Willamette Valley to provide incentives and technical support for adoption and demonstrate the ecological and economic benefits.
“I hope that, with the research we're doing, we can offer more of a tailored scientific perspective and experience to what each individual farmer is doing,” Lane-Massee said. “The blanket science will not work for every situation. It's really important that science learns from the people it's trying to help and that farmers learn from science.”
Paul Massee, a hazelnut farmer, uses a forklift to pick up a loaded tote of harvested hazelnuts.
Until the cows come home
One of the hurdles of the work is overcoming the tendency to return to the conventional method, Massee said. Transitioning from bare dirt to a woodland-like understory, he said there will be resistance to change due to the generations of programming to keep an orchard tidy.
“Farmers, and I know I’m in this category too, we're awfully skeptical of new stuff,” Massee said. “Until somebody's brave enough — or foolish enough, as is the case sometimes — to try something different, folks are thinking with their pocketbooks. Especially since we've had a spate of low-income years recently in the hazelnut industry.”
A seed mix of a flowering perennial plant, Rumex salicifolius
Another barrier is the expenses. Currently, native wildflower seeds and basalt dust amendments are not as cost effective or widely available as conventional methods, Hallett said. But in order to make them economically feasible, you need to demonstrate the practice as powerful, she said.
"It’s a bit of a chicken-and-egg problem,” Hallett said.
The research pair said it will likely take a generation, or more, until the soil health management system becomes standard practice. But they believe the new federal backing could be the tipping point in gaining industry and agricultural support.
“I hope someday when I drive down I-5, I just see fields of wildflowers and happy growers,” Hallett said.
A farmer of the Lane-Massee orchard drives a machine to sweep fallen hazelnuts into piles.
This work was supported by funding from the U.S. Department of Agriculture and the National Science Foundation.
