Leucaena-Based Alley Cropping System: An Approach for Reclaiming Degraded Land, Reducing the Use of Inorganic Nitrogen Fertilizer, and Improving Crop Productivity

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Nitrogen-3544157

Leucaena-Based Alley Cropping System: An Approach for Reclaiming Degraded Land, Reducing the Usage of Inorganic Nitrogen Fertilizer, and Improving Crop Productivity

 

General Comments

L24: Please add which parameters were measured in this study.

L137: For Table 1 and Table 3 (L297), authors should remove the border lines to align with standard academic formatting guidelines. Only essential horizontal lines (e.g., above and below the column headers and at the bottom of the table) should be retained. Please refer to Table 2 as an example. 

L171: When were the soil samples collected for the initial and post-harvest periods? Please specify the exact date/month.

L183-195: Please provide a brief explanation of each method used to analyze soil organic carbon, total nitrogen, available phosphorus, and exchangeable potassium.

L228: What do authors use for fixed and random effects?

L278: For Table 2 and Table 4 (L327), authors should remove the different alphabetical letters indicating statistical significance where no interaction effects were found (e.g., % Total N, Available P, and microbial biomass C). Additionally, authors could include the P-values for each parameter by adding a row at the bottom of the table.

L327: What do the abbreviations OC and TN stand for?

L338: Authors should ensure proper formatting by using an indent at the beginning of each paragraph.

L338-L340: The authors state that there were no statistically significant differences found for the interaction of alley widths and N levels on edible head weights and head yields (p > 0.05). However, authors later claim that the least significant difference (LSD) analysis revealed significant differences among some of the treatment combinations compared with others. These statements contradict each other because if no significant interaction was detected, it would be inappropriate to conduct LSD tests on treatment combinations. I suggest the authors either report the interaction as a trend with the exact p-value if it was marginally significant, or correct their reporting if there was indeed a significant interaction that justifies the LSD analysis.

L356: For Table 5, please see Table 2 and Table 4’ s comment.

L363: Please add an indent at the beginning of this paragraph and ensure consistent indentation throughout the entire manuscript.

L443-458: The authors reported the microbial biomass C/microbial biomass N ratio and microbial biomass C/soil organic C ratio in the results, but these important metrics are not addressed in the discussion section. I recommend adding an interpretation of these ratios to the discussion, as they might provide valuable insights into soil microbial dynamics and nutrient availability & turnover.

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Author Response

Dear Editor,

Thanks a lot for providing us the opportunity to submit the revised version of our manuscript entitled "Leucaena-Based Alley Cropping System: An Approach for Reclaiming Degraded Land, Reducing the Usage of Inorganic   Nitrogen Fertilizer, and Improving Crop Productivity" to the journal of Nitrogen. We are really grateful to you and the reviewers for giving valuable insights and comments for the improvement of our manuscript. We have corrected all the comments and suggestions provided by the reviewers. The changes done in the manuscript are highlighted with red color within the manuscript.

Point-by-point responses to the Reviewer comments

Reviewer 1

Comment 1: L24: Please add which parameters were measured in this study.

Response: Thank a lot for your valuable suggestion to improve our manuscript. We have included the parameters measured (L25-28).

Please see in below;

Control plots with similar N doses were applied accordingly without addition of pruned materials to compare the results with alley cropping. Data were collected on bio-chemical properties of soil [soil pH, organic carbon (C), total N, available phosphorus (P), exchangeable potassium (K), microbial biomass C and biomass N] and quantified the yield of cabbage [edible head weight (kg plant^‒1) and head yield (t ha^‒1)] under different alley widths and control. Findings revealed that organic C, total N, available P, exchangeable K, microbial biomass C and biomass N in the topsoil exhibited maximum in the L. leucocephala-based alley plot which proves a possible solution of restoration of degradable land.

 

Comment 2: L137: For Table 1 and Table 3 (L297), authors should remove the border lines to align with standard academic formatting guidelines. Only essential horizontal lines (e.g., above and below the column headers and at the bottom of the table) should be retained. Please refer to Table 2 as an example.

Response: Thanks a lot for pointing out this. We have corrected the table formatting in the revised manuscript (L143; L352).

Comment 3: L171: When were the soil samples collected for the initial and post-harvest periods? Please specify the exact date/month.

Response: We have specified the exact date of soil samples collection for the initial and post-harvest periods in the revised manuscript (L177-178).

Comment 4: L183-195: Please provide a brief explanation of each method used to analyze soil organic carbon, total nitrogen, available phosphorus, and exchangeable potassium.

Response: According to your suggestion, we have written the method of analysis in brief in the revised manuscript (L192-198; L201-206; L209-214; L218-222).

Comment 5: L228: What do authors use for fixed and random effects?

Response: Thank you very much for pointing out this. In our study, three specific alley widths were fixed in main plots and five N levels were distributed in sub-plots where both of the factors were specific and pre-determined and we only focused to compare their effects.

For each alley width, we used all of the sub plots treated with specific N levels for collecting data and analysis. That’s why, we considered all of our treatments (alley width, N level, and their interaction) as fixed effects.

Comment 6: L278: For Table 2 and Table 4 (L327), authors should remove the different alphabetical letters indicating statistical significance where no interaction effects were found (e.g., % Total N, Available P, and microbial biomass C). Additionally, authors could include the P-values for each parameter by adding a row at the bottom of the table.

Response: Thanks a lot for your suggestions. We have removed the statistically insignificant alphabetical letters from your suggested parameters and included the P-values for each parameter by adding a row at the bottom of the table (L311; L340; L344-345). Moreover, we have mentioned in the table footnote for better understanding.

Comment 7: L327: What do the abbreviations OC and TN stand for?

Response: OC stands for organic carbon and TN for total nitrogen. We have mentioned it in the revised manuscript (L345-346).

Comment 8: L338: Authors should ensure proper formatting by using an indent at the beginning of each paragraph.

Response: Thank you for your suggestion. We have corrected it entirely in the revised manuscript.

Comment 9: L338-L340: The authors state that there were no statistically significant differences found for the interaction of alley widths and N levels on edible head weights and head yields (p > 0.05). However, authors later claim that the least significant difference (LSD) analysis revealed significant differences among some of the treatment combinations compared with others. These statements contradict each other because if no significant interaction was detected, it would be inappropriate to conduct LSD tests on treatment combinations. I suggest the authors either report the interaction as a trend with the exact p-value if it was marginally significant, or correct their reporting if there was indeed a significant interaction that justifies the LSD analysis.

Response: Thank you very much for your critical evaluation. According to your suggestion, we have corrected our reporting as a trend with the exact p-values (L374-378; L393-395).

Comment 10: L356: For Table 5, please see Table 2 and Table 4’ s comment.

Response: We have fixed it in the revised manuscript (L390; L393-395).

Comment 11: L363: Please add an indent at the beginning of this paragraph and ensure consistent indentation throughout the entire manuscript.

Response: We have now corrected it in the entire revised manuscript.

Comment 12: L443-458: The authors reported the microbial biomass C/microbial biomass N ratio and microbial biomass C/soil organic C ratio in the results, but these important metrics are not addressed in the discussion section. I recommend adding an interpretation of these ratios to the discussion, as they might provide valuable insights into soil microbial dynamics and nutrient availability & turnover.

Response: Thanks a lot for your critical evaluation to improve our manuscript. According to your recommendation, we have written and included it in the revised manuscript (L490-499).

Please see in below;

Our research was endorsed by Yadav et al. [66] and Tian et al. [67] where they reported that tree-based agroforestry provides higher microbial BC and BN compared with no tree and/or monoculture. Microbial BC and BN are considered as easily accessible and dynamic soil carbon and nitrogen fractions, which are the key factors regulate the microbial community in soil that influence the mineralization of organic C [68, 69]. The microbial BC/BN ratio is an important benchmark of the activity of microbes in soil. We observed comparatively lower BC/BN ratio in most of the alley cropped plots compared to control, where the ratios decreased with the increase in N level irrespective of alley widths (Table 5). The low C:N ratio of microbial biomass promotes the nitrogen mineralization and balanced ratio favors the decomposition of OM [70, 71], Therefore, these findings suggest that alley cropping is a promising approach for enhancing nutrient availability and increasing soil fertility compared to open field condition.

 

 

 

We look forward for the best regarding our submission from you in due time.

Kind regards,

Tofayel Ahamed

 

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Comments and Suggestions for Authors

 

Title: Leucaena-Based Alley Cropping System: An Approach for Reclaiming
Degraded Land, Reducing The Usage of Inorganic Nitrogen Fertilizer, and
Improving Crop Productivity

Dear Authors and Editors

The scope of research presented in the manuscript is consistent with the Nitrogen journal publishing profile. The obtained research results are local in nature due to Leucaena leucocephala, however, alley cultivation is used in mountain crops in many countries of the world. The presented research results fit into the sustainable crop production combined with increasing soil fertility and crop productivity. The manuscript is well planned and presented. Minor corrections and additions are required in selected sections. The Discussion and Conclusion sections are well written.

In order to increase the usefulness of the article, Authors must refer to the following points. Additions should be made to increase the scientific value of the manuscript.

Comments:

1. Abstract: Please provide N rates in kg N ha^-1. This note applies to the entire manuscript. Line 30….(p < 0.05)…. should be removed. This note applies to the entire manuscript.
2. Introduction: Please add a research hypothesis.
3. Methods and Materials: Subsection 2.1 - Please provide organic carbon and total nitrogen in g kg-1 (this note applies to the entire manuscript). Add the available K content in the soil. Table A1 should be placed below line 117. Subsection 2.3 - Nitrogen doses should be given in kg N ha^-1 (this remark applies to the entire manuscript). Subsection 2.4 Please provide the names, formulas and % content of the component in fertilizers. Please provide N, P and K doses in kg N ha^-1, kg P ha^-1 and kg K ha^-1. Subsubsections 2.5.1 – 2.5.5 Rules for the methods used should be added. Line 192 - Why was the available K not determined?
4. Results: Table 2, 4, 5 - Letter markings should be placed next to numerical data regarding results. Table 2 - The content of organic carbon and total nitrogen should be given in g kg^-1. The units used throughout the manuscript should be corrected: mg Kg^-1 (should be mg kg^-1), Kg ha^-1 (should be kg ha^-1), etc.

Specific comments

1. The MS must be corrected according to the editorial requirements of the publisher.
2. Introduction and Discussion sections - the number of one-off citations should be reduced.
3. Line 537 - abbreviation explanations should be removed.

Best regards

 

 

Author Response

Dear Editor,

Thanks a lot for providing us the opportunity to submit the revised version of our manuscript entitled "Leucaena-Based Alley Cropping System: An Approach for Reclaiming Degraded Land, Reducing the Usage of Inorganic   Nitrogen Fertilizer, and Improving Crop Productivity" to the journal of Nitrogen. We are really grateful to you and the reviewers for giving valuable insights and comments for the improvement of our manuscript. We have corrected all the comments and suggestions provided by the reviewers. The changes done in the manuscript are highlighted with red color within the manuscript.

Point-by-point responses to the Reviewer comments

 

Reviewer 2

Comment 1: Abstract: Please provide N rates in kg N ha-1. This note applies to the entire manuscript. Line 30….(p < 0.05)…. should be removed. This note applies to the entire manuscript.

Response: We really appreciate your observation to improve our manuscript. We have provided the N rates in kg N ha^-1 in the entire revised version of our manuscript (L19-21; L35-36). From line 30, p< 0.05 was removed and also from the entire manuscript.

Please see in below;

Abstract: Alley cropping holds the potential to improve both crop yields and soil health. It is found effective for upland crops in many countries of the world. However, the utilization of alley cropping to improve soil health in the terrace ecosystem of Bangladesh is poorly understood. Therefore, this study was undertaken to assess the changes in soil biochemical properties and quantify the cabbage yield under three alley widths of Leucaena leucocephala (3.0, 4.5, and 6.0 m size) and five nitrogen (N) levels [0 kg N ha^‒1, 40 kg N ha^‒1, 80 kg N ha^‒1, 120 kg N ha^‒1, and 160 kg N ha^‒1 (0, 25, 50, 75, and 100% of recommended N rates, respectively) plus pruned materials of L. leucocephala].

 

Comment 2: Introduction: Please add a research hypothesis.

Response: Thank you very much for your suggestion. We have added it in the revised manuscript (L92-95).

Comment 3: Methods and Materials: Subsection 2.1 - Please provide organic carbon and total nitrogen in g kg^-1 (this note applies to the entire manuscript). Add the available K content in the soil. Table A1 should be placed below line 117. Subsection 2.3 - Nitrogen doses should be given in kg N ha-1 (this remark applies to the entire manuscript). Subsection 2.4 Please provide the names, formulas and % content of the component in fertilizers. Please provide N, P and K doses in kg N ha^-1, kg P ha^-1 and kg K ha^-1. Subsubsections 2.5.1 – 2.5.5 Rules for the methods used should be added. Line 192 - Why was the available K not determined?

Response: Thanks a lot for your critical evaluation to improve our manuscript. We are responding to your whole comment in the following segments:

Comment 3.1: Subsection 2.1 - Please provide organic carbon and total nitrogen in g kg^-1 (this note applies to the entire manuscript).

Response: We have provided organic carbon and total nitrogen in g kg^-1 in your suggested subsection (L117-118) as well as in the entire revised manuscript.

Comment 3.2: Add the available K content in the soil.

Response: We are sorry that it was not measured, but we measured the exchangeable K.

Comment 3.3: Table A1 should be placed below line 117.

Response: We have placed it in your suggested location in the revised manuscript (L125-126).

Comment 3.4: Subsection 2.3 - Nitrogen doses should be given in kg N ha^-1 (this remark applies to the entire manuscript).

Response: We have given nitrogen doses in kg N ha^-1 in subsection 2.3 and in the revised manuscript (L151-152; L273-275).

Comment 3.5: Subsection 2.4 Please provide the names, formulas and % content of the component in fertilizers. Please provide N, P and K doses in kg N ha-1, kg P ha-1 and kg K ha-1.

Response: We have corrected and included in the revised manuscript (L163-168).

Comment 3.6: Subsubsections 2.5.1 – 2.5.5 Rules for the methods used should be added.

Response: We have written the methods in brief in the revised manuscript (L187-222).

Comment 3.7: Line 192 - Why was the available K not determined?

Response: We really appreciate your observation. We are apologies that we didn’t determined the amount of available K in our experiment although it would strengthen our MS. We will take consideration in our future experiment. However, we determined the exchangeable K in soil as it represents the readily available amount of K for plant uptake which remain adsorbed in soil particles (Schulte and Kelling, 1998). Besides, we considered it a more accurate measure that express the soil’s ability to supply K immediately.

Schulte, E. E., & Kelling, K. A. (1998). Understanding plant nutrients: soil and applied potassium. Univ. Wisc. Ext. Publ. A, 2251.

We would appreciate if the respected reviewer considers this issue for this time.

 

Comment 4: Results: Table 2, 4, 5 - Letter markings should be placed next to numerical data regarding results. Table 2 - The content of organic carbon and total nitrogen should be given in g kg^-1. The units used throughout the manuscript should be corrected: mg Kg^-1 (should be mg kg^-1), Kg ha^-1 (should be kg ha^-1), etc.

Response: Thanks a lot for your suggestions to improve our manuscript. We have placed letter markings next to numerical data in the revised manuscript. The content of organic carbon and total nitrogen have been provided in g kg^-1 in Table 3 (L311) as well as in the entire revised manuscript. We have corrected the units as per your recommendation in the entire manuscript.

Comment 5: The MS must be corrected according to the editorial requirements of the publisher.

Response: Thanks for your suggestion. We have corrected accordingly.

Comment 6: Introduction and Discussion sections - the number of one-off citations should be reduced.

Response: Thanks for your valuable suggestion to improve our manuscript. We have revised it in the introduction and discussion sections which will be found in red in the revised manuscript.

Comment 7: Line 537 - abbreviation explanations should be removed.

Response: We appreciate your valuable suggestion. We have removed the abbreviation explanations from the revised manuscript.

 

We look forward for the best regarding our submission from you in due time.

Kind regards,

Tofayel Ahamed

 

 

 

Author Response File: Author Response.docx