Why Do Farmers Burn Crops? The Economics Nobody Talks About

Approximately 6.15 million tonnes of rice straw are burned in Thailand every year (FAOSTAT Global Carbon Estimation, 2021 -- 2023 average). That is not a typo. It is also not the whole picture -- the total across all crops is closer to 18.9 million tonnes (Thai Department of Agricultural Extension, 2024). Every February through April, the smoke blankets northern Thailand, pushes PM2.5 to 13 -- 27 times the WHO guideline, and dominates international headlines with photographs of haze over Chiang Mai.

What the headlines rarely explain is why.

The standard narrative -- that farmers are ignorant, reckless, or indifferent -- collapses the moment you look at the economics. I grew up on a rice farm in Lampang province. My father burned his fields every year. He was not indifferent. He was broke.

This article lays out the economic reality that drives crop burning in Thailand, drawing on FAOSTAT production data, Thai Office of Agricultural Economics (OAE) provincial records across 41 provinces, and Bhumi's original cross-referenced research. Every number is cited. Where the data is incomplete, I say so.

The scale: what actually gets burned

Thailand is one of the world's top three rice producers. The country's 3.7 million farming households cultivate roughly 10 million hectares. Between February and April each year -- the dry season window before the next planting cycle -- Thailand generates approximately 48.6 million tonnes of crop residue from rice, maize, sugarcane, cassava, and fruit trees (Thai Department of Agricultural Extension, 2024).

About 29.7 million tonnes (61%) are utilised for fertiliser, livestock feed, or sale. The remaining 18.9 million tonnes are left to burn.

For rice specifically, Bhumi's analysis of FAOSTAT data -- cross-referencing Thai rice production with the Global Carbon Estimation's biomass-burned figures for 2021 -- 2023 -- shows an annual average of approximately 6.15 million tonnes of rice straw dry matter burned. That is material with 32 -- 47% cellulose content by weight (FAO, 2023), meaning it has genuine industrial value as a feedstock for packaging, biochar, or composite materials. Instead, it generates an estimated 50,000 tonnes of PM2.5 and roughly 530 kilotonnes of CO2-equivalent greenhouse gases every year (IPCC emission factor: 8.3 g PM2.5 per kg dry matter, IPCC 2019 Table 2.5).

Satellite data confirms the pattern. GFW VIIRS fire alerts recorded over 235,000 fire events across Thailand in 2024 -- 2025 alone. The peak is March. Every year.

The five economic forces behind the match

The decision to burn is not one decision. It is the end point of five intersecting economic pressures, any one of which would be difficult to overcome. Together, they make burning the only rational choice for millions of farming households.

1. Burning is free. Alternatives cost money farmers do not have.

The simplest explanation is often the most accurate. Burning a field costs nothing. Hiring a baler costs approximately 2,000 THB (around US$55) per operation (ASEAN Agrifood, 2024). For a small rice farmer earning less than the national average income, that is not a trivial expense -- it is a week's food for a family.

Manual clearance is even more expensive. It requires labour that either must be hired (scarce and costly during harvest season) or contributed by family members who are already working 12 -- 14 hour days during the post-harvest window.

The maths is unforgiving. The cost of not burning is real and immediate. The cost of burning -- health impacts, soil degradation, climate damage -- is diffuse, delayed, and borne by everyone except the individual farmer.

2. The market for crop residue barely exists.

According to MDPI research on Thai agricultural practices, only 9.29% of farmers sell their crop residue (MDPI, Prospects of Controlling Open Burning, 2024). Nearly half (49.76%) use it as fertiliser by incorporation into soil. About 19.18% use it for livestock feed.

That 9.29% figure deserves attention. It means that for the overwhelming majority of Thai farmers, there is no buyer standing at the farm gate offering to take the straw away. No collection infrastructure. No aggregation point. No supply chain.

When there is no market, there is no price signal. When there is no price signal, waste has no value. And when waste has no value, the cheapest disposal method wins. Fire is the cheapest disposal method in human history.

3. The maize-animal feed connection nobody discusses

Thailand's maize production is concentrated in northern provinces -- Chiang Mai, Chiang Rai, Nan, Phrae, Lampang -- the same provinces that suffer the worst air quality during burning season (OAE provincial data, 41 provinces, 2010 -- 2024). This is not a coincidence.

The vast majority of Thai maize is produced for animal feed, not human consumption. The supply chain runs from upland farmers in the north through feed mills and into the poultry and livestock industries. The maize itself is harvested, but the stalks and husks -- with a residue ratio of approximately 1:1 by weight (IPCC Tier 1 default) -- are left in the field. With no buyer for maize residue and the next planting season approaching, burning is the fastest way to clear the ground.

This means the smoke choking Chiang Mai every March is, in significant part, a by-product of the animal feed industry. The connection between the chicken on your plate and the air quality in northern Thailand is direct, traceable, and almost entirely absent from public discussion.

4. Farmer debt makes long-term thinking impossible

The vast majority of Thai rice farmers carry debt (Borgen Project, 2024). When you are servicing loans and your margins are measured in hundreds of baht, investing in residue management equipment or paying for baling services is not a strategic oversight. It is financially impossible.

Debt changes the time horizon of every decision. A farmer with savings can afford to think about soil health over five years. A farmer with debt thinks about the next harvest. Crop burning is a short-term rational response to a short-term financial reality -- even though its long-term costs, in soil nutrient loss and respiratory health alone, are devastating.

This is what makes prohibition alone insufficient without economic alternatives. Thailand has taken the step of making open burning illegal -- a clear signal of intent. But the burning continues because legislation, on its own, cannot change the underlying economics. The gap is not political will. It is infrastructure.

5. The institutional gap: US$14 million per year to fix

The Stockholm Environment Institute (SEI) has estimated that the cost of overcoming social and institutional barriers to reducing crop burning in Thailand is approximately US$14 million annually over a 10-year period -- a 70% increase on the US$21 million Thailand planned for controlling burning in 2026 (SEI research, cited in MDPI 2024).

That number deserves unpacking. "Social and institutional barriers" means the extension services still scaling to reach remote farms. The cooperative structures still developing in every district. The demonstration projects awaiting funding. The training programmes for alternative residue management that have not yet reached scale.

It is not that solutions are unknown. Biochar conversion, composting, baling for industrial use, mushroom substrate production -- these all work. What does not exist is the infrastructure to deliver them to 3.7 million farming households spread across 41 provinces.

What burning actually costs

The economics of burning extend far beyond the farm gate. The full cost of crop burning in Thailand includes direct health impacts, lost tourism revenue, soil degradation, and climate damage. Some of these can be quantified. Others cannot, which does not mean they are small.

What would actually change this

I am cautious about the word "solutions" because it implies the problem is simpler than it is. What follows are the conditions that would need to exist for burning to decrease. None of them is quick.

NASA's ASIA-AQ research collaboration, which conducted atmospheric measurement flights over Thailand in March 2024, is adding to our understanding of how burning-season emissions move through the atmosphere -- a collaboration that reflects Thailand's openness to international scientific partnership. Better data will help target interventions. But data alone does not build the collection infrastructure that farming communities need.

What we do not know

Transparency requires admitting gaps. Here are the things this analysis cannot tell you.

FAQ

Why is crop burning legal if it causes so much pollution?

Open burning is actually illegal in Thailand. The practice continues because enforcement is difficult across millions of small farms, and because prohibition without viable economic alternatives leaves farmers with no realistic option. The cost of crop residue management -- baling alone costs approximately 2,000 THB (US$55) per operation -- is beyond what many indebted farming households can absorb.

How much crop waste does Thailand burn each year?

Thailand burns approximately 18.9 million tonnes of crop residue annually across all crop types, according to the Thai Department of Agricultural Extension (2024). For rice straw specifically, FAOSTAT data shows approximately 6.15 million tonnes of dry matter burned per year (Bhumi analysis, 2021 -- 2023 three-year average). This generates roughly 50,000 tonnes of PM2.5 particulate matter.

What is the connection between maize farming and air quality in Thailand?

Thai maize production is concentrated in northern provinces -- Chiang Mai, Chiang Rai, Nan, Phrae, Lampang -- which are also the worst affected by burning-season haze. The majority of Thai maize is grown for animal feed. After harvest, the stalks and husks (roughly equal in weight to the grain itself) are burned to clear fields before the next planting cycle, contributing directly to the PM2.5 crisis in the north.

Could crop waste be used for something instead of being burned?

Yes. Rice straw contains 32 -- 47% cellulose by weight, making it viable as feedstock for biodegradable packaging, biochar (which improves soil when returned to fields), composite building materials, and mushroom substrate. Bhumi's analysis estimates that burned rice straw alone could yield 2.4 million tonnes of packaging feedstock annually, worth US$535 million to US$2.9 billion. The barrier is infrastructure, not technology.

What would it cost to stop crop burning in Thailand?

The Stockholm Environment Institute estimates that overcoming the social and institutional barriers to reducing crop burning costs approximately US$14 million per year over a 10-year period -- roughly 70% more than the US$21 million Thailand budgeted for burning control in 2026. This covers extension services, cooperative development, equipment subsidies, and market-building for crop residue. The technology exists. The delivery infrastructure does not.