By Subir Bhaumik
BBC News, Gossainbarie, Assam
Production at Gossainbarie tea estate has gone up since it started using organic manure
Visitors making their way along the muddy track leading to the Gossainbarie tea estate in India's north-eastern Assam state will be greeted by huge mounds of cow dung, rotting water hyacinth, as well as and fish and meat waste.
But this is no cause for alarm - the tea-estate has gone organic and is following the principles of India's ancient plant medicine Vriksh Ayurveda.
"This is our fertiliser because we don't use any chemical ones in our gardens," says Gossainbarie's owner Binod Saharia.
He has enlisted the help of a hermit-like bearded figure - former management consultant Swami Valmiki Iyengara.
Mr Iyengara says he has studied Vriksh Ayurveda, a system of traditional medicine, and evolved a concept of organic farming that is both sustainable and profitable.
"All pollutants are useful wastes and we can convert most of them into organic manure," he says.
"The ancient Indian plant medicine details processes for creating organic fertiliser from virtually anything.
"Much as poisons like mercury are used in traditional Indian medicine, pollutants diluted with other materials produce the best fertiliser," he adds.
Half of India's tea output comes from Assam
Water hyacinth, cow dung and cow urine have long been used as manure.
But Mr Iyengara has also developed organic manure from fish waste, "charasuda" (butcher house waste), "indsafari" (small fish) and the "bhasmas" (made from herbs and metals).
"We have enough organic fertilisers for a few planting seasons," he says.
Mr Iyengara and Mr Saharia say they have almost perfected the practice of organic farming.
They believe this could clean up India's - and Assam's - rural environment, which has been polluted by high use of insecticides, pest repellent and highly toxic chemical fertilisers.
Environmentalists argue these are penetrating the food chain and threatening the health of millions.
'Ailing estate' rescued
Going organic can also boost the market price of Indian tea and open up new niche markets.
These are factors that can help the country's tea industry overcome the high production costs caused by rising wages and expensive chemical fertilisers.
When Mr Saharia took over the ailing Gossainbarie tea estate from Assamese planter Mohammed Arfanulla early last year, the 140-year-old tea estate was waiting for someone to turn it around.
Locally available water hyacinth is also used to make manure
The estate's annual output had plummeted from its peak 900,000 kg of green leaves to 355,000 kg a year.
One year on and things are looking up - the estate is poised to produce 600,000 kg.
Mr Saharia says he now wants other Indian tea planters to adopt his technology.
"We have no trade secrets. We want the whole of Indian tea industry to go organic all the way.
"In many estates, lazy managers routinely use chemical fertilisers even after the soil has gone dead. We want them to be creative."
Inderjit Singh Oberoi, a retired soldier-turned-manager, has worked for estates much bigger than Gossainbarie, but he joined up six months ago to gain experience.
"The concept being tried out here is unique and I want to be part of it," he says. "This could save Indian tea and get it niche buyers."
India's tea industry is burdened with rising costs of production and falling prices.
Cows are a useful income supplement for the labourers
Rampant use of chemical fertilisers and adulteration have denied Indian tea access to health conscious European markets.
India produced 981m kg of tea in 2009 - almost a quarter of the world's total tea output. Nearly 200m kg were exported.
Half of India's tea output - nearly 450m kg - comes from Assam's 800-odd tea estates.
Mr Saharia and Mr Iyengara say they encourage labourers at the estate to keep cows and collect waste.
That way, they are never short of raw material for organic fertiliser and also "it is an income supplement for the poor labourers".
Some Indian tea planters, such as Swaraj Banerji of the famous Makaibari tea estate, in the Darjeeling Hills of West Bengal state, turned organic long ago.
The Makaibari estate pioneered the practice of motivating tea labourer families to keep cows and supply the dung and urine to the estate.
"But we have shown the way for all tea planters to go organic on a sustainable basis because we can develop organic fertilisers from virtually all kinds of locally available material," Mr Saharia says.
Mr Iyengara has also used his knowledge of modern management to develop a system by which fewer labourers are needed to apply the organic manure, over a wider area and in less time.
"Labour costs are the biggest overhead in Indian tea production and they make our teas less competitive in global markets," he says.
"But we have found a way to cut down hugely on labour costs by saving up on manure application time."
Mr Oberoi says he had "reservations" about the organic tea cultivation until he joined Gossainbarie.
"Now I know that the ancient plant medicine and the modern management concepts can work magic," he says.