The Use of Wood Ash as Fertiliser on Mineral Forest Soil

On the 19th of May, Tapio organised a fieldtrip in North Karelia for Finnish stakeholders to trace the path and use of recycled wood ash, and to visit the VALERIE field trial on the use of wood ash as a fertiliser on mineral forest soil. The visit generated great interest, including the possibility of utilising wood ash in a similar way in southern Finland.

The stakeholders were shown a new pilot area in Kiihtelysvaara where wood ash will be used as a fertiliser for forest regeneration. The trees were felled & harvested in 2016, and in June 2017 the clear felled area was cultivated and planted. In mid-August the Natural Resources Institute Finland (LUKE) led by Hannu Ilvesniemi, will establish a network of experiment areas (30 x 30 m) with a range of wood ash treatments (0, 3000 and 9000 kg of ash). Prior to ash spreading, soil and plant samples will be collected.
The stakeholders also visited Stora Enso Kitee Saw Mill which produces woodchips and bark, and Kiteen Lämpö Oy, a small thermal power plant in Kitee, where woodchips are the main fuel.


Ash from the power plant is used by a local company, Tuhka Hukka Ltd., as a fertiliser in agriculture and forestry.

A brief summary of the wood ash recycling field trip can be found on the European Forest Institute (EFI) Facebook page: