More biofuel extraction requires more ash recycling

The increased extraction of biofuel is threatening the nutrient balance in the forest.

“Harvesting slash removes ten to fifteen times as many nutrients from the forest than what’s lost when you just remove the stems,” explains Daniel Glimtoft of Svensk Skogsgödsling AB.

The solution is to return incineration ash to the forest. Even though the Swedish Forest Agency has prioritised this measure, currently only ten to fifteen percent of ash from the incineration of pure wood fuel is being recycled to the Swedish forests.

“The rest is used to cover landfill sites,” Daniel says.

Svensk Skogsgödsling AB trains landowners in how to ensure their forests have the right nutrient balance, and how to spread ash and fertiliser correctly. At SkogsElmia on 26-28 May, in Jönköping, Sweden the company presented the latest innovation in ash recycling: ash granules whose slow release nutrients benefit the forest for many years.

“Unfortunately people still think this method is too expensive. They want a short-term return on their investment – but this industry has a rotation period of seventy to eighty years,” Daniel says.

A few years ago, an official commission of inquiry in Sweden suggested that more intensive forestry be done on a smaller percent of the country’s land surface, on naturally fertile land further improved with fertiliser and ash. Doing so could increase total timber growth by fifty percent, while most of Sweden’s forested land would still be managed as before, or with even greater environmental consideration.

Everything is already in place to implement such a plan. The ash produced by incinerating pure wood fuel is exactly enough to give the forests the nutrients they need.

“What’s missing is the willpower,” Daniel says, though he adds that more and more landowners are seeing the bigger picture.

“It’s about what kind of forests we want to leave to our children and grandchildren.”

Daniel Glimtoft shows the latest innovation in ash recycling: granules that slowly release nutrients over a long period of time.