Fig. 1. Spectral fingerprints of CO and N₂O in working range of laser. (a)(b) Simulated absorption spectra of CO and N₂O; (c) experimentally measured absorption spectra

Fig. 2. Schematic of gas sampling system

Fig. 3. Soil samples indifferent ecological environments. (a) Sampling pools; (b) soil samples

Fig. 4. Measured spectral data from different soil samples. (a) Reed soil; (b) pond silt; (c) organic soil; (d) grassland soil

Fig. 5. Results of dynamic measurement from 20:00 to 22:00 on November 5, 2018. (a) Measured gas pressure; (b) measured gas temperature and humidity; (c) result of real-time measurement of N₂O; (d) results of real-time measurement of CO

Fig. 6. Multiple measurements of N₂O and CO gas release and absorption in different soil samples. (a) Measured concentration of N₂O at 20:00 on November 5, 2018; (b) measured concentration of N₂O at 8:00 on November 7, 2018; (c) measured concentration of N₂O at 8:00 on November 8, 2018; (d) measured concentration of CO at 20:00 on November 5, 2018; (e) measured concentration of CO at 8:00 on November 7, 2018; (f) measured concentration of CO at 8:00 on Novembe

Fig. 7. Variation of CO relative concentration with time

Fig. 8. Changes of N₂O relative concentration with time