‘The usual Stubble Burning Problem’
13th Oct, 2020
Delhi’s overall air quality, which currently lies in the ‘moderate’ category, is all set to deteriorate in the coming days due to a spike in stubbing burning activity across northwest India and other meteorological conditions.
- Every year, a choking smog descends on northwest India as the region's farmers burn their fields following the rice harvest - a phenomenon that has helped make New Delhi one of the world's most polluted cities.
- The states surrounding Delhi are known collectively as the "grain bowl" of India after the agricultural sector underwent a green revolution in the 1960s, leading to a dramatic increase in rice and wheat productivity.
- In Haryana alone, 80% of the almost 5 million hectares of land is now under cultivation, producing over 13 million tons of grain per year.
- But as production grew, the sector could not keep up with an increasing demand for labor, with farmers eventually abandoning hand harvesting in favor of less labor-intensive methods such as the combine harvester.
- Unlike manual harvesting techniques however, combine harvesters leave behind rice stubble, which prevents machines from sowing wheat seeds.
- With as little as 10 days between rice harvesting season and the sowing of wheat, farmers often turn to stubble burning to quickly remove the remaining rice crop residue.
- When farmers are unable to move the loose residue, they are left with no option except burning.
What is Stubble Burning?
- Stubble burning is, quite simply, the act of removing paddy crop residue from the field to sow wheat.
- It’s usually required in areas that use the ‘combine harvesting’ method which leaves crop residue behind.
- Combines are machines that harvest, thresh i.e separate the grain, and also clean the separated grain, all at once.
- The problem, however, is that the machine doesn’t cut close enough to the ground, leaving stubble behind that the farmer has no use for.
- There is pressure on the farmer to sow the next crop in time for it to achieve a full yield. The quickest and cheapest solution, therefore, is to clear the field by burning the stubble.
Spike in stubble burning
- Stubble burning remains a persistent contributor to Delhi’s high pollution levels, causing a smog-like situation in Delhi-NCR every year post autumn and creating a health hazard for its residents.
- A sharp increase in stubble burning fires was observed around Punjab, Haryana, and neighbouring border regions,” as per
- The first two weeks of paddy harvesting that started from September third week this year saw the number of stubble burning cases across Punjab rise to a whopping 1,206!
- This is almost five times the number of cases (264) recorded during the Kharif harvest of 2019 in the corresponding time period.
- SAFAR added that the boundary layer wind direction has remained favourable for the transportation of stubble smoke into the landlocked capital, and hence, the stubble fires are expected to start impacting Delhi’s atmosphere in the days to come.
- For the rest of the ongoing week, however, SAFAR forecast indicates Delhi’s AQI will deteriorate marginally but remain in the moderate category nevertheless.
What happens every year?
- According to a 2018 studyconducted by The Energy and Resources Institute (TERI) and the Automotive Research Association of India (ARAI), the major sources of pollution in Delhi in the summer include-
- dust and construction activities (38-42 per cent)
- transport (15-17 per cent)
- industry (22 per cent)
- However, as the winter approaches, farmers in Punjab and Haryana begin to clear out the paddy residue on their farmlands by setting it on fire.
- The particulate matter from these fires travels down the entire Gangetic plain, enveloping vast swaths of northern India in smoke.
- Cities like Delhi, Noida and Gurgaon, which are already choked with pollution from vehicles and industries that operate year-round, bear the brunt, as their meteorological conditions prevent the smoke from dissipating.
- As winter sets in, the cold makes it harder for the particulate matter to rise up — leaving people exposed to the toxic smog.
- The festival of Diwali introduces more pollutants as people light firecrackers.
- Between 2016 and 2018, Delhi pollution levels did dip by about 25 per cent, but the AQI numbers remained far higher than what is considered to be safe.
- According to a studyby the Centre for Science and Environment, Delhi needs to cut its pollution levels further by 65 per cent to meet air quality standards.
Is it a crime?
- Burning crop residue is a crime under Section 188 of the IPC and under the Air and Pollution Control Act of 1981.
- However, government’s implementation lacks strength.
Assessing the impacts of Stubble Burning
- Burning crop residue directly contribute to environmental pollution, and are also responsible for the haze in Delhi and melting of Himalayan glaciers.
- One ton of residue contains 4-6 kg of nitrogen, 1-2 kg of phosphorus, and 15-20 kg of potassium.
- Besides causing air pollution, burning stubble also affects the fertility of the soil as it causes loss of nitrogen, sulphur, potassium and bacteriological content of the soil.
- The heat from burning paddy straw penetrates 1 centimetre into the soil, elevating the temperature to 33.8 to 42.2 degree Celsius. This kills the bacterial and fungal populations critical for a fertile soil.
- Burning of crop residue causes damage to other micro-organisms present in the upper layer of the soil as well as its organic quality. Due to the loss of ‘friendly’ pests, the wrath of ‘enemy’ pests has increased and as a result, crops are more prone to disease. The solubility capacity of the upper layers of soil have also been reduced.
Could new technology trigger a second revolution?
- India urgently needs to undergo a second, "evergreen" revolution, driven by technology such as the-
- happy seeder, a machine which allows wheat to be sown on top of rice stubble
- the super sms (straw management system), a machine which attaches to the rear of a combine harvester to cut and spread loose residue across the field.
Important Artificial Machines
- Happy Seeder(used for sowing of crop in standing stubble)
- Rotavator (used for land preparation and incorporation of crop stubble in the soil)
- Zero till seed drill (used for land preparations directly sowing of seeds in the previous crop stubble)
- Baler (used for collection of straw and making bales of the paddy stubble)
- Paddy Straw Chopper (cutting of paddy stubble for easily mixing with the soil)
- Reaper Binder (used for harvesting paddy stubble and making into bundles)
- Agricultural productivity can be improved with the use of happy seeders and super sms machines by between 10 and 15%, by reducing labor costs and time and allowing nutrients from the crop residue to be recycled back into the soil.
- Instead of burning of the stubble, it can be used in different ways like cattle feed, compost manure, roofing in rural areas, biomass energy, mushroom cultivation, packing materials, fuel, paper, bio-ethanol and industrial production, etc.
What else can be done?
- Agriculture conservation should be promoted with “low lignocellulosic” crop residues such as rice, wheat and maize.
- Crop residue-based briquettes ought to be encouraged and thermal power plants in the vicinity ought to be encouraged to undertake co-firing of crop residues with coal.
The problem is complex and needs a solution. But the solution should take into consideration the economic condition of farmers, the scientific options available and the willingness of the Central government to change policy and fund a major part of the expenditure.