The Effect of Biochar Amendment, Microbiome Inoculation, Crop Mixture and Planting Density on Post-Mining Restoration

Round 1

Reviewer 1 Report

Dear autors,

The article must be rewritten or in its entirety. Authors should characterize the biochar they have used as well as the hydrogel. They must detail the preparation of the samples and their characterization with the appropriate techniques. The discussion of the results should be improved taking into account the characteristics of the materials used. The conclusions should be conclusions of your work

Author Response

Thank you for your comments on the manuscript. We have followed up on some of the suggestion as follow:

• The description of the biochar and hydrogel has been revised
• It was not clear which part of the details, here we have trying to write the process as detail as possible, but some parts could be missing our attention
• The material factor has some effect on the greenhouse experiment only, and we have written this in the discussion.  There was no interaction effect between the material, so we didn't write it much. In the field experiment, we were not analyzing the data on waste rock materials because of the 70% mortality. Then again, we couldn't find the effect of materials. 
• The conclusion has been revised      

Reviewer 2 Report

Dear authors,

 

thank you fot the paper, which consider an bunch of factors in improving tree growth on bad sites! However, there are some specific effects!

I do not under stand while biochar application improves tree growth in field conditions but not in your "pot" experiments? Do you have an idea for this effect?

L 108: Fertilization 20-8-50, 50 ppm. Do not use ppm! So you have applied 50 mg/kg soil ! This means appr. 200 kg of your fertilizer per ha! Than you have applied 40 kg N/ha! This N application could have improved the growth of your cover crops und decreased by this the development of your tress?? Can that be?

Author Response

Thank you for your comments on the manuscript.

• This biochar effect was discussed in section 4.1 Biochar amendment. In the last paragraph, we conclude that the phenomenal effect is due to its correlation to the microclimate. The plant got more benefits from biochar in a harsh environment (field trial), with seasonal winter and summer. In a stable environment, biochar became a disadvantage for the plants. We did discuss this complex interaction in section 4.3 Mixed system interactions
• The N application was recommended by an expert in our lab with consideration of the poor material that we use. The trees were so small (almost didn't grow), although with that amount of fertilizer. so we don't think there were interactions (competition with the crops)        

Reviewer 3 Report

Dear authors, a few comments to improve your manuscript:

1.- Tilte.- is too long. The title should be concise and direct, focus on the key idea of the manuscript, with a general perspective. 

2.- Abstract.- please specify the study area (city, country).

3.- Introduction.- the general and specific objectives of the manuscript should be stated in concrete terms so that they are evident to any reader.

4.- Study area.- please add a figure of the study area (geographical location).

5.- Methods.- in general, throughout this section, when describing experimental methods, it is necessary to add references to previous studies that have been consulted.

6.- Results.- please only add in the manuscript the relevant results, there are too many large tables that should go to annexes (commenting in the manuscript your main results).

7.- Synthesize the conclusions.

8.- There is an excess of self-citations in the manuscript, especially quotations from the last author. There are a total of 16 citations out of 90 references. It is recommended not to exceed 10% of self-citations, which would be a maximum of 9 references. Authors should consult additional literature that has been produced outside their research team, not focusing so much on studies of their own team.

9.- I think the authors should add a discussion of why their study is based on restoration and not rewilding. They are different concepts that should be manifested in a study of this type.

Kind regards, 

Author Response

Thank you for your suggestion and comments on this manuscript.

1. The title has been revised
2. The suggestion has been added
3. A clearer objective has been added
4. The suggestion has been added
5. We were doing experiments using a lot of factors in a harsh environment which is rarely done by others. But we did refer to some of the partial work that has been done before. You may suggest some ref that we may miss in this study
6. The suggestion has been done accordingly
7. The conclusion has been revised
8. The references have been revised
9. I'm just checking the concept of "rewilding" which is more into the re-introduction of natural ecosystems, and it was part of restoration too. Here we were working in a very hard environment, which might need a few more "steps" before the "rewilding". So we were focusing on these "steps", and the discussion of the "rewilding" could be a little bit out of context. But we are open if you can point us to some refs with the same case as this study related to "rewilding"  

Reviewer 4 Report

 

The manuscript titled ‘’ Post-mining restoration strategy: the effect of biochar amendment, microbiome inoculation, crop mixture, and planting density on initial plant growth 4’’, is a very interesting work with valuable findings. However, there are some points that need to be corrected.

1. The abstract is too long. Please make this section shorter! the Max word for an abstract is 200 words! As I see described methods are too much. You can make it shorter.
2. Almost, there is nothing about the background of biochar in the introduction! Just line 79. Please give readers an explanation of why you preferred to use biochar. Is there any background in biochar application in agroforest areas? You need to bring some information about biochar characteristics too which made it suitable for soil improvement. (such as:https://doi.org/10.3390/plants11111424)
3. Lines 120-122: ‘’ Biochar is organic carbon made from biomass through pyrolysis processes. In pyrolysis the biomass is heated to temperatures between 300 and 1000 °C, under low or zero oxygen concentrations [30].’’. -> This information doesn’t belong here, but maybe the introduction! Moreover, giving a range of temperatures for your study doesn’t make any sense! Which temperature your biochar had been produced? Just one number!
4. Line 191: Al (5500 to 6100 mg/kg) -> Scientific units should be like mg kg-1 (-1 superscript). I just mention it as an example, but there are more. Please check entire the text.
5. As a suggestion -> Can ANOVA tables move to a supplementary file?
6. The conclusions section is too long! Actually, this section should be in one single paragraph (15-20 lines) that represents your finalized opinion, and without any reference!

Author Response

Thank you for your suggestion and comment on this manuscript

1. The abstract has been revised 
2. The focus of our study was more on the inoculation of microsysmbiont because were working in a very harsh environment. The biochar is expected to improve the microsysmbiont in this case, and we also include a lot of factors in this study which could be too much to be described in the introduction. But we did put a lot of refs on biochar in the discussion. 
3. The paragraph has been revised accordingly
4. The correction has been made accordingly
5. The suggestion has been done
6. The conclusion has been revised      

Round 2

Reviewer 3 Report

Dear authors, thanks for your responses. I recommend to publish the manuscript in its prestn version. Kind regards,