2.3.8—Agriculture as carbon store/source/sink
- Syllabus
- First assessment 2026
- Objective
- 2.3.8
- Level
- HL
Audit Farming by Its Carbon Flows
Judge a farming practice by whether it adds durable carbon to soil and biomass faster than it releases or exports it.
Cover crops, residues and reduced disturbance can increase inputs and reduce oxidation or erosion; drainage, heavy tillage and burning can increase losses. The balance is site- and time-dependent.
A cover crop adds roots before the cash crop; if residues remain in soil, carbon input rises, but measuring soil stock is still needed to verify a sink.
No. Check whole-system inputs, decomposition, erosion and whether gains persist at depth.
One practice label cannot replace a net carbon balance over a defined boundary and period.