What is stubble burning?

• Stubble burning is the process of intentionally setting fire to the straw stubble that remains after grains, like paddy, wheat, etc., have been harvested, to remove them from the field to sow the next crop. 
• This is commonly practiced by farmers of Punjab and Haryana.

Evolution of stubble burning

• During the late 1970s and early 1980s, which was the Green Revolution era, Punjab and Haryana shifted from their traditional crops (maize, pearl millet, pulses and oilseeds) to the wheat-paddy cultivation cycle. Free or subsidized power supply for groundwater extraction plays a role here in the shift.
• In Punjab and Haryana, while the paddy crop is usually harvested between the first and last weeks of October, the wheat crop is sown from the first week of November. 
• Paddy harvesting and threshing are labor-intensive and in case of shortage of cheap labor machines like the Combined Harvester are used which only pick the plant’s top part (panicle) and leave the remaining stalk of about 2-3 feet (stubble) standing in the field. 
• With only 10-15 days between the rice-harvesting season and the wheat-sowing time, farmers often burn the stubble to quickly eliminate the paddy stubble.

Why do farmers resort to stubble burning?

• Lack of knowledge about effective alternatives to stubble burning.
• Lack of affordable mechanisation to cater the needs of millions of farmers.

Issues surrounding the stubble management

• Unlike wheat straw, which is commonly used as animal feed and sells at good prices, rice is unfit to be fed to cattle because of its high content of unpalatable silica, and, therefore, has little market value. 
• If ploughed back into the field, it interferes with subsequent crop operations. 
• Only some farmers use farm machines like happy seeder and straw management machines to incorporate the stubble back into the soil instead of setting it on fire.
• Even after encouraging multiple initiatives including applying a decomposer to encourage in-situ management of stubble or using the direct seeding of rice (DSR) technique by the center and state, the problem remains intractable.

Possible solutions

• Rethink the policy of providing free power: Give a direct cash/benefit transfer (DBT) instead of a power subsidy. This can avert the over-exploitation of groundwater and help diversify crops away from paddy.
• Create a market for paddy straw/stubble: An effective market has to be created for stubble that at least compensates them for the extra effort and cost involved in its harvest, collection and disposal. 
• Convert straw to CBG: Among various options, the use of straw for the production of compressed biogas through methods of anaerobic digestion is best from economic and environmental perspectives. It also produces bio-slurry, which can go back into the soil to replenish soil fertility. 
• Subsidized machineries: Further modifications and subsidized supply of machinery for in-situ use of paddy stubble will also be very helpful in preventing farm fires in some areas.
• Legal enforcement: Once an effective channel for procuring paddy straw is created, a law against the burning of any crop straw should be strictly enforced. 

Why in News?

• Stubble burning is in the news due to its seasonal impact on air quality, particularly in North India.
• The Supreme Court recently criticized Punjab and Haryana for selectively penalizing stubble-burning, stating that this practice violates citizens’ right to a pollution-free environment under Article 21.