How deep-rooted vetiver could be a useful ally against climate change

Environmental benefits and economic potential of vetiver cultivation in India's sustainable development initiatives.

Across a swathe of over 600 acres in New Chennai Township Private Limited (NCTPL) MARG Swarnabhumi, in Chengalpattu, a perennial grass has been pressed into service to lay the foundation of a net zero carbon campus of six industries and 1,300 homes.

The plant in question is Vetiver (Chrysopogon zizanioides) whose roots tend to make headlines. Derived from the Tamil word that means ‘root that is dug up’, vetiver is also known as ramaccham in Malayalam and kuruveru in Telugu. The Mughals called it ‘khus’ (not to be confused with ‘khus-khus’ or poppyseed).

The roots of the vetiver are the source of a tantalising essential oil obtained through steam distillation, which has been used in perfumes and skincare products for centuries. . It is said that King Harshavardhana of Kannauj, levied a ‘khus tax’, indicating its importance in the perfumeries of yore. Even today, a kilo of pure vetiver oil can cost upwards of ₹20,000 online.

Its evolution as a tool for environmental rehabilitation is a recent phenomenon in India. In the face of extreme weather phenomena like the recent landslides in Kerala, deep-rooted plants like vetiver can prove to be a useful ally against soil erosion.

The ‘gulabi’ strain of vetiver, sourced from Bihar, is being planted initially on 18 acres of the Swarnabhumi project. A vetiver incubation and propagation centre and the development of by-products such as cattle feedstock pellets and sustainable construction materials are also on the anvil.

“Vetiver can sequester 100-500 tonnes of carbon per hectare, outperforming many trees. It helps reduce water run-off and stabilises slopes. The unique quality of this grass is that it can also rehabilitate soil, and treat wastewater through phytoremediation. We have started sowing vetiver in the areas of our project that have been earmarked for afforestation,” says S Sampath Kumar, chief technical officer, Swarnabhumi SEZ.

The Tamil Nadu Agricultural University (TNAU) lists two types of vetiver prevalent in the country: the seeding variety of north India, that grows wild, and the non-seeding variant of south India. Farmed with the help of ‘slips’ (a propagation piece of the grass which represents a small individual plant), vetiver’s roots can grow up to a metre in three months into the ground, and require earth-movers for harvesting. The top half of the plant is used for mulching.