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.
Maximum recommended spacing between scarified strips.