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 practised by farmers of Punjab and Haryana.

Origin of stubble burning practice

• Before the 1980s, farmers used to till the remaining debris back into the soil after harvesting the crops manually. 
• 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. 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. Shortage of labour, less efficacious combined harvesting technique and 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.

Issues associated with stubble burning 

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

Impact on agriculture

Harms microorganisms

• The heat from burning paddy straw which when penetrated into the soil, elevating the temperature and thereby kills the bacterial and fungal populations critical for a fertile soil.

Vulnerability to diseases

• It causes damage to friendly microorganisms and facilitates growth of ‘enemy’ pests and as a result, crops are more prone to disease. 

Loss of essential nutrients

• Stubble burning leads to a loss of significant amounts of nitrogen, phosphorus, potassium and sulfur  besides organic carbon resulting in additional fertilizers being used by farmers to replenish the same.

Growth of weeds

• Weeds are more prone to grow in the field cleared by burning the stubble and since growth of weeds affects the health of the principal crop, farmers respond by using chemical weedicides that increase the cost of production and aggravates biomagnification.

Air Pollution

• Crop residue burning releases large amounts of harmful pollutants like carbon dioxide (CO2), carbon monoxide (CO), oxides of sulphur (SOX), particulate matter and black carbon which directly contribute to environmental pollution.
• As per a TERI (The Energy and Resources Institute) report, in 2019 the air pollution in New Delhi and other parts of north India was 20 times higher than the safe threshold level as prescribed by the World Health Organization. 

Adverse effect of laws

• Adverse effect of laws like Punjab Preservation of Subsoil Water Act, 2009 which aims at conserving groundwater by mandatorily delaying the transplanting of paddy to beyond June 10, when the most severe phase of evapotranspiration is over. This necessitated farmers resort to stubble burning.

Impact during pandemic

• Stubble burning during a pandemic could worsen the situation by making lungs weaker and people more susceptible to disease and could also impact those recovering from infection.

Government measures to curb stubble burning

• In 2013, stubble burning was banned by the Punjab government. 
• In 2015, the National Green Tribunal imposed a ban on stubble burning in Rajasthan, Uttar Pradesh, Haryana and Punjab and directed the government to assist farmers by obtaining equipment like happy seeders and rotavator. 
• Stubble burning is an offence under Section 188 of the Indian Penal Code and the Air (Prevention and Control of Pollution) Act of 1981.
• Haryana took numerous steps to curb stubble burning in Punjab and Haryana, including the development of an app to detect and notify authorities about stubble burning committed in a particular field. 

Crisis of stubble burning into an opportunity

• Timely removal of stubble

The action plan of Punjab and Haryana appears to focus more on setting up Custom Hiring Centres which will facilitate farmers removing stubble by providing them with machinery such as the happy seeder, rotavator, paddy straw chopper, etc. on rent.

As per a study by the International Maize and Wheat Improvement Centre, the application of happy seeders can improve agricultural productivity by 10% to 15% while reducing labour costs and allowing the soil to become more fertile.

1. Promote use of crop residue-based biochar briquettes in local industries, brick kiln and

hotel/dhaba as an alternate fuel. 

1. Create markets for crop residue-based briquettes and mandate nearby thermal power plants to undertake co-firing of crop residues with coal. 
2. From stubble high-grade organic fertilizers can be prepared by mixing with cow dung and few natural enzymes.

• For example, Chhattisgarh model of gauthans can be replicated wherein a five acre plot held common by each village, all stubble from fields of various farmers are mixed with cow dung and few natural enzymes to produce organic manure.

1. Paddy straw can be used as fodder for cattle as it also contains the required nutrients. 
2. Using straw for electricity generation is another productive way of generating wealth from residue.
3. Expansion of schemes like the MGNREGA for harvesting and composting of parali can be considered.
4. Paddy straw can be converted into ethanol, a renewable fuel which helps India in achieving the target of 20% ethanol blending with petrol by 2030.

Innovative solution

• The Union government is testing an innovative method, the PUSA Decomposer, developed at the Indian Agricultural Research Institute, Pusa. 
• The PUSA Decomposer is a set of four tablets made by extracting fungi strains that help the paddy straw to decompose at a much faster rate than usual, giving farmers the option to shred the straw, spray a solution containing the fungal strains, and mix it with the soil for decomposition. 

• If methods such as this become successful, it will be a new revolution in farming which has the potential to both reduce air pollution and increase soil fertility.

However in the long term, shifting the cropping pattern away from paddy to maize, cotton or fruits etc., and promoting the practice of conservation of agriculture with low lignocellulosic crop residues can be a way forward.

Reference:

1. https://www.thehindu.com/todays-paper/tp-opinion/less-pollution-more-soil-fertility/article32977233.ece