The trouble with stubble

Paddy stubble burning, which worsens air pollution, particularly in the cities of northern India, has abated significantly in three key farming states. Can this year’s unusually wet monsoon season reverse the gains?

- SANJEEB MUKHERJEE

Paddy stubble burning is down, a trend that has sharpened on the back of three years of decline.

This year, the first 25 days of the stubble-burning season, which runs from September 15 to November 30, have seen a 65 per cent drop, with Punjab and Haryana — the two states that lead in the polluting practice — seeing a dramatic fall of 64 percent and 96 per cent, respectively.

Madhya Pradesh, which has over the past few years emerged as a new hot-spot of paddy stubble burning, has also seen a drop of almost 45 per cent in the same period.

Experts put down the consistent decline to a mix of policies: Subsidies, incentives, and punitive measures. However, they warn, the recent rains over northern states could lead to some of the pollution gains unravelling.

Chokers: The facts

A 2023 study by Bhopal-based Indian Institute of Science Education and Research found that there had been a 75 percent increase in harmful greenhouse gas emissions from agricultural residue burning across India in the decade from 2011 through 2020.

The study also found that most emissions occurred during the end of the Kharif season, followed by rabi, caused by the burning of rice and wheat residues. Rice, wheat, and maize accounted for 97 percent of India’s agricultural burning emissions, with paddy being the largest contributor at 55 per cent.

Burning one tonne of paddy straw, according to the Council on Energy, Environment and Water (CEEW), a public policy think-tank, releases 3 kilograms of particulate matter, 60 kg of carbon monoxide, 1.46 tonnes of carbon dioxide, 199 kg of ash, and 2 kg of sulphur dioxide into the atmosphere.

Not only that, scientists at the Indian Council of Agricultural Research (ICAR) estimate that each tonne of stubble burnt leads to a loss of at least 12-13 kg of phosphorus, 35 kg of potassium, and 20 kg of nitrogen in the soil.