Stories
Delhi's Air Quality Dips to Moderate as Stubble Burning Season Begins
- •Delhi's AQI reached 129 (moderate) after five satisfactory days, coinciding with 114 crop-residue burning events across six states.
- •Punjab accounted for 59 of the 114 fires detected between September 15-30, followed by Uttar Pradesh (32) and Madhya Pradesh (17).
- •Stubble burning, or parali burning, is the practice of setting fire to crop residue after harvest, releasing pollutants into the atmosphere.
- •The short window between paddy harvesting and wheat sowing, partly due to groundwater conservation efforts, drives farmers to burn stubble.
- •While farm fires contribute significantly, Delhi's air pollution is also caused by local emissions, weather conditions, and regional factors, including emissions from Pakistan's Punjab.
Key Questions Answered
Stubble burning, or parali burning, involves setting fire to leftover crop residue after harvesting. In north-western India, farmers burn paddy stalks and material to quickly and inexpensively clear fields before sowing wheat, due to a narrow planting window caused by groundwater conservation rules.
Research shows crop-residue burning is not the sole cause of Delhi's pollution, though it significantly worsens specific episodes. While one modelling study estimated non-local stubble burning contributed about 20% to Delhi's PM2.5 on average during October-November, a newer 2025 study estimated Punjab's burning contributed roughly 14% to overall PM2.5 in Delhi-NCR.
Between September 15 and 30, a total of 114 residue-burning events were detected across six states including Punjab, Uttar Pradesh, Madhya Pradesh, Haryana, Rajasthan, and Delhi. Punjab recorded 59 events, followed by Uttar Pradesh with 32, Madhya Pradesh with 17, Haryana with 3, Rajasthan with 2, and Delhi with 1.
