Measurement solution for soil chamber gas flux - Monitoring and Testing

Closed chamber gas flux measurements can be made with Protea FTIR analysers to allow researchers in the field of atmospheric gas analysis from agricultural and livestock to measure evolved gases such as N2O, CO2, CO, NH3, and CH4. Nitrous oxide (N2O) and Methane (CH4) emissions from soil, plant and livestock are especially important gases to measure, given their high potential as greenhouse gases (GHGs). NH3, whilst not a greenhouse gas on the scale of N2O, CH4 and CO2, is a major emission from agricultural, such as after the spreading of liquid manure, and steps are required to measure and reduce the NH3 emissions and the effects they have on the ecosystem.

FTIR is ideally suited for greenhouse gas measurements, with the potential for many gas measurements with a single instrument. With high sensitivity and modular choice of component parts, Protea can tailor the supplied solution to meet the needs of the measurement. Protea’s use of high resolution FTIR instruments enables clearer, more distinct and larger absorption peaks to be measured.

FTIR chamber measurements can be made in the field from a closed chamber around soil, plants, crops or livestock manure, in which the evolved gases are left to build up in the chamber. If there is a large enough volume of gas in the chamber, then it can be extracted and injected into an FTIR gas cell for analysis. Alternatively, a field-based FTIR analyser and soil chamber closed system can be set-up, with the evolved gases being continuously fed through the FTIR measurement system. A low enough flow rate of gas is set-up so as to not disturb gas flux inside the chamber. The FTIR analyser software is pre-programmed and calibrated for the measurements of interest and will give live, dynamic readings of the flux gases.

Alternatively, for quick indicative measurements Protea’s portable mass spectrometer can be used. With very low extraction flow rates and extremely flexible and low measurement ranges, the mass spectrometer can be an ideal tool for in-field measurements.

  • N2O: 100ppb
  • CH4: 1000ppb
  • CO2: 100ppm
  • CO: 1000ppb
  • NH3: 1000ppb