Context: As the paddy harvesting season approaches, Punjab and neighbouring States are likely to again face the problem of stubble (parali) burning, contributing to severe air pollution in northern India.
- Farmers face a difficult choice because paddy residue is bulky, costly to remove and must be cleared within a narrow window before wheat sowing.
- While governments have focused on enforcement and machinery subsidies, the emerging market value of paddy straw suggests that a decentralised, farm-level processing model may offer a more sustainable solution.
Changing Economics of Paddy Residue
- Earlier, farmers in several regions had to pay for straw removal; today, paddy straw in parts of Punjab can fetch around ₹1.5–2/kg due to rising demand from power plants, Compressed Biogas (CBG) units and pellet manufacturers.
- Thus, parali is increasingly shifting from being treated as agricultural waste to an economic resource.
Biochar: Converting Waste into a Resource
- Biochar is a carbon-rich material produced by heating biomass under limited oxygen, and can be made from paddy, maize, cotton and mustard residues.
- Around 100 kg of dry paddy straw can yield nearly 30 kg of biochar.
- When applied to soil, biochar can improve water retention and nutrient-use efficiency while storing carbon for a long period, potentially around a century.
Biochar vs. Biomass Burning
- Using crop residue merely as fuel recovers energy but releases much of its carbon back into the atmosphere.
- Biochar can retain a significant portion of the carbon while also providing an agricultural benefit when returned to soil.
- This is particularly relevant for Punjab's rice–wheat system, which faces soil degradation, intensive fertiliser use and groundwater depletion.
The Logistics Problem
- Paddy straw must be collected, baled, stored and transported within the short period between paddy harvesting and wheat sowing.
- Since straw is bulky and has relatively low value per unit weight, long-distance transportation quickly reduces its economic viability.
- Consequently, farmers often supply the raw material while most value addition occurs away from the village, limiting the economic benefit reaching them.
Why Decentralised Processing Matters
- Processing residue closer to farms can reduce transportation costs and allow greater value capture by farmers and rural communities.
- The model is comparable to the traditional village flour mill (chakki), where wheat is processed close to where it is produced and consumed instead of transporting bulky raw material over long distances.
- Similarly, paddy residue can be processed through village-level biochar units, reducing logistics costs and making residue management more economically attractive.
Proposed Village-Scale Biochar Model
- A Build–Operate–Transfer (BOT) model can be used, where a technology provider initially installs and operates the biochar unit, trains local operators and maintains quality and emission standards.
- Over time, ownership and operational capability can be transferred to Farmer Producer Organisations (FPOs), Self-Help Groups (SHGs) or cooperatives.
- Farmers could bring straw to nearby processing centres, receive some biochar for use on their fields and sell the remainder where viable markets exist.
Role of Government and Panchayats
- The government need not directly operate thousands of decentralised units; instead, it can provide technical standards, training, concessional finance and initial support.
- Gram Panchayats can facilitate land availability, local coordination and aggregation of farmers.
- This approach can avoid the problem of subsidised machinery remaining underutilised because villages lack technical expertise or viable operating models.
Changing the Incentive Structure
- Stubble burning remains attractive because it is quick, inexpensive and requires minimal additional labour, while alternatives often involve cost, logistics and uncertainty.
- Enforcement and machinery subsidies can reduce burning, but long-term behavioural change is more likely when paddy residue itself becomes economically valuable.
- Developing local biomass markets can therefore convert the farmer's incentive from “dispose of waste” to “monetise a resource.”
Important Concept: Circular Economy
- Circular economy seeks to minimise waste by keeping materials and resources in productive use through reuse, recycling, recovery and value addition.
- Converting paddy straw into biochar and returning it to agricultural soils represents a circular approach by transforming farm residue into a soil and carbon-management resource.
Way Forward
- Shift from an exclusive focus on stubble-burning enforcement towards creating viable local markets for crop residues.
- Promote decentralised biomass-processing units close to farms, supported by FPOs, SHGs and cooperatives.
- Develop standards and quality certification for biochar, facilitate concessional rural finance, and create assured demand through agriculture, carbon markets and biomass-based industries.
- Ensure that a greater share of the value created from parali remains with farmers, making sustainable residue management economically preferable to burning.
