Soil carbon sequestration
Soil carbon sequestration is the process of transferring atmospheric carbon dioxide into soil organic matter or inorganic carbon and retaining it there through biological, chemical, and land-management processes. Its climate value depends on additional net storage over a defined baseline, measurement boundaries, duration, saturation, leakage, and the risk that stored carbon is later released.
In simple terms
Plants take up carbon dioxide and transfer some carbon below ground through roots, residues, and interactions with soil organisms. Practices such as retaining residues, cover cropping, improved grazing, agroforestry, erosion control, or restoring degraded land may increase soil carbon in suitable contexts. Outcomes vary with climate, soil, prior management, depth, inputs, and time. Measurement should specify the carbon pool, sampling depth, area, baseline, period, and uncertainty, and should account for associated greenhouse gas changes rather than infer sequestration from a practice alone.
Why it matters
Soils hold large carbon stocks, so even modest changes can affect climate outcomes, soil condition, water retention, and agricultural resilience. Claims based only on Activity data or practice adoption can overstate results. Credible estimates need repeated measurement or validated models, transparent uncertainty, and safeguards against reversal and displacement of emissions.
Example
A farm compares soil organic carbon stocks under a new cover-crop and reduced-tillage system with a documented baseline. Sampling uses consistent locations, depth, bulk-density methods, and timing. The assessment reports uncertainty and changes in fertilizer-related nitrous oxide, then monitors whether stored carbon persists after weather and management changes.
How it differs
Carbon sequestration
Carbon sequestration includes carbon uptake and storage in multiple reservoirs or technologies, whereas soil carbon sequestration concerns additional carbon retained specifically in soil carbon pools.