Soil compaction in timber skidding in winter conditions

Abstract

The research of soil compaction in timber skidding was carried out on two skid trails of uniform slope –15%and 30 %. The degree of soil compaction is shown by changes of water-air soil characteristics of the skid trail after a certain number of passes of a loaded skidder and by comparison between these values and the characteristics of untreaded soil during research. The research was carried out in winter conditions at low air and soil temperatures and with the research site covered with snow. Multiple passes of a loaded skidder affect the degree of soil compaction. The result of soil compaction is the decrease of momentary moisture content, porosity and soil water capacity, as well as the increase of native bulk density. Soil compaction is higher if the soil is not frozen. Due to low air temperatures and disappearance of snow from wheel ruts during skidding, the rut soil gets frozen more easily during the night than the untreaded soil. Soil compaction during the day does not cause squeezing out of water from soil micropores and consequently its freezing enlarges the volume of micropores and increases soil porosity and soil water capacity and decreases its native bulk density