Vetiver: Collection, Harvesting, Processing, Alternative Uses and Production of Essential Oil
Vetiver grass, in particular the species Vetiveria zizanioides, has been known to be a useful plant for thousands of years. It is mentioned in the ancient Sanskrit writings and it is part of Hindu mythology. Rural people have used it for centuries for the oil from its roots, for the roots themselves, and for the leaves. Its domestication appears to be in southern India and it has been spread around the world through its value as a producer of an aromatic oil for the perfume industry. In the late part of the last century and in this century the sugar industry, particularly in the West Indies, the offshore eastern African islands such as Mauritius and Reunion, and Fiji, have used the grass for its soil conservation properties.
Uses and Economic Importance of Vetiver
Vetiver: Planting Techniques
Vetiver was introduced into Europe by the company “Tecnagrind S.L.” from whom the plants are obtainable.
Reproduction of vetiver by separating the clumps
In view of the vetiver high reproduction potential, it can be worthwhile organizing the reproduction of planting material on the farm. The culms which have sprouted can easily be separated by hand, opening out and stripping the leaves off the clump and subsequently transplanting into the field.
Rooting in a pot
When planting for soil conservation, the use of good quality material, well rooted in polystyrene bags or possibly in pots, allows for a higher percentage of plants to take root, greater speed of conservation and less failures. The material can be transplanted into the field when there is no longer a risk of frost. The most suitable containers are of hard plastic, square, 7–8 cm in width and 18–20 cm deep, with a capacity in the region of 1–1.5 litres. The ideal potting material for growth consists of a mixture of peat, sand and soil with a pH close to 7. This is mixed with a substrate of 1.5–2.0 kg/m3 of long release fertilizer (6–8 months).
Farming dedicated to the plant(s) grown in pots is similar to that dedicated to any other green species. Vetiver cultivation requires frequent irrigation to maintain an adequate level of moisture in the substrate and nitrogenous fertilization for 2–3 weeks during the growth cycle. Pruning to a height of 30–40 cm encourages growth of the plants and strengthens the clumps. Due to the lack of pests or diseases in Mediterranean areas, no phytosanitary measures need be taken.
The place built for root and leaf storage must be cool, well ventilated and clean, in order to avoid the development of moulds and bacteria or contamination related to mouse or other animal defecation. This is important to maintain a high quality level, to avoid loss of a part of the harvest and to warrant the conformity to the standard sanitary rules of the raw, semi-manufactured and manufactured products. The store is composed of an uncovered area of about 300 m2 where it is possible to lay the roots after extraction from the soil and to allow them to dry naturally until the optimal humidity degree (15%) is reached. This is about 10 days in the climate present in the Murcia region in November. The store has also a covered area of about 150 m2, that had been employed as a wine vault for wine aging at the farm where the pilot project took place. This choice has been made in order to get a cool and dry place where it is possible to store the roots before distillation.
The store also possesses electrical power, running water at environmental pressure, and enough ventilation for correct root and final product storage. These facilities are also useful for perfect operation of the mobile distillation unit.
Vetiver: Oil Extraction
Vetiver grass is a coarse perennial plant which adapts well to the Mediterranean climate, achieves a high percentage of plants that take root successfully, spreads rapidly and is not a potential weed. The roots develop rapidly in any type of soil, reaching a depth of over one metre in just a few months, and several metres after only a few years, thus making a natural underground barrier, effective in erosion control. Furthermore, a highly valued essential oil can be extracted from the roots.
The economic advantages which derive from vetiver can be subdivided into indirect advantages and direct advantages.
These refer to the economic, environmental and social advantages which derive from using vetiver. In fact, a plant of this type allows erosion control to take place without environmental impact and without the use of complex and expensive man-made constructions. These constructions are often damaging to the environment as rigid control of river and stream waters can provoke dangerous and subsequently disastrous floods possibly causing considerable damage. Furthermore, the planting of vetiver is an agronomical technique which does not involve any kind of pollution. Vetiver holds the soil, the fertilizers, etc. and does not allow the soil to be transported downstream, which would result in the impoverishment of the soil for farming purposes. The fact that the soil is not washed away and that the fertilizers are used in a more efficient way reduces the use and the waste of fertilizers and has important agricultural, ecological, economical and environmental repercussions.
A further indirect economic advantage of vetiver is the increase in the technical abilities of the farmer and the opening of new horizons and cultural awareness.
As was outlined in the paragraph “oil extraction” the vetiver farmer will be able to start small industrial and commercial enterprises which make the work more pleasant, especially for the young farmers. These activities should stimulate the young farmers so that they are less likely to give up farming. This stimulus, together with the use of vetiver in its formidable soil erosion control capacity, has important ecological, agronomical, social and political implications.
The direct advantages from the increase in the farmer’s income derive from:
- the optimal use of the soil, and from soil conservation rather than erosion, which would otherwise lead to waste;
- the increased fertility of the soil due to the reduced erosion of the fertile topsoil and consequent reduction in the use of fertilizers;
- the opportunity to extract essential oil from the roots, with low-cost equipment, low energy consumption and easy maintenance;
- the sale of handicraft products and manufactured handicraft articles based on the vetiver oil and plant;
- the optimum use of time and workers on the farm: indeed, vetiver oil extraction and the production of handicraft products can be performed by female and elderly workers even during the periods of limited farming activity.
Planting vetiver is a simple, low-cost technique, lower in cost for example than other soil conservation techniques, artificial or natural. Vetiver oil (currently solely imported from third world countries) is sold at a price of approximately 110 ECU/kg in the European Union. The average return per hectare is estimated at least 40kg/ha with a surplus value of approximately 4,000 ECU/ha. To this amount the earnings that follow from the sale of handicraft. Finally, it must be considered that the large quantity of biomass produced per hectare (approximately 40 tons of dry matter per hectare) makes it possible to generate electricity on the farm itself.
All this makes vetiver a commodity with great potential and therefore of great interest for farmers in the European regions where a Mediterranean climate exists.
Selections from the book: “Vetiveria. The Genus Vetiveria”. Edited by Massimo Maffei. Series: “Medicinal and Aromatic Plants — Industrial Profiles”. 2002.