Changes in Soil Labile Organic Matter as Affected by 50 Years of Fertilization with Increasing Amounts of Nitrogen

Round 1

Reviewer 1 Report

Specific comments

Please add some basic soils´ properties (e.g. pH, clay particles content, conductivity, CEC).

Line 144, 164, 190 and 209 There are missing space between a number and the unit (28oC),

Line 208 “10-ml” change to 10 ml

 

Line 169 and 193 Do not use , M as concentration you have to use mol L^-1

Line 155 and 175  the “-kt” must in superscript

Figure 2.: “mg kg-1 soil” the “-1” must in superscript

 

Line 159

“SPSS Inc., Sigma Plot 2011” Please correct it and decide which software was used IBM SPSS or SYSTAT SigmaPlot

https://www.capterra.com/statistical-analysis-software/compare/13990-102698/SPSS-vs-SigmaPlot

Reference:

Please use similar DOI format at the references It is not uniform

Example:

https://doi.org/10.1016/0038-0717(94)90085-X

doi: 551 10.3390/su1205173

Author Response

Dear Reviewer,

Thank you for your keen revision of the manuscript

we have responded to all your suggestions and corrected the manuscript accordingly: 

1.Please add some basic soils´ properties (e.g. pH, clay particles content, conductivity, CEC). - the data with basic soil characteristics (pH, clay and CEC) were added into Table 1 after the first revision -

2. Line 144, 164, 190 and 209 There are missing space between a number and the unit (28oC), - corrected

3. Line 208 “10-ml” change to 10 ml- corrected

4. Line 169 and 193 Do not use , M as concentration you have to use mol L^-1 - corrected

5. Line 155 and 175  the “-kt” must in superscript - corrected

6. Figure 2.: “mg kg-1 soil” the “-1” must in superscript - corrected

7. Line 159 “SPSS Inc., Sigma Plot 2011” Please correct it and decide which software was used IBM SPSS or SYSTAT SigmaPlot - corrected

8. Reference: Please use similar DOI format at the references It is not uniform- corrected

Reviewer 2 Report

Attached.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

thank you for your keen revision of the manuscript.

We have corrected the manuscript in accordance with your suggestions.

line 106: the unclear sentence was corrected as "Selected experimental treatments and control plots were arranged in a randomized block design in four replications (a single plot size was 6 × 10 m)"

line 111-113: the sentence was changed as ". In addition, a composite soil sample was taken from the adjacent natural meadow to establish the magnitude of any changes due to the long-term application of mineral fertilizers"

line 132: the sentence was changed for: "Five composite subsamples were taken from each replicate"

line 140: the sentence was complemented: "...organic carbon (OC) was calculated by substracting the mineral carbon from the total amount of carbon"

Lines 280-289: all mentions and data of forest soil was removed from the manuscript (tables, table-titles, and textual mentions). All changes are highlighted. 

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

Dear Authors,

It is an interesting study and novelty.

In the Titile you have mentioned SOM. It might might be difficult to follow as soil organic matter if you use abbreviation.  

Huang et al showed.... - In this sentence what do you mean by SOC?Please elaborate it.

Please elaborate GHG. 

 

 

 

Author Response

Dear Reviewer,

 

Thank you for high scores of the manuscript and suggested corrections.

1. We have decoded the abbreviation SOM in the title
2. We have decoded the abbreviation SOC in the Introduction section
3. We have decoded the abbreviation GHG

Reviewer 2 Report

General comments: This manuscript is well structured, but the page and line numbering are unordered. There are missing paces (28oC), subscripts (CaCl2, CO2, Table 6), Italic types (qCO2,) and Not necessary parenthesis („autumn and spring, respectively) (Table 2)” line 62

Specific comments

Introduction

Missing information and aim what it the purpose the analysis of the two natural meadow and forest soils samples.

Materials and Methods

The basic soils´ properties are missing (e.g. pH, clay particles content, conductivity, CEC).

Why use not use an Elemental analyser to determine inorganic carbon (IC)? Before determining the OC by the elemental analysis, the soil is firstly pre-treated with concentrated H3PO4 acid and left to wait for 12 h to remove the carbonate. After that, the carbon content of the sample can be determined by an elemental analyser.

What is the advantage Scheiber calcimeter?

Do not use N and M as concentration you have to use mol L-1

Equation 1 and 2 will be a better expression, you must use e-kt

I recommend not using C0 at equation 2. you must use a different letter.

MBC: The determination of solutions carbon content of the solutions were not described

Author Response

Dear Reviewer,

Thank you for your keen revision and constructive comments that were accepted. All inconsistencies mentioned as general comments were corrected. 

1. Missing information about the purpose of the analysis of the natural meadow and forest soils samples was added in the Introduction section.

2. The basic soils´ properties (pH, clay particles content and CEC) were added in the Table 1.

3.  Inorganic carbon was analysed according to the protocol accepted in the laboratory of the Institute.

4. Concentrations of the solutions were changed from normality (N) and molarity (M) to mol L^-1.

5. Equations 1 and 2 were corrected as suggested

6. in the equation 2 the C0 was replaced by N_imb

7. method of determination of Microbial biomass carbon was complemented