Soil organic carbon
Also called: SOC · Topic: Soils of India: Types, Degradation and Conservation · NCERT: Beyond NCERT
Meaning
Soil organic carbon (SOC) is the carbon held in decayed plant and microbe matter in the soil. It makes soil fertile and crumbly, helps it hold water, and feeds soil life. Many Indian soils have less than 0.5 per cent SOC. Three things lower it: high temperatures, which speed up decay; intensive tillage (repeated ploughing); and stubble burning. Organic carbon is one of the 12 tests on the Soil Health Card (launched in 2015).
Example
In Punjab and Haryana, farmers burn rice stubble after the harvest. This burns off residue that could have added organic carbon to the soil, so these intensively farmed soils keep losing SOC.
Don't confuse with
- Humus: humus is the dark, decayed organic matter itself. SOC is a measure of the carbon held in that matter.