Why Biomass Burning Continues: Cultural and Agricultural Factors

Across the world, from the rice paddies of South Asia to the maize fields of sub-Saharan Africa, farmers regularly set fire to the plant material left after harvest. This practice – open biomass burning – is not new. It is deeply embedded in both cultural traditions and the practical realities of modern agriculture. Research shows that burning is one of the most widely used methods for disposing of crop residues, applied to crops ranging from wheat and rice to sugarcane and cotton. Yet despite mounting evidence of its environmental costs, it continues at a significant scale. Understanding why it persists requires looking at the agricultural, economic, and cultural forces that keep it in place – and at the very real challenges of moving beyond it.

Biomass burning as an agricultural tool
Deep cultural roots: slash-and-burn and shifting cultivation
Economic and logistical factors driving the practice
Environmental consequences: what burning actually costs
Soil degradation
Air quality and public health
Greenhouse gas emissions
Alternatives and the challenges of transition
Residue incorporation and mulching
Biochar production
Composting
Policy, awareness, and the missing link

Biomass burning as an agricultural tool

At its most basic, biomass burning is a field management strategy. After a crop is harvested, large quantities of straw, stalks, leaves, and husks remain on the field. These residues need to be cleared before the next crop can be planted. Burning clears the field quickly, costs almost nothing, and – in the short term – releases nutrients from the ash back into the soil.

The widespread adoption of mechanized crop harvesting in cereal-based production systems, combined with limited time between cropping seasons, has made residue burning a common field management strategy. When a farmer has only a few weeks between the rice harvest and the wheat planting window, there is simply not enough time to manually remove or process tonnes of leftover straw. Fire does the job in hours.

Beyond clearing, farmers also burn residues for pest and weed control. The heat kills weed seeds, fungal spores, and pest insects that survive in crop debris. In surveys of smallholder farmers in Burkina Faso, faster field clearance (cited by 41% of respondents) and improved soil fertility (cited by 23%) were the primary reasons given for adopting biomass burning. These are rational responses to real farming challenges, not simply a lack of awareness.

Deep cultural roots: slash-and-burn and shifting cultivation

For many communities, burning is not just a practical choice – it is a cultural one. Slash-and-burn agriculture, known as jhum or jhoom cultivation in India and Bangladesh, has been practiced for thousands of years as a form of shifting cultivation. In this system, farmers cut and burn vegetation on a plot of land, use the ash-enriched soil for a few seasons, and then move on to a new area, allowing the original plot to regenerate over a decade or more.

When practiced with sufficient fallow periods and at low population density, traditional slash-and-burn can be ecologically sustainable. In its traditional form, the cleared area would revert to secondary forest during the fallow period, and after about a decade, the old site could be reused. This rotation allowed soils to recover and forests to regrow.

The problem arises when population pressure shortens fallow cycles or when commercial agriculture drives burning at a much larger scale. Increased worldwide demand for tropical commodities such as palm oil and natural rubber industrialized a practice that had for centuries been managed sustainably by small farmers. As burning scaled up, its environmental consequences became far more severe.

In Papua New Guinea, parts of West Africa, and throughout Southeast Asia, burning remains integrated into land management customs passed down across generations. In these contexts, transitioning away from fire is not just a technical or economic challenge – it requires engaging with deeply held cultural practices and local knowledge systems.

Economic and logistical factors driving the practice

For farmers operating on thin margins, economics often override environmental concern – not out of indifference, but out of necessity. When the cost of renting machinery for residue management runs into thousands of rupees while a box of matches costs only a few, the financial logic of burning becomes difficult to argue against, even for farmers who are aware of the environmental damage.

The primary drivers behind crop residue burning in South Asia are the high cost of incorporating, collecting, transporting, and processing crop residues, combined with labour shortages and the short window between harvest and the next planting season. In places like Punjab and Haryana in India, mechanized combine harvesters leave behind large quantities of straw that would require significant labour or expensive machinery to manage any other way.

The marketability of crop residues is another factor. In regions where there is no established market for straw – as a feedstock for bioenergy, animal feed, or composting – farmers have little incentive to handle it. Burning remains the default because no economically viable alternative has been made accessible to them. This is fundamentally a market and infrastructure failure, not simply a knowledge gap.

Burning is among the most commonly used methods for removing crop residues globally, and while farmers often defy their own understanding of the value of biomass residues for soil nourishment, the practice persists because alternatives have not been made economically feasible at scale.

Environmental consequences: what burning actually costs

The short-term benefits of burning – cleared fields, a pulse of ash-based nutrients – come at a significant long-term environmental price. Open burning releases a complex mix of pollutants. These include methane (CH₄), sulfur oxides (SOₓ), nitrogen oxides (NOₓ), carbon monoxide (CO), carbon dioxide (CO₂), and particulate matter including PM2.5 – fine particles that penetrate deep into the lungs.

Soil degradation

One of the most damaging but least visible effects of biomass burning is what it does to soil. Burning destroys the organic matter in residues that would otherwise break down and feed soil microbes, improve soil structure, and retain moisture. Crop residue burning degrades soil, increases the risk of erosion, raises soil temperature, and kills soil microorganisms. This forces farmers to use more synthetic fertilisers to maintain yields, creating a cycle of increasing chemical dependency and further soil degradation.

The ash released by burning does temporarily supply some minerals like calcium and potassium. But nitrogen – one of the most critical nutrients for crop growth – is largely lost to the atmosphere during combustion. Over repeated burning seasons, soil fertility declines, undermining the very productivity the practice is meant to support.

Air quality and public health

The air quality impacts of crop residue burning are severe, particularly in densely populated agricultural regions. Research tracking Indian crop residue burning from 2003 to 2019 found that agricultural residue burning caused an estimated 44,000 to 98,000 premature deaths annually due to particulate matter exposure, with Punjab, Haryana, and Uttar Pradesh accounting for the majority of these deaths. These are not statistics from a distant environmental problem – they represent real health outcomes in communities living near burning fields.

The smoke from biomass fires also travels. It contributes to regional haze, affects neighbouring countries, and disrupts air quality far beyond the field where the fire was set. Open burning of biomass and crop residues produces black carbon particulate matter, which directly contributes to atmospheric warming by absorbing solar radiation, adding a climate dimension to the immediate public health burden.

Greenhouse gas emissions

Open burning of crop residues releases greenhouse gases and toxic pollutants into the atmosphere, and its contribution to global warming potential is substantially higher than that of alternatives such as fertiliser or biochar production from the same residue. Biomass burning is also a leading source of black carbon – a potent short-term climate forcer. Agricultural biomass burning, including crop residue burning and forest fires, contributes to approximately 37% of global black carbon emissions.

Alternatives and the challenges of transition

Sustainable alternatives to burning do exist. The challenge is making them practical and affordable for the farmers who currently rely on fire.

Residue incorporation and mulching

Crop residues can be chopped and incorporated into the soil using appropriate machinery, or left on the surface as mulch. This retains nutrients, improves soil organic matter, suppresses weeds, and reduces erosion. However, it requires mechanised equipment that many smallholders in low-income countries cannot afford. Where labour is expensive, it also adds time and cost that burning eliminates. Addressing this problem requires encouraging the use of agricultural machines capable of sowing crops in standing stubble, alongside in-situ residue management practices and crop varieties with shorter growing durations.

Biochar production

Rather than burning residues openly, they can be converted into biochar – a charcoal-like material produced by heating biomass at high temperatures in low-oxygen conditions (pyrolysis). Biochar has a porous structure, high cation exchange capacity, and nutrient retention capabilities that enhance soil fertility, water-holding capacity, and microbial activity. Unlike open burning, biochar production sequesters carbon in a stable form rather than releasing it into the atmosphere. Biochar production schemes reduce global warming potential by 2.46 to 3.22 times compared to open burning, while also generating positive economic returns.

The barrier here is the upfront investment. Pyrolysis equipment is expensive, and the supply chains for collecting, processing, and selling biochar are not yet established in many farming regions. For smallholder farmers with no access to credit or subsidy, these costs are prohibitive.

Composting

Composting turns crop residues into nutrient-rich organic matter that can be returned to the soil. Composting and biochar production are among the most effective sustainable residue management techniques for retaining the nutrients present in crop residue within the soil. Like other alternatives, composting requires time, labour, and space – resources that are not always available between cropping seasons.

Policy, awareness, and the missing link

Government bans on field burning have been implemented in several countries, including India, but enforcement is difficult and often contested. Farmers who cannot afford alternatives will continue to burn regardless of regulation. Education level and access to agricultural extension services are among the most significant factors influencing farmers’ awareness of the environmental impact of biomass burning and greenhouse gas emissions, suggesting that outreach and training – not just regulation – are critical to lasting change.

Ultimately, the persistence of biomass burning is a systems problem. It will not be solved by addressing any single factor in isolation. It requires coordinated efforts that combine affordable technology, viable markets for residue products, accessible finance for smallholders, and culturally sensitive engagement with farming communities. Research from Pakistan confirms that farmers with larger landholdings and higher education levels are significantly more likely to adopt sustainable crop residue management practices – pointing to the importance of land tenure, credit access, and education as structural preconditions for change.

Biomass burning will not disappear through awareness campaigns alone. As long as it remains the cheapest and most logistically convenient option, many farmers will continue to choose it. The real challenge is closing the gap between what is environmentally necessary and what is economically possible for the people who grow our food.

What do you think? If you were a smallholder farmer with limited resources and a narrow window between cropping seasons, what would it take for you to abandon burning in favour of a sustainable alternative? And do you think governments and agribusiness have done enough to make those alternatives genuinely accessible?

References

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Table of Contents

Biomass burning as an agricultural tool 🔗

Deep cultural roots: slash-and-burn and shifting cultivation 🔗

Economic and logistical factors driving the practice 🔗

Environmental consequences: what burning actually costs 🔗

Soil degradation 🔗

Air quality and public health 🔗

Greenhouse gas emissions 🔗

Alternatives and the challenges of transition 🔗

Residue incorporation and mulching 🔗

Biochar production 🔗

Composting 🔗

Policy, awareness, and the missing link 🔗