Soil carbon credits are certificates for carbon that farming practices have stored in a field's soil. A carbon credit is a certificate that one tonne of carbon dioxide has been kept out of the air, or removed from it. Companies buy credits to make up for their own emissions.
Plants take carbon dioxide from the air as they grow. Some farming practices leave more of that carbon in the soil, for example growing a cover crop between two main crops, or ploughing less. The company that issues soil carbon credits measures how much carbon the field holds before and after the change. It uses soil samples, satellite images and computer models. The difference is the carbon kept out of the air. An independent body checks the measurement before the credits are issued.
Say a group of farmers on 100 hectares near Karnal sows wheat without ploughing and grows a cover crop between seasons for a year. The measurement shows that the fields kept 150 tonnes of carbon dioxide out of the air. That produces 150 credits. A company with emissions to offset buys the credits, and the money is shared with the farmers.
Two checks decide whether a credit is trusted. The first is that the carbon would not have been stored without the change, so the farmers must show what the field held before. The second is that the carbon stays in the soil. If a farmer ploughs deep the next year, the carbon may return to the air, so issuers keep some credits back as a safety margin and watch the field in later years. Credits sold in India's voluntary market are priced by the buyer and the issuer. India is also building a compliance carbon market, in which the government sets targets for industries.
The company advises farmers on the practices to follow through a farm AI adviser. It scans fields with hyperspectral imaging, a camera that sees many more colours than the eye does. Seeds and other inputs reach the farmers through the agri-input channel. A buyer enters the credits it holds in carbon accounting software, against its Scope 1, 2 and 3 emissions. Credits do not reduce a company's own emissions. They are used for the part that the company cannot yet remove.