Erosion Control Toolbox: Decompact Soil Surface


Decompact soil surface

Decompaction of Soil Surfaces involves loosening compacted soils by pulling subsoiling equipment in successive passes in approximately perpendicular directions. It is typically performed via two methods: (1) Bulldozer-drawn winged subsoiler (as seen in the left-hand photo above) which is commonly used to decompact soils for agriculture; and (2) Tracked excavator equipped with a subsoiling grapple rake or excavator bucket (as seen in the right-hand photo above). Unlike bulldozer-drawn tilling, the grapple rake raises the soil surface slightly, leaving a small furrow on the surface. The grapple rake leaves the nutrient-rich surface layer intact, allowing water, microscopic fungi and plant roots to penetrate more deeply.

When to Use This Treatment

  • Use on cut and fill slopes 3:1 and flatter. For specific maximum slope gradients, consult your geotechnical engineer
  • Use on highly compacted soils that require tilling to restore infiltration, water holding capacity, and promote seed germination
  • Consider using with compost and/or soil amendment to expand opportunities for cost-effective stormwater pollution control


  • Reduced stormwater runoff volume and velocity
  • Improved infiltration rate
  • Improved soil water holding capacity
  • Improved soil structure, porosity and texture
  • Improved plant rooting depth
  • Improved potential for vigorous long-term vegetation coverage
  • May increase effectiveness of Incorporate Materials when used in heavily compacted soils


  • More costly (yet more effective) than surficial treatments such as Erosion Control (Hydroseed and Hydromulch)
  • May increase the cost of earthwork activities
  • Requires site accessibility by earthwork equipment
  • Not practical for shallow rocky soils, or if excessive soil moisture exists.
  • Not cost effective for compacted clay soils


  • Wendi Goldsmith, Marvin Silva, and Craig Fischenich. May 2001
  • Caltrans Soil Compaction Webinar

Updated: October 1, 2021