Shahjahanpur, India

HOURS after a mechanised harvester chugged through the rice paddy, flames and a thick plume of black smoke rose into the twilight sky in India's northern Haryana state as farmers burned the residue to prepare for the next season's planting.

Similar fires seen by a Reuters reporter last week in the nation's farm states of Haryana and neighbouring Punjab suggest that efforts by authorities to stave off a massive spike in pollution in nearby New Delhi in the next few weeks may fail.

Late last year, Delhi and a large part of northern India were covered in a dangerous toxic smog that forced authorities to shut schools, ban diesel-run generators, construction, burning of garbage and non-essential truck deliveries.

The World Health Organisation said earlier this year India was home to the world's 14 most polluted cities, with Delhi ranked the sixth most polluted.

As pollution levels climbed to 12 times the recommended limit and the Indian Medical Association declared a public health emergency in the capital last year, Delhi Chief Minister Arvind Kejriwal called the city a "gas chamber." On Friday, he warned the city may face the same fate this year because of the unrestrained stubble burning.

Gurkirat Kirpal Singh, a spokesman for the Punjab government, said the state administration had formed a committee of senior officials which was working to ensure that incidents of stubble burning drastically come down this year. He did not elaborate.

The smog worsens when the heavy smoke from crop burning combines with vehicle and industrial emissions at a time of year when wind speeds drop significantly. Fireworks set off to celebrate the major Hindu festival of Diwali, that fell on Oct 19 last year and will be on Nov 7 this year, exacerbated the problem.

After last year's crisis, the Indian government introduced some measures aimed at curbing the crop fires, in particular offering to pay up to 80 per cent of certain farm equipment, such as a Straw Management System (SMS) that attaches to a harvester and shreds the residue.

The plan was for the shredded material to be mulched using another machine and irrigated at least twice to get it to decompose. All this would be done without any crops being burned.

The only problem is that 14 farmers Reuters spoke to on a visit last week to six villages in the rice and wheat growing areas of Haryana and Punjab, said the plan wasn't working.

They say that was largely because the subsidy for SMS and mulching machines wasn't covering the costs of the equipment and the labour involved. It was still much cheaper and easier to burn the residue.

"Farmers know about the repercussions of burning crop stubble and that's why you won't come across a single farmer who really wants to continue with the practice," said Hardev Singh, 58, who grows rice and wheat in the village of Shahjahanpur, which is part of Haryana's Karnal district.

But the cost of disposing of crop residue is so prohibitive that most farmers are forced to set the stubble on fire, Mr Singh said.

It is also time consuming, and the farmers do not have a lot of time. After harvesting rice, farmers get a short window to plant winter crops such as wheat and rapeseed, and late sowing means lower yields.

The farmers also complained about the lengthy bureaucratic processes to claim the subsidies for the machines.

"The fact that government officials want us to use expensive machines like SMS clearly shows that they are far removed from reality," said Sandeep Pannu, who leases his farms to small growers in Phulak village in Haryana state.

For most farmers, burning the residue does not cost more than 2,000 rupees (S$37.37) per acre but using the machines raises the cost to 6,000 rupees despite an 80 per cent subsidy from the government, Mr Pannu said.

Three other farmers standing in the shade under a tree with Mr Pannu also complained about a sharp fall in the prices of their produce and the rising cost of diesel, widely used in tractors and farm equipment. With their incomes under strain, they said they have less capacity, and enthusiasm, to address environmental issues.

The message from Haryana and Punjab could be disconcerting for the government of Prime Minister Narendra Modi, whose office has been actively involved in framing policies and taking initiatives to help avoid the repeat of last year's dangerous spike in pollution levels.

"The message from the top office is to take steps to avoid the repeat of 2017. Otherwise heads will roll," said a senior Indian government official who declined to be identified in line with government policy.

Other measures by the authorities to combat air pollution this year include pressing road sweeping machines and water sprinklers into service in an attempt to reduce dust in Delhi, and the large-scale planting of saplings to eventually act as a shield against pollution, said the official.

"We'll also ensure that no one gets to burn dry leaves, garbage and other solid waste and we'll see to it that all construction sites get covered," he said, conceding that the first two weeks of November, when crop residue burning peaks, would be critical. REUTERS