Soil Organic Carbon (SOC) represents the largest terrestrial sink for carbon stocks.
Furthermore, SOC is directly linked to agricultural productivity – the higher the SOC level, the more productive the land.
These factors present an attractive ‘nature-based solution’ for climate change. Management actions that increase SOC and improve agriculture are scalable across many projects to the gigatonne sequestration level per annum. For example, a 1% increase in SOC in the top 30 cm of soil translates to sequestration of approximately 165 tCO2e per hectare. ( assuming bulk density of 1.5t Soil/m3).
‘Co-benefits’ of building soil organic carbon
The challenge to realising these benefits at a commercial level has been the viability of accurately measuring soil organic carbon stocks. The ability to create carbon credits from changed management practices that build SOC levels provides a strong incentive to develop measurement solutions. Programs such as the Emissions Reduction Fund in Australia provide the methodology and funding incentive that enables farmers to be paid for building SOC.
Management practices to build SOC include:
- grazing management
- pasture cropping
- compost application
- biological farming systems.