1. Scientific significance

The manuscript presents a direct comparison between GC and a portable mid-infrared laser system for closed-chamber flux measurements of CO₂, N₂O, and CH₄. This is an important and timely study: many institutions are currently transitioning from GC-based methods to laser analyzers, and independent validation is valuable. The results clearly demonstrate high agreement for CO₂ and N₂O, while highlighting the challenges for CH₄. The work will be of interest to the Biogeosciences readership, particularly those involved in field flux measurements and monitoring networks.

2. Scientific quality

The experimental design is sound, with simultaneous chamber measurements across two contrasting field days. Data handling and statistical treatment (RMSE, nRMSE, flux model selection) are appropriate. However, several methodological details are still unclear or inconsistent and need to be addressed before the results can be fully trusted:

- The timing of fertilizer application relative to the flux campaigns should be reported and discussed, as it directly affects interpretation of the N₂O pulse.

- The choice of regression approaches should be justified more clearly. Given the richness of the LAS dataset, it would be useful to explain why parametric models were favored and why non-parametric approaches (e.g. GAMs) were not pursued beyond citation. Even a short discussion would help.

- The discussion of CH₄ fluxes should be made consistent across the text and figures. At some points the manuscript refers to “comparatively high” oxidation rates (line 332), while the figures clearly show values in the common range for aerated soils. Please ensure that the wording throughout matches the actual flux magnitudes.

- It would be helpful if the authors could reflect on whether the observed GC > LAS (line 375) could be related to chamber handling, calibration gases, or model selection differences, even if only speculative. This would provide more context for readers, especially those considering method choice in their own work.

3. Presentation quality

The manuscript is generally well written and easy to follow, but a number of technical clarifications are needed:

- Ensure consistency of terminology (GA, LGA, LAS). At present, the switching between terms could confuse the readers.

- Describe the laser systems in more detail: principle of operation, pump rate, cell volume, tubing volume, and whether the cells were heated. Many readers will not be familiar with this instrumentation.

- GC methods: include additional details such as detector temperatures and a clearer explanation and justification for the overpressurization of vials.

- Tables and figures:

     > Table 1 shows identical LAS values for CO₂ and N₂O, please check again since it seems likely to be a copy error.

     > As pointed out by Reviewer 1, units could be presented in more standard forms (e.g. mg CO₂ m⁻² h⁻¹, or µg N₂O m⁻² h⁻¹) for easier comparison with literature.

     > Please check Figure 3c labeling (as already noted by the Reviewer 1).

4. Further comments

The paper convincingly shows that LAS is a reliable alternative to GC for CO₂ and N₂O, and highlights the sensitivity limitations of GC for CH₄. To strengthen the impact for a Biogeosciences audience, I suggest the authors add a short reflection on how these findings apply to long-term monitoring networks and national GHG inventories (e.g. ICOS). This would underline the broader significance of the comparison.