5.2 GROWTH IN HIGHWAY EMBANKMENTS WITH VERY DIFFICULT SOIL TYPES

A small stretch of the North-South Highway near Taiping, Perak Darul Ridzuan, was specially selected because the maintenance engineers had failed to establish any grass covers despite repeated attempts. The following photos highlight the planting of Vetiver hedgerows and the good results. The tops of the Vetiver hedgerows grew well. Excavation of the two difficult soil types in this small area showed that Vetiver roots will seek out any weak spot in the soil. Despite the rather poor root system, highway engineers are most impressed by the performance of these Vetiver hedgerows to trap soil-wash and other debris from polluting the drain. Also by slowing down the run-off, the hedgerows have allowed other grasses to grow where they were not able to earlier.