Artikkelit kirjoittajalta Jyrki Hytönen

Annually 2 500–3 500 hectares have been released from peat production in Finland. To meet European Union targets for reducing greenhouse gas emissions, Finland has aimed at substituting fossil fuels with wood-based fuels. The afforestation of cutaway peatlands could create carbon sinks and compensate soil carbon fluxes (Hytönen et al. 2018). High nitrogen content of the residual peat enables high biomass production, while potassium and phosphorus nutrition can be secured e.g. by ash fertilization. Cutaway peatlands could be afforested cost-efficiently with native downy birch (Betula pubescens Ehrh.), which is a primary successional tree species thriving on peatlands. Wood production would be based on natural seeding, early clear-cutting with whole-tree method, and coppice regeneration. This stand management system has shown potential for profitable production of energy biomass without subvention (Jylhä et al. 2015). The present study was aimed at assessing the profitability of growing downy birch on cutaway peatlands, based on empirical productivity models and a larger dataset than in the case study above.

• Jylhä, Luonnonvarakeskus Sähköposti: paula.jylha@luke.fi
• Ahtikoski, Luonnonvarakeskus Sähköposti: anssi.ahtikoski@luke.fi
• Hytönen, Luonnonvarakeskus Sähköposti: jyrki.hytonen@gmail.com
• Aro, Luonnonvarakeskus Sähköposti: lasse.aro@luke.fi

In Finland peat is used in power generation, often burned with wood mixture resulting in mixed ash types. Peat ash is usually rich in phosphorus (P) but poor in potassium (K) and thus not as good fertilizer for peatland forests as wood ash. In this study we compared the effects of peat ash and peat ash with added potassium (potassium chloride or biotite) on the growth and nutrition of Scots pine seedlings on a cutaway peatland. In addition, peat ash was pelletized with biotite in one treatment. The treatments were applied around single trees with 10 replications. The study site was rich in N, but poor in P and K. Peat and foliar samples were analysed, and the height growth of seedlings was monitored for 17 years following the treatments. Pure peat ash had a positive effect on the growth of Scots pine but the survival rate of seedlings was not satisfactory. Peat ash enriched with potassium increased substantially growth of seedlings and increased the foliar K concentration compared to unfertilized control and peat ash alone. Pelletized peat ash and biotite gave similar results as the use of un-pelletized peat ash and biotite. Peat ash alone is not recommended for fertilization of Scots pine stands on drained peatlands. Adding K to peat ash enables recycling of large amounts of nutrients back to peatland forests, and is a good alternative to low-soluble P and K fertilizer. The granulation of the product would ensure good spreadability.

• Hytönen, Natural Resources Institute Finland, Silmäjärventie 2, 69100 Kannus, Finland Sähköposti: jyrki.hytonen@luke.fi
• Aro, Natural Resources Institute Finland, Itäinen Pitkäkatu 3, 20520 Turku, Finland Sähköposti: lasse.aro@luke.fi
• Issakainen, Ratapellontie 11, 91500 Muhos, Finland Sähköposti: ji@nn.fi
• Moilanen, Natural Resources Institute Finland, Paavo Havaksen tie 3, 90014, University of Oulu, Finland Sähköposti: mikko.moilanen@luke.fi

• Hytönen, Natural Resources Institute Finland, Silmäjärventie 2, 69100 Kannus, Finland Sähköposti: ei.tietoa@nn.oo
• Moilanen, Sähköposti: ei.tietoa@nn.oo

• Hytönen, Finnish Forest Research Institute, Kannus Research Unit, P.O. Box 44, FI-69101 Kannus, Finland Sähköposti: ei.tietoa@nn.oo
• Moilanen, Sähköposti: ei.tietoa@nn.oo
• Silfverberg, Sähköposti: ei.tietoa@nn.oo

• Hytönen, The Finnish Forest Research Institute, Kannus Research Station, P.O. Box 44, FIN-69101 Kannus, Finland Sähköposti: ei.tietoa@nn.oo

• Hytönen, The Finnish Forest Research Institute, Kannus Research Station, P.O.Box 44, FIN-69101 Kannus, Finland Sähköposti: ei.tietoa@nn.oo
• Wall, Sähköposti: ei.tietoa@nn.oo

• Wall, The Finnish Forest Research Institute, Kannus Research Station, P.O.Box 44, FIN-69101 Kannus, Finland Sähköposti: ei.tietoa@nn.oo
• Hytönen, Sähköposti: ei.tietoa@nn.oo

• Hytönen, The Finnish Forest Research Institute, Kannus Research Station, Box 44, FIN-69J 01 Kannus, Finland Sähköposti: ei.tietoa@nn.oo

• Veijalainen, The Finnish Forest Research Institute, Box 18, FIN-01301 Vantaa Sähköposti: ei.tietoa@nn.oo
• Silfverberg, Sähköposti: ei.tietoa@nn.oo
• Hytönen, Sähköposti: ei.tietoa@nn.oo

• Hytönen, Sähköposti: ei.tietoa@nn.oo