The roots of this grass can go deep down in the soil. Some ecotypes can push down the roots as deep as four, five or even six metres while other may be only at three metres. This helps protect the soil from eroding and build up the strength of the soil making it usable as needed. For example, along the roadsides up to Doi Tung, the soil was bound together tightly and the plants grown were kept in their place. The roads were safe and strong because of the vetiver grass. Therefore, the vetiver grass enabled us to safely plant trees along the roadsides and to prevent erosion which would otherwise cause damages to agriculture."