Greenhouse gas emissions from soil
Biological and abiological processes in soil represent a major source of Greenhouse Gases (GHGs). The measurement of GHGs from soil therefore represents an important part of climate change research. GHGs, such as Carbon Dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O), released from soils into the atmosphere are primarily biogenic by origin.
Generally there are two different ways to measure GHG soil fluxes: either the samples are collected by syringe for laboratory analysis or measurements may be undertaken onsite in order to avoid the delays, costs and sample transport errors that this entails. Historically, this has been impractical because the required sophisticated instrumentation has been unsuitable for field operation and required mains power. However, the development of portable, robust, battery-powered FTIR gas analyzers by Gasmet Technologies has enabled the reliable onsite analysis of GHGs.
One of the most widely used techniques to measure soil fluxes is a chamber method in which an open-bottom soil chamber is placed on the ground and the concentration changes per chamber footprint area are measured over time. The soil chamber can be integrated with a Gasmet gas analyzer, forming a closed-loop system in which the gas sample is circulated through the analyzer back to the chamber.
See below a demonstration video of Gasmet Greenhouse Gas measurements:
For more information about collar/chamber-placements, please see these articles:
1. Pihlatie, M. et al., 2013,
Comparison of static chambers to measure CH4 emissions from soils
2. Christiansen, J.R. et al., 2011,
Assessing the effects of chamber placement, manual sampling and headspace mixing on CH4 fluxes in a laboratory experiment
Gasmet provides two field-deployable non-destructive FTIR gas analyzers for continuous multicomponent gas analyses: DX4040 and DX4015. These robust gas analyzers enable the measurement up to 50 different gas compounds simultaneously, and the results can be obtained in less than three minutes. Both of the analyzers are ideal for field work and capable of taking samples from several chambers automatically.
The FTIR technology is well-suited for measurements of multiple gases over wide ranges, and is ideal for different soil types, such as terrestrial ecosystems, agricultural soils and aquatic environments, with varying GHG emissions. Gasmet gas analyzers provide the users with the ability to follow concentration changes in real-time, and to study and analyze the results as soon as they are collected.
In addition, Calcmet Software facilitates the retrospective analysis of collected spectra. These analyzers do not require span calibrations; zero calibration with nitrogen gas or ambient air is all that is necessary. As a result, field operations are quick and simple, and their small footprint makes them attractive in the laboratory environment.
The GasmetTM analyzers have been used successfully in many soil chamber flux applications especially in North America. (See the list of reference articles in Downloads)
Advantages in a nutshell:
- Simultaneous multicomponent analysis
- FTIR measures ALL significant GHGs
- Calcmet software gives the whole sample spectra
- Rapid sampling and continuous live readings
- Precise results in demanding field conditions
- Low weight, battery powered
- Ability to QUANTIFY knowns and IDENTIFY unknowns
- Cross-interferences automatically compensated
- Non-destructive analysis
- Only daily zero calibration needed
- Simultaneous analysis of up to 50 compounds
The DX4040 can be operated by PDA with integrated GPS and digital camera.