Soil compaction caused by 450C Timber Jack wheeled skidder (Shefarood forest, northern Iran)

Abstract

ABSTRACT:In forest harvesting operations usually after using skidding machinery (skidders), traces of soil damage in the form of soil compaction and wheel and logs ruts can be seen in the forest soil. Soil bulk density, which represents soil compaction, decreases soil porosity, infiltration rate and aeration and these in turn increase runoff and water erosion in the harvested area. On the other hand, a decrease in soil aeration prevents root growth and decreases the vegetative cover. In this study the changes in soil bulk density and relative soil compaction due to a different number of wheeled skidder passes from stump to landing for two soil types (clay soil with high and low liquid limits, CH, CL) are analyzed. The results showed that the effect of skidder traffic on an increase in soil bulk density at sample locations was significant (α = 0.05). The range of soil bulk density increases in sample pits due to a different number of machinery passes was from 15.8% to 62.6% compared to the control area. The findings of this research showed that the interaction effect of skidder traffic and soil type on soil bulk density changes was not significant. Also the highest significant increase in soil bulk density occurred at the first 11 passes in skidding trails and from this number of passes onwards there was no significant difference in the soil bulk density increase in sample locations. 315In a study carried out by Jansson and Johansson (1998), the effect of wheeled and tracked machinery was studied on soil bulk density in silt loam soil in Sweden. The results showed that average bulk density increased 23% and 14% at 15 and 20 cm depth, respectively, after two passes of wheeled forwarder machinery (20 ton weight). The traffic of wheeled machinery at the first pass produces the highest compaction in soil and the following machinery passes have a lower effect, but overall soil compaction is produced which significantly affects the root growth (Hatchel et al. 1988). Studies by Burger et al. (1985) showed that the number of machinery passes significantly affects soil bulk density and the soil bulk density of top soil increases very rapidly in the first three passes and the following passes have a lower effect.Skidding operations are the most common way of causing soil compaction (Senyk, Craigdallie 1997). The skidding machinery is designed and manufactured in a way so that it can transport heavy loads in off-road conditions. Hence a major part of soil degradation occurs on skid trails and landings due to skidding operations (Heninger et al. 2002). Froehlich and Mcnabb (1984) came to the conclusion that the initial few passes of skidder have the highest compaction effect on soil. In other words, the initial 5 passes exceptionally increase soil compaction whereas the following passes cause less soil compaction. Gent et al. (1983) proved that in skidding operations using wheeled skidders, the severest compaction occurred at 10 cm depth of soil and the effect of compaction decreases with an increase in soil depth. In skidd...

Effect of Compaction on Physical and Micromorphological Properties of Forest Soils

“…Naghdi et al [5] in their research for two soil types (clay soil with high and low liquid limits) using 450 C Timber Jack wheel skidder showed that the effect of skidder traffic on an increase in soil bulk density at sample locations was significant. The range of soil bulk density increases in sample pits due to a different number of machinery passes was from 15.8% to 62.6% compared to the control area.…”

Rutting and soil displacement caused by 450C Timber Jack wheeled skidder (Asalem forest northern Iran)

“…By measuring the amount of soil dry bulk density in sample locations of skid trail, it was also concluded that by increasing the traffic of a skidder from 14 to 20 passes, soil bulk density changes were insignificant. Naghdi et al (2007) showed that the soil bulk density increase compared to the control caused by different rates of traffic of Timber Jack 450C skidder along skid trails was between 15.8% and 62.6%. The study that was carried out along the skid trail with clay soil showed that there was no significant difference in the soil bulk density increase between two types of soil (clay soil with high liquid limit and clay soil with low liquid limit).…”

Effects of rubber-tired skidder and farm tractor on physical properties of soil in plantation areas in the north of Iran

“…So previous research was focused on soil compaction during skidding operations in mountainous conditions in Iran while there seems to be no study to show its influence in plain areas which is considerably different from mountainous conditions (Mosaddeghi et al 2000;Naghdi et al 2007;Najafi et al 2009;Agherkakli et al 2010;Bagheri, Naghdi 2011). Moreover, few studies have focused on soil compaction caused by rubber-tired skidders such as Timber Jack 450C or farm tractor and even fewer have followed a mechanized logging operation study in plantation areas like the study by Nikooy et al (2013).…”