EFFECT OF TRAFFIC INTENSITIES OF A DIRECTIONAL FELLER AND SKIDDER ON THE COMPACTION OF A BRUNO NITISOL

ABSTRACT This study evaluated the compaction of a Bruno Nitisol caused by traffic intensities by a directional feller and skidder used to wood harvesting in a Pinus taeda stand. Data were collected at a forest company located in Parana State, Brazil. Samples were performed using an installation of four blocks (30 × 15 m) with subdivided plots and the treatments included a combination of five traffic simulations of directional feller and skidder machines, with the simulations performed in the plots at four soil depths, referred to as subplots. Compaction was evaluated by soil density, total porosity, microporosity, and macroporosity. The data were submitted to analysis of variance and the means were compared with the Tukey test at a 5% level of significance. Linear regression equations were also adjusted to represent the relation between traffic intensity, depth, and the variable of interest. The results showed that machine traffic caused higher compaction of the superficial soil layers, resulting in a 14.6% increase in soil density compared to the soil subjected to no machine traffic. The increase in traffic intensity of the skidder tractor reduced macroporosity by 62.5% and 53.8% at depths of 0-10 and 10-20 cm, respectively. Dragging of the logs by the skidder tractor increased soil compaction due to the several trips by the machine in a single line.