Nitrogen Dynamics from Conventional Organic Manures as Influenced by Different Temperature Regimes in Subtropical Conditions
and Md Khairul Alam 4,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript entitled ‘’ Nitrogen Dynamics from Conventional Organic Manures as Influenced by Different Temperature Regimes in Subtropical Conditions’’ investigated the nitrogen release pattern from organic manures (poultry manure, vermicompost, bio-slurry, cow dung, water-hyacinth compost, and rice straw compost at three temperature regimes (15, 25, and 35°C). The idea of the paper is interesting. Because the lack of line number in the manuscript I put my comments for each section. Please see them as below:
Abstract
The start of the abstract isn’t impressive. The abstract needs to (1) state the principal objectives and scope of the investigation; (2) describe the methods used; (3) summarize the results; and (4) tell the principal conclusions. This abstract hasn’t clearly provided enough information but is wordy.
One more thing: there isn’t any percentage for the result of the abstract. Which treatment is the best? State the result based on the percentage.
Introduction
Introduction should be expanded. The novelty of research is missing. There isn’t any connection between the current research and previous ones, gap of knowledge is unclear.
In the second paragraph, the authors bring some information about agriculture and soil status of Bangladesh, without mention previous research in this area!
In the third paragraph, there isn’t any research background on the way for enhancing soil organic matter. Add previous research and state which method have better results!
In the fourth paragraph, add previous research on organic and non-organic amendments. For example, in general, farmers prefer to increase N application. Organic amendments or fertilizers, such as composts, has been implemented for decades to maintain and enhance agricultural soil functioning. In addition to providing crop nutrients, organic fertilizer could quickly enhance a wide range of soil characteristics, including water dynamics. Here is a recently published work (https://doi.org/10.3390/plants13040509) about the function of compost fertilizer and you can use it here. Also, add more references for this section.
The hypothesis of the research is missing, add it at the last paragraph of the introduction.
Material and Methods
An important thing that missed in the Material and method is soil analysis! Why there isn’t any information about soil characteristics before starting the experiment? You need to present a comprehensive experimental condition. Putting a table containing soil characteristics is highly recommended.
Results
Add significant letters for Figure 3, and 4.
The main problem of the result section is that there isn’t any comparison between treatments with percentage.
Discussion
Many sentences in this section are general. For example: Asagi and Ueno [50], Hlaing et al. [51] and Ishikawa [52] reported that N mineralization of green manure (GM) in paddy soils reached its peak within 4 to 6 weeks at 23 to 30°C.!!!! rewrite the discussion section with more and precise information of previous research and make a connection between them and the current research.
One more thing, many parts of the discussion is repetition of the result section! Especially the discussion for sections 4.2.1, 4.2.2, and 4.2.3 should be enhanced.
Conclusion
It is better if the authors add suggestions for future research at the end of the conclusion.
References
The paper contain 7 self-citation! References number: 4, 5, 6, 7, 8, 10, and 27! I would suggest that replace some of them. Also, please check the format of the references based on the journal format.
Comments on the Quality of English Language
Minor editing of English language required
Author Response
Reviewer comments: The manuscript entitled ‘’ Nitrogen Dynamics from Conventional Organic Manures as Influenced by Different Temperature Regimes in Subtropical Conditions’’ investigated the nitrogen release pattern from organic manures (poultry manure, vermicompost, bio-slurry, cow dung, water-hyacinth compost, and rice straw compost at three temperature regimes (15, 25, and 35°C). The idea of the paper is interesting. Because the lack of line number in the manuscript I put my comments for each section. Please see them as below:
Authors’ response: Thanks for the positive comments.
Reviewer comments: Abstract
The start of the abstract isn’t impressive. The abstract needs to (1) state the principal objectives and scope of the investigation; (2) describe the methods used; (3) summarize the results; and (4) tell the principal conclusions. This abstract hasn’t clearly provided enough information but is wordy. One more thing: there isn’t any percentage for the result of the abstract. Which treatment is the best? State the result based on the percentage.
Authors’ response: Now we revised the abstract according to the reviewer suggestion
Reviewer Comments: Introduction
Introduction should be expanded. The novelty of research is missing. There isn’t any connection between the current research and previous ones, gap of knowledge is unclear.
In the second paragraph, the authors bring some information about agriculture and soil status of Bangladesh, without mention previous research in this area!
In the third paragraph, there isn’t any research background on the way for enhancing soil organic matter. Add previous research and state which method has better results!
In the fourth paragraph, add previous research on organic and inorganic amendments. For example, in general, farmers prefer to increase N application. Organic amendments or fertilizers, such as composts, has been implemented for decades to maintain and enhance agricultural soil functioning. In addition to providing crop nutrients, organic fertilizer could quickly enhance a wide range of soil characteristics, including water dynamics. Here is a recently published work (https://doi.org/10.3390/plants13040509) about the function of compost fertilizer and you can use it here. Also, add more references for this section.
The hypothesis of the research is missing, add it at the last paragraph of the introduction.
Authors’ response: Now we have revised the introduction section according to the reviewer comments and suggestions. Changes are made in the track changes mode.
Reviewer Comments: Material and Methods
An important thing that missed in the Material and method is soil analysis! Why there isn’t any information about soil characteristics before starting the experiment? You need to present a comprehensive experimental condition. Putting a table containing soil characteristics is highly recommended.
Authors’ response: The soil characteristics are given in the revised manuscript as below.
Table 1a Morphological characteristics of the experimental field
|
Morphological characteristics |
|
|
Locality |
BARI, Joydebpur, Gazipur |
|
Geographic position Altitude |
230- 24'13” N Latitude, 900-24'22”E Longitude, 14.6 m high above the sea level |
|
AEZ |
Modhupur Tract (AEZ 28) |
|
General Soil type |
Grey Terrace Soils (Aeric Albaquept) |
|
Taxonomic soil classification |
|
|
Order |
Inceptisol |
|
Sub order |
Aquept |
|
Sub group |
Aeric Albaquept |
|
Soil series |
Chhiata |
|
Physiographic unit |
Madhupur Tract |
|
Drainage |
Moderate |
|
Flood level |
Above flood level |
|
Topography |
Medium high land |
Table 1b Physical and chemical properties of soil in the experimental field
|
Physical properties |
Values |
|
Sand (%) |
27.18 |
|
Silt (%) |
38.30 |
|
Clay (%) |
34.52 |
|
Textural class |
Clay loam |
|
Particle density (g cm-3) |
2.48 |
|
Bulk density (g cm-3) |
1.42 |
|
Porosity (%) |
42.74 |
|
Hydraulic conductivity (cm sec-1) |
2.10×10-5 |
|
Chemical properties |
|
|
pH |
6.5 |
|
Organic C (%) |
0.85 |
|
Organic matter (%) |
1.47 |
|
Exchangeable K (cmol kg-1 soil) |
0.18 |
|
Exchangeable Ca (cmol kg-1 soil) |
4.80 |
|
Exchangeable Mg (cmol kg-1 soil) |
2.10 |
|
Total N (%) |
0.07 |
|
Available N (µg g-1 soil) |
50.00 |
|
Available P (µg g-1 soil) |
12.93 |
|
Available S (µg g-1 soil) |
15.00 |
|
Available Zn (µg g-1 soil) |
0.71 |
|
Available B (µg g-1 soil) |
0.26 |
Results
Add significant letters for Figure 3, and 4.
The main problem of the result section is that there isn’t any comparison between treatments with percentage.
Authors’ response: The significant letters are added in Figures 3 and 4.
Some sentences are added in the results section that compares treatments with percentage.
Discussion
Many sentences in this section are general. For example: Asagi and Ueno [50], Hlaing et al. [51] and Ishikawa [52] reported that N mineralization of green manure (GM) in paddy soils reached its peak within 4 to 6 weeks at 23 to 30°C.!!!! rewrite the discussion section with more and precise information of previous research and make a connection between them and the current research.
Authors’ response: I would like to thank the reviewer for the comment as I have made the following improvements in the manuscript.
“Asagi and Ueno [50] found that N mineralisation of various 15N-labeled green manures in paddy soils peaked within 4 to 6 weeks at temperatures ranging from 23 to 30°C, highlighting the critical role of temperature in accelerating microbial activity. Similarly, Hlaing et al. [51] demonstrated that green manure crops significantly enhanced mineralisable N in paddy soils under similar temperature conditions, corroborating the influence of warm temperatures on N release. Ishikawa [52] further supported these findings by detailing how green manure applications in Japanese rice farming systems optimized N availability during the critical early weeks of decomposition. These studies align with the present research, which also underscores the substantial effect of temperature on N mineralisation rates, particularly in the context of organic manure use in subtropical conditions.”
One more thing, many parts of the discussion is repetition of the result section! Especially the discussion for sections 4.2.1, 4.2.2, and 4.2.3 should be enhanced.
Authors’ response: The sections 4.2.1, 4.2.2 are revised accordingly (Track changed).
The incubation research showed that the greatest CAf was observed with PM at a temperature regime of 35°C, reaching 39.3%, whereas the minimal CAf was noted in RSC under the 15°C regime, registering at 10.4% (Table 3 and Fig 3). The clear positive relationship between higher temperatures and increased CAf suggests that elevated temperatures boost microbial activity and N mineralisation rates, corroborating other scholarly works that link enhanced mineralization to stimulated microbial metabolism and enzymatic activities in warmer conditions [60, 61, 62].
Additionally, our findings indicate a significant impact of manure types on CAf. Soils amended with PM consistently presented the highest CAf values (36.5%), outperforming those treated with VC. On the contrary, RSC-applied soils manifested the lowest CAf levels. Precisely, PM amendments resulted in CAf being 5.28%, 7.52%, 12.9%, 20.5%, and 21.2% greater relative to VC, BS, CD, WHC and RSC, respectively. This trend highlights the superior N release potential of PM, making it the most effective organic manure for maximising N availability under varying temperature conditions. The consistent performance of PM, followed by VC, underscores the importance of manure selection in achieving optimal N mineralisation, particularly in warmer climates.
Chadwick et al. [64] also reported variability in mineralisable N in organic manure used as N source. However, Indraratne et al. [65] reported that the current guidelines for applying manure as a source of N often take a one-size-fits-all approach, ignoring the significant variability in manure quality from even the same species [64]. This oversight disregards key factors and results in inaccurate predictions of plant-available N. Stanford and Smith [66] and Alvarez and Alvarez [67] conducted research into decomposition kinetics assumes that organic-N breaks down at a first-order rate, a pattern commonly seen in the decay of organic materials, while variable mineralisable N pool are reported in different organic manures during decomposition.
The study of Azeez and Averbeke [68], Stanford and Smith [66] and Alvarez and Alvarez [67] identified distinct stages in the N release pattern: a rapid initial release during the first 30 days, followed by consistent releasing from day 40 to 55, a marked decrease between days 70 and 90, and then a significant rise at day 120, likely due to the breakdown of microbial cells. It suggests that if nitrate isn't captured by microbes or absorbed by crops within the initial 30 days, it is likely to be lost through leaching. Therefore, timing the crop absorption with periods of high N availability from manures/composts is crucial [68].
However, Moharana and Biswas [69] suggest that field studies conducted in the actual environment on PMN fraction and its changes during the crop's growth could provide more useful information than common incubation studies for assessing how organic fertilisers release mineral-N.
Conclusion
It is better if the authors add suggestions for future research at the end of the conclusion.
Authors’ response: Suggestions for future research are added at the end of the conclusion section as follows:
References
The paper contain 7 self-citation! References number: 4, 5, 6, 7, 8, 10, and 27! I would suggest that replace some of them. Also, please check the format of the references based on the journal format.
Authors’ response: The number of self-citations are now reduced.
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Authors,
After reviewing the manuscript, I find it very interesting. The results presented illustrate the dynamics of nitrogen which can be useful for agricultural practice due to the selection of the best type of organic fertilizer for the given climatic conditions.
Introduction
In my opinion, the introduction is well written. It adequately introduces the issue undertaken in the research work. The purpose of the manuscript is correctly formulated. A minor addition that I suggest would be a mention of the degree of utilization of nutrients mainly N from various sources by crops and the related consequences. It would also be a good addition to highlight both economic and environmental benefits of using organic fertilizers compared to synthetic fertilizers.
Materials and methods
I have no comments on this section. In my opinion, it is properly written. It describes in detail the research undertaken in a way that makes it replicable. If possible, I suggest adding a statistical table in the supplementary materials.
Results
The section is generally correctly structured. The numbering of headings should be improved. I also suggest in sections 3.1.X to provide percentage changes in results.
Discussion
The authors in the section compare the obtained results to the works of other researchers and try to suggest possible reasons for the obtained correlations. In my opinion, this is correct.
Certainly, it is true what the authors included in the heading 4.1 in the final lines, however, in my opinion, it is somewhat of an unfinished thought. Reading these lines, one can get the impression that microorganisms take N and it is “lost”. I think the Authors here meant free-living microorganisms that take up N in their life processes and release it into the soil after their death. If this is indeed what the Authors meant I suggest supplementing with this information.
Conclusions
In my opinion, the conclusions are correctly formulated I suggest an additional supplement: formulate possible recommendations for agricultural practice and suggest further possible research in this area.
References
The references used in the manuscript are appropriate. However, this section should be technically refined. The form should be standardized. Names of publications are written in both abbreviations and full names. The abbreviations use “.” as well as without. The year of the manuscript is written in “(...)” as well as without. Authors are given in various forms.
Good luck
Author Response
Reviewer Comments: After reviewing the manuscript, I find it very interesting. The results presented illustrate the dynamics of nitrogen which can be useful for agricultural practice due to the selection of the best type of organic fertilizer for the given climatic conditions.
Introduction
In my opinion, the introduction is well written. It adequately introduces the issue undertaken in the research work. The purpose of the manuscript is correctly formulated. A minor addition that I suggest would be a mention of the degree of utilization of nutrients mainly N from various sources by crops and the related consequences. It would also be a good addition to highlight both economic and environmental benefits of using organic fertilizers compared to synthetic fertilizers.
Authors’ response: The authors would like to thank you for your positive comments. Now we have revised the introduction according to your suggestions.
Reviewer Comments: Materials and methods
I have no comments on this section. In my opinion, it is properly written. It describes in detail the research undertaken in a way that makes it replicable. If possible, I suggest adding a statistical table in the supplementary materials.
Authors’ response: The authors would like to thank you for your positive comments.
Results
The section is generally correctly structured. The numbering of headings should be improved. I also suggest in sections 3.1.X to provide percentage changes in results.
Authors’ response: The authors would like to thank you for your positive comments. We have added some comparative results with percentage.
Discussion
The authors in the section compare the obtained results to the works of other researchers and try to suggest possible reasons for the obtained correlations. In my opinion, this is correct.
Certainly, it is true what the authors included in the heading 4.1 in the final lines, however, in my opinion, it is somewhat of an unfinished thought. Reading these lines, one can get the impression that microorganisms take N and it is “lost”. I think the Authors here meant free-living microorganisms that take up N in their life processes and release it into the soil after their death. If this is indeed what the Authors meant I suggest supplementing with this information.
Authors’ response: The authors would like to thank you for the valuable comment. The authors have corrected the manuscript so that actual meaning of the process happened with the microorganisms can be conveyed to audiences.
Conclusions
In my opinion, the conclusions are correctly formulated I suggest an additional supplement: formulate possible recommendations for agricultural practice and suggest further possible research in this area.
Authors’ response: Some recommendations and future research scopes are added at the end of the Conclusions.
References
The references used in the manuscript are appropriate. However, this section should be technically refined. The form should be standardized. Names of publications are written in both abbreviations and full names. The abbreviations use “.” as well as without. The year of the manuscript is written in “(...)” as well as without. Authors are given in various forms.
Authors’ response: The references are now revised following the Journal Style.
Good luck
Authors’ response: Many thanks to the reviewer.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsRevised version is acceptable. Minor English editing is required.
Comments on the Quality of English Language
Minor editing of English language required.
