Soil Organic Carbon (SOC)
Definition
Soil Organic Carbon (SOC) is the major component of Soil Organic Matter (SOM). It is the most important measurement in the Soil Carbon Check. Soil organic carbon plus inorganic carbon is the total amount of carbon in soils.
Percentage of SOC in SOM
The percentage of SOC in SOM can range from 45-60%. The more SOC in the SOM, the less nitrogen and sulphur present. More SOC in SOM is an indicator of stability. The organic matter is then less easily broken down by soil life, and therefore there is also less decomposition.
Clay/SOC ratio
The clay / SOC ratio is an indicator of the structural condition of the soil. Generally, the soil structure quality increases with a decreasing clay / SOC ratio.
- A clay / SOC ratio of 8:1 is an average for a very good structure quality
- A clay / SOC ratio of 13:1 or higher is less favourable (Johannes et al., 2017) .
