Researcher: Forestry waste could boost Estonia's mushroom cultivation

Expanding the use of forestry and agricultural residues could help grow Estonia's mushroom cultivation sector, an associate professor at the Estonian University of Life Sciences says, pointing to untapped potential in both edible and medicinal fungi production.

Mushroom cultivation is a growing field both in Estonia and worldwide, covering not only edible and medicinal mushrooms but also yeasts and biocontrol antagonists. According to Kalev Adamson, associate professor at the Estonian University of Life Sciences, broader use of fungi could help add more value to local forestry and agricultural waste.

Mushrooms have been cultivated industrially in Estonia to some extent since the 1970s. Companies have come and gone, but Adamson believes there is still room for growth in the local sector. "If you pick up a box of mushrooms in a store and look at the country of origin, it often says Poland. There isn't a huge amount of local produce," he notes.

Since mushroom cultivation is developing globally, including in Estonia, Adamson is now contributing to its advancement as an associate professor at the university. In his venia legendi lecture on June 12, he discussed recent trends in the field, including growing edible mushrooms on clear-cut areas, cultivating chaga (Inonotus obliquus), and fungal viruses that alter mushroom properties.

In Estonia, oyster mushrooms, shiitake, and lion's mane (often marketed as a health product) are already cultivated. Yeasts are also produced, and mushroom-based biofungicides are developed. "Quite a few companies are already growing mushrooms in Estonia, both for food and other purposes. So it's certainly worth pursuing these topics," the associate professor says.

One line of research by Kalev Adamson and researcher Marili Vester has examined mushroom cultivation in the Järvselja training and experimental forest. Specifically, they used stumps left behind after thinning operations in mixed forests.

"We have grown various edible mushrooms there over several years—around four to five species: oyster mushroom, phoenix oyster, and velvet shank," Adamson explains.

The research group inoculated the stumps with selected species in spring 2024 using mushroom dowels. Since some species take longer to fruit, final conclusions cannot yet be drawn. "Some mushrooms require the substrate to be fairly decomposed — the stump needs to be quite decayed before fruiting begins. For those, we're only expecting the first harvest this year," he says.

However, it is already clear that not every strain works on every type of stump. The experiment u