Chemical Speciation of Trace Elements in Soil Fertilized with Biomass Combustion Ash and Their Accumulation in Winter Oilseed Rape Plants
Round 1
Reviewer 1 Report
The MS titled “Chemical speciation of trace elements in soil fertilized with biomass combustion ash and their accumulation in winter oilseed rape plants” has scientific relevance and quality to be published in Agronomy Journal. The MS title reflects the content of the article. The MS presents the results of original research that are of scientific interest and practical significance, besides the topic is very relevant. Generally, the work is easy to understand. However, there are relatively high number of remarks, which need to be addressed before its publication.
It is not recommended to use abbreviations without deciphering, especially in Abstract as well as Keywords:
Abstract. P. 1, line 16 – BCR, lines 20, 25, 26 – F1, F2, F4.
P. 1, line 19 – the given data on the total content of chromium and nickel in the ash do not correspond to the data in Table 1 (the values are confused).
Keywords. It is not recommended to include the words used in the title of MS.
Introduction
P. 2, line 69. The authors consider zinc as one of the toxic elements, but it is known that copper is a more toxic metal than zinc, however, this information is missing from the text.
P. 2. There is no clear statement of the purpose of the study. What is the exact gap in the knowledge that your study hopes to fill? In my opinion, the wording of the aim does not fully correspond to the title and content of MS.
Materials and Methods
P. 3, lines 124, 125 – the information about F1–F4 is a repetition of the information previously given (P. 2, lines 78–80).
In Statistics the number of measurement replicates was not reflected (n = ?). If their number differed, then it is desirable to show this information in tables and figures.
Results
The authors presented quite a lot of figures and tables, which illustrate the work well. On the other side, 7 Tables and 14 Figures are too much (overkill)! It is desirable to reduce this amount either by arranging (combining) some illustrations, or transfer part of them to Supplementary materials.
P. 3. The caption under Figure 1 (Meteorological conditions…) erroneously contains the number 2. The link in the text to this Figure is also wrong (line 103).
P. 4. There is no uniformity in the listing of metals in the heading to Table 1 (Zn, Cu, Cr, Ni, Pb, Cd) and in the Table itself (Zn, Cu, Ni, Cr, Pb, Cd). It is recommended also to unify the order of listing metals in other sections of the MS (lines 14, 19, 82, 88 etc.). In addition, the data in Table 1 do not have units of measurement.
Figure 2 illustrates the information given in Table 1. At the same time, for four metals (Zn, Cu, Pb, and Cd) there is a correspondence between the data of the Table 1 and Figure 2, but for Ni and Cr there is an obvious confusion!
The figure captions (Figures 3–14) are made incorrectly: it is necessary to decipher each figure marked with a letter (at first A, then B etc.) but not to use A–D.
Also, there are typos in the sentence: D1-D5 – doses of BAs: 0.5, 1.0, 1.5, 2.0, and 2.5 Mg ha-1.respectivielly (extra letters), captions under Figures 3–14.
In subtable captions (Table 2–7), it is also necessary to correct typos in the word “respectivielly”.
Discussion.
P. 20, line 506: no need to re-enter and re-decipher the abbreviation TEs.
P. 20, lines 512–513: “TEs are not degraded and converted into harmless forms through microbiological and chemical transformations but persist for a long time in the environment”.
P. 20, lines 514–515: “After deposition in soils, they (TEs) undergo various transformations depending on soil properties”.
In my opinion, these two sentences contradict each other. Thus, the reframing of these sentences is required for better clarity.
P. 21, line 526: The legitimacy of the statement about the low level of Pb in the ash that was used as fertilizer raises doubts, since its total amount was even higher than that of chromium.
P. 22, line 574: The reference to the source is incorrectly given (the number of the source must be indicated in square brackets rather than year).
There are a lot of typos and inaccuracies in the text of MS. The review highlights only a few of them. It needs numerous modifications and substantial changes to fit the requirements of the Journal MDPI. For example, in references it is necessary to write Table rather than Tab., Figure (in full) but not Fig. etc.
Conclusion: I recommend the publication of the MS “Chemical speciation of trace elements in soil fertilized with biomass combustion ash and their accumulation in winter oilseed rape plants” in Agronomy Journal after serious revision.
Author Response
Dear Reviewer 1,
The authors are grateful for the contribution of the reviewer. Numerous errors were removed and various sections of the manuscript were improved.
Please see the attachment.
Best regards
Authors
Author Response File: 
Author Response.pdf
Reviewer 2 Report
1. Explain the meaning of F1, F2, F3, and F4 in the abstract.
2. The innovation of this article should be explained in the introduction.
3. In article 2.3, the risk degree is determined according to the value of the RAC. Please explain the specific risk.
4. In Annex S1, what is the reason for choosing 70% forest biomass and 30% agricultural biomass? Why not choose another ratio? It should be explained in the text.
5. Supplement the preparation conditions for biomass combustion ash and the use mode of biomass combustion ash in soil in the annex.
6. What is the basis for adopting 20 plants in each region? Random selection, or selection based on certain conditions? Please explain in the attachment.
7. The contents of elements in BAS under different forms are analyzed in Appendices S1 and 3.1, but there are five biomass combustion ashes (D1-D5) with different amounts in this paper. Which group is analyzed in S1 and 3.1? Please explain in the text. Whether the amount of biomass combustion ash will cause the doubling of element content or there will be a great difference is need to be analyzed.
8. The content changes of elements Zn, Cu, Cr, Ni, Pb, and Pd in different forms are given in 3.2, 3.3, 3.4, 3.5, 3.5 (repeated), and 3.6. Please analyze the reason for the change of element content in soil with different biomass combustion ashes (D1-D5) under the same state.
9. Two headings 3.5 appear in the text; please correct them. In addition, other parts of the article should meet the format requirements of the journal.
10. In article 3.7, the same element content tested in different parts of the winter oilseed rape plants is different. Please analyze the reasons for the different elemental contents in combination with the literature. In addition, the addition of different amounts of biomass combustion ash causes the change of the same element in the same part of the winter oilseed rape plants. Please analyze the reasons in combination with the literature.
11. In the discussion, the mobility and bioavailability of trace elements are affected by soil pH, and the addition of different amounts of biomass combustion ash will cause changes in soil pH. Please supplement the data on soil pH and analyze the change in different element contents in combination with the change in soil pH.
Author Response
Dear Reviewer 2,
The authors are grateful for the contribution of the reviewer. Numerous errors were removed and various sections of the manuscript were improved. Please see our responses in the attachment.
Best regards
Authors
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear authors! Thanks to the changes made, the content of the article improved, but not all comments were taken into account. As noted earlier, there is no correspondence between the data of Table 1 and Figure 2 in terms of nickel and chromium. Apparently, their histograms in Figure 2 are confused (if the tabular data are correct). Accordingly, in the text on page 5, much does not match the table, for example:
Page 5:
L. 173 : Cr instead of Ni;
L. 175: Ni instead of Cr, ans instead of and;
L. 177: Сr instead of Ni;
L. 178: Ni instead of Cr
Author Response
Dear Reviewer 1,
Thank you very much for the detailed indication of shortcomings in the manuscript text. The manuscript was significantly improved. Please find in the attachment our responses.
Best regards
Authors
Author Response File: Author Response.pdf
Reviewer 2 Report
I commend this paper published in the journal of Agronomy.
Author Response
Dear Reviewer 2
Thank you very much for the positive evaluation of our manuscript.
Best regards
Authors
Author Response File: Author Response.pdf
