Why Delhi’s air quality remains in the red despite a fall in stubble burning
Summary
- Weather patterns probable cause of persisting air pollution problem in national capital region
Sangrur/Sirsa: The air quality in Delhi saw no improvement in November despite a significant fall in stubble burning in neighbouring states, pointing to weather patterns as the probable culprit for what has ballooned to an air pollution crisis in the national capital region.
The incidence of stubble burning in Punjab and Haryana dropped 26.5% on year to 36,663 and 37% to 2,303, respectively between September 15 and November 30. Yet, the dangerous PM2.5 level in Delhi this November was 33% worse than the corresponding period last year, according to an analysis by climate tech firm Respirer Living Sciences.
The average air quality index last month was 372, the second highest for the month since 2017, after an average of 377 recorded in 2021.
This is higher than the average of 320 recorded last year, 327 in 2020, and 312 in 2019, according to data from the Central Pollution Control Board (CPCB) and Consortium for Research on Agroecosystem Monitoring and Modeling from Space (Creams) laboratory.
There has been a downtrend in farm fire cases observed over the last few years. While Punjab registered 49,922 cases in 2022, 71,304 in 2021 and 83,002 in 2020, Haryana recorded 3,661 such events in 2022, 6,987 in 2021 and 4,202 in 2020.
However, according to CAQM (Commission for Air Quality Management), the “significant reduction" in the number of farm fires did not reflect proportionally in the daily average AQI of Delhi/NCR in November.
This, it said, is “primarily owing to highly unfavourable meteorology and climate conditions prevailing over the region particularly since the last week of October, with low-speed winds from the north-westerly direction, very low rainfall and near-calm wind conditions over Delhi which badly impeded the dispersion of pollutants, thus reflecting in a much higher AQI during November 2023 as compared to the November months in preceding years."
The drop in stubble burning is attributed to a series of measures like crop residue management in the soil, machinery support, awareness programmes, financial incentives to farmers, and setting up biomass power plants to use the stubble.
“Initiatives such as machinery support and incentives to farmers for in-situ and ex-situ management, the compulsion of using 20% paddy straw pallets by coal-based plants, and diversion of paddy straws for ethanol production have helped reduce the cases," said Onkar Singh Sidhu, officer on special duty to the Punjab chief minister.
“An ethanol plant based in Jahangir village of Sangrur has collected 40,000 tonnes of paddy straws from Dhuri tehsil alone this season and the next season’s target is 60,000 tonnes."
In-situ management involves incorporating the stubble into the soil using machines, while ex-situ management involves lifting the stubble from the fields and supplying it to industrial units.
“It is difficult to say when it can fully be prevented, but there has been significant improvement, which will continue in the coming years," Singh added.
A Haryana agriculture ministry official from Sirsa district said that there should be a supply chain linkage, be it by the government or the private sector, to manage crop residue better.
“Sirsa has 234,000 hectares area under Kharif paddy, and the paddy straw is 20 quintals per acre on average. There is no consumption of paddy stubble at the commercial level due to the lack of industrial plants in the district. If supply and demand are in sync, we may see no stubble burning cases next year," the official said. “Farmers are realizing the perks of not burning paddy stubble and hence cases are coming down every year," said Ramesh Chauhan, a farmer holding 40 acres of farmland in Fatehabad’s Ratia.
According to farmers, there has been a substantial reduction in fertiliser requirements and an improvement in soil quality and moisture due to in-situ management. Additionally, pollution went down.
“Earlier, it required 35 kg of urea for one wheat acre and now 25 kg is sufficient after mulching by super seeders. Similarly, the savings on weedicide are now ₹1,200-1,300 per acre," said Manpreet Singh, secretary of Kotduna Multipurpose Co-operative Society, which is based in Barnala of Punjab.
“Pollution level has also come down. Earlier, we didn’t see sunlight for a fortnight straight in November, but this year, pollution was less and hence, sunlight was missing for only 3-4 days before rainfall around Diwali."
Although farmers in most of the villages of Punjab and Haryana, including Dholu, Kotduna, Mohamadpuria and Kandhargarh claim a significant reduction of 80-90% over the years, partial burning is still going on.
Sikhara Singh, a farmer who has a 35-acre farmland in Barnala’s Kotduna partially burnt 10-15% of paddy straw this year due to the use of a combined harvester instead of a super or smart seeder. The combine harvester is equipment that recovers grain while also cutting standing crops, while a super seeder is a combination of a Rotary Tiller and seed Planter with press wheels and is extensively used for planting seeds.
In partial burning, farmers let the loose straw dry for a couple of days and then they set these dumps on fire to prepare the field for the next crop. In such cases, the standing stubble, which is mostly green, does not get burnt fully but it gets scorched close to those places in the field where loose straw is burnt.
From April to May and October to November each year, farmers mainly in Punjab, Haryana, and Uttar Pradesh burn an estimated 35 million tonnes of crop waste from their wheat and paddy fields after harvesting as a low-cost straw-disposal practice to reduce the turnaround time between harvesting and sowing for the first (summer) crop and the second (winter) crop.
Crop-residue burning has intensified over the past decade because of several reasons, including some long-term basmati paddy varieties such as Pusa 44 and PB 1401 having higher yields and delaying harvests, a shift from cotton and sugarcane to paddy amid purchase at the assured minimum support price (MSP) and large size of landholdings in Punjab and Haryana, according to farmers.
“Implementing techniques like using crop residue for mulching, animal feed, composting, bioenergy production, mushroom cultivation, optimizing fertilizer and input use and construction material, reduces air pollution, and benefits agriculture, and the environment. However, the endeavour is not without its challenges. These include the need for agri stakeholders’ awareness and education, upfront investment costs, and potential yield fluctuations.
Overcoming these hurdles involves offering training programs, financial incentives, and establishing support networks. Collaborative efforts with governmental bodies can facilitate the adoption of sustainable practices. Policy frameworks that incentivize eco-conscious farming and provide resources for seamless transitions can be encouraged," said Harshal Sonawane, Head of Sustainability, nurture.farm, an agriculture solution-providing company.
Meanwhile, non-governmental organisations (NGOs) and organisations like the Confederation of Indian Industry (CII) are working in the fields of Punjab this paddy season to motivate farmers against burning the crop residue to keep air and soil pollution in check.
Under CII’s Cleaner Air Better Life initiative, 88,000 farmers across 432 villages in Punjab and Haryana are encouraged to do mulching, straw incorporation, and baling of paddy straw, which has resulted in the prevention of straw burning in 497,684 hectares this year.