No Smoke Without Fire

Stubble burning envelopes Delhi and the NCR in a deadly smog every winter. BW Businessworld examines why the practice is so hard to fight, even though it is such an obvious health hazard.

- Prabodh Krishna

Can you imagine the air filled with smoke? It was. The city was vanishing before noon or was it earlier than that? I can’t say because the light came from nowhere and went nowhere

Smoke by Philip Levine

WAS POET PHILIP LEVINE really speaking of a city enveloped in fumes, dust particles and smoke of stubble burning on farm fields in the distance? Inadvertently, though, he does describe the national capital of India in the weeks before the onset of chilly winter. According to a 2015 report on air pollution by IIT Kanpur, the overall contribution of biomass burning to pollution from particulate matter during winter is fairly high. Smoke emanating from crop residue burning on the agrarian lands around Delhi contribute as much as to 17 per cent of PM10 and 26 per cent of PM2.5.

The irony is that burning stubble erodes nutrients from the soil. In an extensive study published nearly a decade ago, the Indian Council of Agricultural Research (ICAR) pointed out that burning stubble results in loss of nutrients present in crop residues. All of the carbon, 80 - 90 per cent of the nitrogen, 25 per cent of the phosphorus, 20 per cent of the potassium and 50 per cent of the sulphur in crop residues literally go up in smoke, when crop residue is set on fire. Burning crop residue just once erodes 1.43 million tonnes of nutrients from the topsoil. A recent Food and Agriculture Organisation (FAO) report says an inch of top soil develops across a 1,000 years.