Soil changes after traffic with a tracked and a wheeled forest machine: A case study on a silt loam in Sweden

Abstract

Alterations to some soil physical parameters were evaluated after passes by a tracked forest machine and a wheeled one of equal mass (about 20 000 kg). Measurements were made after a range of machine passes, with a maximum of eight. The measured soil physical parameters were dry bulk density, penetration resistance, intrinsic air permeability, saturated hydraulic conductivity, porosity and pore-sized distribution. Rut depth was also measured. Although the wheeled machine caused deeper ruts than the tracked one, alterations caused by the two machines to the measured soil parameters were similar, except in the uppermost 5-10 cm. The wheeled machine caused a decrease in bulk density at 5 cm depth, whereas the tracked machine caused an increase, despite its lower ground pressure.