Logging residue chipping options for short rotation poplar plantations

Abstract

Short rotation poplar plantations grow on flat and even terrain, and the inter-row spacing is wide enough for easy machine access. If the terrain is firm enough, one may consider moving the classic roadside chipping operation directly into the field ( i.e. , terrain chipping), thus saving on wood extraction cost. This study compared the efficiency and cost of roadside and terrain chip-ping conducted with exactly the same equipment, to assess the benefits offered by the versatile deployment of a standard chipping operation, whereby the operation can be moved inside the stand whenever terrain conditions are suitable. The study was conducted at 12 sample plots, containing about one truck load of chips each ( i.e. , approximately 11 bone-dry tons or BDT). Plots were arranged as alternate windrows on a 8.5 ha field. Data was collected for the whole supply chain, from field to factory. The factory was located 14 km from the field. Delivered cost was 53 € BDT -1 and 70 € BDT -1 for roadside and terrain chipping, respectively, i.e. , terrain chipping was 1/3 more expensive than roadside chipping, even if the latter included the additional cost of forwarding the residues to the roadside. The chipper-truck used for the test could not cope with small scattered residue piles (32 BDT ha -1 ), and the cum-bersome reposition maneuver became the main hurdle to efficient operation. Further improvements might be achieved by pre-bunching the residues, introducing a dedicated terrain chipper or bundling the residues and taking the bundles to the factory for centralized chipping.