Soil Gas Exchange Monitoring

What Spot Measurements Cannot Capture

Soil releases carbon dioxide, methane, and nitrous oxide continuously. The rate changes by the hour with soil temperature, moisture, microbial activity, and water table depth. A single manual reading captures only one moment. Automated, continuous monitoring captures the day-night cycles, rainfall events, and seasonal changes that determine how much gas a soil releases over time.

The biggest limitation in understanding soil greenhouse gas emissions is simply the lack of measurement data. Without continuous, reliable readings, carbon budgets and emissions inventories rely on rough estimates from one-off measurements, a major source of uncertainty for research, reporting, and carbon accounting.

Wetec soil gas systems can be set up to measure these gases and supporting conditions:

• CO₂ (carbon dioxide) — released by soil respiration. The primary indicator of how active a soil is biologically and how it is contributing to or storing carbon.

• CH₄ (methane) — released from wetlands, peatlands, flooded fields, and waste sites. A potent greenhouse gas, emissions rise sharply when the water table is high.

• N₂O (nitrous oxide) — released from agricultural soils, especially when fertilised and wet.

• CO₂ isotopes — used to identify where the CO₂ is coming from. For example, separating CO₂ from plant roots from CO₂ released by soil microbes.

• Supporting conditions — soil temperature, soil moisture, and air pressure are measured alongside gas concentrations to support accurate calculations.