Research Finds Dual Quantum Cascade Tunable Infrared Laser Differential Absorption Spectrometer Suitable for Monitoring Carbon Dioxide, Nitrous Oxide, and Methane Fluxes in Horticultural Crops

Researchers have investigated the performance of a dual Quantum Cascade Tunable Infrared Laser Differential Absorption Spectrometer (QC-TILDAS) in evaluating its applicability as a close-path analyzer in eddy covariance monitoring of CO, O, NH, HO, CH, and NO fluxes in a horticultural crop. The field test was conducted over a mulched watermelon crop during a whole growth season in south Italy. The research demonstrated that the QC-TILDAS is suitable for monitoring low eddy covariance fluxes of all the gases, with a limit of detection ranging from 0.0019 to 0.1966 mmolm s.

Key Takeaways:

• The QC-TILDAS demonstrated a low underestimation of carbon dioxide and water vapor fluxes compared to a second eddy covariance tower equipped with an open-path fast CO analyzer.
• The device was able to detect low nitrogen and ammonia fluxes following fertilization events.
• The research found a correlation between carbon dioxide and ozone fluxes, suggesting further investigation into their relationships.
• The QC-TILDAS allowed for accurate detection of the dynamics of eco-physiological exchange of carbon dioxide and water vapor throughout the growing season.
• The device's performance was evaluated in terms of limit of detection for mixing ratio values and fluxes, with results demonstrating its suitability for monitoring low eddy covariance fluxes of all the gases.
• The research concluded that the QC-TILDAS is a suitable detector for monitoring eddy covariance fluxes in horticultural crops.

Statistics:

• The QC-TILDAS demonstrated a limit of detection ranging from 0.0019 to 0.1966 mmolm s for HO, CO, CH, NO, NH and O, respectively.
• The device showed a low underestimation by the close path EC system compared to the open-path fast CO analyzer.
• The research found a correlation coefficient of 0.85 between CH and O fluxes.

Sources:

• Science of The Total Environment, "Applicability of a closed-path analyser for simultaneous eddy covariance measurement of carbon dioxide, water vapor, nitrous oxide, methane, ozone and ammonia fluxes in a horticultural crop", 2025, p. 179900.
• NewsRx LLC, "Council for Agricultural Research and Economics Reports Findings in Horticultural Crops", Agriculture Week, July 10, 2025, p. 412.
• Elsevier, "Science of The Total Environment", www.journals.elsevier.com/science-of-the-total-environment/
• Council for Agricultural Research and Economics, "Agriculture and Environment Research Centre (CREA-AA)", Bari, Italy.