Air pollution has hit dangerously high levels in India, with pronounced negative effects. As per the recent findings, an additional 10 μg/m3 of PM2.5 exposure can reduce life expectancy by 1.1 years in India. Also, around 4.8 and 6.7 years of life can be saved in the Indo-Gangetic Plains and Delhi, respectively, if the national standards for PM2.5 are met in these regions.
Heavily polluted regions in the world have witnessed a higher incidence of cardiorespiratory diseases as per the WHO. Hence, reducing air pollution is an important policy imperative.
Stubble burning has been one of the major sources of air pollution in the country. This year around, the problem has displayed changed dynamics. According to the data released by the Central Pollution Control Board, while Punjab showed an increase in stubble burning incidents in 2020 by 46.5%, Haryana reduced the count by about 29% since 2019. Nonetheless, stubble burning persists and is assuming a greater share in air pollution (according to the Ministry of Environment, Forest & Climate Change, the average contribution of stubble burning to PM2.5 grew from 10% in 2019 to 15% in 2020.)
The problem stems from the thrust on raising the production of paddy in the country whereby farmers in North India, in particular, were encouraged to cultivate it on a massive scale.
Paddy is harvested in October–November. Unlike other crop residues, paddy residues are on average harder to chew, have low calorific value and high silica content, all of which make them unsuitable for use as animal fodder. The thrust on mechanised farming also compounded the existing problem, since harvesters leave out 1-2 ft tall stubbles compared to less than six inches in manual harvesting.
Paddy residue left by harvesters takes one-and-a-half months to decompose while farmers don't have sufficient time to sow their next crop - wheat. Any delay in sowing of wheat leads to reduced yield to the tune of 1% decrease for each day that wheat sowing was postponed after the optimum sowing date.
This fixed upper bound on the wheat sowing date coupled with the lack of alternative avenues for utilisation of paddy residue creates pressures for stubble burning by farmers in winter. An individual farmer is unable to fathom the repercussions of his action of burning stubble on others when the enforcement of legal restrictions on stubble burning is lax. This leads to unabated stubble burning.
Given the limitations of mechanised farming, extra labour can be employed for the timely removal of residue from the farms by institutionalising the process through the MGNREGA. This would provide adequate incentives for farmers to not burn the residue since no extra cost will be incurred to them in the process.
In the long run, it is desirable for farmers in the region to switch from cultivating wheat and paddy to fruits, vegetables and other crops. This will not only solve the current issue but also avoid an impending water crisis in the region.
Further, we need to focus on genetically modified varieties of paddy that offer coveted outcomes such as reduced maturity period (so that harvesting can be completed well in advance, allowing stubble, if any, to assimilate with and enrich the soil), shorter crop height (so that bulk of the stubble currently generated gets reduced), lower cellulose content in the stalk (allowing stubble to be acceptable as fodder), etc.
Further, we need a shift of focus towards solution-approaches that emphasise farmers to re-use stubble productively and commercially (making paper and packing materials, generating energy or using in cement plants), thus casting them as problem shooters rather than problem creators. This effectively leverages behavioural aspects to create a feel-good factor.
This has two benefits over current remedies: it avoids confining stubble in the land, which has a negative connotation while extolling farms as self-contained ecosystems that confer benefits other than just food security to the nation.
In the long-term, petroleum companies can be incentivised to initiate investment plans for churning out 2G ethanol out of crop stubble. Given that many oil majors are within the government fold, they can take this up on a priority basis.
Also, 2G ethanol so produced can give a much-needed fillip to the ethanol blending programme of the government, which is currently at lower than laudable levels of achievement. This solution is advocated on two counts — this would be a purely Central government-driven project (ensuring sustained thrust on its implementation over time), and this would transform the image of the crop stubble from being the root of plumes of smoke to the nucleus for clean fuel, egging farmers to wholeheartedly support this.
(The writers are IES Officers attached to Department of Economic Affairs)