The Synergistic Effects of Different Phosphorus Sources: Ferralsols Promoted Soil Phosphorus Transformation and Accumulation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

 The topic of the manuscript is interesting, and the study is correctly conducted. However, some parts are hard to read due to sentences that are too long and confusing.  Also, discussion could be supplemented.   

I have included all the suggestions in the attached manuscript. 

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Language and grammar levels should be improved. Many sentences are too long and hard to read. I indicated some suggestions in attached manuscript.   

Author Response

Dear Reviewers:

Thank you for spending your valuable time on our manuscript, we have carefully checked the full text as recommended by the reviewers, and major revise the manuscript according to every suggestion made by the reviewers. In order to ensure that the main idea can be maintained after the revision of the manuscript, we have systematically sorted out the manuscript. At the same time, we have also proofread the contents in the manuscript one by one (such as the paper format, references, etc.).

We are very grateful to the reviewers for their careful revision of the PDF version of the manuscript, and we have deeply felt the professionalism and dedication of the reviewers. The following is an item-by-item reply to the suggestions of the reviewers.

 

Dear authors,

 The topic of the manuscript is interesting, and the study is correctly conducted. However, some parts are hard to read due to sentences that are too long and confusing.  Also, discussion could be supplemented.   

Response: We would like to thank the reviewers for their valuable time and effort in revising the manuscript, and also thank you for your meticulous revision of the full text. We have revised the full text one by one. We have also made corrections in the revision mode and marked the revised parts with blue fonts.

(1) In line 15 to 17, we have reorganized and made clearer the purpose and methodology of the study.

(2) Throughout the manuscript, monotonous abbreviations, misspellings, and grammatical errors have been corrected on a case-by-case basis. (Grammatical proofreading of the whole by a professional proofreading agency)

(3) This manuscript contains a large number of sentences that are too long. We have submitted it to a professional organization for touch-ups and revisions.

(4) Add relevant content to the manuscript based on the reviewer's suggestions, e.g., Fig. 2, Fig. 5c, etc.

I have included all the suggestions in the attached manuscript. 

Language and grammar levels should be improved. Many sentences are too long and hard to read. I indicated some suggestions in attached manuscript. 

Response: There are indeed many problems with the language description and grammar in the paper, and we have systematically revised the manuscript and submitted it to a friend who is more fluent in English to help correct it. If it is still not up to par, we are willing to submit the manuscript to the professional team of MPDI for revision and grammatical touch-ups as the next step. We thank the reviewers for their suggestions.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Comments for author:

This manuscript “Responses of soil P fractions in relation with P accumulation to different type of phosphate varieties in low phosphorus red soil” contains some interesting data. However, here are some of my concerns with respect to the current version of the manuscript:

1.     Revise the title to make it concise and more attractive. I suggest adding "phosphorus sources" instead of "phosphorus varieties." Avoid using abbreviations in the title.

2.     The hypothesis is not well explained in the abstract. Clearly state the main problem and the purpose of the experiment.

3.     The abstract is too lengthy and should be revised. Avoid using abbreviations in the abstract.

4.     The introduction lacks focus on the main problem and current knowledge gap. Cite more recent related works, and clearly explain the problem the authors aim to address. Do not mix phosphorus and phosphate, as they are different.

5.     Use "phosphorus sources" instead of "P fertilizers" throughout the manuscript.

6.     Provide more details about the methodology used to measure various parameters.

7.     The analysis is not perfect. It is unclear why the authors used one-way ANOVA instead of two-way ANOVA by adding the year as a source of variation. This would show the difference between the years. Revise the analysis and all the figures accordingly.

8.     The discussion section is a bit lengthy. Revise it to focus on the main results, discuss them succinctly, and correlate them properly with the latest previous work.

9.     Check the whole manuscript for spelling, spacing, and grammatical mistakes and italicize all the scientific names.

 

 

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Moderate editing is required. 

Author Response

Dear Reviewers:

Thank you for spending your valuable time on our manuscript, we have carefully checked the full text as recommended by the reviewers, and major revise the manuscript according to every suggestion made by the reviewers. In order to ensure that the main idea can be maintained after the revision of the manuscript, we have systematically sorted out the manuscript. At the same time, we have also proofread the contents in the manuscript one by one (such as the paper format, references, etc.).

We are very grateful to the reviewers for their careful revision of the manuscript, and we have deeply felt the professionalism and dedication of the reviewers. The following is an item-by-item reply to the suggestions of the reviewers.

Dear Authors, 

• Revise the title, clarity of title is needed. You should avoid acronyms in title. P stands for what? Kindly describe in title.

Response: Thank you to the reviewer, we have refreshed the title and also changed the abbreviation in the title to the full title. The adjusted title is ‘Responses of soil phosphorus fractions and phosphorus accumulation to different varieties of phosphorus fertilizers in low phosphorus red soil’.

• Please proofread the abstract and improve it by mentioning the methodology which you followed briefly.

Response: Thank you to the reviewers for their suggestions, we have re-proofread and revised the abstract section of the manuscript, briefly explaining the methodology you used and highlighting it in blue.

• In line 23 TP acronym is used. Kindly write the full form of this first time, then you can use the acronym in remaining manuscript.

Response: With many thanks to the reviewers, we have identified some places with full names and filled in the abbreviations in parentheses. In addition, the abbreviations in other parts of the text have been proofread in full by using full names and filling in the abbreviations in parentheses when they are first used.

• What is RDA? You mentioned in 28 line

Response: We have added the full name of the RDA to the manuscript accordingly.

• Give the significance of your study into 3-4 lines

Response: Thanks to the reviewer's suggestion, we have added a description of the significance of the study at the appropriate place in the preface of the manuscript. The details are given below: ‘The transformation process of different phosphorus fertilizer varieties in the soil affects the effectiveness of soil phosphorus, which in turn affects crop yield and phosphorus uptake and utilization, and it is of great significance to explore the maize yield effect of different varieties of phosphorus fertilizers and phosphorus uptake and utilization characteristics of different varieties of phosphorus fertilizers on red soil for the rational selection of phosphorus fertilizer varieties and improvement of the efficiency of phosphorus utilization in red soil.’

• Why you use “hedley sequential extraction” for estimation of phosphorus

Response: Hedley sequential extraction presented a widely used and relatively rational method of phosphorus fraction. It describes individual soil P fractions in terms of the procedure used to isolate them and considers the distinction between Pi, labile P, and stable Po, which is more conducive to comprehensively evaluating changes in P forms (Redel et al. 2019).

Redel Y, Staunton S, Durán P, Gianfreda L, Rumpel C, de La Luz Mora M (2019) Fertilizer P uptake determined by soil P fractionation and phosphatase activity. J Soil Sci Plant Nutr 19:166–174. https://doi.org/10.1007/s42729-019-00024-z

• In line 130 clearly mention about V6 and V12 stages.

Response: Two periods of nitrogen fertilizer follow-up have been specified for row 130. Topdressing at trumpet stage (V6) and topdressing at big trumpet stage (V12), respectively. Corrections have been made in the manuscript and are highlighted in blue font.

• Line 133. Write clearly how many seeds you used, either 3 or 4?

Response: Thanks to the advice of the reviewer, the production records were consulted again to clarify that the number of seeds sown was 4 seeds. Corrections have been made in the manuscript and are highlighted in blue font.

• Which chemical was used for pest control?

Response: Thank you to the reviewer, we have not used chemical pesticides for pest control throughout our field trial, we simply performed uniform mid-tillage yard grassing.

• H₂SO₄ and H₂O₂ was used for digestion of sample. What ratio was used?

Response: Thanks for your query. We are not able to provide the exact ratio of H₂SO₄ and H₂O₂ here, but we can state the whole process of analysis.

Weigh the finely ground and dried plant samples (0.25-0.5 mm sieve), 0.1-0.2 g (universal balance scale), placed in a 100 ml digestion tube, the first distilled water to wet the sample, add 5 ml of concentrated H₂SO₄, gently shaking (placed overnight), the mouth of the bottle to put a curved-necked funnel, slowly heated at low temperatures in the digestion furnace, to be decomposition of the concentrated acid white smoke gradually increase the temperature. When the solution is brownish-black, remove the digestion tube from the digestion furnace, slightly cold, add 10 drops of 300 g of H₂O₂ drop by drop, and constantly shake the digestion tube, to facilitate the full reaction, and then heated to a slight boil 10-20 min, a little cold, and then add 5-10 drops of H₂O₂, and so on for 2-3 times until the digestive solution was colorless or bright color, and then heated for 5-10 min, in order to get rid of the excess hydrogen peroxide, and then cooled with a small amount of water, and then heated for 5-10 min. Remove the digestion tube cooling, with a small amount of water to rinse the small funnel, wash the liquid into the bottle, the digestive solution is fixed to 100 ml, take the filtrate (placed on the clarified upper layer of the clear liquid), for the determination.

 

• Provide proper reference for soil sampling.

Response: References have been added at soil sampling methods. The soil sampling methods used in this study are the same as those described in the previous study.

• A little bit explanation of P measurement is required for convenience for reader.

Response: We thank the reviewers! We have explained the Olsen-P assay and added it to the manuscript in blue font at the appropriate place.

Weigh 2.50 g of air-dried specimen through the 2 mm aperture sieve, put it in a 200 ml plastic bottle, add about 1 g of phosphorus-free activated carbon, add 50.0 ml of sodium bicarbonate extract at 25 ℃±1 ℃, shake well, and then shaking it in an oscillator at a temperature of 25 ℃±1 ℃ with a frequency of 180 r/min±20 r/min for 30±1 min, and then filtering it into dry 150 ml triangular bottles through a phosphorus-free filter paper immediately.

• In line 111 it is mention ‘The field trial experiment was initiated in May 2017’. But later on, ‘2018 and 2019’ year of study was mentioned. kindly revise it.

Response: We thank the reviewers for the suggestion that this study was a long-term positional field trial with a trial start year of 2017, but the years studied in the manuscript of this paper are 2017 and 2018, which have been further clarified in the manuscript.

• In Figure 2 you should indicate the meaning of the abbreviations

Response: We have added the meaning of each processing abbreviation in the caption of Figure 2. CK is no P fertilizer, SSP is single superphosphate (90 kg ha⁻¹), CMP is calcium magnesium phosphate (90 kg ha⁻¹), MAP is monoammonium phosphate (90 kg ha⁻¹), and DAP is diammonium phosphate (90 kg ha⁻¹); the same applies below.

• In figures what information is drawn by using lower case letter.

Response: We have made additional improvements in the figure captions. Values with the same lower-case letters are not significantly different among different P fertilizer varieties and years at the 5% level by the LSD.

• In Figure 3 you should indicate the meaning of the abbreviations and lower-case letters. In all figures you should mention it.

Response: We have noted the meaning of abbreviations and lower case letters in Figure 3, and have also examined and labeled the other figures.

• In figures you used mg kg^-1but in methodology used use different units as ‘g kg^-1 for total P kindly revise it.

Response: Thanks to the suggestions of the reviewers, we have harmonized the units in the methods section.

• What is meaning of labile?

Response: Labile means movable, unstable. The labile P pools is an important component of soil effective phosphorus, which is more easily absorbed and utilized by roots in the soil, mainly include Resin-P, NaHCO₃-Pi, NaHCO₃-Po.

• In Figure 10 you should indicate the meaning of the abbreviations

Response: Thanks to the reviewers, we have clarified the meaning of the abbreviations.

• Improve the discussion part.

Response: Thanks to the reviewers, we have refreshed the manuscript and further revised and improved the discussion section of the manuscript, which is highlighted in blue.

• Revise your conclusion

Response: Thanks to the reviewers, we will revise and correct the conclusion section with the revision of the paper.

English extensive revision required before publication. Lots of grammar mistakes and typos seen in the manuscript.

Response: Thank you again, reviewer, for providing your valuable time and energy to the manuscript. Your suggestions are suggestive, and we have systematically revised the manuscript and submitted it to a friend who is more fluent in English to help correct it. If it is still not up to par, we are willing to submit the manuscript to the professional team of MPDI for revision and grammatical touch-ups as the next step. We thank the reviewers for their suggestions.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors This manuscript “Responses of soil P fractions in relation with P accumulation to different type of phosphate varieties in low phosphorus red soil” contains some interesting data. However, here are some of my concerns with respect to the current version of the manuscript: 1. Revise the title to make it concise and more attractive. I suggest adding "phosphorus sources" instead of "phosphorus varieties." Avoid using abbreviations in the title. 2. The hypothesis is not well explained in the abstract. Clearly state the main problem and the purpose of the experiment. 3. The abstract is too lengthy and should be revised. Avoid using abbreviations in the abstract. 4. The introduction lacks focus on the main problem and current knowledge gap. Cite more recent related works, and clearly explain the problem the authors aim to address. Do not mix phosphorus and phosphate, as they are different. 5. Use "phosphorus sources" instead of "P fertilizers" throughout the manuscript. 6. Provide more details about the methodology used to measure various parameters. 7. The analysis is not perfect. It is unclear why the authors used one-way ANOVA instead of two-way ANOVA by adding the year as a source of variation. This would show the difference between the years. Revise the analysis and all the figures accordingly. 8. The discussion section is a bit lengthy. Revise it to focus on the main results, discuss them succinctly, and correlate them properly with the latest previous work. 9. Check the whole manuscript for spelling, spacing, and grammatical mistakes and italicize all the scientific names. Comments on the Quality of English Language  Check the whole manuscript for spelling, spacing, and grammatical mistakes and italicize all the scientific names.

Author Response

Dear Reviewers:

Thank you for spending your valuable time on our manuscript, we have carefully checked the full text as recommended by the reviewers, and major revise the manuscript according to every suggestion made by the reviewers. In order to ensure that the main idea can be maintained after the revision of the manuscript, we have systematically sorted out the manuscript. At the same time, we have also proofread the contents in the manuscript one by one (such as the paper format, references, etc.).

We are very grateful to the reviewers for their careful revision of the manuscript, and we have deeply felt the professionalism and dedication of the reviewers. The following is an item-by-item reply to the suggestions of the reviewers.

This manuscript “Responses of soil P fractions in relation with P accumulation to different type of phosphate varieties in low phosphorus red soil” contains some interesting data. However, here are some of my concerns with respect to the current version of the manuscript: 

1. Revise the title to make it concise and more attractive. I suggest adding "phosphorus sources" instead of "phosphorus varieties." Avoid using abbreviations in the title. 

Response 1: We thank the reviewing experts for their advice, we have given a lot of thought to the choice of using phosphorus sources or phosphorus varieties, and I think that the expert's description of phosphorus sources is representative, but we think that the use of phosphate fertilizer varieties is more apt in the context of this manuscript. Therefore we thank the reviewing experts for their advice, but we still plan to use phosphorus fertilizer varieties. We have reorganized the title of the script and corrected the abbreviations in the title.

2. The hypothesis is not well explained in the abstract. Clearly state the main problem and the purpose of the experiment. 

Response 2: Thanks to the suggestions of the reviewers, we have freshened up the abstract section and restructured the abstract. The main question and the purpose of the experiment have been clarified.

3. The abstract is too lengthy and should be revised. Avoid using abbreviations in the abstract. 

Response 3: Thanks to the reviewers, we condensed the abstracts and corrected the use of abbreviations in the abstracts according to the journal formatting specifications by using the full name with the abbreviation in parentheses in the first instance and the abbreviation for the same description in subsequent instances.

4. The introduction lacks focus on the main problem and current knowledge gap. Cite more recent related works, and clearly explain the problem the authors aim to address. Do not mix phosphorus and phosphate, as they are different. 

Response 4: Thank you to the reviewers, we have re-checked and proofread the introductory part of the manuscript carefully and made additions and improvements according to the experts' suggestions as much as possible. This is identified in the manuscript by the revision template and in blue.

5. Use "phosphorus sources" instead of "P fertilizers" throughout the manuscript. 

Response 5: We have thought deeply about the choice of using phosphorus sources or phosphorus fertilizer varieties, and we thank the reviewers for their advice on phosphorus sources, but we believe that using phosphorus fertilizer varieties is more relevant and more likely to be of interest to readers in this manuscript. Therefore, we still plan to use phosphorus fertilizer varieties.

6. Provide more details about the methodology used to measure various parameters. 

Response 6: We thank the reviewers for their suggestions, and we have synthesized the suggestions of the remaining reviewers and added the Olsen-P determination method in the Materials and Methods section of the manuscript, and we have clearly shown the Hedley sequential P fractions method through the flowchart and added the cited references.

7. The analysis is not perfect. It is unclear why the authors used one-way ANOVA instead of two-way ANOVA by adding the year as a source of variation. This would show the difference between the years. Revise the analysis and all the figures accordingly. 

Response 7: Thanks to the reviewers, this is a very good suggestion and we have supplemented the analytical methods in the manuscript and revised and supplemented the analysis of the corresponding figures in the manuscript. This is identified in the manuscript by the revision template and in blue.

8. The discussion section is a bit lengthy. Revise it to focus on the main results, discuss them succinctly, and correlate them properly with the latest previous work. 

Response 8: Thanks to the reviewers, we have refreshed the manuscript and further revised and improved the discussion section of the manuscript, which is highlighted in blue.

9. Check the whole manuscript for spelling, spacing, and grammatical mistakes and italicize all the scientific names.

 Check the whole manuscript for spelling, spacing, and grammatical mistakes and italicize all the scientific names.

Response 9: Thankfully, we have re-verified the manuscript for spelling, grammar, and formatting issues, and submitted it to a friend who is more fluent in English to help correct it. If it is still not up to par, we are willing to submit the manuscript to the professional team of MPDI for revision and grammatical touch-ups as the next step. We thank the reviewers for their suggestions.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

Dear Authors, 

·       Revise the title, clarity of title is needed. You should avoid acronyms in title. P stands for what? Kindly describe in title.

·       Please proofread the abstract and improve it by mentioning the methodology which you followed briefly.

·       In line 23 TP acronym is used. Kindly write the full form of this first time, then you can use the acronym in remaining manuscript.

·       What is RDA? You mentioned in 28 line

·       Give the significance of your study into 3-4 lines

·       Why you use “hedley sequential extraction” for estimation of phosphorus

·       In line 130 clearly mention about V6 and V12 stages.

·       Line 133. Write clearly how many seeds you used, either 3 or 4?

·       Which chemical was used for pest control?

·       H2SO4 and H2O2 was used for digestion of sample. What ratio was used?

·       Provide proper reference for soil sampling.

·       A little bit explanation of P measurement is required for convenience for reader.

·       In line 111 it is mention ‘The field trial experiment was initiated in May 2017’. But later on, ‘2018 and 2019’ year of study was mentioned. kindly revise it.

·       In Figure 2 you should indicate the meaning of the abbreviations

·       In figures what information is drawn by using lower case letter.

·       In Figure 3 you should indicate the meaning of the abbreviations and lower-case letters. In all figures you should mention it.

·       In figures you used mg kg^-1 but in methodology used use different units as ‘g kg^-1 for total P kindly revise it.

·       What is meaning of labile?

·       In Figure 10 you should indicate the meaning of the abbreviations

·       Improve the discussion part.

·       Revise your conclusion

Comments on the Quality of English Language

English extensive revision required before publication. Lots of grammar mistakes and typos seen in the manuscript.

Author Response

Dear Reviewers:

Thank you for spending your valuable time on our manuscript, we have carefully checked the full text as recommended by the reviewers, and major revise the manuscript according to every suggestion made by the reviewers. In order to ensure that the main idea can be maintained after the revision of the manuscript, we have systematically sorted out the manuscript. At the same time, we have also proofread the contents in the manuscript one by one (such as the paper format, references, etc.).

We are very grateful to the reviewers for their careful revision of the manuscript, and we have deeply felt the professionalism and dedication of the reviewers. The following is an item-by-item reply to the suggestions of the reviewers.

Dear Authors, 

• Revise the title, clarity of title is needed. You should avoid acronyms in title. P stands for what? Kindly describe in title.

Response: Thank you to the reviewer, we have refreshed the title and also changed the abbreviation in the title to the full title. The adjusted title is ‘Responses of soil phosphorus fractions and phosphorus accumulation to different varieties of phosphorus fertilizers in low phosphorus red soil’.

• Please proofread the abstract and improve it by mentioning the methodology which you followed briefly.

Response: Thank you to the reviewers for their suggestions, we have re-proofread and revised the abstract section of the manuscript, briefly explaining the methodology you used and highlighting it in blue.

• In line 23 TP acronym is used. Kindly write the full form of this first time, then you can use the acronym in remaining manuscript.

Response: With many thanks to the reviewers, we have identified some places with full names and filled in the abbreviations in parentheses. In addition, the abbreviations in other parts of the text have been proofread in full by using full names and filling in the abbreviations in parentheses when they are first used.

• What is RDA? You mentioned in 28 line

Response: We have added the full name of the RDA to the manuscript accordingly.

• Give the significance of your study into 3-4 lines

Response: Thanks to the reviewer's suggestion, we have added a description of the significance of the study at the appropriate place in the preface of the manuscript. The details are given below: ‘The transformation process of different phosphorus fertilizer varieties in the soil affects the effectiveness of soil phosphorus, which in turn affects crop yield and phosphorus uptake and utilization, and it is of great significance to explore the maize yield effect of different varieties of phosphorus fertilizers and phosphorus uptake and utilization characteristics of different varieties of phosphorus fertilizers on red soil for the rational selection of phosphorus fertilizer varieties and improvement of the efficiency of phosphorus utilization in red soil.’

• Why you use “hedley sequential extraction” for estimation of phosphorus

Response: Hedley sequential extraction presented a widely used and relatively rational method of phosphorus fraction. It describes individual soil P fractions in terms of the procedure used to isolate them and considers the distinction between Pi, labile P, and stable Po, which is more conducive to comprehensively evaluating changes in P forms (Redel et al. 2019).

Redel Y, Staunton S, Durán P, Gianfreda L, Rumpel C, de La Luz Mora M (2019) Fertilizer P uptake determined by soil P fractionation and phosphatase activity. J Soil Sci Plant Nutr 19:166–174. https://doi.org/10.1007/s42729-019-00024-z

• In line 130 clearly mention about V6 and V12 stages.

Response: Two periods of nitrogen fertilizer follow-up have been specified for row 130. Topdressing at trumpet stage (V6) and topdressing at big trumpet stage (V12), respectively. Corrections have been made in the manuscript and are highlighted in blue font.

• Line 133. Write clearly how many seeds you used, either 3 or 4?

Response: Thanks to the advice of the reviewer, the production records were consulted again to clarify that the number of seeds sown was 4 seeds. Corrections have been made in the manuscript and are highlighted in blue font.

• Which chemical was used for pest control?

Response: Thank you to the reviewer, we have not used chemical pesticides for pest control throughout our field trial, we simply performed uniform mid-tillage yard grassing.

• H₂SO₄ and H₂O₂ was used for digestion of sample. What ratio was used?

Response: Thanks for your query. We are not able to provide the exact ratio of H₂SO₄ and H₂O₂ here, but we can state the whole process of analysis.

Weigh the finely ground and dried plant samples (0.25-0.5 mm sieve), 0.1-0.2 g (universal balance scale), placed in a 100 ml digestion tube, the first distilled water to wet the sample, add 5 ml of concentrated H₂SO₄, gently shaking (placed overnight), the mouth of the bottle to put a curved-necked funnel, slowly heated at low temperatures in the digestion furnace, to be decomposition of the concentrated acid white smoke gradually increase the temperature. When the solution is brownish-black, remove the digestion tube from the digestion furnace, slightly cold, add 10 drops of 300 g of H₂O₂ drop by drop, and constantly shake the digestion tube, to facilitate the full reaction, and then heated to a slight boil 10-20 min, a little cold, and then add 5-10 drops of H₂O₂, and so on for 2-3 times until the digestive solution was colorless or bright color, and then heated for 5-10 min, in order to get rid of the excess hydrogen peroxide, and then cooled with a small amount of water, and then heated for 5-10 min. Remove the digestion tube cooling, with a small amount of water to rinse the small funnel, wash the liquid into the bottle, the digestive solution is fixed to 100 ml, take the filtrate (placed on the clarified upper layer of the clear liquid), for the determination.

• Provide proper reference for soil sampling.

Response: References have been added at soil sampling methods. The soil sampling methods used in this study are the same as those described in the previous study.

• A little bit explanation of P measurement is required for convenience for reader.

Response: We thank the reviewers! We have explained the Olsen-P assay and added it to the manuscript in blue font at the appropriate place.

Weigh 2.50 g of air-dried specimen through the 2 mm aperture sieve, put it in a 200 ml plastic bottle, add about 1 g of phosphorus-free activated carbon, add 50.0 ml of sodium bicarbonate extract at 25 ℃±1 ℃, shake well, and then shaking it in an oscillator at a temperature of 25 ℃±1 ℃ with a frequency of 180 r/min±20 r/min for 30±1 min, and then filtering it into dry 150 ml triangular bottles through a phosphorus-free filter paper immediately.

• In line 111 it is mention ‘The field trial experiment was initiated in May 2017’. But later on, ‘2018 and 2019’ year of study was mentioned. kindly revise it.

Response: We thank the reviewers for the suggestion that this study was a long-term positional field trial with a trial start year of 2017, but the years studied in the manuscript of this paper are 2017 and 2018, which have been further clarified in the manuscript.

• In Figure 2 you should indicate the meaning of the abbreviations

Response: We have added the meaning of each processing abbreviation in the caption of Figure 2. CK is no P fertilizer, SSP is single superphosphate (90 kg ha⁻¹), CMP is calcium magnesium phosphate (90 kg ha⁻¹), MAP is monoammonium phosphate (90 kg ha⁻¹), and DAP is diammonium phosphate (90 kg ha⁻¹); the same applies below.

• In figures what information is drawn by using lower case letter.

Response: We have made additional improvements in the figure captions. Values with the same lower-case letters are not significantly different among different P fertilizer varieties and years at the 5% level by the LSD.

• In Figure 3 you should indicate the meaning of the abbreviations and lower-case letters. In all figures you should mention it.

Response: We have noted the meaning of abbreviations and lower case letters in Figure 3, and have also examined and labeled the other figures.

• In figures you used mg kg^-1but in methodology used use different units as ‘g kg^-1 for total P kindly revise it.

Response: Thanks to the suggestions of the reviewers, we have harmonized the units in the methods section.

• What is meaning of labile?

Response: Labile means movable, unstable. The labile P pools is an important component of soil effective phosphorus, which is more easily absorbed and utilized by roots in the soil, mainly include Resin-P, NaHCO₃-Pi, NaHCO₃-Po.

• In Figure 10 you should indicate the meaning of the abbreviations

Response: Thanks to the reviewers, we have clarified the meaning of the abbreviations.

• Improve the discussion part.

Response: Thanks to the reviewers, we have refreshed the manuscript and further revised and improved the discussion section of the manuscript, which is highlighted in blue.

• Revise your conclusion

Response: Thanks to the reviewers, we will revise and correct the conclusion section with the revision of the paper.

English extensive revision required before publication. Lots of grammar mistakes and typos seen in the manuscript.

Response: Thank you again, reviewer, for providing your valuable time and energy to the manuscript. Your suggestions are suggestive, and we have systematically revised the manuscript and submitted it to a friend who is more fluent in English to help correct it. If it is still not up to par, we are willing to submit the manuscript to the professional team of MPDI for revision and grammatical touch-ups as the next step. We thank the reviewers for their suggestions.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Revised manuscript is acceptable for publication

Author Response

Thank the reviewers again for the evaluation of our manuscripts, and we sincerely appreciate the valuable time spent by the reviewers in the process of reviewing the manuscripts. In this revision, we mainly supplement and improve the manuscript according to the suggestions of the editorial department.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have not adequately revised the manuscript as suggested in the previous comments. Therefore, my decision for the current version is to reject it.

Comments on the Quality of English Language

The authors have not adequately revised the manuscript as suggested in the previous comments. Therefore, my decision for the current version is to reject it.

Author Response

Dear Reviewer:

We still want to thank you for the valuable time spent on the review of the manuscript. We re-examine the reviewer 's recommendations and revise them one by one. The manuscript is modified in the modified mode, and the modified part is marked in red font. The modified reply is as follows:

This manuscript “Responses of soil P fractions in relation with P accumulation to different type of phosphate varieties in low phosphorus red soil” contains some interesting data. However, here are some of my concerns with respect to the current version of the manuscript: 

1. Revise the title to make it concise and more attractive. I suggest adding "phosphorus sources" instead of "phosphorus varieties." Avoid using abbreviations in the title. 

Response 1: Thanks to the reviewers' suggestions, we have replaced the ' phosphorus source' with the 'phosphorus varieties' in the entire document and re-refined the title according to the editorial department’s statement that the title is too descriptive and not informative.

 

2. The hypothesis is not well explained in the abstract. Clearly state the main problem and the purpose of the experiment. 

Response 2: Thank the reviewers for their suggestions on the abstract part. We have reorganized the content of the summary and adjusted it accordingly to the requirements of the elements of the summary. The main question and the purpose of the experiment have been clarified.

3. The abstract is too lengthy and should be revised. Avoid using abbreviations in the abstract. 

Response 3: Thanks to the reviewer, we have further standardized and condensed the abstract part according to the format of the abstract, and controlled the length of the abstract within 200 words. Meanwhile, we corrected the use of abbreviations in the abstracts according to the journal formatting specifications by using the full name with the abbreviation in parentheses in the first instance and the abbreviation for the same description in subsequent instances. See the abstract part of the manuscript for details.

4. The introduction lacks focus on the main problem and current knowledge gap. Cite more recent related works, and clearly explain the problem the authors aim to address. Do not mix phosphorus and phosphate, as they are different. 

Response 4: Thank you to the reviewers, we have re-checked and proofread the introductory part of the manuscript carefully and made additions and improvements according to the experts' suggestions as much as possible. And proofread the correct use of phosphorus and phosphate.

5. Use "phosphorus sources" instead of "P fertilizers" throughout the manuscript. 

Response 5: Thanks to the reviewers, we have recommended to use ' phosphorus sources ' instead of ' P fertilizers' throughout the manuscript.

6. Provide more details about the methodology used to measure various parameters. 

Response 6: We thank the reviewers for their suggestions. We have added the determination methods of pH, organic matter, Olsen-P, Fe₂O₃, Al₂O₃ and CaCO₃ to the material and method section of the manuscript, supplemented the calculation method of soil organic phosphorus, and also added the cited references.

7. The analysis is not perfect. It is unclear why the authors used one-way ANOVA instead of two-way ANOVA by adding the year as a source of variation. This would show the difference between the years. Revise the analysis and all the figures accordingly. 

Response 7: Thanks to the reviewers, this is a very good suggestion and we have supplemented the analytical methods in the manuscript and revised and supplemented the analysis of the corresponding figures in the manuscript. This is identified in the manuscript by the revision template and in blue.

8. The discussion section is a bit lengthy. Revise it to focus on the main results, discuss them succinctly, and correlate them properly with the latest previous work. 

Response 8: Thanks to the reviewers, we have refreshed the manuscript and further revised and improved the discussion section of the manuscript, which is highlighted in blue.

9. Check the whole manuscript for spelling, spacing, and grammatical mistakes and italicize all the scientific names.

 Check the whole manuscript for spelling, spacing, and grammatical mistakes and italicize all the scientific names.

Response 9: Thankfully, we have re-verified the manuscript for spelling, grammar, and formatting issues, and submitted it to a friend who is more fluent in English to help correct it. If it is still not up to par, we are willing to submit the manuscript to the professional team of MPDI for revision and grammatical touch-ups as the next step. We thank the reviewers for their suggestions.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

Its fine.

Author Response

Thank the reviewers again for the evaluation of our manuscripts, and we sincerely appreciate the valuable time spent by the reviewers in the process of reviewing the manuscripts. In this revision, we mainly supplement and improve the manuscript according to the suggestions of the editorial department.