2 TYPES of SOIL CARBON

Soil Inorganic Carbon (SIC):

Found primarily in arid and semi-arid environments as carbonate minerals (like calcium carbonate/limestone).

Soil Organic Carbon (SOC):

Makes up the vast majority of soil carbon. It is the foundation of soil organic matter (SOM) and comes from decaying plant roots, leaves, and soil microbes.

Why It Matters

- Soil Health: Carbon gives soil its dark, rich color and spongy texture. It helps soil retain water, prevents erosion, and acts as a reservoir for essential plant nutrients like nitrogen and phosphorus.
- Climate Change Mitigation: Through a process called soil carbon sequestration, healthy soils can pull excess carbon dioxide CO² from the atmosphere and lock it safely underground.

How Carbon Enters the Soil

Photosynthesis: Plants pull CO² from the atmosphere and convert it into sugars to grow.
Exudates & Decomposition: Plants release carbon-rich sugars into the soil through their roots. When plants die or shed leaves, this material decays into the soil.
Microbial Conversion: Microorganisms (like bacteria and fungi) break down the plant material, stabilizing the carbon into the soil structure where it can be stored long-term.

Farming Practices That Build Soil Carbon

Agricultural practices like tillage and monocropping deplete soil carbon over time. To actively rebuild soil carbon reserves, farmers utilize regenerative agriculture methods, such as:

Cover Cropping: Keeping living roots in the soil year-round to continuously feed carbon to microbes.
No-Till Farming: Avoiding plowing to prevent the physical disruption of soil, which releases stored carbon into the atmosphere.
Crop Rotation: Alternating different crops to maximize biodiversity and root depth.