Agroecological Transformation in the Salt Composition of Soil under the Phosphogypsum Influence on Irrigated Lands in Ukraine

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

This revised manuscript has been substantially improved, and I have no further comments.

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Agroecological transformation in the salt composition of soil under the phosphogypsum influence on irrigated lands in Ukraine (Agriculture-2887759)

We appreciate the reviewers' thorough reconsideration of our updated manuscript. We've strived to integrate any additional suggestions and feedback provided during the second review stage to the best of our ability. All pertinent modifications are now indicated in green throughout the text.

 

Responses to comments on review 1

 

This revised manuscript has been substantially improved, and I have no further comments.

Minor editing of English language required.

 

Response

Thank you very much.

Minor adjustments to the English were made.

 

Reviewer 2 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

          This is my second review, the authors have made some progress. Please refer to my   further observations:

The content in the introduction should be organized in terms of the importance of the research conducted and the presentation of achievements in this topic, and the presented patterns related to the circumstances should be included in the methodology.

 

Please indicate in which years the research was performed.

 

What new scope of research was undertaken in relation to the article published by the authors relating to irrigation; salinization; phosphogypsum, Prevention of degradation processes of soils irrigated with mineralized water through plastering: D Onopriienko, T Makarova, A Tkachuk, H Hapich, H Roubik, Ukrainian Black Sea Region Agrarian Science Vol. 27, No. 2, UDC: 631.42 DOI: 10.56407/bs.agrarian/2.2023.09

 

In tables, use symbols instead of descriptions, more, less.

 

Tables 1 and 2 supplement with the source of information. Additionally, the data presented in Table 1 are average .values and should be supplemented with SD.

 

Use uniform terminology throughout your work in tables, figures and text.

 

Correct the layout of tables 6 and 7 to improve their readability.

 

The layout of the work should be improved, the paragraphs used make the work difficult to read.

 

The concept of presenting the results in Figures 2 and 3 should be reconsidered, especially since the description of the variability of the examined parameters in the text is based on average values from 5 years.

 

Please present the probable mechanism of the influence of the studied factors on the parameters, what may be the causes of the obtained variations in individual years and the experimental variants used.

 

Ultimately, there is no reference as to which of the tested variants is the most optimal from the point of view of the soil.

Author Response

Responses to comments on review 2

 

Comments and Suggestions	Corrections
Please indicate in which years the research was performed.	We specified and added a list of research years to the text of the article and in the table – 2014, 2015, 2016, 2017, 2018.
The content in the introduction should be organized in terms of the importance of the research conducted and the presentation of achievements in this topic, and the presented patterns related to the circumstances should be included in the methodology.	Several literary sources have been included in the article's introduction to underscore the significance and timeliness of revitalizing chernozem soils affected by extended irrigation with poor-quality water. Further sentences have been crafted integrating these literary references.
What new scope of research was undertaken in relation to the article published by the authors relating to irrigation; salinization; phosphogypsum, Prevention of degradation processes of soils irrigated with mineralized water through plastering: D Onopriienko, T Makarova, A Tkachuk, H Hapich, H Roubik, Ukrainian Black Sea Region Agrarian Science Vol. 27, No. 2, UDC: 631.42 DOI: 10.56407/bs.agrarian/2.2023.09	The provided material now includes an additional two years of field and laboratory research, which validate earlier findings and support the role of phosphogypsum in diminishing both absolute and relative indicators of salinity in irrigated chernozem soils over an extended duration using subpar water quality.
In tables, use symbols instead of descriptions, more, less.	It is taken into account. Fixed in tables
Tables 1 and 2 supplement with the source of information. Additionally, the data presented in Table 1 are average .values and should be supplemented with SD.	It is taken into account. The standard deviations (SD) have been included in Table 1, following water sampling and analysis conducted by the authors. These findings are corroborated by other research [12], focusing on the overall mineralization level of the Samara River (an irrigation source). Furthermore, data from specialized laboratories of the Regional Office of Water Resources in the Dnipropetrovsk region, engaged in ongoing water quality monitoring, were incorporated and cited as a reference [83].   Table 2 data originate from the meliorator's passport (product certificate) without independent investigation, hence precluding the inclusion of SD. This information is presented as an additional reference for the literature utilized [84].
Correct the layout of tables 6 and 7 to improve their readability.	To enhance understanding, we have included and detailed the years of conducting the research in tables.
The layout of the work should be improved, the paragraphs used make the work difficult to read.	Compiling research data is challenging due to the extensive amount of information required to assess the ecological and agroameliorative condition of irrigated soils, using standardized indicators and normative parameters.
The concept of presenting the results in Figures 2 and 3 should be reconsidered, especially since the description of the variability of the examined parameters in the text is based on average values from 5 years.	To enhance the quality of information in figures 2 and 3, we have included the average deviation values (5%).
Please present the probable mechanism of the influence of the studied factors on the parameters, what may be the causes of the obtained variations in individual years and the experimental variants used.	The determined trends in the alterations of indicators and physicochemical properties of irrigated typical chernozem under varying levels of ameliorative interventions.
Use uniform terminology throughout your work in tables, figures and text.	It is taken into account.
Ultimately, there is no reference as to which of the tested variants is the most optimal from the point of view of the soil.	The text of the article and the conclusions detail the commentary on the most favorable methods of utilizing phosphogypsum as a soil ameliorant on degraded chernozem soils.

 

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The submitted work “Ecological and agronomic features of using phosphogypsum on degraded chernozem soils in Ukraine under conditions of prolonged irrigation” by Onopriienko et al. discusses the use of phosphogypsum to improve the ecological and agronomic features of degraded chernozem soils in Ukraine under conditions of prolonged irrigation. The research evaluates the agroecological condition of soils and recommends meliorative doses of phosphogypsum to improve soil conditions. The study found that the use of phosphogypsum can improve soil structure, increase soil fertility, and reduce soil salinity. The recommended doses of phosphogypsum depend on the initial soil conditions and the desired outcomes. The research also highlights the importance of sustainable agricultural practices to prevent soil degradation processes in irrigated lands.

 

Interesting research work but it has the following TWO critical serious issues:

1. The absence of detailed statistical analysis in the text is a significant limitation. This omission hinders our comprehensive assessment of the study's methodological rigor and the statistical significance of its findings. For instance, the text mentions that 'The experiment was repeated four times with systematic plot placement' (line 148), but it fails to provide further statistical details. Such information is crucial for understanding the reliability and replicability of the results. Without it, the validity of the conclusions drawn from the experiment remains questionable.

2. It was crucial to include data that demonstrates the impact of phosphogypsum application on soil quality and salinity management, particularly through soil analyses conducted at various depths. Such comprehensive analyses would offer a deeper understanding of the phosphogypsum's effectiveness and the dynamics of soil salinity throughout different layers. This could have allowed to assess the extent of salt leaching with the used amendment. Additionally, the paper does not mention the depth at which the soil samples used for analysis were collected.

 

Additionally, the following are other critical questions that need to be addressed:

Line 44: with water of low mineral content high quality. “High quality”?

Line 57: water is classified into three quality classes: I – suitable, II – limited suitability, III – unsuitable. According to what?

Line 113: What the full soil classification of these soils. – A least to the subgroup level.

Line 116:  Based on the amount of toxic salts (0.48%), the soils are classified as moderately saline [33, 34]. Why the standard soil salinity categories classification criteria of ECe, ESP, SAR, pH, etc were not used?

Line 118: Salinity type in the research areas is sulphate and sodium. For sodium, is this referred to Sodium carbonates?

Line 121: mg/l Liter should always be capitalized as “L”

 

Line 124-125: In a moist state, the soil is highly plastic, sticky and swells significantly; it easily forms aggregates. Was there any swelling test? What types of clays?

Line 128: Mineralisation of irrigation water ranged from 2.3 to 3.1 g/l [12] and varied significantly. What method was used to determine mineralization of irrigation water? Also, What is the quality of this irrigation water i.e. other parameters such as EC, pH, ionic composition, etc.?

Line 206: The results of the chemical composition of water extract in meq/100 g of soil for the years of observation are presented in Table 2. What method of Extraction (Soil; Water) 1:1, 1:2, 1:5 or saturated paste?

Comments on the Quality of English Language

Most of the statements were well written, with no major problems in the English or grammar.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript presents the results of a plot experiment aimed to examine the effects of soil irrigation with saline water on soil salinity parameters and the co-occurring effects of phosphogypsum applied at different doses on these parameters. As a background to the research, the problems of soil degradation in Ukraine, especially soil increasing salinity, was described quite extensively, taking into account the dramatic changes related to the Russian-Ukrainian war in the last two years.

These issues seem quite important, so the results of research focusing on this topic should be considered worth publishing. However, the scientific level of this manuscript is very poor and I believe that it should be thoroughly rewritten, re-edited and corrected. Only then will it be eligible for review.

My most important comments are:

1. The title is incorrect and actually misleads the reader. The term "Features" should be used as a distinctive attribute of something. What are these features about? Soils? Water? Crops? The title should be clarified. It would also be good to clearly indicate in the title that the subject of the research was the extraction of salts from soils.

2. The text is ordered very chaotically. Some fragments included in the methodology and in the discussion of the results should be included in the introduction, because without them the purpose of the work and the assumptions made are not clear. In particular:

-          - L. 70: Information on the use of gypsum for amelioration of saline soils should be supplemented with the description of mechanism of how gypsum reacts in saline soils and provision of appropriate references. The fragment on this topic included in the discussion L. 341-353 should be moved to the introduction

-          Prior to L. 84, where authors write about the effects of possible application of phosphogypsum to soils, it will be definitely required to characterize phosphogypsum in terms of its composition and general properties

-          Various methods that can be applied to assess the rates of soil amendments should also be presented and discussed (!) in introduction, and not in the section “Methods”. The related paragraph: L. 159-180 should be moved to introduction.

-          The factors which allow the use of phosphogypsum to improve ecosystem services, mentioned in the summary of discussion (L. 398 and hereinafter L. 399-410),  should definitely be included in the introduction to the article, as assumptions for the experiment, but certainly not in the discussion and summary of the results. The statements listed here (L. 399-410)  have nothing to do with the results of the experiment.

-          Experimental methods should be described more clearly and systematically (see below)

3. The description of research methodology is unclear and incomplete. Many aspects require clarification. In particular:

-          Research plots should be characterized in more detail (and the information that the research was conducted as a plot experiment should be provided right at the beginning of the description of the methodology). The location of the research object should also be described in more detail. There is no information whether it was a strictly planned, random, experiment and whether soil properties were examined before setting up the experiment. Soil data is given, as I understand it, based on average data for some large region (what region, references ???). It is not known how representative the provided values are for the research object. It is also unknown how long the irrigation lasted? (the abstract states that it wass over 50 years, but there is no such information or references in the text).

-          The description of methodology lacks information about the statistical methods used to determine the significance of differences between variants. It is not clear whether the experiment was performed in replicates. The text (L. 148) "The experiment was repeated four times with systematic plot placement" is unclear. This needs to be clarified. Without information about the statistical significance of differences, the term "significant" cannot be used (e.g. significant reduction, L. 288, etc.). Moreover, the charts and tables should indicate groups that do not differ statistically significantly.

-          L. 113-115 The methods applied for determining soil properties should be at least briefly described, because the references 31 and 34, as well as 36, are unavailable to international readers. Additionally, the classification should be provided according to which the soil was classified as "light loamy" (L. 114). An appropriate soil textural group should be provided according to the commonly used classification (e.g. USDA accepted by FAO-WRB).

-          How was the sum of exchangeable cations in the soil sorption complex calculated, presented in the description of the results??? (L. 304 and further). One could guess that the reference 35 (Ukrainian) contains the number that indicates the ISO standard, but this number was used in the past as the standard regarding soil salinity, and not the examination of soil sorption complex.

-          This research is in fact focused not on soil examination, but only on water extracts. However, it is not known how these extracts were obtained. The reference 36 is not available to international readers. Was overhead shaking or percolation used? What were water:soil ratio and time (or conditions) of extraction?

-          There is no information about the methods used to determine the concentrations of cations in the extracts and whether validation of analytical methods was used? What was the range of analytical uncertainty? And was it justified to provide the results with 5 significant digits? (e.g. Table 2). This all needs to be explained!!!

-          Information about radiation measurements (L. 390-394) should be indicated in Methods and the method applied  should be described or referred to.

-          - The SAR (sodium adsorption ratio) parameter presented in the discussion (L. 277, figure 3) should be explained, a reference should also be provided and the method of SAR calculation in the particular case of this study should be provided.

4. There are many terminological ambiguities in the manuscript. The most important of them:

-          L. 45, L. 70 and further: The terms "black soil" and "chernozem soils" (L. 103, 110) are colloquial terms, imprecise in the scientific sense. They should be supplemented with scientifically-based terms (e.g. providing the soil group according to FAO-WRB, along with the relevant classification source)

-          L. 156, 204 etc… What does the term "toxic salts" mean? It should be clearly defined.

-          The graph (Fig. 2) shows eCl, meq and toxic salts,%. It's not clear what these results are. Such parameters have not been defined anywhere. Clear definitions should be provided when a particular term is first introduced.

5. My doubts regarding the interpretation of some data:

-          - L. 112. The humus content in the ploughed layer: 2.5% (L. 112) is very low. I wonder why the authors classified this soil as "black" soil or "chernozem"? The method used to determine the humus content should be provided, as well as the number of replicates of the analysis and the significance range for this value.

-          Soil pH is one of crucial parameters that decide on the stability of soil aggregates. The data on soil pH should be provided (in particular in the cases of phosphogypsum-amended soils, because this material is usually highly acidic)

-          L. 137 A reference for the assessment of agricultural suitability and „Norm indicators” in Table 1 is definitely required !. Additionally, pH of phosphogypsum should be provided

-          L. 157-158. Reference required for the assessment of non-saline and weak-salinity soils

 

6. Other important comments:

-          It is unclear whether Table 3 shows "exchangeable Na+" or "the sum of exchangeable cations". This needs to be clarified and corrected. The discussion should also briefly comment on the fact that the sum of exchangeable cations remained unchanged throughout the experiment

-          Conlcusions: they are essentially a summary of the results, without a clear message as to how appropriate and safe the use of phosphogypsum can be considered - and under what conditions. The last conclusion has nothing to do with the research conducted.

7. Technical and editorial comments

-          There are several linguistic errors and unclear statements in the text that require correction, e.g.:

o        L. 40: Plural or singular,

o        L. 44: Unclear: “low mineral content high quality”

o        L. 51: Unclear: “physical and moral wear of reclamation infrastructure”

o        L. 113: clayy forest soil

o        A unit „meq” should be replaced by mmol(+) according to SI (L. 119, 163 and further – 26 cases !)

o        L. 335: preventing water filtration losses of water

 

-          Editorial flaws:

o        Decimal commas in data (Tables, figures, text) should be replaced by dots

o        There should be superscripts: km2 – L. 41, m3 - L. 132

References – descriptions need to be unified and some of them need to be supplemented. This applies to the formal arrangement of information and, for example, the use of initials or full names of authors, shortened or full titles of journals, names of publishers of books and brochures (e.g. No. 10, 11, 17, 23, 30 etc...)

Comments on the Quality of English Language

There are several minor errors

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

1.   The abstract should be improved

2.   I suggest presenting the soil properties in a table. Climatic conditions are also important

3.   For table 2 - provide the source of information for the given properties, the specific value of the parameter defining the "aggregate state", do not use, -not less, no more-, use another way to define limit values

4.   Why were different fertilization dates used at different doses, what criteria were used - line 146

5.   How many experiments were performed, I understand that in different plots, therefore, the soil conditions could be different, which may ultimately affect the results obtained - line 147

6.   Where were the plots located, in what place, region and in what years was the experiment carried out

7.   The presentation of results in the form of tables and figures should definitely be improved, as well as the style of work organization

 

General comments:

Methodology and work organization must be improved.

The topic of the work is important, but in its current form I do not see any new elements. This topic is repeated in 3 articles already published by the authors. One of them was not cited in this publication "Prevention of degradation processes of soils irrigated with mineralized water through plasterin". Ukrainian Black Sea Region Agrarian Science Vol. 27, No. 2. DOI: 10.56407/bs.agrarian/2.2023.09.

The authors should develop a new approach, taking into account their experience and the importance of the subject matter.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Please find my comments below 

Line41 :  In km2 … 2 should be superscript

Line 42: Please write the full form of FAO. Authors should provide the full form of abbreviation wherever first time any abbreviation or short form use/come.

Line 112: Please correct the spelling of clayy … it should be clay

Line 114:  In cm3 … 3 should be superscript

Line 131:  In m3 … 3 should be superscript

In figure 1, 2 and Table 1, 2 authors used the letter such as C, Ci, M, M_1.4 etc.  Please explain what does it mean or provide the full form of all the letter at the end of table and figure.  Also provide the unit of data given in table 2

In figure 2 author used small e and capital S to represent of data in x-axis. Please explain the mean of its. Also put the scale bar of X and Y axis of the figure 2 and 3.

Line 231, 252, and 276:  Please check and correct the formulas of SO4, HCO3-1, and Na+1.

Line 286:  In am unable to find the value mentioned that is highest value 7.62 in figure and tables. Please check it

Line 288-294: Please provide the reference to justified your statement and interpretation

 Line 304-312: Please provide the reference to justified your statement and interpretation

 

Table 3: Please follow the ditto suggestion as given for table 1 and 2 for putting the full form of letters used in table. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf