The Influence of Black Soldier Fly Residue on Watermelon Growth and the Properties of a Coarse-Textured Ultisol

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Title:  Influence of black soldier fly residue on watermelon growth and properties of a coarse-textured ultisol: The title accurately reflects the content of the paper, focusing on application of black soldier fly residue for growth of watermelon and its effect on soil properties.

Abstract: The abstract clearly summarizes the objectives, methodology, key findings, and implications But it showing only soil physico-chemical properties. Emphasis should also be given to the growth attributes as per title of the manuscript and should be briefer and numerical value should be included. Please recheck the percent increase in hydraulic conductivity in line number 26. In line number 28 relative to words should be replaced by: with respect to

Keywords: Keywords has been nicely mentioned. Please mention full form of BSF for better readability and searching by users.

Introduction: Introduction part is clear and indicated the importance, review of previous work and hypothesis focusing the work done. The author has chosen important research problem to tackle nutrient issues in watermelon.

Materials and Methods: Procedures employed for execution of the experiment and recording different observations have been nicely presented.

Results and Discussion: The data on various parameters have been reported in the form of tables/ figures. Interpretation of the data has been done as per set standard. Few observations have been made in the text of paper. Kindly see them and make necessary changes as below:

1. In line number 150 “Textually” should be write as “Texturally”
2. In line number 169 “relative to” should be replaced with “with comparison to”
3. In line number 186 “Effect of black soldier fly residue application chemical properties of the soil” should be changed to “Effect of black black soldier fly residue application on chemical properties of the soil”
4. In line number 293 % symbol is already mentioned. Please delete percent.
5. Figures are not much clear. Please improve the quality of figures

References: The references are mostly relevant and include well-regarded sources. Follow the guidelines of journal for citing the references. Somewhere, doi of the references has been given somewhere it is missing. So, recheck it.

Comments for author File: Comments.pdf

Author Response

RESPONSE TO REVIEWER 1’s COMMENTS

 

1. In line number 150 “Textually” should be write as “Texturally”

 Our Response:

Done, see Line 160

2. In line number 169 “relative to” should be replaced with “with comparison to”

 Our Response:

Thanks for your suggestion.  The sentence is modified. See L180

3. In line number 186 “Effect of black soldier fly residue application chemical properties of the soil” should be changed to “Effect of black soldier fly residue application on chemical properties of the soil”

Our Response:

Thank you for your suggestion. Done, see Line 199

4. In line number 293 % symbol is already mentioned. Please delete percent.

 Our Response:

Done, see Line 310

5. Figures are not much clear. Please improve the quality of figures

 Our Response:

Thank you for your suggestion to improve the quality of figures.  We tried but the quality did not improve much.

 

 

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

First, the paper attempts to reveal the effects of the use of black soldier fly (BSF) frass on soil properties and watermelon (Citrullus lanatus) growth on an ultisol with low soil fertility. BSF waste has attracted great attention in the context of organic agriculture and circular economy in recent years.

However, the degree of novelty of the study is limited. In terms of novelty, it is a shortcoming that deeper parameters such as biological activity, the effect of BSF frass on microbial communities, or plant nutrition dynamics were not measured.

1. Methodology:

BSF Residue Characterization:
The greenhouse trial appears methodologically sound on the surface, but critical information is either missing or underreported. For example, the characterization of the BSF residue is quite limited. Knowing only the NPK content and organic matter percentage does not provide enough detail for reproducibility or for assessing the potential variability of the amendment.

I strongly recommend that the authors include:

• the C/N ratio,

• moisture content,

• electrical conductivity,

• and, ideally, basic microbial parameters or stability indicators of the frass.

Given the diversity in BSF frass compositions depending on feedstock, such data are essential. Furthermore, details about the source material used to raise the larvae (e.g., animal waste, food scraps, plant residues) should be clearly disclosed.

Experimental Controls:

The study is lacking in the provision of positive controls, such as manure, compost, or NPK, which would assist in the contextualisation of the effects of BSF residue. The sole comparison to an unamended control is insufficient for concluding performance relative to common practices.

Statistical Rigor:

Authors employed the least significant difference (LSD) for post-hoc analysis, which is not sufficiently conservative for four-group comparisons. To prevent Type I error, Tukey HSD is recommended to be used instead.

Missing Data:

Nutrient uptake analysis (leaf/tissue NPK) is essential to confirm the actual benefit.

Additionally, the baseline watermelon yield data is missing, even in instances where the discussion is limited to vegetative growth. This limitation impedes a comprehensive understanding of the practical outcomes.

2. Conclusion

The conclusions of the study are mostly in agreement with the results presented, but a few of the claims are perhaps overstated:

As an example, the writers assert that "BSF application at 30 t/ha may not pose a pollution risk," but no leaching experiment, runoff determination, or remnant N/P in leachate was performed. This conclusion is tenuous and requires more substantiation.

While the data indicate that BSF enhanced plant growth parameters, the absence of physiological data (e.g., photosynthesis rate, tissue nutrient content) precludes confirmation that this resulted from improved nutrition.

The assertion that BSF frass can "improve a coarse-textured Ultisol for watermelon production" is only partially valid, as no long-term effects or field testing are included.

Based on these findings, recommendations are made that future research should: Authors need to be more careful in making conclusions and consider the limitations of greenhouse trials without field follow-up.

3.References:

References are relevant, but too narrow or outdated.

Issues:

A significant percentage of the citations are local or regional papers not indexed worldwide or accessible through the peer-review process.

Most missing are core and high-impact research on BSF frass. Furthermore, no references support claims like "BSF improves mobility of nutrients" or "BSF residue poses no environmental issue.".

It is recommended that:
It is recommended that the discussion and literature review be updated with international peer-reviewed literature that has been published during the previous 3–5 years.

4. Comments on Tables: 

1. Tables 2 and 3 lack standard deviation (SD) or standard error (SE) values.
2. Units in some tables (e.g., “g/kg” vs. “%”) are inconsistently formatted.
3. “F-LSD” in tables is not intuitive to all readers; please clarify this as “Fisher’s Least Significant Difference”.

Author Response

RESPONSE TO REVIEWER 2’s COMMENTS

Abstract:

First, the paper attempts to reveal the effects of the use of black soldier fly (BSF) frass on soil properties and watermelon (Citrullus lanatus) growth on an ultisol with low soil fertility. BSF waste has attracted great attention in the context of organic agriculture and circular economy in recent years. However, the degree of novelty of the study is limited. In terms of novelty, it is a shortcoming that deeper parameters such as biological activity, the effect of BSF frass on microbial communities, or plant nutrition dynamics were not measured.

 Our Response:

We cannot agree less on the novelty of measuring biological activity, the effect of BSF frass on microbial communities, or plant nutrition dynamics. We believe that research is a continuum and will consider these parameters in our future studies. The aforementioned parameters are not within the scope of the present study. Thank you for your suggestions.

1. Methodology:

Question 1

BSF Residue Characterization:

The greenhouse trial appears methodologically sound on the surface, but critical information is either missing or underreported. For example, the characterization of the BSF residue is quite limited. Knowing only the NPK content and organic matter percentage does not provide enough detail for reproducibility or for assessing the potential variability of the amendment. I strongly recommend that the authors include: the C/N ratio, moisture content, electrical conductivity, and, ideally, basic microbial parameters or stability indicators of the frass.  Given the diversity in BSF frass compositions depending on feedstock, such data are essential. Furthermore, details about the source material used to raise the larvae (e.g., animal waste, food scraps, plant residues) should be clearly disclosed

 Our Response:

We sincerely appreciate your insightful comments regarding the characterization of the BSF (Black Soldier Fly) frass used in our greenhouse trial. We acknowledge the importance of including a more comprehensive set of physicochemical and microbial parameters such as the C/N ratio, moisture content, electrical conductivity, and stability indicators for both reproducibility and assessment of amendment variability.

 

 

Unfortunately, as the experiment has already been concluded, we are currently unable to conduct additional laboratory analyses on the BSF frass sample. However, we fully agree with the reviewer’s recommendation and will ensure that these parameters are thoroughly analysed and reported in future studies involving BSF frass.

Regarding the source material used to rear the larvae, this information has been provided in the revised manuscript (Lines 100–103), and we hope this clarification addresses the reviewer’s request.

Question 2

Experimental Controls:

The study is lacking in the provision of positive controls, such as manure, compost, or NPK, which would assist in the contextualisation of the effects of BSF residue. The sole comparison to an unamended control is insufficient for concluding performance relative to common practices.

 Our Response

We appreciate your valuable comment regarding the absence of positive controls such as manure, compost, or NPK in the current study. As noted in the manuscript, the use of BSF frass as a soil amendment is relatively novel in the study area. One of the primary aims of this preliminary investigation was to identify the most effective application rate of BSF frass that could enhance soil fertility.

We agree that including conventional amendments would have provided a useful benchmark. However, establishing the optimal BSF rate was a necessary first step before undertaking a more comprehensive comparative study. A follow-up field experiment is already proposed, in which the identified optimal BSF frass rate will be evaluated alongside equivalent rates of poultry manure, pig manure, cow manure, compost, and NPK fertilizers—all of which are widely used and accepted in the study area.

We believe this stepwise approach will allow for a more robust assessment of BSF frass performance in context with conventional practices, and we thank the reviewer for highlighting the importance of such comparative analysis.

 Question 3

Missing Data:

Nutrient uptake analysis (leaf/tissue NPK) is essential to confirm the actual benefit. Additionally, the baseline watermelon yield data is missing, even in instances where the discussion is limited to vegetative growth. This limitation impedes a comprehensive understanding of the practical outcomes.

 Our Response:

We agree with the reviewer. From 10 week after sowing, there was pest infestation that defoliated the plant leaves, which significantly impacted the yield produced. We did not apply pesticide because we wanted to produce an organic watermelon. Due to the impact from the pest attack, we decided to report only on the plant growth parameters obtained.

2. Conclusion:

The conclusions of the study are mostly in agreement with the results presented, but a few of the claims are perhaps overstated: As an example, the writers assert that "BSF application at 30 t/ha may not pose a pollution risk," but no leaching experiment, runoff determination, or remnant N/P in leachate was performed. This conclusion is tenuous and requires more substantiation.

 While the data indicate that BSF enhanced plant growth parameters, the absence of physiological data (e.g.photosynthesis rate, tissue nutrient content) precludes confirmation that this resulted from improved nutrition.

 The assertion that BSF frass can "improve a coarse-textured Ultisol for watermelon production" is only partially valid, as no long-term  effects or field testing are included.

 Based on these findings, recommendations are made that future research should: Authors need to be more careful in making conclusions and consider the limitations of greenhouse trials without field follow-up

 Our Response:

Thank you the reviewer for this thoughtful and important feedback. We acknowledge that some of the conclusions in the original manuscript may have been stated too definitively, particularly regarding the environmental safety and long-term agronomic implications of BSF frass application.

1. On pollution risk at 30 t/ha:
   We agree that our conclusion suggesting that BSF frass application at 30 t/ha "may not pose a pollution risk" was not supported by direct measurements such as nutrient leaching, runoff, or residual N/P analysis. This was an overstatement, and we have revised the manuscript to more cautiously frame this claim as a hypothesis that requires further empirical validation through dedicated environmental impact studies.
2. On physiological indicators of improved nutrition:
   We appreciate your observation that plant growth promotion does not necessarily equate to improved plant nutrition. As no physiological measurements (e.g., photosynthetic activity or tissue nutrient analysis) were conducted, we have revised the related statements in the conclusion section to reflect this limitation and now emphasize that the observed improvements in growth parameters suggest a potential nutritional benefit, which warrants further investigation.
3. On claims regarding improvement of coarse-textured Ultisols:
   We agree that this conclusion should be moderated. While our findings suggest that BSF frass improved some physical and chemical properties of the Ultisol in a controlled greenhouse environment, we recognize the limitations of extrapolating these results to field conditions or long-term soil improvement. We have accordingly revised the statement to indicate that BSF frass has the potential to improve coarse-textured Ultisols, pending confirmation from longer-term field trials.
4. On overall caution in conclusions and recommendations:
   We fully concur with the reviewer that greenhouse results should be interpreted conservatively when making practical recommendations. The manuscript has been revised to explicitly acknowledge the limitations of greenhouse studies and the need for follow-up field experiments to validate the findings under real-world agronomic conditions.

We thank the reviewer once again for helping us improve the clarity and scientific rigor of our conclusions.

 References:

References are relevant, but too narrow or outdated.

Issues:

A significant percentage of the citations are local or regional papers not indexed worldwide or accessible through the peer-review process.

 Most missing are core and high-impact research on BSF frass. Furthermore, no references support claims like "BSF improves mobility of nutrients" or "BSF residue poses no environmental issue.".

 It is recommended that the discussion and literature review be updated with international peer-reviewed literature that has been published during the previous 3–5 years.

 Our Response:

We have improved on the quality of the literature in the manuscript

 

3. Comments on Tables:
4. Tables 2 and 3 lack standard deviation (SD) or standard error (SE) values.
5. Units in some tables (e.g., “g/kg” vs. “%”) are inconsistently formatted.
6. “F-LSD” in tables is not intuitive to all readers; please clarify this as “Fisher’s Least Significant Difference”.

Our Response:

1. The standard error (SE) values are provided for Tables 2 and 3
2. Units are now harmonised; see Tables 1, 2 and 3
3. We have made appropriate corrections. F-LSD is defined in all the Tables where it appears.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript is an interesting study of impacts of a special animal waste (black soldier fly reside) as an organic fertilizer on soil properties and water melon growth in ultisol field in Africa. It is generally well prepared. However, there are still rooms for improvement in respect to both scientific and editorial quality. Below are comments for authors’ consideration.

Specific comments

1. Extra effort on English polishing is encouraged. For example, L19. Better to change the past tense of “necessitated” to the present tense of “necessitates”. L20. “an” should be deleted to be consistent with “alternatives”.
2. L27 and other places. Many journals recommend the reservation of the term “significant”, significantly” or alike for reporting statistically treated data with the p levels given (i. e., at p ≤ 0.05, 0.01 or 0.001)
3. The term “organic manure” seems not an accurate term hereby nowadays with emerging organic farming practices. The term should be referred to the manure yielded in organic farming. Please elaborate the relevant terms you used with reference to He (2020, Organic animal farming and comparative studies of conventional and organic manures, p. 165-182, In Animal Manure: Production, Characteristics, Environmental Concerns and Management. doi:10.2134/asaspecpub67.c9). Double check the accuracy of all relevant terms.
4. BSF residue is a rare type of animal waste. You may provide some basic information on the product, such as the production, collection, and storage. Especially, please elaborate if its physicochemical and nutriment properties are different from the typical animal manure or not, compared to those in the Animal Manure mentioned above. If not, your study is surely more highlightable.
5. L179 and other places. You used p< 0.05 as the criteria for significance. What about p=0.05 which is normally also considered as significance.
6. Figures should be self-explanatory. Are the errobs SD or SE? n=?.
7. L394. “Black soldier fly (BSF) amendment” should be “Black soldier fly (BSF) residue amendment”. Similarly, L395, Application of BSF” should be “application of BSF residue”. Correct such sloppy expressions throughout the manuscript.

Author Response

1. L19. Better to change the past tense of “necessitated” to the present tense of “necessitates”.

 Our Response:

We appreciate your observation. Correction effected.

 L20. “an” should be deleted to be consistent with “alternatives

 Our Response:

Done.  “an” deleted

2. L27 and other places. Many journals recommend the reservation of the term “significant”, significantly” or alike for reporting statistically treated data with the p levels given (i. e., at p ≤ 0.05, 0.01 or 0.001)

 Our Response:

Your spot on suggestion is taken. Significant at p ≤ 0.05 effected.

3. The term “organic manure” seems not an accurate term hereby nowadays with emerging organic farming practices. The term should be referred to the manure yielded in organic farming. Please elaborate the relevant terms you used with reference to He (2020, Organic animal farming and comparative studies of conventional and organic manures, p. 165-182, In Animal Manure: Production, Characteristics, Environmental Concerns and Management. doi:10.2134/asaspecpub67.c9). Double check the accuracy of all relevant terms.

Our Response:

We appreciate your valuable comment regarding the term “organic manure”. We want state that the “organic manure” mentioned in the present study was not the authors’ coinage but was adapted to corroborate other research findings. See lines 58 and 206. See also the below references:

Choudhary, R.C.; Bairwa, H.L.; Mahawer, L.N.; Meena, V.K.; Tak, J.K. Effect of Organic Manures on Yield and Quality Characteristics of Pomegranate (Punica granatum L.) Cv. Bhagwa. Int’l. J. Plant Soil Sci., 2023, 35(3), 120-128. https://doi.org/10.9734/IJPSS/2023/v35i32782

Gelaye, Y. Effect of combined application of organic manure and nitrogen fertilizer rates on yield and yield components of potato: A review. Cogent Food Agric., 2023, 9(1), 2217603. https://doi.org/10.1080/23311932.2023.2217603

4. BSF residue is a rare type of animal waste. You may provide some basic information on the product, such as the production, collection, and storage. Especially, please elaborate if its physicochemical and nutriment properties are different from the typical animal manure or not, compared to those in the Animal Manure mentioned above. If not, your study is surely more highlightable.

Our Response:

Thank you for that observation. Your suggestion is taken. See lines 100-103 and lines 169 and 174.

5. L179 and other places. You used p< 0.05 as the criteria for significance. What about p=0.05 which is normally also considered as significance.

Our Response:

Your valuable suggestion is taken. Significance corrected to p ≤0.05 as against p< 0.05.

6. Figures should be self-explanatory. Are the errobs SD or SE?; n=?.

Our Response:

We have ensured that the figures are self-explanatory. Bars denote Fisher’s least significant difference (F-LSD) at 5% probability. See figures 1 and 2.

7. L394. “Black soldier fly (BSF) amendment” should be “Black soldier fly (BSF) residue amendment”. Similarly, L395, Application of BSF” should be “application of BSF residue”. Correct such sloppy expressions throughout the manuscript.

 Our Response:

Thank you for your invaluable suggestion. The suggested correction has been effected throughout the manuscript.

 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Dear Authors,

I found the manuscript novel and clearly written. I suggest some minor changes before publishing the paper:

1) L62: Also fill in the Latin name of black soldier fly, as it is the first mention.

2) L66: Correct: “Beesigamukama et al. [9] reported…”

3) L76: Shortly give some examples which used BSF residue to improve production of important food crops.

4) L103 and 105: Delete (6) and (10). They are unnecessary.

5) L105–106: “measuring 30 cm long, 40 cm wide, and 60 cm deep” It is unclear. Are they the dimensions of one pot? It seems to be too large for 10 kg soil.

6) L108: Use mL or cm3 instead of cl.

7) L120–121: Delete “Data on the number of leaves were obtained by counting”, as it is evident.

8) L140–143: Consider to delete the subsection “2.2. Percentage changes in soil chemical properties relative to the baseline soil”. The method to calculate percentage change is trivial.

9) L150–163: The first paragraph of the Results (3.1. Chemical properties of BSF and its effect on physical properties of soil) contains only the initial properties of the test soil and the BSF residue. This is not belongs to the Results, and thus should be inserted into the Materials and Methods section.

10) Table 1 seems to be unnecessary, and could be deleted, these information can be shown within the text (in L160–161).

11) L173–174: “BSF-amended soils had circa 50%-160% higher hydraulic conductivity than the control treatment.” Indicate the importance of this finding. Is the originally low hydraulic conductivity of the utisol is a restricting property for watermelon cultivation?

12) L181: Use hectare instead of acre. Change the unit.

13) L188–189: “The pH of the soil was significantly lower in the control treatment than the BSF-amended soils.” Give the optimum pH for watermelon cultivation. Is the observed change in soil pH advantageous for cultivation? It is required to draw conclusions from this finding.

14) L192–193: Write Wang et al. [32] and Sushma et al. [29] instead of “ref.”.

15) L204, 207: Again, write the first author’s name to ref. [15], [34] and [29].

16) L220–221: “Furthermore, P is reported to be an integral component of nucleic acids as well as nucleotides, coenzymes and sugar phosphates [36,37].” It is evident, delete it with the references. Furthermore, interpret the potential relationship between the increased P availability and altered pH, as P solubility and availability is known to be highly depend on soil pH.

17) L235–236: Again, add names to ref. [31] and ref. [11].

18) L256: Setting the pH value (which is logarithmical per se) as a percentage is meaningless. Express the change directly in pH units. Furthermore, use pH unit in the axis of Fig. 1A.

19) Fig. 2A, 2B: Move the group names from the category axis to the bottom of the figure.

20) Table 4: Instead of table, consider to display these results as five line diagrams with means and LSDs. This would be a better way to illustrate changes over time.

21) L343–344: “Wider leaves provide a greater surface area for light interception, which directly enhances photosynthetic efficiency [44].” It is a false statement. The photosynthetic efficiency does not depend on the leaf area, but on e.g. chlorophyll content or rather the quantum efficiency of the PSII photosystem (Fv/Fm). This properties was not measured in this study.

22) L347: Add author names to ref. [45].

23) L359–361: “Leaf number is a key determinant of a plant's photosynthetic capacity, as more leaves equate to greater energy capture for growth and fruit development [46].” It is not obvious as well, without chlorophyll content measurements. Greater leaf biomass can be associated with the dilution effect of the chlorophyll as a function of N availability, which does not result in increased photosynthetic capacity. Such statements are not substantiated in the absence of physiological measurements.

24) L380, 381, 389: Add author names to ref. [47] and [35].

25) Conclusions: A weakness of the study is the missing of fruit yield measurement. Without this information, profitability of using BSF amendment cannot be evaluated. This profitability is questionable in larger farms, considering that a high amount (10–30 t per hectare) of amendment should be produced and transported in the area. This self-critics have to be added to the conclusion section.

Based on the above comments, I suggest minor revisions to improve the paper.

Author Response

RESPONSE TO REVIEWER 4’s COMMENTS

1.), L62: Also fill in the Latin name of black soldier fly, as it is the first mention.

Our Response:

Done, see L62

2) L66: Correct: “Beesigamukama et al. [9] reported…”

Our Response:

Thank you for your suggestion. However, we consulted a few recent works published by Soil Systems Journal.  The format “…ref. [9] reported…” was the format the authors used.

3) L76: Shortly give some examples which used BSF residue to improve production of important food crops

 Our Response:

Your observation is apt. Your suggestion is effected; see L72.

4) L103 and 105: Delete (6) and (10). They are unnecessary.

Our Response:

We appreciate your suggestion. Correction effected, see L112 and L114.

 5) L105–106: “measuring 30 cm long, 40 cm wide and 60 cm deep” It is unclear. Are they the dimensions of one pot? It seems to be too large for 10 kg soil.

 Our Response:

Thank you for spotting this obvious error. We mistakenly wrote the pot measurement of another study we carried out. Correction effected, see L114.

6) L108: Use mL or cm³ instead of cl.

 Our Response:

Done, see L116.

 

7) L120–121: Delete “Data on the number of leaves were obtained by counting”, as it is evident.

Our Response:

Done, see L128.

8) L140–143: Consider to delete the subsection “2.2. Percentage changes in soil chemical properties relative to the baseline soil”. The method to calculate percentage change is trivial.

 Our Response:

We appreciate your suggestion; however, we think that+ subsection 2.2. is necessary to provide clarity to readers who may want to carry out a similar study.

9) L150–163: The first paragraph of the Results (3.1. Chemical properties of BSF and its effect on physical properties of soil) contains only the initial properties of the test soil and the BSF residue. This is not belongs to the Results, and thus should be inserted into the Materials and Methods section.

 Our Response:

We appreciate your suggestion; nevertheless, we don’t think it is inappropriate to have the first paragraph of the Results (3.1. Chemical properties of BSF and its effect on physical properties of soil) where is it. This is because the discussion is an aftermath of laboratory analysis. However, there are ample published studies that reported their work in a similar way.

10) Table 1 seems to be unnecessary, and could be deleted, these information can be shown within the text (in L160–161).

Our Response:

Thanks for your suggestion; however, we think that putting the contents of Table 1 in writing will be wordy. Thus, we think it is okay to have Table 1 the way it is.

11) L173–174: “BSF-amended soils had circa 50%-160% higher hydraulic conductivity than the control treatment.” Indicate the importance of this finding. Is the originally low hydraulic conductivity of the utisol is a restricting property for watermelon cultivation?

Our Response:

Done, see L183-185.

12) L181: Use hectare instead of acre. Change the unit.

 Our Response:

Thanks for your valuable suggestion. However, in the present study we reported the findings of Sushma et al. (2024) whose report was in ton/acre. Thus, we think it will be unnecessary changing the unit to ton/hectare. It may not be out of place if that sentence reads thus: “According to the authors, higher treatments rates had lower soil BD than lower treatment rates” instead of “According to the authors, higher treatments rates (7 ton/acre) had lower soil BD than lower treatment rates (5 ton/acre and 2.5 ton/acre, respectively)”.

13) L188–189: “The pH of the soil was significantly lower in the control treatment than the BSF-amended soils.” Give the optimum pH for watermelon cultivation.

 Is the observed change in soil pH advantageous for cultivation? It is required to draw conclusions from this finding.

 Our Response:

Your valuable observation is well noted and effected, see L344-345.

14) L192–193: Write Wang et al. [32] and Sushma et al. [29] instead of “ref.”

15) L204, 207: Again, write the first author’s name to ref. [15], [34] and [29].

Our Response:

We consulted a few recent works published by Soil Systems Journal. The format “…ref. [15], [34] and [29] found…” was the format the authors used. We simply adopted the same format.

16) L220–221: “Furthermore, P is reported to be an integral component of nucleic acids as well as nucleotides, coenzymes and sugar phosphates [36, 37].” It is evident, delete it with the references. Furthermore, interpret the potential relationship between the increased P availability and altered pH, as P solubility and availability is known to be highly depend on soil pH.

 Our Response:

Thank you this importance observation. Done. See L232

17) L235–236: Again, add names to ref. [31] and ref. [11].

Our Response:

You suggestion is well noted. However, we consulted a few recent works published by Soil Systems Journal.  The format “…ref. [31] found…” was the format the authors used. We simply adopted the same format.

18) L256: Setting the pH value (which is logarithmical per se) as a percentage is meaningless. Express the change directly in pH units. Furthermore, use pH unit in the axis of Fig. 1A.

Our Response:

Thank you for your observation. We appreciate the point you raised. However, the initial data obtained was recomputed on percentage basis hence the reason the percentage (%) unit was used irrespective of the parameter presented.

 19) Fig. 2A, 2B: Move the group names from the category axis to the bottom of the figure.

 Our Response:

Thank you for your suggestion you raised. Unfortunately, we unable to manipulate the graphs as you suggested.

 20) Table 4: Instead of table, consider to display these results as five line diagrams with means and LSDs. This would be a better way to illustrate changes over time.

 Our Response:

We appreciate your view that was also our initial thought. But adding extra 5 figures will exceed the Journal’s page limit for a research article. Hence the reason we adopted the table presentation format

 21) L343–344: “Wider leaves provide a greater surface area for light interception, which directly enhances photosynthetic efficiency [44].” It is a false statement. The photosynthetic efficiency does not depend on the leaf area, but on e.g. chlorophyll content or rather the quantum efficiency of the PSII photosystem (Fv/Fm). This properties was not measured in this study

 Our Response:

22) L347: Add author names to ref. [45]

24) L380, 381, 389: Add author names to ref. [47] and [35].

Our Response:

We consulted a few recent works published by Soil Systems Journal.  The format “…ref. [47] found…” was the format the authors used. We simply adopted the same format.

23) L359–361: “Leaf number is a key determinant of a plant's photosynthetic capacity, as more leaves equate to greater energy capture for growth and fruit development [46].” It is not obvious as well, without chlorophyll content measurements. Greater leaf biomass can be associated with the dilution effect of the chlorophyll as a function of N availability, which does not result in increased photosynthetic capacity. Such statements are not substantiated in the absence of physiological measurements.

 Our Response:

Noted

 25) Conclusions: A weakness of the study is the missing of fruit yield measurement. Without this information, profitability of using BSF amendment cannot be evaluated. This profitability is questionable in larger farms, considering that a high amount (10–30 t per hectare) of amendment should be produced and transported in the area. This self-critics have to be added to the conclusion section

 Our Response:

Your point is well taken. The greenhouse yield challenge was due to pest attack. Nevertheless, in our conclusion, “we suggested further investigation under field conditions to validate the study findings and assess long-term sustainability of BSF residue use for watermelon cultivation in a coarse-textured Ultisol”. Surely, during the field trials, crop yield data will be provided.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Peer Review of the Manuscript

Title:  Influence of black soldier fly residue on watermelon growth and properties of a coarse-textured ultisol

Title: The title accurately reflects the content of the paper, focusing on application of black soldier fly residue for growth of watermelon and its effect on soil properties.

Abstract: The abstract clearly summarizes the objectives, methodology, key findings, and implications. As suggested, growth attributes has been emphasized in abstract. Numerical values have been also added.

Keywords: Full form of BSF has been mentioned.

Introduction: Introduction has been improved.

Materials and Methods: Materials and methods have also been improved.

Results and Discussion: Results and Discussion has also been improved, but  “Effect of black soldier fly residue application chemical properties of the soil” has been not changed as per my suggestions, it should be changed to “Effect of black soldier fly residue application on chemical properties of the soil” in subheading

References: The references are mostly relevant and include well-regarded sources. Follow the guidelines of journal for citing the references. Somewhere, doi of the references has been given somewhere it is missing. So, recheck it.

 

Final Recommendation

Revise and Resubmit (Minor Revisions Required)
The paper is very pertinent. Few observations have been made and mentioned in the text of the manuscript, which needs to be looked into before final submission.

 

Comments for author File: Comments.pdf

Author Response

RESPONSE TO REVIEWER 1’s ROUND 2 COMMENTS

1.  

 

Our Response:

Thank you for your observation. Done, see Line 199

 2.

 

Our Response:

Done, articles’ doi are provided. See references; Lines 444, 451,454, 469, 476, 478, 502, 505, 510, 515, 518, 520, 523, 526,

More so, I used 2025 articles published in Soil Systems Journal to modify in text citation such as: Ref [ ] to  Beesigamukama et al [ ] in L68.  See Lines 191, 206, 208, 221, 222, 237, 248, 254, 301, 363, 397, 399, 408

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks.

Author Response

Dear Editor 

 

I did not see comment from Reviewer 2.