Smog is used to refer to a type of air pollution caused by a combination of smoke (and other pollutants) and fog. It has become a perennial problem in Delhi and adjoining areas of the National Capital Territory of India where air pollution peaked on both PM 2.5 and PM 10 levels.

Stubble Burning

Paddy stubble burning in areas around Delhi, at the onset of winter every year, increases the severity of smog, creating a health crisis. Due to paucity of time and to save on costs of stubble disposal, farmers in Punjab, Haryana and Delhi burn their combine harvested fields to prepare it for sowing of wheat crop.

Smog gets accentuated as cold weather and stagnant winds in this season trap the smoke particles near the ground surface. However, stubble burning is only one of the several factors responsible for this smog.

Other Factors Contributing To Smog

• Vehicular emissions, especially from trucks, which have large contribution.
  
  
• Power plants, industries and domestic cooking 
  
  
• According to a study by IIT Kanpur, road dust accounts for about 35% of PM 2.5 in the air.
  
  
• Municipal solid waste burning
  
  
• Dust from construction activities like land clearing, demolition etc.
  
  

Alternatives to Stubble Burning

In light of health emergency created by severe smog, and the far reaching impact of stubble burning, there have been calls from all stakeholders for finding alternative methods to dispose of the paddy straw.

• Paddy straw can be used by Biomass energy plants for generating power.
  
  
• Using Turbo Happy Seeder Machine, which can drill the wheat seeds into soil and deposit the straw over the sown area as mulch cover. The Government of Punjab distributed 24,000 tractor-mounted ‘happy seeders’ to cut down the rice stubble and sow wheat seeds simultaneously.
  
  
• It can be used along with sugarcane leaves to make rich quality of organic manure in a compost pit.
  
  
• Another machine is the paddy straw chopper-cum-spreader – to chop paddy straw left behind on mechanically harvested paddy fields. It chops the straw into pieces and spreads it around the field in a single operation, so wheat-sowing becomes easy.
  
  
• In-situ decomposition with microbial application such as the accelerated straw decomposition process. The Indian Agricultural Research Institute has developed a solution it has named ‘Pusa’, which can decompose crop residue into manure by accelerating the decomposition process. These agents act on the straw to make it soft and ploughable, break down its molecular components and release the nutrients into the field.
  
  
• Crop diversification from rice to other crops.
  
  

There is a need to holistically address the problem. Considering most farmers are small and marginal, Government needs to provide them with either financial incentives or alternative modes of disposal. Meanwhile, in regions in and around Delhi, measures must be taken to mitigate other pollutants through public transportation, ban on old diesel vehicles and polluting industries, vaccum cleaning of road dust etc.