DELHI'S BURNING FARMS

HARPAL Singh struck a match and watched the fields burn, the acrid smoke drifting toward New Delhi where a lethal smog cocktail is once again intensifying over the world's most polluted megacity.

Every November, air pollution in northern India reaches levels unimaginable in most parts of the world, forcing schools shut and filling hospital wards, with wheezing patients.

As winter descends, cooler air traps car fumes, factory emissions and construction dust close to the ground, fomenting a toxic brew of harmful pollutants that regularly exceed 30 times the World Health Organization safe limit.

The scourge is compounded as farmers like Singh - rushing to ready their fields for next season's  wheat crop - use fire to quickly and cheaply to clear their land.

He knows slash-and-burn farming is illegal and that doing so, year after year, helps sicken millions  in the Indian capital  and beyond.

But local authorities appear powerless to stop it  and - looming health  crisis or not in Delhi - the narrow window to plant for the winter  harvest is closing.

''We have no other choice but to burn the straw,'' Singh told AFP in Ishagarh, a village in Haryana state, about 120 kilometers [75 miles] northwest of Delhi.

''We know the smoke pollutes the air. But it is the easiest and cheapest way to get rid of the  [crop]  residue,'' the 65-year-old  farmer told AFP, as burning straw crackled and  popped behind them.

This smoke is already reaching Delhi, bringing a familiar sepia haze and a bad omen for officials wanting to avoid a  third straight year of record-setting smog. [Agencies]