WATER PURIFICATION AND SOIL CONSERVATION

The root of the solution

Vetiver grass plants, vetiveria zizanioides (in Tamil, the word means 'dug up root') have long been known to provide economical protection against soil and water loss, and more recently they have also been found to be useful for water purification. However, the bone of contention is, while other nations have rapidly embraced it, in India its adoption remains rare.

In 1987, noting that soil erosion is the most serious agricultural problem in the world, Richard Grimshaw and John Greenfield, two agricultural scientists of the World Bank decided this had to be tackled on war footing. During their visits to different states of India, they chanced upon the solution they were so eagerly looking for in a sleepy village near Gundlupet in Karnataka. "We learnt from these farmers that they have been successfully growing vetiver against soil erosion for centuries. It reduced rainfall runoff by as much as 70%, recharged groundwater (villages that use vetiver have much higher water levels in their wells), and improved ephemeral stream flow."

In the hilly terrains where tea is grown, soil erosion is a big problem. The tea estates established by the British didn't have permanent soil and water conservation measures. As such, during replanting, a lot of expenditure has to be incurred for this. In the past, our company too spent heavily to construct stonewalls (revetments) across the slope. Depending on the gradient, normally two or three walls (top, middle and bottom) will be needed. On an average, stone revetments for a hectare of tea garden would require 350 man-days. Instead, 100 man-days would be sufficient if you opt for vetiver hedges."

Subsequent studies prompted the World Bank to launch The Vetiver Network (TVN), which has been disseminating vetiver technology to the world with a missionary zeal. Now there are more than 20 vetiver networks in the world and newer ones are being formed every year. In China alone, vetiver is so popular that the country now has a Chinese Vetiver Network and 6 corporations for the implementation of vetiver systems for environmental protection.

Best candidate for 'earth repair' :
What makes vetiver so popular? It's perennial and requires minimal maintenance. It's both xerophyte and hydrophyte. Once established, it can withstand drought, flood and long periods of water logging. It will grow in all types of soil regardless of fertility, pH or salinity. It is highly tolerant to toxic levels of aluminium, manganese, arsenic, cadmium, chromium, nickel, copper, mercury, lead, selenium and zinc. It will grow in a wide range of climates, survives in areas with average annual rainfall between 200 and 6000 millimeters and with temperatures ranging from 1 to 45 degree C. It is a climax plant and therefore even when drought, flood, pests, diseases, fire or other adversity destroys all surrounding plants, vetiver will remain to protect the ground from the onslaught of the next rains. It has a strong fibrous root system that penetrates and binds the soil to a depth of three meters and can withstand the effects of tunneling and cracking.

The vetiver system is low cost and extremely effective system for soil and water conservation, infrastructure stabilization, pollution control, wastewater treatment, mitigation and prevention of storm damage and many other applications.

Vetiver grass, vetiveria zizanioides, is central to all vetiver system based bioengineering and conservation applications. It can be used in the tropics and semi tropics, and areas outside the latter (such as Italy and California that have a Mediterranean climate) where there are hot summers, and winters that do not include permanently frozen soil conditions.

The roots of the grass have an average tensile strength of Mpa 75 (one-sixth the strength of Mild Steel), and improve the shear strength of soil by between 30 and 40%. Engineers liken them to a "living soil nail". (for more details see: http://www.vetiver.com/)

Crutch for rain-fed farmers

Richard Grimshaw, now President of TVN recalls "When I was introducing the vetiver system in areas, I introduced it by saying 'We have a technology that can improve your yields by 15-50%, that is permanent, once established, costs nothing and will drought proof your crops'. Then I go on with the explanation of how vetiver hedges conserve runoff and increase the moisture in the soil. Farmers are not interested in spending money on "soil conservation". Vetiver hedges providing moisture conservation are of course preventing soil erosion; you just don't need to mention it."

Are these vetiver hedges in any way better than contour bunds? "A bund diverts runoff to the drainage network, thus denying the rainfed farm the full benefit of the rainfall it gets. The area immediately in front of the bund rarely gets sufficient moisture for crop growth. The vetiver hedge holds the rainfall back, spreads it out and gives it a chance to soak in to the ground as stored moisture. Excess runoff filters through the hedge and carries on down the slope at greatly reduced speed, but wetting all the ground as nature intended it to do."

"In a particular case in Karnataka," he recalls, "the farmers had planted their Ragi, received six millimeters rainfall, enough to germinate their seed but then no more rain for over a month, the seedlings died. Their neighbors who had planted vetiver hedges retained enough moisture in the soil to carry their plants over and produce very good yields."

"Soil moisture is essential for crop growth", analyses John Greenfield, "So, it is no use talking about the benefits of 'drought tolerant' and especially 'drought resistant' (which don't exist) crop varieties, as without sufficient moisture none of these will survive. Therefore it is essential that the rain fed farmer controls runoff to enhance moisture conservation - controlling runoff also control soil loss. The only efficient way to control runoff is with the use of vetiver hedges."

Apart from its value for soil and water conservation, vetiver can check weed invasion too. It can block the spread of other grasses including some of the world's worst creeping grasses. In Zimbabwe tobacco farmers reportedly plant vetiver around their fields to prevent invasion of other tough grasses. In Mauritius sugar cane growers rely on vetiver to prevent Bermuda grass from penetrating their fields from adjacent roadsides. In High Range, for example, a vetiver plot established at Kundaly in the early 1990s kept Kikyu grass (Pennisetum clandestinum) from creeping in. Obviously establishing vetiver hedges along the periphery of tea fields could prevent invasion of deep rooted tough grass weeds. "

Water ponds and tanks that are being cleaned and desilted would benefit from surrounding vetiver hedgerows to prevent future siltation, and floating platforms of vetiver on the ponds would significantly increase water quality. Springheads can also be very effectively protected by vetiver.

Water purification

One recently discovered attribute of vetiver is its capacity to purify water, and thus to help in wastewater treatment. Vetiveria zizanioides, a species widely present in India, can absorb many heavy metals, nitrogen and phosphorous from water. In studies conducted in China using vetiver to treat effluents from piggery farms, the results were quite encouraging. Using vetiver to purify water bodies is easy, too. Being hydrophyte, the plants don't require a separate medium to grow in water. The only arrangement required to make vetiver plants survive in water properly is a float to maintain the balance between roots and shoot and to make the plant stand erect. Cut pieces of bamboo make a good float.

TVN has been awarding certificates to individuals who have been doing good work and demonstrating a high level of knowledge in specific areas of the vetiver System technology. Only one person from India Mr. Haridas, to get this recognition so far, and is one of 14 persons from around the world.

While more and more countries are embracing vetiver technology, it is quite ironic to see that in India itself, vetiver is a sort of 'touch me not' plant, despite having its origins here! A few months ago, a report in an English daily stated that upon hearing a success story of railroad stabilisation in China courtesy vetiver, Konkan Railways approached the railway authorities of China to know more about this while the technology has in reality originated from our own country.

The link with soil conservation is also a strong motivator. "To get the water stored properly you need a medium, which is the earth - hence our soil too has to be protected from erosion. Let us work on SOS (Save our Soil)".

Vanishing Vultures

Vultures are nature's scavengers and their effectiveness in disposing off dead cattle has been a critical public health safeguard in India. But with the sub-continent losing 95% of its vulture population in just 15 years, scientists and conservationists have been scrambling to understand why, and propose remedies.

Spare a thought for the scrawny vultures – those once-familiar birds of prey that used to circle lazily high in the air, scanning for anything to scavenge. In my youth, they even perched on tall tadgola trees in suburban Mumbai, peering disdainfully at the goings-on below. People may be forgiven for wondering why anyone should shed a tear about the disappearance of these ungainly beasts with scruffy, elongated necks and menacing beaks.

Just two decades ago, there were 85 million in this country; they are now estimated to number just a paltry 3-4,000. The one community that is only too well aware of this phenomenon are the Parsis, the descendants of exiles from Persia who still resort in Mumbai and a few other cities to dispose of their dead in the Towers of Silence – by exposing them on open platforms where vultures, kites and crows are supposed to dispose of them cleanly, speedily and efficiently.

Due to the rampant urbanization and the proliferation of high-rises, vultures can no longer land and take off as they once used to from the two towers in Mumbai, where most of the world's Parsis are based. In city after city, in India and Pakistan, these towers are being closed. But there is another, far more sinister, reason for the disappearance of these birds, which lies in the countryside.

Over the last decade, the 155-year-old Bombay Natural History Society (BNHS), one of the most reputed wildlife research organizations in South Asia, the Royal Society for the Protection of Birds (RSPB) in the UK, the Zoological Society of London and the Peregrine Fund in the U.S., began to put their heads together to find out what was responsible for the sudden decline in the vulture population. The Peregrine Fund traced the cause in Pakistan to an anti-inflammatory drug called diclofenac, which veterinarians also introduced into India at the same time. Humans also use Diclofenac. A much smaller threat is aircraft, including those of the Indian Air Force, which hit the birds at high altitudes.

If cattle, buffaloes, sheep or goats injected with this commonly used pain-relieving drug die of natural causes and are consumed by vultures, it causes the birds to suffer from dehydration when uric acid forms, leading to gout in the viscera and eventual kidney failure and death. It does not, as may be imagined, lead to accumulation of chemicals in the body, like DDT; even a one-time ingestion can prove fatal to the vultures. Scientists show that even if 1% of carcasses contain diclofenac, it can lead to such a precipitate decline in this raptor population. BNHS' examination of 1,800 samples from around the country show the actual prevalence of diclofenac in carcasses is ten times higher.

Little surprise then that India; Nepal and Pakistan have in the short period of 15 years lost 95% of their vulture population. There are eight species in the region. In 2000, the International Union for the Conservation of Nature (IUCN) listed three species as critically endangered, which is the highest category under risk. Two years later, all three were similarly listed under Schedule I of the Indian Wildlife (Protection) Act, which also applies to the tiger and one-horned rhino.

The precarious situation has been also been recorded on film. At a recent launch of a shortened version of his film titled The Vanishing Vultures in Mumbai, the Delhi-based filmmaker Mike Pandey pointed out why it was important to save these unpopular birds. Although they are dismissed as dirty scavengers, "they are the vital link between death and life," he said, because in their absence, carrion lies unattended and breeds diseases, several of which may be unknown to humans in future. This is yet another reminder of nature's role in recycling potentially harmful waste. A flock of vultures has the ability to dispose of an ox-sized animal in just 30 minutes. "We have lost a critical link in the food chain," Pandey warned.


According to Dr Asad Rahmani, the BNHS Director, who noticed a decline in this raptor species at the world-famous Bharatpur bird sanctuary much earlier, India, which has the largest cattle population in the world, is especially at risk. As many as 10-20 million cattle which die of natural causes every year can lie and rot in the sun, preyed upon by dogs and crows, instead of vultures, says Rahmani. Pandey observed that these "are breeding grounds which can unleash pathogens throughout the world." He has visited villages in Gujarat where 18 children have died of rabies: the dogs, which carried this highly communicable disease, could conceivably have consumed such carrion. Equally worrisome is that Anthrax – which caused such a scare post 9/11 in the U.S. -- has once again surfaced in this state.

Diclofenac is cheap, and is used by thousands of poor herders, which is largely the problem. There are some 25 companies that formulate this drug and 110 companies that market Rs.25 crore worth annually. The companies claim that it does not form a major part of their operations and could cooperate, provided the government subsidized their switch-over to a substitute called meloxicam, which is used in the West.

However, at the Indian National Board for Wildlife meeting in March last year, under pressure from wildlife enthusiasts, Prime Minister Manmohan Singh, who chairs the board, ordered that its use be discontinued in the country within six months. However, the Drugs Controller has still not acted on this directive and the Agriculture Ministry also remains lethargic. Meloxicam, which is harmless, is two-and-a-half times more expensive. The board is meeting at the end of this month (April), where ornithologists hope that some firmness will be shown.

Diclofenac is banned in most countries, including in Africa, the exception being South Asia. Either subsidising the price of meloxicam or raising the price of diclofenac would be the right thing.

RSPB has taken the initiative in starting two vulture breeding centres – in Pinjor in Haryana and at the Buxa tiger sanctuary in West Bengal. However, it is observed that vultures breed so slowly – they only give birth to one chick a year, and it takes up to four years for it to mature – that "we cannot hope for the population to be restored to its original size, at least within our lifetime." The RSPB has raised £150,000 (Rs.1.2 crore) for each of these two aviaries, which is why only two have been established when twice are many are required in India and another six in South Asia.

"It is necessary to pass the message to other South Asian countries, which are looking to India to take the lead in saving this bird."