Work efficiency and harvester costs in Brazilian eucalyptus plantations

Abstract

ABSTRACT The awareness of machine productivity is essential when considering the management of mechanized forest harvesting costs, an important issue for sustainable economic planning, especially when considering the significant contribution of this activity to the total cost of timber production. The aim of the study was to evaluate the productivity and production costs of the harvester (cut-to-length system) according to the average volume per tree (AVT), in stands located in the northeast region of Brazil, which varied from 0.16 to 0.58 cubic meters without bark (m3 wb). We considered the commercial volume of wood in this assessment. The productivity of the harvester in stands with different characteristics, including small, medium and large trees, was evaluated. The time study method was employed to perform the technical analysis, which assisted in the calculation of productivity, mechanical availability and utilization rate. Regarding the economic analysis, the fixed and variable costs were evaluated. The results revealed an operating cost of USD 101.75 he−1 for the harvester, being 16.48% for fixed costs and 83.52% for variable costs. The costs of maintenance and repairs, labor, fuel and depreciation represented 84.42% of this total. The harvester showed a lower production cost for large trees (higher average volume per tree). Considerable machine efficiency reduction was observed in a low productivity forest, significantly increasing the costs per cubic meter harvested, varying from USD 2.56 m−3 (large trees) to USD 5.75 m−3 (small trees).