Delhi Air Pollution: Stubble being burnt in Punjab since 1980's, why has air quality deteriorated only in the last decade?

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As a thick blanket of smog engulfs the National Capital Region (NCR) because of rising air pollution, the clamour around stubble burning also emerges.

Anyone who has lived in Delhi long enough knows that the issue of intense air pollution – to the extent of lethal, toxic air enveloping the city – has become apparent only in the last decade.

Delhi Chief Minister Arvind Kejriwal has maintained his stance that a major contributor to air quality deteriorating exponentially in this season (late October-early November) has been extensive stubble burning in the neighbouring states of Punjab and Haryana.

However, it is important to note that the practice of stubble burning is being carried out in the two states since 1980’s, when combine machines replaced manual labour for harvesting and threshing their paddy. Harvesting paddy manually does not result in stubble burning.

What has changed is the time of burning. And this is significantly because of a law passed in 2009, called the Punjab Preservation of Subsoil Water Act.

What was the practice before the Act was formulated?

Farmers in Punjab sowed paddy nurseries in the second half of April and transplanted the seedlings in the second half of May. Consequently, the paddy, including 155-day varieties such as Pusa-44, got harvested by early October. This meant, that the burning of 50-60 cm tall standing stubble was over before mid-October.

What was the Act and why was it formulated?

The Punjab Preservation of Subsoil Water Act 2009 barred the sowing of paddy nurseries before May 15 and transplanting the seedlings before June 15 – essentially pushing the process by a month. This was done because transplanting the paddy seedling in mid-summer had led to massive groundwater depletion.

Paddy requires daily irrigation and water-logged conditions to prevent the growth of weeds. By pushing the process ahead by a month, the Punjab government was ensuring that the crop’s water requirement is met from monsoon rains.

According to a report in The Indian Express, while the 2009 Act has helped replenish the groundwater table, it is contributing to the current environmental crisis in the National Capital.

How is this act contributing to air pollution in Delhi?

Late transplanting of the paddy means that it will be harvested later, which implies that farmers are setting fire to their fields between the third week of October and the first week of November. This time marks the onset of winter in North India, when the wind movement is typically slow and the lower atmosphere has high levels of moisture.

These factors lead to all the particulate matter and gases from stubble burning, as well as from vehicular and industry emissions, to get trapped instead of being carried away by the wind.

In addition, at this time of the year, winds in Punjab blow from the northwest to the southeast. According to the Indian Meteorological Department (IMD), the northwesterly winds have been calm with a speed of less than 2 kmph for the past several days. In several places, there is ‘air locking’, too. Hence, Delhi, which is located to the southeast of Punjab, bears the maximum brunt.

This air-locking can be broken either though heavy rain or fast winds, which has been evident in the last couple of days where winds have diffused the particulate matter and relatively improved air quality in the city.      

Is stubble still being burnt?

Despite an intervention and warning from the Supreme Court of India, stubble is still being burnt extensively across Punjab as well as Haryana.

A report by The Times of India has cited data from NASA which suggests that there were 5,412 fires in the two states on November 5, with 5,053 recorded from Punjab alone. The highest daily count this season was on November 4, when 6,882 fire spots were detected in the two states.

NASA Image of fires on November 5, 2019. (Image: NASA VIIRS and Modis satellites)

NASA Image of fires on November 5, 2019. (Image: NASA VIIRS and Modis satellites)

Punjab records more fires as compared to Haryana as out of about 30 lakh hectares of land where paddy is grown, over 24 lakh hectares is under non-basmati varieties. Whereas, in Haryana, of the total 13.50 lakh hectares of paddy acreage, over 5 lakh hectares is non-basmati. Farmers generally resort to manual harvesting of basmati paddy, which does not lead to stubble burning. This year, a total of 31,267 field fires have been recorded in Punjab since September 23, The Indian Express has reported.

However, several experts have pointed out that if stubble burning was the sole cause of deteriorating air quality in the national capital region, then Punjab should have been more polluted than Delhi. Air quality levels in many districts of Punjab are ‘poor’, but not as severe as in Delhi.

What is the alternative?

Agriculture scientist M S Swaminathan has pointed out that stubble is not burnt in South India, as it holds economic value as animal feed. “For years, I pointed out many economic uses of rice straw. We should adopt a do-ecology approach with farmers to convert rice stubble into income rather than making them agents of eco-disaster,” he tweeted.

He said that recently, his foundation established a Rice BioPark at Nay Pyi Taw in Myanmar, which was funded by the Ministry of External Affairs and inaugurated by President Ram Nath Kovind. The rice biopark shows how stubble can be utilized to make products including paper, cardboard and animal feed.

“I suggest that the Delhi, Haryana and UP govts put up Rice BioParks where farmers can convert stubble into income and employment.  We should stop blaming farmers since it will take us nowhere. Instead we should propose methods which are economically and ecologically desirable,” he said.

Delhi Chief Minister Arvind Kejriwal, in an attempt to offer an alternative to stubble burning, on November 6 tweeted:

I had several meetings today wid experts. It is technologically and commercially possible to convert stubble into CNG. This will provide jobs, additional income to farmers and solve our annual problem of pollution. However, it requires all govts to come together n work on this

— Arvind Kejriwal (@ArvindKejriwal) November 6, 2019