Pakistan consistently ranks among the top three most polluted countries globally, primarily due to high levels of particulate matter from vehicle exhaust, industrial emissions, and the widespread practice of crop residue burning. Air pollution continues to escalate unchecked, further deteriorating public health.

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The issue is particularly pronounced in winter, when smog forms from a combination of fog and smoke, worsened by temperature inversions and low wind speeds. During October and November, large-scale rice stubble burning (setting crop harvesting residues on fire by farmers to clear and prepare their fields for the next crop) contributes to pushing the Air Quality Index several times higher than the World Health Organisation’s recommended limit.

During the same months, corn (maize) stalk (residue left after harvesting) is also extensively burned in Punjab. However, it has received far less attention compared to rice stubble burning, despite its significant acreage and higher biomass ratio.

Recently, the Punjab Government announced measures to curb air pollution and smog. However, the measures aimed at controlling rice stubble (crop residues) burning are predominantly centred on command-and-control approaches, such as fines and imprisonment, rather than focusing on sustainable market-based, technology driven, and educational solutions.

Farmers resort to in-situ burning due to a lack of effective and affordable residue management technologies, coupled with labour shortages

Given the vast geographic spread of rural areas, the question arises whether traditional, long-standing practice can truly be changed through administrative and regulatory measures alone, without offering viable alternatives.

The government’s approach carries an inherent risk of relapse once control and oversight are relaxed over time, because the large-scale crop residue burning — particularly millions of tonnes of rice straw and corn stalks — results from a complex interplay of technological limitations, farmers’ economic challenges, and the socio-cultural dynamics of rural areas.

The issue is not as simple as it seems. In recent years, cropping intensity has increased, leaving farmers with a narrow time window to plant wheat, potatoes, oilseeds, and other crops after harvesting rice and maize. The growing use of full-feed combine harvesters (for rice) and corn pickers has exacerbated the issue of residue (biomass) burning, as these machines shred rice straws and corn stalks into pieces during threshing.

Importantly, half-feed rice harvesters — now widely available — address the rice residue issue to a great extent. However, winds and heavy dew that falls after mid-October causes the rice crop to lodge in many areas, necessitating the use of full-feed combine harvester.

Furthermore, a baler is needed to collect and compress the residues into compact bales, as practiced in many countries and harvesting methods involve additional costs and reasonably expensive machinery, whether through ownership or access to a well-established rental market.

Resultantly, such lack of effective and affordable residue management technologies, coupled with labour shortages, leaves farmers with little option but to resort to in-situ burning — a quick, cheap, and convenient solution for managing crop residues.

Previously, in an effort to reduce rice stubble burning, the Punjab Agriculture Department provided farmers with subsidised implements such as rotavators, zero-tillage drills, happy seeders, and rice straw shredders (choppers). However, these were distributed in limited quantities, insufficient to cover the vast area within the short sowing period.

Additionally, they are primarily aimed at wheat sowing and do not provide workable solutions for other Rabi crops. For instance, potatoes are planted on raised ridges/beds, which require finely prepared land; exactly why potato farmers are more likely to burn crop residues.

The distributed implements are purposed for incorporating crop residue back into the soil after rice harvest, but they do not facilitate the collection of crop residue (biomass) from the fields. On the other hand, industry is grappling with high energy costs, and is in desperate need of more affordable energy solutions. Therefore, demand for biomass as an alternative fuel for industrial boilers has experienced an upward trend in recent years.

In the given situation, establishing a well-functioning market with multiple buyers to collect the biomass at field level — ideally compensating the farmers, or at the very least, doing so at no cost to them — would be a more practical solution.

Already, the biomass market for crops like cotton, wheat, sesame, canola, mustard, and other Brassica family members — known for their relatively higher calorific value and low silica and lignin contents — is well-established.

However, the market for rice straw and maize stalk — two significant biomass sources that contribute smog — remains underdeveloped due to the limited availability of tractor-driven balers that convert leftover straw from rice and maize fields into bales which can be utilised in industry or repurposed in rural households for fodder, animal bedding, cooking, and mulching.

In addition to this, several proven technologies are being used widely around the world to reduce crop residue burning. One is to convert crop residues into biomass ash, which is rich in potash and can be used as soil amendment. Another is biomass briquetting to transform crop residues — a renewable fuel — into biomass pellets that are utilised in both industry and households.

In conclusion, over the past two years, Pakistan’s farmers have been hit hard by three challenges: the adverse effects of climate change on maize, rice, sesame, and other crop yields; falling crop prices; and rising agricultural input costs. Implementing command-and-control measures without providing feasible alternatives will just add to farmers’ woes.

The situation presents an opportunity for the government to tackle crop residue burning by increasing the supply of balers and related machinery, promoting untapped technologies, and supporting small and medium enterprises to serve as formal biomass suppliers.

Khalid Wattoo is a farmer and a development professional, and Dr Waqar Ahmad is a former Associate Professor at the University of Agriculture, Faisalabad

Published in Dawn, The Business and Finance Weekly, September 16th, 2024