Vetiver Grass Technology (VGT) or Vetiver system (VS) as it is called now, in its most common form, is the establishment of a narrow live grass barrier, in the form of a hedge, across the slope of the land. A well established grass hedge will slow down rainfall run off, spreading it out evenly, and will trap runoff sediments to create natural terraces. Apart from soil and moisture conservations, VGT has been extensively used for watershed development, engineered structure stabilization, pollution control, groundwater improvement, flood control, land rehabilitation, disaster mitigation, control of water borne erosion in costal regions, handicrafts (pest-free mattress and pillow stuffing, floor mats) medicines etc.
The Company is a pioneer in adopting VGT in tea plantations and carried out extensive studies on various aspects/applications of the same. Vetiver was introduced in tea plantations of the High Range (Kerala), south India for preventing soil erosion and moisture conservation by the R&D Department. Use of this technology by establishing live hedges of vetiver grass resulted in replacement of conventional revetments for soil and moisture conservation. When planted as a contour hedge it acts as a continuous filtering system that slows down rainfall runoff resulting in reduction of rilling and gullying, and collects soil sediments at the hedge face. Soil and nutrient loss is reduced, soil moisture and ground water improves significantly, and natural terraces and ground leveling develops behind the hedge. An important feature is that Vetiver grass takes up minimal space and is virtually non competitive with adjacent crops. A germplasm with more than 40 cultivars collected from various sources has been established and their suitability for various technical applications is being studied periodically. Varieties like ‘Madupatty’, ‘Silentvalley’ and ‘Gundumallay’ with diverse characters for soil and moisture conservation/extraction high quality oil were identified.
Beach stabilization/conservation in Fisherman’s Cove (Chennai):
Water borne erosion and tidal surges are making it difficult to maintain the coastal embankment area. Due to high tidal activities, the beach in front of Fisherman’s Cove has been eroding into the sea. To prevent erosion, vetiver variety ‘Madupatty’ multiplied at Munnar was planted in the beach in contour rows without disturbing the aesthetics. The plants established well and growing vigorously forming a thick edge for preventing the erosion of beach into the sea. The plants are periodically trimmed at about 9 to 12″ to induce more laterals.
Use of Vetiver Grass Technology for capping of Jarofix dump site and Management, HZL, Chittorgarh, Rajasthan:
This is a unique project taken up by the Company in collaboration with Hindustan Zinc Limited, Chittorgarh, Rajasthan. During the production of zinc, large quantities of Jarosite along with smaller quantities of other process residues, spent catalyst, ETP sludge, etc., are being generated. The Jarosite is converted into an inert, non-leachable and reutilizable material known as ‘Jarofix’. After necessary treatments the Jarofix is being maintained in the secured landfill sites to prevent contamination. Due to non availability of essential nutrients like organic carbon, nitrogen and high quantities of heavy metals, in general plants do not grow on Jarofix.
The Company recommended VGT for providing green cover and phyto-remediation in the Jarofix dump site. Under this project, more than 10 lakh vetiver tillers of ‘Madupatty’ and ‘Silentvalley’ were transported from Munnar to Rajasthan (about 2200 km) under critical supervision and established in contour rows in the Jarofix dump site. The tillers are establishing well and observations on biometric parameters and physical, chemical and biological changes in the Jarofix due to planting of vetiver are under progress.