Impact of NPK, Plant Residue, Soil Type, and Temperature on the Half-Life of Atrazine Herbicide

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

There are some suggested revisions as follows:

 

1. Title

It is suggested to specify the type of temperature here, such as soil temperature or atmospheric temperature.

 

2. Keywords

It is suggested to add the following keywords: ‘half-life’, ‘soil type’, and ‘temperature’, and delete the following keywords: ‘degradation’ and ‘persistence’. To sum up, the final suggested modification of the keywords is: ‘atrazine; half-life; NPK; plant residue; soil type; temperature’.

 

3. Line 56 on page 2

It is suggested to change ‘primary’ to ‘important’, as the situation is not specified here. In some cases, water flow may be the main sink for pesticides.

 

4. Line 74 on page 2

It is suggested to add 'and application method' after' physicochemical properties', as the "concentration" mentioned later does not seem to be a physicochemical property but rather a method of application.

 

5. Line 89 on page 2

It is suggested that the specific longitude and latitude of this location be supplemented.

 

6. Table 1

It is suggested that the case of P in the ‘P value’ of the table be unified. The same applies to other parts of the entire manuscript.

 

7. Figure 1-4

Why are there no letters marked here to indicate whether there are statistically significant differences?

 

8. Lines 224, 229, 233, 234 on page 6, and line 252 on page 7

It is suggested that the names of the researchers in the cited literature be marked to show respect for them.

 

9. Abbreviations

I didn't find "AOAC" anywhere else in the manuscript except for "Abbreviations", so I suggest deleting this.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer, attached is the response document.

Besrt regards.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I have reviewed the manuscript by Elgaber et al. entitled: “Impact of NPK, plant residue, soil type, and temperature on the half-life of Atrazine herbicide” with keen interest. However, the findings presented by the authors fit the Nitrogen journal. The results obtained are interesting. Extrapolating the results to other parts of the world seems difficult to me, as soils would need to be classified using a soil classification system such as the WRB.

 

Specific comments

 

Abstract

Line 40. Delete “at an” at the end of the line.

Line 47. Keywords: replace “NPK” by “NPK fertilizer”

 

Materials and Methods

Lines 89-93 and 95-96. How many composite samples were collected for the study, only one sample divided into five 600g lots, or several?

Lines 94-95. Please replace semicolon (;) by comma (,). Also, add a unit to Ece: deciSiemens per meter (dS/m), milliSiemens per centimeter (mS/cm) or microSiemens per centimeter (µS/cm). In addition to these characteristics, the soil name in a classification system (WRB for example) would allow the results obtained to be extrapolated.

Line 105. Please replace “in [19]” by “in AOAC [19]”

Lines 109-110. Please replace semicolon (;) by comma (,). Also, add a unit to Ece: deciSiemens per meter (dS/m), milliSiemens per centimeter (mS/cm) or microSiemens per centimeter (µS/cm). In addition to these characteristics, the soil name in a classification system (WRB for example) would allow the results obtained to be extrapolated.

Line 114: delete the comma after et al. In addition, et al. should not be in italics.

Line 127-131. More details would be important for this work. You choose one-way factor analysis of variance (ANOVA). Before performing the analysis, did the data follow a normal distribution? If so, you are right to perform this analysis. If not, have you normalised the data? If so, how? All these questions deserve answers, and the reader needs to know the answers before looking at your results.

 

Results

Line 146. The table number has been omitted. Add the table number (Table 1).

Line 149. Revised the following subtitle “3.2. Effect of Initial Atrazine Concentration on Degradation Rate” by adding the of soil “Gerif soil”. What was the initial concentration? Even in Figure 1, the initial concentration is not perceived. We have just the different concentrations of atrazine in this figure. I think that the revised subtitle should be as follow: Atrazine Degradation in Gerif Soil at 28ºC

Line 176-185. Why have you chosen to apply NPK fertilizer and plant residues just on Algeraif soils? The application of NPK and plant residues on Gerif soils would have helped to appreciate the effect of soil type. I believe this is a significant limitation in your work.

This work would be interesting if you put the soil types into a soil classification system that everyone knows, like the WRB. That would make it possible to apply your findings in other places around the world.

 

Discussion

Line 224. Replace “In this context, [20, 21] stated” by “In this context, Singh and Kulshrestha [20] and Pan [21] stated” or revised the sentence.

Line 229. Replace “These findings align with those of [26]” by “These findings align with those of Osman [26]” or revised the sentence.

Line 233. Replace “[27] indicated that biodegradation” by “Mohamed et al. [27] indicated that biodegradation” or revised the sentence.

Line 234-235. Replace “[28, 29] reported that half- life Benomyl–MBC” by “Lee et al. [28] and Xuan and Gergon [29] reported that half- life Benomyl–MBC” or revised the sentence.

Line 252. Replace “[48, 49, 50] reported similar findings” by “Shirkot and Gupta [48], Sherif et al. [49] and Reddy et al. [50] reported similar findings” or revised the sentence.

 

Conclusion

Line 259. Delete the semicolon (;) in the following: namely; NPK

Lines 268-272. The punctuation problem needs to be resolved. There are full stops that need to be replaced by commas.

The manuscript in its current state need major revision before publication.

Author Response

Dear Reviewer, attached is the response document.

Best regards.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Brief Summary. The manuscript investigates the degradation dynamics of atrazine herbicide under the influence of NPK fertilization, maize residue addition, soil type (silty clay vs. sandy loam), and temperature (28 °C vs. 40 °C). Laboratory incubation experiments over 150 days revealed that atrazine half-life decreases with higher temperature, organic amendments, and NPK addition, with the strongest degradation observed in Algeraif soil amended with plant residues. The study provides useful insights into abiotic and biotic factors affecting pesticide persistence and supports the role of soil management practices in promoting sustainable agriculture.

General Concept Comments. The manuscript addresses a relevant topic in environmental agronomy, pesticide management, and soil health. Atrazine persistence is a long-standing issue, and the combined effects of soil type, fertilization, and crop residues are worth exploring. The experimental design is straightforward, but some aspects require clarification to ensure reproducibility. While the results are consistent with previous findings, novelty lies in the combined assessment of factors within Sudanese soils. The manuscript is generally clear but would benefit from improving methodological detail, statistical reporting, and discussion of ecological implications beyond degradation rates.

Article-Specific Comments

Clear experimental aim, linking practical soil management strategies with pesticide dissipation. Combination of abiotic (temperature, soil texture, nutrient content) and biotic (organic matter, microbial stimulation) factors provides a multifactor perspective. Use of multiple atrazine concentrations enhances robustness of conclusions.

The source and pre-treatment of maize straw are insufficiently described (sterilized? particle size?). Soil microbial activity was inferred indirectly but not measured. Including microbial biomass or enzyme assays would strengthen the interpretation. Atrazine measurement method cites AOAC but lacks specific details (e.g., extraction solvents, detection limits).

Only one soil with NPK/maize residue was tested; Gerif soil amendments were not included. This limits generalizability. Lack of sterile controls makes it difficult to separate chemical degradation from microbial degradation.

One-way ANOVA is appropriate, but no F-values, degrees of freedom, or exact p-values are reported. Including these would improve transparency.

The discussion largely repeats results rather than exploring mechanisms (e.g., role of clay-organic matter interactions). Broader ecological risks (e.g., atrazine metabolites, groundwater leaching) are only briefly mentioned.

While recent references (2022–2024) are included, there are several older citations (>15 years). Some more recent atrazine degradation studies should be integrated. Self-citation is minimal, which is good.

 

Specific Comments

The introduction nicely highlights the importance of pesticide degradation, but it could be improved by clearly stating the specific research gap this study addresses compared to earlier atrazine degradation studies. (Lines 49–72)

The objective mentions “the role of soil microorganisms” but no direct microbial data were collected. The phrasing might be reconsidered to avoid overinterpretation. (Line 83–86)

Atrazine concentrations are listed as “0.0, 0.0678, 1.69, 3.39 or 5.08 mg g⁻¹ soil”. The 0.0 mg g⁻¹ treatment is the control; this should be stated clearly in text and tables. (Line 97)

Ensure correct formatting of logarithmic formula. Currently, subscript placement and spacing are confusing. (Line 122)

Please specify the software version of Statistica used and whether data were checked for normality and homogeneity of variance before ANOVA. (Lines 126–131)

The table is informative, but the lettering for significance overlaps across soil treatments; clarify whether comparisons are within rows or columns. (Line 147)

The figures are readable but should include error bars (standard deviation or standard error) to illustrate variability. Axis labels and legends would benefit from clearer descriptions (e.g., “Atrazine concentration (mg g⁻¹ soil)” instead of just numerical series). (Figures 1–4)

The statement on temperature effects cites general pesticide literature but does not mention whether the results in this study align quantitatively with those ranges. Adding a direct comparison would strengthen the argument. (Line 221–229)

Recommendations could be strengthened by emphasizing the need for field validation and assessment of atrazine metabolites. While future research directions are listed, the practical implications for farmers or soil managers are not highlighted. A short note on how these findings might inform actual field practice would increase applied relevance. (Line 257–274)

 

Additional questions for the authors

Could you clarify whether the soils used in your study were collected in a single season or across multiple sampling times? This may influence microbial activity and degradation dynamics.

Were there any preliminary tests to ensure homogeneity of atrazine distribution within soil samples before incubation?

Did you monitor soil moisture content during the 150-day incubation, and if so, how was it controlled? Small fluctuations could strongly affect microbial activity and pesticide degradation.

Can you provide more detail about the storage conditions of soil and plant residues before the experiment? For example, were residues dried or fresh, and for how long were soils stored before incubation?

Author Response

Dear Reviewer, attached is the response document.

Best regards.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The "AOAC" in "Abbreviations" was not deleted, perhaps because the author uploaded the wrong version of the manuscript on the system.

Author Response

We thank the reviewer for these careful observations, and the abbreviation has been deleted.

Thank you for the observation, we had read through and improved the English.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for taking my comments into consideration.

Author Response

We will like to thank you for taking your time and made valuable input to our article.

Best regards