Soil Nitrogen Sorption Using Charcoal and Wood Ash
Round 1
Reviewer 1 Report
Comments and suggestions
Authors: Nur Hidayah Hamidi, Osumanu Haruna Ahmed, Latifah Omar, Huck Ywih Ch’ng
Title: Soil Nitrogen Sorption using Charcoal and Wood Ash
Manuscript number: agronomy-1227365
Summary of the manuscript
The manuscript reports the use of charcoal and ash in acid soils as adsorbents to improve the nitrogen availability and improving their soil fertility beside crop productivity.
The manuscript is the original review paper of the authors. The subject of the manuscript is interesting and current.
The theme of the manuscript’s scope fits the aims of the journal. This paper is new and valuable contribution to merit publication in an international journal. It is suitable for publication in Agronomy journal. The basic idea of this review was carried out precisely, the study provided large amount of high quality information about on the relationship between acid soils, organic matter and charcoal. The studies very significant because it is presents the results of many information.
The Abstract is concise enough. It is summarizes the essence of the manuscript. It summarizes the contents of the entire manuscript in a clear and concise way.
Keywords are well chosen, make the manuscript searchable, there is no overlap with the title of the manuscript.
In my opinion, this review manuscript summarizes very well the possible effects of charcoal and soil.
Introduction
This chapter supports and complements the research topic of the manuscript. Appropriate and timely references are built in the introduction chapter. The chapter detailed and processed, in my opinion, it is a well-structured chapter. This chapter covers the most important areas of the entire topic of the manuscript.
It would be useful to add some new ones to the used literature. Some additions would be needed to the chapter. I suggest some more references:
Line 73 write after " to decomposition" Kocsis et al. 2018: Time-lapse effect of ancient plant coal biochar on some soil agrochemical parameters and soil characteristics. Environmental Science And Pollution Research 25(2). This publication mentions the degradation of charcoal (biochar) in soil.
The end of the chapter adequately mentions the objective of the research. The objectives are realistic and well defined.
The other chapters adequately mention the details of the chosen topic, summarizing the experience. However, reading it is like reading a textbook. It is important to note that this "summary" study is very gap-filling, definitely necessary and useful.
Its weakness would be mentioned so that it would be very useful to mention in the manuscript, for a short chapter, some of the risks of charcoal (biochar) (in addition to the many benefits mentioned earlier). I am thinking, for example, of the environmental risks associated with production; or when during incineration (and pyrolysis) harmful substances are formed due to insufficient incineration, e.g. PAH compounds.
The tables are necessary and useful for the presentation of the information’s.
The figures is illustrative, practical and definitely needed for illustrate the results and the statements.
The manuscript is suitable for publication after a few above-mentioned minor revisions.
Great job! I wish further success to the authors.
Author Response
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Reviewer 2 Report
The work deals with an important and current topic. The work was prepared on the basis of large amount of literature. The topic was comprehensively developed.
Author Response
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Reviewer 3 Report
The manuscript is about the use of charcoal and wood ash in tropical acid soil. The hypothesis is that these materials can improve the soil N availability. The question is a relevant question although tricky to deal with as it is only aspect, and possible a minor aspect of using charcoal and wood ash in soils. As a result the authors use 865 lines before eventually coming to the hypothesis they want to discuss. But this discussion is less than one page, is not quantitative, and therefore not interesting for the readers. More importantly, it is not critical or up to date. Of course many aspects can be discussed in a review, but it should, as MDPI states „Reviews: These provide concise and precise updates on the latest progress made in a given area of research. ...“. The current manuscript is not concise, and does not give updates on the latest progress. Most aspects can be read in textbooks, and the current manuscript does not a add a update as most aspect are discussed only a little and not quantitively. Previous reviews about this hypothesis have been given also in Agronomy, and these are not mentioned, and are in my opinion, better. For example: A Review of Biochar and Soil Nitrogen Dynamics. https://doi.org/10.3390/agronomy3020275. Also other reviews on biochar or woods ash in relation to nitrogen, also in Agronomy, are not mentioned by the authors.
I think the authors want to discuss the relevance of charcoal and wood ash for acid soils in Malaysia. In that case, for a review, they should not be looking specifically into nitrogen sorption. If you want to know more about nitrogen sorption in soils and the possible role of these materials, then specific experimental studies, such as recently published ( Evaluation of biochar effects on nitrogen retention and leaching in multi-layered soil columns DOI: 10.1007/s11270-010-0366-4 , DOI: 10.17221/276/2020-PSE) are more to the point. The study of Ding et al (2010) has exactly the same hypothesis as the authors, is from 2010, and is also not mentioned by the authors. Also the effect of biochar on nutrient retention in tropical soils has been studied in detail: DOI: 10.1016/j.geoderma.2018.09.043.
Author Response
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Reviewer 4 Report
The topic is current and presents important and useful elements, necessary for the application of a correct soil management, in terms of the correct realization of plant cultivation technologies, with economic efficiency and the practice of a sustainable agriculture. The paper is well structured, presents many details, the expression is clear and brings useful and up-to-date information in the field.
Author Response
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Reviewer 5 Report
The manuscript entitled "Soil Nitrogen Sorption using Charcoal and Wood Ash" describes : (1) effects of charcoal and wood ash on the sorption behaviour of inorganic N, and (2) mechanisms that can be used to improve N availability by charcoal and wood ash. The manuscript is well-written and well organised. It can be very useful for researchers working in the field of charcoal and wood ash application in acid soils. In my opinion, the paper can be accepted for publication in the Agronomy after minor revisions. In particular, since the paper is quite long, some sections can be shortened or condensed. In addition, in the conclusion section, a critical evaluation of the advantages and limitations of the existing techniques, the future perspectives and the expected outcomes in the field of soil nitrogen sorption using charcoal and wood ash are necessary and strongly recommended.
Author Response
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Round 2
Reviewer 1 Report
The authors corrected the manuscript accordingly. The previous version of the manuscript was corrected based on my previous review, the suggestions and comments were reviewed in detail, and the manuscript was amended accordingly.
With these changes and additions, the manuscript is suitable for publication in the journal. I have no further suggestions or requests for amendments to the manuscript.
I definitely recommend the manuscript for publication.
Thank you, excellent work.
I wish the authors much more success!
Author Response
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Reviewer 3 Report
I rejected the previous manuscript as I think it is not concise and does not give update on the latest progress. My advice was to give a different focus to the manuscript: towards the overall merits of using biochar and woodash in Malaysia, and not focus on nitrogen sorption. This new version has basically not changed. The authors just do not give a very good overview of nitrogen sorption to these materials. I will give some arguments for this.
The manuscript is about many things but hardly about „soil nitrogen sorption“. None of the soil chemical tools to determine and quantify sorption are quantified in this study: affinity constants, surface area, micropore volume, sorption isotherm, adsorption maxima. The only aspect mentioned by the authors is that various type of mathematical equations are used for adsorption isotherms. If this manuscript would be about nitrogen sorption I would certainly expect an overview of various Kd, PZC, BET surface areas, experimental adsorption isotherms, for example from the here mentioned studies (Hale et al., 2013; Wang et al, 2015; Yin et al., 2018). Surface groups have been identified using various types of spectroscopy (NMR, FTIR, XPS, EXAFS) or acid-base titrations (Boehm et al., 1994; Li et al 2017; Mia et al, 2017). This simple approach to review the current literature is lacking in the current manuscript. But most importantly for NH4 adsorption in a soil environment is the competition with the other cations. Therefore basic data from leaching experiments using soil and biochar are already relevant (for example Iqbal et al, 2015). This quantitative approach is also lacking in the manuscript. It is therefore not interesting, and not up to date.
Hale et al 2013. DOI: 10.1016/j.chemosphere.2012.12.057
Wang et al 2015 Chemosphere DOI: 10.1016/j.chemosphere.2014.07.084
Wang et al 2015. DOI: 10.1016/j.chemosphere.2015.05.062
Yin et al. 2017 DOI: 10.1007/s11356-017-0778-4
Iqbal et al.,2015 DOI: 10.1016/j.scitotenv.2015.03.060
Boehm et al., 1994 DOI: 10.1016/0008-6223(94)90031-0
Li, et al 2014, DOI: 10.1021/sc500432d
Mia et al 2017 DOI: 10.1021/acs.est.7b00647
Author Response
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