Why stubble fires flare every October, and why they are so hard to stop

Why do the fires come in October?

Because that is when Punjab and Haryana harvest their paddy, and the next crop has to go in almost at once.

The paddy harvest in the two states begins in October. Wheat, the winter crop, should ideally be sown by early November. That leaves farmers about two to three weeks to clear their fields of the straw and stubble left behind. Setting it alight takes an afternoon and costs nothing. Every other method costs money, machines, labour or time.

The burning season officially runs from mid-September to the end of November, but the bulk of it is packed into a few weeks. That is why the count rises so steeply: Punjab logged 51 fires on a single day this week, its worst of the season, taking its total to 174 by 13 October, and most of the crop is still standing.

What does a groundwater law have to do with it?

A great deal. In 2009 Punjab passed the Preservation of Subsoil Water Act, which barred farmers from transplanting paddy before mid-June. Until then many had planted in May. The idea was sound: planting later avoids the hottest weeks, when flooded fields lose the most water to evaporation, and so eases pressure on the state’s fast-falling water table.

The side effect was to push the harvest later, from September into late October. That shortened the gap before wheat sowing and moved the burning into the weeks when north India’s air is already at its most vulnerable.

Why is there so much straw?

Because paddy produces an enormous amount of it, and machines leave much of it behind.

Punjab produces roughly 20 million tonnes of paddy straw a year, and Haryana about 7 to 8 million. Most of the crop is cut by combine harvesters, which take the grain but leave tall stubble standing in the field. Long-duration varieties such as Pusa-44, still popular because of their yields, ripen even later and leave even less time.

How much does it add to Delhi’s pollution?

A large share at the peak, though less across the season.

Some studies put stubble smoke at 15% to 30% of Delhi’s fine particulate pollution during the peak burning weeks. The rest comes from vehicles, construction and road dust, industry and household fuel. The fires matter so much because they coincide with the change of season, when smoke and dust tend to linger over the National Capital Region instead of dispersing.

Aren’t the numbers falling?

Yes, but they are harder to read than they look.

Punjab recorded 5,114 farm fires in the whole of last season, among the lowest counts in recent years. This season began faster, about 38% ahead of last year’s pace by mid-October. The official counts also rely on satellites, which do not pass over in the late afternoon. Environment Minister Bhupender Yadav told states this week that monitoring cannot rest on satellite data alone, especially after 3 pm, and experts have warned that some farmers burn later in the day to avoid detection.

The stubble season in numbers

• 20 million tonnes paddy straw in Punjab each yearHaryana adds roughly 7 to 8 million tonnes.
• 2-3 weeks between paddy harvest and wheat sowingSqueezed after the 2009 law moved planting to mid-June.
• 3.54 lakh residue machines supplied to statesIncluding 26,109 this year, though not all are in use.
• 15-30% of Delhi's fine particles at the peakEstimates from several studies, for the worst weeks only.

What is being done?

A mix of machines, money, rules and new seeds.

The Centre has supplied more than 3.54 lakh crop residue management machines, such as the Happy Seeder, which sows wheat straight into the stubble so the straw can stay in the soil. Other schemes send straw to biomass power plants, compressed biogas units and ethanol refineries. Agriculture Minister Shivraj Singh Chouhan has pressed states to make sure the machines actually run in the fields, and to move farmers to shorter-duration varieties such as PR126 and Pusa 2090, which clear the land sooner.

There are penalties too. Flying squads are out across Punjab, fines have been issued, and the National Green Tribunal and the Supreme Court have upheld keeping farmers who burn stubble out of minimum support price benefits.

Why is it still so hard to stop?

Because the incentives still point the other way. Assured government buying of paddy and wheat, and cheap or free farm power for pumps, keep farmers locked into the water-hungry rice-wheat cycle. Until that cycle changes, or the cheaper alternative to a matchstick reaches every small farmer in time, the October fires will keep returning.