Root out erosion

King Bhumibol Adulyadej of Thailand has claimed to have found a solution to soil erosion. Vetiver grass ( Vetiver zizinoidis) boasts of the longest roots in the plant kingdom. A vetiver root can grow to a depth of 568 m in three years. Vetiver poses no threat to native plants and can effectively bind topsoil.

The king is trying hard to popularise the grass in his country. Since currently, the world's trees are being cut and burned 30 times faster than they are being replanted and 20 billion tonnes of topsoil are being washed away annually, vetiver should perhaps be given a chance ( Earth Island , Vol 11, No 3).