General Comments

This manuscript proposes moss restoration as a strategy for reducing erosion in vineyards, and presents the results of a plot-scale field experiment implementing the technique. Moss restoration, bare soil, and grass cover crop are compared, and the rates of runoff, erosion, and infiltration are measured using three simulated rainfall events. The paper demonstrates potential for moss to reduce runoff and erosion, and also identifies gaps for future research. Overall, the quality of the writing is very strong, and the content is presented very clearly. The introduction is particularly concise and comprehensive, to the great benefit of the manuscript.

While the central findings of runoff and erosion are solid, the manuscript could still be improved with changes to the data presentation and discussion. The most serious shortcoming of this manuscript is the conditions of the field trial itself. The study site previously had mixed grass and moss in the interr-row, not fallow or cultivated soil as in standard practice. Thus the initial soil conditions may have been different than typical vineyard soils. As the manuscript describes, the weather during the beginning of the trial was unusually warm and dry, leading to challenges establishing the moss matts. Combined with the fact that the “moss” treatment was implemented by spreading moss-impregnated burlap over the soil, it is difficult to disentangle the effects of the burlap from the moss, especially in the first two rain simulation events. The manuscript could be improved by discussion of how widely-applicable moss could be to vineyards, given the range of aridity experienced in wine-growing regions. 

The experimental design and results clearly demonstrate the runoff and erosion rates for the various treatments, but the treatment of long-term soil moisture is lacking in the present manuscript. The introduction identifies that concern about water competition is a primary barrier to implementing cover crops, but the data presented in the manuscript does not effectively characterize the water use of the three treatments. Soil moisture data is only presented for 3 points in time, and at 5 millimeter depth. This zone is particularly sensitive to recent weather, and is not necessarily representative of the water availability to roots. The formulation of hypothesis 3 and presentation of 30-minute time series of water content during simulated rain does not capture the important hydrological properties of the treatment.

Specific Comments

• Hypotheses 1 and 2 are very strong, but hypothesis 3 seems less strongly motivated. From the data collected for soil moisture at 5mm, perhaps there could be some analysis of infiltration rate at the surface that would be interesting. But I would suggest that hypothesis 3 and the associated data could be moved to the supplement, and the discussion could be relatively unchanged. This could also allow the information in figures 1 and 2 to be streamlined or moved to the supplement.
• The introduction very nicely identifies the state of knowledge for moss restoration and erosion. However, I think the readability would be improved by specifically acknowledging knowledge gaps, especially those that will be addressed in this study.
• The introduction rightly identifies water consumption as a major risk of moss/cover crops, but the experiment mostly does not address this topic. I think this would be great to identify as a knowledge gap in the discussion for future work.
• The applicability of moss to vineyards should be better addressed in the introduction. Vineyards in semi-arid regions or mediterranean climates with a long dry season may not be suitable for moss restoration. Could add this information in the sentences starting around line 67.
• Grape yield is also identified as a major risk, but not addressed in this study. If you are able to comment on this it would be interesting, but otherwise it should be identified as an area for future work.
• Along with the risks of water use and yield reduction, another risk that is understated in the current manuscript is the lack of knowledge of how to implement moss restoration in vineyards at scale. This should be treated seriously as a barrier to implementation, and as a knowledge gap which the present work partially addresses.
• The description of the site’s geology can be reduced, as the topsoil is the focus of this manuscript

Technical Corrections

• Line 54 repace “vines positiviely influenences soil fertility, for example, it increases the” with “vines can positively influence fertility by increasing”
• Line 74 replace “they do not require” with “moss does not require”
• Line 75 add “mosses may thrive in conditions where …”
• Line 110 “Overgrown with cover crops” is not clear precisely what was done
• Line 143 switch to “three rainfall simulations were conducted on April 13..”
• Line 178 “June” should be changed to “October”
• Lines 216-218 verb tense should be switched to all past tense
• Line 286 remove comma after Especially

Dear Authors,

Thank you for submitting your manuscript for review. I found the paper to be interesting and novel, offering a valuable contribution to the field of vineyard management.

I have included some comments in the attached PDF to help you strengthen your well-written manuscript.

Here are some general considerations:

1. Rainfall Simulations: Please consistently refer to "experiments" when discussing rainfall simulations.
2. Climate: Given the limited timeframe of your data, I recommend avoiding broad generalizations about climate.
3. Vineyard-Specific References: Consider including more references related specifically to vineyards in your discussion, particularly when comparing your results to those of forests. There is a wealth of literature on rainfall simulation experiments with different soil management practices and countries.
4. Visual Elements: Please include photos of the vineyard, a map, and a detailed soil description (using English terms).
5. Rainfall Simulation Frequency: It would be helpful to justify the decision to conduct only three rainfall simulations in a single year. Some readers may question the representativeness of this data. If you used a large-scale rainfall simulator, please provide photos and explain the logistical challenges that may have limited the number of experiments. I perfectly know them, but not all readers must be familiar with this.

I believe that by addressing these points, you can further enhance the quality and impact of your manuscript.

Thank you for your time and consideration.