Farm Waste Can Become Biochar, Can It Improve Soil and Give Farmers Another Use for Crop Residues?

Farmers often have crop residues left after harvest. These materials may be burned, left in the field or used as animal feed. Another option is to convert suitable residues into biochar. This carbon-rich material can then be added to soil as part of a wider soil management plan.

Biochar is made by heating biomass under limited oxygen through a process called pyrolysis. Unlike fresh plant residues, which break down relatively quickly, biochar contains stable forms of carbon that can remain in soil for a long time.

The idea is receiving fresh attention from agricultural researchers. In August 2026, ICAR-CCARI in Goa organised a Carbon Pathshala for farmers that included a practical demonstration of producing biochar from plantation and farm residues using a portable unit.

The programme was linked to a pilot project exploring whether biochar production could also create opportunities in voluntary carbon markets. Around 100 farmers participated and were introduced to biochar, soil management and the possible carbon-credit pathway.

How can biochar help the soil?

Biochar has a porous structure that can influence the way soil holds water and nutrients. Its effects can differ according to the raw material used, production method, soil type and application rate. Farmers should therefore avoid treating all biochar products as identical.

Research and field demonstrations have linked suitable biochar applications with improvements in soil properties. It can contribute to soil organic carbon and may help improve the physical condition of some soils when used correctly.

Biochar can also be combined with other organic materials. Farmers may charge or enrich biochar with compost, manure or suitable nutrient sources before applying it. This can help prevent the material from initially tying up some nutrients in certain soil conditions.

The goal should not be to replace compost, manure or other soil inputs with biochar. Instead, biochar can form one part of an integrated soil management system. Soil testing remains important because the right approach depends on the existing nutrient status and soil condition.

ICAR’s December 2025 Indian Farming publication described biochar as a carbon-farming practice because the stable carbon produced during pyrolysis can remain in soil for very long periods.

Can farmers make biochar from crop residues?

Farm residues such as stalks, husks, shells and other suitable biomass can be used as feedstock, but the material must be clean and appropriate for the production system. Painted, treated or contaminated materials should not be used.

The production process needs controlled heating. Simply burning crop residues in an open fire does not produce the same material and can create smoke and pollution. Farmers need suitable equipment or a properly designed production system that controls oxygen and temperature.

ICAR-CIRCOT has demonstrated biochar production as one option for managing cotton by-products. Its farmer programmes in Nagpur highlighted biochar alongside composting, briquetting and pellet making as ways to use cotton residues rather than burn them.

This can give farmers another way to handle residues after harvest. Instead of treating stalks only as waste, they can become an input for soil management or, where a viable market exists, another farm-based product.

Farmers should first calculate the cost of collecting, transporting and processing residues. If the residue is already needed for livestock feed, mulching or another productive use, converting it into biochar may not always be the best option.

How should farmers use biochar?

There is no single application rate suitable for every farm. Biochar properties vary widely depending on the feedstock and production temperature. Soil texture, pH, nutrient status and crop requirements also affect the response.

Farmers should therefore begin with advice from agricultural scientists, soil experts or a KVK rather than applying large quantities on their own. A small field trial can help farmers observe how the soil and crop respond before expanding its use.

Biochar should also be incorporated properly into the soil or used according to the recommendation for the particular product. Mixing it with compost or another organic material may be useful in some situations.

Farmers should keep records of the quantity used, production cost, labour and crop response. This will help them determine whether the practice is actually improving farm economics.

Biochar may also become linked with carbon markets. The Goa pilot is exploring this possibility, but farmers should not assume that simply producing or applying biochar will automatically generate carbon-credit income. Carbon projects require approved methods, measurement, verification and other conditions.

For farmers, the immediate opportunity is simpler: biochar can provide another way to manage suitable crop residues while adding a potentially useful soil amendment. Its value will depend on how it is produced, what material is used, how much is applied and whether the practice fits the farm’s soil and crop needs.