Predicting the Base Neutralization Capacity of Soils Based on Texture, Organic Carbon and Initial pH: An Opportunity to Adjust Common Liming Recommendation Approaches to Specific Management and Climate Conditions

Round 1

Reviewer 1 Report

The authors developed the Pedotransfer function to calculate the lime requirements required to change the initial pH to the desired pH, and compared the results with recommendations for dusting in agricultural practices. By comparing the numerical difference between the lime requirement for the lime spreading recommendation and the Pedotransfer function, the annual acidification rate can be calculated based on soil texture, organic matter content and initial pH. This work may help to optimize ash dispersal recommendations by adapting to different regions, diverse management measurements, and changing climates. However, there are still some problems that need to be explained and modified:1.

1."Ca (OH) ₂" as a chemical name, in the lines 198, 199, 201 and 206 of the page 6, should not be indicated in italics.

2.There are some ambiguities in the English writing of the article, and the sentence is very long, which makes the reader feel jumbled and difficult to understand. It is suggested that the author check and revise the English expression of the whole article, and break down the long and difficult sentences.

3.Figure 3 in the page 8. Why are there borders around it? Improved clarity is also recommended.

4.Please give a detailed introduction and origin of Eq.(4).

There are some ambiguities in the English writing of the article, and the sentence is very long, which makes the reader feel jumbled and difficult to understand. It is suggested that the author check and revise the English expression of the whole article, and break down the long and difficult sentences.

Author Response

Author's Reply to the Review Reports

Review report 1

1."Ca (OH)" as a chemical name, in the lines 198, 199, 201 and 206 of the page 6, should not be indicated in italics. The suggestion was considered.

2. There are some ambiguities in the English writing of the article, and the sentence is very long, which makes the reader feel jumbled and difficult to understand. It is suggested that the author check and revise the English expression of the whole article, and break down the long and difficult sentences. I wonder about this comment because the English language of the article was edited by the American Journal Experts before submission. Additionally, reviewer 3 commented: English is good - only a minor check is necessary. Nevertheless, the English language was again edited by a native speaker and long sentences were break down.
3. Figure 3 in the page 8. Why are there borders around it? The borders of Fig. 3 were removed.

Improved clarity is also recommended. The data shown in this figure are divided in four SOC classes – each of them is clearly visualized by specific colors and symbols. Additionally, the effect of MPD and pH0 is shown for two examples with corresponding markings and descriptions. Therefore, it is difficult to understand the intention of the reviewer regarding the clarity – I’m missing his suggestion. However, we made some changes in the caption of the figure – hoping it contributes to more clarity.

4. Please give a detailed introduction and origin of Eq. (4). To analyze the relationship (positive or negative, linear or non-linear, if non-linear: logarithmic or exponential) is a fundamental part of data analyzes. As I wrote in the result section, a regression model shows the relationship of the dependent variable to the independent variables. How can I describe better?

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

please read my suggestions:

1.       Authors’ affilitations: I do not understand the criteria for the numeration.

2.       Title: delete the hyphen and insert colon after “initial pH”.

3.       Abstract: add numerical results for the sentences at lines 38-40.

4.       Introduction. Add some relevant information about liming change after application on soils referring to some case studies reported in the scientific literature (Lines 47-51). Lines 69-71: those examples “e.g.” should be reported in parenthesis. Line 76: what is BAD? The reference is in German and it not clear for non-German speakers. Line 109: what is BNC? Explain it and introduce the acronyms when they first appear. Its meaning is located at line 122-123 and that’s not ok. Lines 115-126: I think the goal is not well explained. Try to fit it better in the context of state of art and add more relevant information.

Materials and Methods. Pr. 2.1: what is the soil classification in terms of taxa as reported by WRB or USDA? It is very important for similar studies as the soil taxon gives you immediate information about the possible content of carbonates.In addition, I think you should consider the initial quantity of carbonates inside your soils (both total and active) in order to be really sure that your treatments can work well and all the analysis is reliable. Please add this pivotal information.

5.       Lines 163-167: What software did you use for the prediction models? Line 180 and 222: what is MPD? What is EXP? Explain them and introduce the acronyms when they first appear.

6.       Results and Discussion. Give more emphasis to the pedotransfer function that you created. It seems that you used one already reported elsewhere.

The manuscript needs English revision.

Author Response

Author's Reply to the Review Reports

 

Review report 2

1. Authors’ affiliations: I do not understand the criteria for the numeration. Sorry for this, we changed the numeration.
2. Title: delete the hyphen and insert colon after “initial pH”. Done
3. Abstract: add numerical results for the sentences at lines 38-40. We added: “In the result, the lime demand to change the initial to the desired pH increased by approximately 1/6 of the lime demand proposed by the liming recommendation scheme, that is commonly used in Germany.”
4. Add some relevant information about liming change after application on soils referring to some case studies reported in the scientific literature (Lines 47-51). The lime requirements to change a currently measured soil pH to an optimum pH value depend mainly on soil texture and soil organic matter content as mentioned in the corresponding lines. They are listed in detail in the look-up tables, which serve the needs of lime fertilization in agricultural practice since decades in the mentioned countries and as explained in this section. Lines 69-71: those examples “e.g.” should be reported in parenthesis. We change this sentence and substituted “e.g.” by “as”. Line 76: what is BAD? The citation form was changed. The reference is in German and it not clear for non-German speakers. We translated the reference and indicated its German origin. Line 109: what is BNC? Explain it and introduce the acronyms when they first appear. Its meaning is located at line 122-123 and that’s not ok. Sorry. Now, all acronyms are defined at their first appearance in the text. Lines 115-126: I think the goal is not well explained. Try to fit it better in the context of state of art and add more relevant information. Hence, the objective of the present paper is to separate the VDLUFA-based calculated lime demand into proportions necessary i) to change the initial pH to the desired pH (Task A) and ii) to compensate acidification processes taking place within the liming interval (Task B).

Materials and Methods. Pr. 2.1: what is the soil classification in terms of taxa as reported by WRB or USDA? It is very important for similar studies as the soil taxon gives you immediate information about the possible content of carbonates. In addition, I think you should consider the initial quantity of carbonates inside your soils (both total and active) in order to be really sure that your treatments can work well and all the analysis is reliable. Please add this pivotal information. We extended Fig. 1 by a soil texture triangle corresponding to the WRB classification. The carbonate content is in relation to our approach non-relevant because we consider the present soil pH (pH₀) in our pedotransfer function (Eq. 3). Soil pH is mostly higher in the presence of carbonates – consequently, less amounts of lime will be recommended. Additionally, the majority of the tested soils has and sandy texture – these soils are carbonate-free under our annual precipitation amounts of ca. 550 mm.

5. Lines 163-167: What software did you use for the prediction models? Line 180 and 222: what is MPD? What is EXP? Explain them and introduce the acronyms when they first appear. Sorry, now all acronyms are defined at their first appearance in the text. “EXP” is a product of the formula editor indicating an exponential term. Such abbreviations are also used in cases of sin, cos, log etc.. To avoid misunderstandings, we applied lower case for this abbreviation in all formulas.
6. Results and Discussion. Give more emphasis to the pedotransfer function that you created. It seems that you used one already reported elsewhere. To successfully create regression models, a carful pre-analysis of the kind of relationship between the dependent variable and the independent variables is necessary (as mentioned above -> review report 1, comment 4). We derived these relationships from the related literature and built our regression model (Eq. 3) on this basis. Both, the kind of the relationship as well as the corresponding literature are given in the first section of “Results & Discussion” dealing with our pedotransfer function. We cannot follow the feeling of the reviewer that “It seems that you used one already reported elsewhere”

Comments on the Quality of English Language: The manuscript needs English revision. The English language was again edited by a native speaker.

Reviewer 3 Report

 

The article is quite interesting. I have only few comments:

1) All the acronyms should be defined at their first appearance in the text, then used in the following without further defining them. Please check.

2) It seems that what is represented in Figure 1 is a soil texture classification, please change the caption; but why not use the USDA classification, more known and widespread worldwide?

3) Why not use mm and cm as unit? It should be clearer, in my opinion.

My main concern is about references: they are insufficient for an international journal, and too many of them are only in German – and please specify the language in all the references that are not in English.

English is good - only a minor check is necessary

Author Response

Author's Reply to the Review Reports

 

Review report 3

1) All the acronyms should be defined at their first appearance in the text, then used in the following without further defining them. Please check. Done

2) It seems that what is represented in Figure 1 is a soil texture classification, please change the caption; but why not use the USDA classification, more known and widespread worldwide? We extended Fig. 1 by a soil texture triangle corresponding to the USDA classification and changed the caption.

3) Why not use mm and cm as unit? It should be clearer, in my opinion. The SI unit of length is meter, therefore, we used “m”.

My main concern is about references: they are insufficient for an international journal, and too many of them are only in German – and please specify the language in all the references that are not in English. The appropriate number of cited references depends on many factors – also on the field of research. To have an idea about the number of references dealing directly with liming and soil pH value, we counted their number in the corresponding papers referred in our paper: Mean value = 36 (19), SD in parentheses. After addition of four further references, our paper has 42 references now.

Regarding the references in German language: The focus in our paper is to optimize lime recommendations. Our reference is the lime fertilization recommendation schema provided by the As-sociation of German Agricultural Investigation and Research Institutions (VDLUFA). It is the most detailed scheme among the recommendation schemes cited in our article. Because most of the research papers dealing with the basics of this scheme were published years ago in the former GDR, they were published in German. The recommendation scheme itself is mainly addressed to German farmers – it is also published in German language as the analysis pH status within the recent German national soil survey. Despite the focus on the German recommendation scheme, our article has international relevance because the results are related to properties of soil (pH, texture, organic matter) and climate (climatic water balance).

Comments on the Quality of English Language: English is good - only a minor check is necessary

The English language was again edited by a native speaker.