Direct and indirect energy input in the harvesting of Scots pine and Norway spruce stump-root systems from areas cleared for farmland
¹Seinäjoki University of Applied Sciences, School of Food and Agriculture, Ilmajoentie 525, FI60800 Ilmajoki, Finland
²University of Helsinki, Faculty of Agriculture and Forestry, Koetilantie 5, Helsinki, Finland *Correspondence: risto.lauhanen@seamk.fi
Abstract:
The aim of this study was to find the net energy and energy ratios for the recovery of Scots pine and Norway spruce stump-root systems when clearing land for cultivations. The energy analyses were carried out for direct and indirect energy under Finnish conditions. In the base study case for direct energy input; the net energy yields for stump-root system harvesting were 446–698 GJ ha-1, and the energy ratios were 22–33. In the case of indirect energy input the net energy yields were 440–692 GJ ha-1, and the energy ratios were 17–26. The proportion of indirect energy was low, because the amount of operating hours annually was high. When calculating indirect energy, only the energy input of machine manufacturing was used, since there was no data on the indirect energy used for repair and maintenance of the machines. The energy assessment for repairing and maintenance operations for heavy forest machines and vehicles in bioenergy procurement will need to be assessed.
Key words:
agricultural land, bioenergy, clarification of forest land, energy assessment, forest machines, wood-based energy.