By Peter Day
BBC News, India
Although India is experiencing huge economic growth, it is also a place where 700 million people still live in the countryside, a world away from the nation's newly acquired shiny image.
But among this vast rural population lies a wealth of wisdom and expertise that has a value all of its own.
Professor Gupta has an engaging smile and a compelling interest in everything
I have just been on a pilgrimage, on foot, across a bit of rural India.
Not to get to a shrine, a saint or a temple.
The point of the walk was the villages we encountered on the way, and the traditional skills and knowledge locked up in them.
This is not the first time I have talked about a remarkable professor called Anil Gupta, who teaches at the Indian Institute of Management in Ahmedebad.
It is, by the way, the hardest management school to get into in the whole world.
He is the moving spirit behind something called the Honeybee Network, a now vast repository of often clever rural inventions and village wisdom about plants and animals in danger of being forgotten in the new brand name-driven India.
Honeybee celebrates this lore and tries to get financial backing for the best ideas.
And for the past eight years, Professor Gupta has taken to the dusty roads of rural India on what is called, in the ancient Indian language of Sanskrit, a Shodhyatra... a walk to find knowledge.
The fanfare of India
Twice a year, in searing summer heat or chilly winter, Professor Gupta and 60 or 70 of the inspired, the curious, and veteran rural innovators traipse out to remote places.
Villagers show walkers the cow dung patties that are used for fuel
The walks last about a week, as the pilgrims journey from village to village along rutted ox cart tracks and noisy main roads, honked at by endless motor horns - the fanfare of India.
Being part of the Shodhyatra is an extraordinary experience, a confusion of travelling circus, revivalist meeting and Gandhi brought back to life.
At walking pace in a country that lives outdoors, things happen.
People who know inventors dash up to the pilgrims.
The walkers themselves dive off the path into a field to clip off a twig of an unfamiliar shrub.
A farmer diverts the walkers to examine his new discovery, a rogue mustard plant that produces all its seed at once, not frond by frond
In the middle of the crowd moves Professor Gupta - tall, bearded, dressed in white - has an engaging smile and a compelling interest in everything.
We stop to admire the individual patterns the women create on the walls of the shelters they build to protect the precious store of handmade cow dung patties used for fuel.
A few miles further and there is another huddle as the professor launches into an off-the-cuff inquiry into the positive uses of the word "crack", inspired by the parched earth before us.
A farmer diverts the walkers to examine his new discovery, a rogue mustard plant that produces all its seed at once, not frond by frond.
In every village, we are greeted and garlanded, and then there is a meeting under the spreading neem tree in the schoolyard for two or three hours, in which rural knowledge is praised, inventors speak and local heroes are acclaimed.
Then centenarians are rewarded with pashmina scarves to celebrate the wisdom locked up in old age, children are exhorted to listen to their grandparents (and inspired to write down inventions they would like to see), and village drunks pledge to give up drink.
One man smashed his full bottle of Mr India spirits in front of the whole gathering.
Walking with Professor Gupta is rather like being back in the New Testament - first-century disciples on the move with a great guru.
Professor Gupta thinks that the Indian soul resides in the wisdom of the poor
Drums greet the Shodhyatra as it enters the village. We eat together from great vats of delicious food whipped up by a family of cooks travelling behind us in a truck.
We all sleep on chilly schoolroom floors or in barns.
Sanitation is primitive or non-existent, but no more primitive than the villagers experience every day of their lives.
Most of these knowledge walks are far from cities, although this one was, at times, only 20 miles from the capital, Delhi.
Even so, it was bandit country.
In one village there had been dozens of vendetta murders - a place the local police stayed away from.
To get to the start, I drove out of Delhi on the first Indian highway built by the British.
The professor is frightened that in the rush to modernise, the wisdom of the poor will be wiped out and lost
Along it, there is now a remarkable explosion of new real estate: multi-storey apartment blocks with alluring names, great shopping malls and new hospitals for medical tourists from abroad.
The new India.
The gap between the towering developments of this new industrial zone and the villages only a walk away, is of centuries, not miles.
Like Gandhi before him, Professor Gupta thinks that the Indian soul resides in the wisdom of the poor, and he is seeking to make it flame up with new purpose.
Much of the new India regards this with sympathetic scorn, the past dragging on the country's global future.
The professor is frightened that in the rush to modernise, the wisdom of the poor will be wiped out and lost... and not just in India.
In an extraordinary move this spring, Professor Gupta will be coming to Britain to do the same thing here.
He will walk from Liverpool to Manchester - a Lancashire Shodhyatra.
From Our Own Correspondent was broadcast on Saturday, 20 January, 2007 at 1130 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.