Initial results from the Indian Council of Agricultural Research (ICAR) about trials on the effectiveness of a microbial consortium to decompose paddy stubble show that the latter can decompose within 25 days amid reports of Delhi-national capital region (NCR) and several other north-western states battling “poor” air quality index (AQI), which has become an annual phenomenon in the past few years around this time of the year.
Trials are in progress in up to 14,000 hectares (ha) of paddy farmland in Punjab, Haryana, Uttar Pradesh (UP) and Delhi, said the ICAR chief.
“There is no requirement for any manual intervention to pick up the stubble after 25 days. A microbial solution can help decompose paddy stubble within 25 days, but trials are still in progress,” said Trilochan Mohapatra, director-general (D-G), ICAR.
“We had been working on the microbial consortium for a couple of years after the happy seeder, which is used for straw management, was introduced. Last year, the concept was tried out in UP, where it had worked,” Mohapatra had said earlier.
The contribution from stubble fires to the national capital’s particulate matter (PM) 2.5 pollution reduced temporarily on Monday, as wind speed during the day time had picked up to 16 kilometres per hour (kmph).
Though widespread stubble fires were observed in Punjab and Haryana on satellite images, their contribution had reduced because of a higher ventilation index, scientists said on Monday.
The air quality early warning system under the Union Ministry of Earth Sciences (MoES) said the current actual contribution from stubble fires was about 7%, even though the forecast was around 19%.
“The reason the impact has lowered is because of clear sunshine and good wind speed during the day. Fires are widespread and wind direction is still north-westerly, where stubble is being burnt. However, we are hoping that it won’t impact Delhi. The AQI is unlikely to worsen for a day or two because of better ventilation,” said Vijay Soni, a scientist at India Meteorological Department’s (IMD) air pollution management division.
Data sourced by the Central Pollution Control Board (CPCB) from System of Air Quality and Weather Forecasting And Research (SAFAR) also indicated an 10% contribution to Delhi’s PM 2.5 load from stubble fires.
SAFAR estimated fire counts in the neighbouring states at around 1,090. The ventilation index is a function of the mixing height and the wind speed and defines the ability of the atmosphere to disperse contaminants. A ventilation index below 2,350 square (sq) metres (m) per second is considered poor.
Mixing height is the level at which pollutants mix in the air.
“An improvement in air quality was noticed because winds up to 18 kmph were recorded in Delhi on Monday. Similar conditions are likely to continue on Tuesday. However, from Wednesday, the wind direction is likely to gradually change to easterly and south-easterly, when the impact of stubble fires may reduce,” said Kuldeep Shrivastava, who heads the regional weather forecasting centre at IMD.
Delhi chief minister Arvind Kejriwal on Monday urged Union Minister for Environment, Forest and Climate Change Prakash Javadekar to start holding monthly meetings of the CMs of all states from northern India in a bid to find a permanent solution to stubble burning.
The Union Ministry of Environment, Forest and Climate Change (MoEFCC) has held 65 meetings with environment ministers of NCR states since 2016, a ministry official said.