Re-Measurement of Agriculture Green Total Factor Productivity in China from a Carbon Sink Perspective
Round 1
Reviewer 1 Report
Theoretical background of the model and variables selected must be improved. Results variations among regions must be explained. Compare your findings with those reported before. English style needs major revision.
Paper tries to empirically calculate the TFP in Chinese agriculture with emphasis on carbon sequestration, and identify its main drivers. It is full of typos. English style is really poor. The method applied as well as variables selection lacks theoretical justification. Spatial analysis requires some preliminary statistical tests which are ignored. Findings need more explanation. The gap between current work and previous ones is not appropriately stated. Another critical point is that all differences in results obtained for different regions must be justified theoretically.Author Response
Please see the attachment
Author Response File: 
Author Response.docx
Reviewer 2 Report
You can add a little more appropriate literature (such as 10.1016/j.resconrec.2021.105661; 10.1038/s41598-017-04182-x), and then give specific data, how much the carbon is fixed and how much carbon emissions can be offset.
Line 167, wrong unit.
Formular 1. I don't think this count as carbon fixation, since the vast majority of these short-lived CO2 fixations are consumed and re-released by animals and humans. The greenhouse effect is on a long-time scale. Agricultural systems are different from forest systems, and a growing number of studies do not consider these fixations as carbon sinks.
Formular 2. There are many details behind this formula that you haven't considered, such as indirect N2O emissions. In addition, you have not provided the emission factor of each section.
You must provide a detailed calculation process for carbon emission and carbon sink, to prove that your basic data is correct and reliable, otherwise everything is empty.
Line 198 and Line 199. The 298 and 25 are very old parameters, and the IPCC has already updated the new coefficients.
Table 1. Please add a guideline to the table.
Figure 1. Where does the description relate to Figure 1? In Line 458? Isn't Figure 1 and the second column of Table 3 duplicate information? What does the high and low level of the Moran’I index on the time scale indicate?
Any abbreviations in figures and tables need to be clearly explained in the comments.
How to prove that regional differences are not caused by differences in planting systems, not by differences in government enforcement, or by differences in economic strength? Is this spatial spillover really the spread of technology? As if this cannot be confirmed by your calculation formula alone.
The countermeasures you propose are universal. Since your results show that there are differences between regions, should different regions have different strategies? I think answering this question may require showing the composition of carbon emissions in different provinces. Some provinces may need to optimize for fertilization, some may need to optimize for irrigation, and some may need to strengthen paddy field management.
Author Response
Please see the attachment
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
I have carefully read your revised draft and reply letter, and I think you have not understood the meaning of some questions accurately. You can carefully read the algorithm in this article （https://doi.org/10.1016/j.resconrec.2021.105661）, the harvested agricultural products should not become a carbon sequestration, it will be released in 1-3 years. All in all, total yield is only a short-term fixation of CO2.
In addition, the indirect emissions of N2O I mean, refers to the potential greenhouse effects from nitrate leaching and ammonia volatilization in the field. And not the animal emissions you're referring to. Also in this article（https://doi.org/10.1016/j.resconrec.2021.105661）, the authors also introduced it in great detail.
The unit of emission factor in Table 2 for irrigation is wrong.
Author Response
Dear reviewer,
Thank you for your positive and constructive comments and suggestions on our manuscript.Please see the attachment for your perusal.
Author Response File: Author Response.docx
