Vetiver Grass and Erosion
Vetiver is a weather tolerant, fast-growing grass with a very large root system. It can penetrate deep into soil and stabilize it, helping retain nutrients and moisture. For this reason it has been promoted as an excellent crop to combat soil erosion. In addition to this the planting of Vetiver is considered a safe bet, as it will not produce seed and so will not spread from the place it was originally planted. Generally Vetiver has been grown as a hedgerow on the sides of crop fields, especially on hilly terrain. [1].
In India, the planting of Vetiver in hedgerows reduced runoff and increased the yield of other crops. After a hurricane in Honduras, erosion on hillside farms was sharply reduced where Vetiver grasses had been planted. [2].
The huge root system of Vetiver grass. (source)
Sounds great! ...What's the catch?
The planting of Vetiver grass is labour intensive. Think about it- would you want to work for hours in the sun, planting seeds in rows on the side of a steep hill, then have to tend to them until they are finally grown?
Still, yields from crops in fields surrounded by Vetiver hedges have been seen to increase by 50%. Natural terraces also begin to form behind the grass hedges after they are planted, providing more stabilization of the soil. As well, the grasses can be used as animal fodder; even if they are sheared, the roots will stay in place and so continue to protect against erosion. So despite the initial labour required, the benefits to the soil quality, the reduction in erosion and the increase in crop yields are greater. [2].
A Vetiver hedgerow terrace system in Madagascar. (source)