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Contour Scarification
What is Contour Scarification?
The upper part of the soil profile is tilled and mixed across the slope on
the contour using small machinery or construction equipment. The purposes of
this practice are to break up the hydrophobic characteristics of soil in
moderate and severely burned areas, to aid in the establishment of vegetative
cover from seed, to reduce runoff velocity, to increase infiltration, and to
reduce erosion.
When is Contour Scarification Used?
Contour scarification is used on burned upland areas with hydrophobic soil
properties that are accessible by machines and will be stabilized with seeded
vegetation. Slopes should be equal to or less than 30 percent to facilitate safe
operation of machinery. Slopes with a stable rock face do not require
scarification. Contour scarification is not used in swales, drainage ways,
gullies, or other areas of concentrated flow. One hindrance to contour
scarification is that there is often too many burned trees in the way to use
equipment.
How is Contour Scarification Performed?
Small tractors, bulldozers, or all-terrain vehicles are fitted with a tool
bar containing tines, rippers, or other devices capable of loosening and mixing
the soil to a depth of two to four inches. A contour line is marked about
one-third the way down the slope to establish a key line. The machines are
operated parallel to the key line. The entire slope may be scarified to
accomplish the maximum effect. To reduce treatment costs, contour scarification
can be accomplished in eight- to 10-foot-wide strips spaced uniformly over the
slope. The maximum recommended spacing between scarified strips is shown below.
| Slope Gradient (percent)
| Contour Strip Spacing (feet)
|
| <5% |
160 |
| 5-10% |
120 |
| 10-20% |
60 |
| 20-30% |
30 |
| >30% |
not recommended |
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