Farmers in northern India burn paddy stubble to clear the soil for their next crop

Farmers in northern India burn paddy stubble to clear the soil for their next crop

"The share of stubble burning in Delhi's pollution can range from 1% to 42%, depending on wind speed and direction," says Dr Gulati.

But a new environment ministry report says the average contribution has grown from 10% in 2019 to 15% this year.

The government has tried offering alternative technology, but that comes with its own share of problems.

For instance, take the Happy Seeder - a machine mounted on a tractor which removes the paddy straw while simultaneously sowing wheat for the next harvest. It was touted as eco-friendly, fast and effective. The government picked up 50 to 80% of the bill, depending on whether it was an individual farmer or a group.

Inderjit Singh, a wealthy farmer in Punjab, says he didn't burn any stubble this harvest because he got a Happy Seeder last year.

But it doesn't come cheap - the machine needs a tractor to work and the two combined can cost up to $15,000 (£11,229). "This explains why many farmers burn stubble - they can't afford not to," Mr Singh adds. And even for those who can, getting their hands on the machine has proved difficult due to long wait times and dwindling stock.

Another potential game-changer, a bio-decomposer developed by the Indian Agricultural Research Institute, turns crop residue into manure in 15 to 20 days. But some farmers say they don't have so much time between crops.

"We aren't allowed to plant paddy in the summer since the crop requires a lot of water and the logic is to conserve water during the heat," says Mr Grewal. "If we were allowed to sow earlier, we would have more time between crops to get rid of the residue."

Does India need another farming revolution?

But some experts, like Dr Gulati, say all these efforts are "irrelevant" to a degree.

Instead, he suggests tackling it at the root - subsidise crops other than paddy, the source of most stubble burning. "Policy and money should incentivise farmers in the region to plant more fruits and vegetables," he says. "India needs more vitamins and protein rather than wheat and rice." This, he adds, will create more greenery and since vegetable and fruit crops don't leave stubble, it'll bring down the number of open fires.