Södra has developed a bio-ash that comprises nutrients from forest raw materials and can be produced at the company’s own mills. The material will be used to return nutrients to the forest in order to close the ecosystem and ensure long-term production capacity, as the company said in the press release received by Lesprom Network.
“There are currently no signs of nutrient depletion, but we must think about the long term and ensure we have a system in place that will enable nutrients to be returned to the forest for many years to come,” said Hedvig Johansson, Project Manager. “Research suggests that – if executed effectively – returning nutrients to healthy forest land could result in increased forest growth for at least ten years after the bio-ash is spread. On fertile land, this could mean an additional 15 m³ fo per hectare.”
The bio-ash is produced by mixing the ash from the pulp mill’s bark boiler with nutrients extracted from wood raw material in the digester. Södra’s bio-ash contains nutrients such as magnesium and potassium as well as a high proportion of calcium, which helps to achieve a lower rate of acidification in the forest.
So far, Södra has spread this newly developed bio-ash on 600 hectares of member forest land in the Sweden’s eastern Småland region, achieving a positive result. The initiative is now being scaled up and the bio-ash will be spread on approximately 1,200 hectares of forest land by autumn 2017.
