Chemical Fertilizer Reduction Combined with Microbial Fertilizer Improved Vegetation and Soil Characteristics in Degraded Alpine Meadows

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript evaluates the effect of reduced chemical fertilizer combined with microbial fertilizer on productivity, vegetation composition, and soil nutrients in a degraded alpine meadow in northwest China. The study is relevant because it addresses an important ecological and agronomic problem in fragile ecosystems and proposes more sustainable alternatives to intensive chemical fertilization. The inclusion of two years of field data increases its applied value.

The title is understandable but too long, grammatically incorrect, and has capitalization issues.

The abstract adequately describes the general objective, treatments, and main results, but it has problems with wording, repetition, grammar, and clarity.

It should be improved in terms of syntactic clarity, fluency, precision of the reported results and avoid repetitions.

Lines 11–16: the authors wrote “Although many restoration methods including fertilization were used… most fertilization relies on chemical fertilizers.”

Suggestion: “Although several restoration methods have been used, fertilization practices still rely heavily on chemical fertilizers.”

Lines 23–24: the authors wrote “The results showed that DP treatment presented the highest production…”
Suggestion: “DP showed the highest biomass production…”

Line 29: the authors wrote : “However, the diversity of alpine meadow communities decreased with the increase of fertilization years.”

Suggestion: “However, community diversity decreased in the second year of fertilization.”

Lines 31–33: the authors wrote “Grey correlation analysis indicated 450 kg.hm-2 of diammonium phosphate combined with 75 kg.hm-2 of microbial fertilizer was the feasible fertilization regime…”
Suggestion: “Grey correlation analysis indicated that 450 kg·hm⁻² of diammonium phosphate combined with 75 kg·hm⁻² of microbial fertilizer was the most suitable regime…”

The introduction is extensive and provides good context on alpine meadow degradation. However, there are numerous grammatical errors. In addition, like in the abstract, ideas appear repeated.

This is an experimental study and the authors have not included explicit scientific hypotheses. Please, write and present them.  The objectives are present but should be stated more clearly and formally.

Lines 41–42: the authors wrote: “The unique geography location and special mountain climatic conditions…”
Suggestion: “The unique geographical location and specific mountain climatic conditions…”

There are many more suggestions to improve clarity and fluency, however, doing them all means rewriting the manuscript, what is not the task of a referee.

Please, revise throught the entire manuscript that all figures are incorrectly referenced. Similarly, make a consistent use of units.

Figure captions need to be improved.

7. Discussion

The Discussion partially interprets the results, but it mostly repeats information already presented in the Results. It does not sufficiently integrate international literature and the ecological mechanisms are not discussed in depth.

The conclusions are generally correct but overly descriptive. They should be written in view of the scientific hypotheses, still to be presented.

- Some references are incomplete and the format does not follow the journal’s style.

The literature is predominantly Chinese; broader international coverage is needed.

The Materials & Methods section is generally well structured and includes the essential components needed for reproducibility: study site description, experimental design, vegetation and soil sampling, laboratory analyses, and statistical procedures. The experimental layout is clear, and the fertilization treatments are well defined.

However, the section requires substantial language revision, clarification of methodological details, and correction of formula formatting. Several sentences are grammatically incorrect, ambiguous, or imprecise. Some methodological aspects are missing or insufficiently described.

Line 316–318: “The study area was set on the Alpine Grassland Experimental Station of Gansu Agricultural University…”Suggestion: “The study was conducted at the Alpine Grassland Experimental Station of Gansu Agricultural University, located in Zhuaxixiulong Town, Tianzhu County, Wuwei City, Gansu Province (37°10′16.97″N, 102°47′17.31″E).”

Line 319:“The study land type was the moderately degraded alpine meadow…”

Suggestion: “The study site consisted of a moderately degraded alpine meadow…”

Line 320–321:“…most of them are topographic rain.”.

Suggestion: “Most precipitation results from orographic lifting.”

Line 321–322: “…the solar radiation is strong in day.”
Suggestion: “Solar radiation is strong during the daytime.”

Line 323: “The plant growth period lasts five months maximum in one year.”
Suggestion: “The growing season lasts up to five months per year.”

Line 324–326: “…mainly Gramineae and Cyperaceae plant species…” Suggestion: Use modern taxonomic names: “Poaceae and Cyperaceae.”

Line 328–329: “The same habitat conditions, flat terrain, and uniform density degraded alpine meadow were selected…”

Suggestion: “A homogeneous area with similar habitat conditions, flat terrain, and uniform vegetation density was selected…”

Line 329–331:“…with plot experiment method.”

Suggestion: “using a randomized plot experimental design.”

Line 331–334:“There were six fertilizer treatments including no fertilization (CK)… ”

Suggestion: Improve clarity and unit formatting: “Six fertilization treatments were established: CK, DP (600 kg·hm⁻²), MF (75 kg·hm⁻²), DPMF1 (600 kg·hm⁻² DP + 75 kg·hm⁻² MF), DPMF2 (450 kg·hm⁻² DP + 75 kg·hm⁻² MF), and DPMF3 (300 kg·hm⁻² DP + 75 kg·hm⁻² MF).”

Line 335–338: “…according to the study of group of our college for that provide the MF products…” Suggestion: “according to recommendations from the microbial fertilizer development team at our institution, who provided the MF product.”

Line 338–340: “Each treatment has three replicates…”

Suggestion: “Each treatment had three replicates…”

Line 340: “Each plot was a 15m2 rectangle with width and length of 3 m and 5 m…”

Suggestion: “Each plot measured 3 × 5 m (15 m²).”

Line 341–344: “Microbial fertilizer was a compound bacterial fertilizer suspension containing phosphate-solubilizing, nitrogen-fixing and growth-promoting bacteria…”

Please, add missing essential details: CFU concentration, strain names, carrier material, pH, storage conditions

Line 348–349:“…sprayed in each plot evenly with a small sprinkling kettle.”
Suggestion: “applied evenly using a handheld sprayer.”

Line 350–351: “…the control treatment without fertilization was applied with the same amount of distilled water.”
Suggestion: Clarify that this controls for water addition.

Line 371–372: “…three quadrat frames was randomly set…”

Suggestion: “three quadrats were randomly placed…”

Line 374–375: “…cut off from the soil top…”

Suggestion: “cut at ground level.”

Line 385–386: “…finished green under 105°C for half an hour…”

Suggestion: “oven-dried at 105°C for 30 minutes to halt enzymatic activity…”

Line 389–390:“…the average of ten measurements was looked as the plant height…”
Suggestion: “the mean of the ten measurements was used as the plot-level plant height.”

Line 392–394:
“Dominance was calculated by relative coverage, biomass and plant height…”
Suggestion: Clarify weighting and formula consistency.

Lines 395–399: The formulas for relative coverage and total coverage are incorrectly formatted and ambiguous.
Please, rewrite using standard notation and define all variables clearly.

Lines 401–409: Diversity indices formulas contain inconsistencies:

• M is used for Margalef index but also earlier for total needle contacts.
• Please, correct symbol definitions and ensure consistency.

Line 412–414: “…Five drills of same soil depth for each plot were mixed as a sample.”
Suggestion: “Five cores per depth were composited into a single sample.”

Line 416–417: “…air dried and sieved to 1 mm and 0.25 mm sieves respectively…”
Suggestion: Clarify which analyses used each sieve size.

Line 418–425: Analytical methods are correct but need citations to standard protocols (e.g., Chinese Soil Standards, ISO, AOAC).

 Grey correlation analysis

• Clarify meaning of “varieties” (should be “treatments”).
• Ensure consistent use of uppercase/lowercase K/k.

Data analyses: This section is clear but needs minor improvements:

• Specify whether assumptions of ANOVA (normality, homoscedasticity) were checked.
• Clarify whether data were transformed when necessary.
• Mention software version formatting consistently (e.g., “SPSS 19.0”).

Comments on the Quality of English Language

The English requires substantial revision due to:

• Grammatical errors
• Incorrect syntax
• Repetitions
• Incorrect use of verb tenses
• Punctuation problems

I have introduced a number os suggestions that I fell improve fluency, but I strongly recommend thorough editing by a professional language service or a fluent/native English speaker.

Author Response

Dear reviewer,

Thank you so much for your kind comments and suggestions for our manuscript. I have completed the point-to -point responses according to the journal's format. I try to paste them on here, but they are so disorganized in the format. So I upload a Word version  response file here for you to reviewer.  I hope this can be appropriate.

Thank you again for your hard working for the manuscript.

Yajuan Li

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this peer-reviewed manuscript, the authors present the results of a two-year study on the influence of fertilization with diammonium phosphate and microbial fertilizer on a moderately degraded alpine grassland in northwestern China. Through this study, the authors aimed to highlight the effect of the two types of fertilizers on vegetation as well as on the soil.

The authors examined the effect of six fertilization treatments on grassland productivity, floristic composition and species dominance, and species diversity, using four indices relevant to grasslands, as well as on soil organic matter content, total nitrogen and phosphorus content, and available nitrogen and phosphorus content.

The parameters monitored are essential for identifying the most favorable fertilizer doses that play a beneficial role in improving mountain grasslands, and the results obtained by the authors can contribute to expanding the scientific knowledge base regarding the development of fertilization systems combining reduced mineral fertilizers with microbial fertilizers.

I believe that the topic addressed by the authors is of broad interest, given the general concern for sustainable agriculture with fewer chemical inputs and the stimulation of microbial activity in the soil. In my opinion, the research conducted by the authors provides good practical support for farmers in areas with conditions similar to those in the experiment for improving the productivity and quality of degraded alpine pastures. The extraordinary role of microbial products in increasing plant absorption capacity—particularly of poorly soluble elements from the soil under extreme environmental conditions—and the evident improvement in plant nutrition are well known and studied, making a focus on degraded grasslands a very good initiative that should be continued.

The research methodology is sound and appropriate for the parameters studied; the presentation of results and statistical interpretation are those frequently used in experiments of this type on grasslands and have been carried out by the authors with great care. However, for greater clarity regarding the experimental conditions and to improve the manuscript, I believe some additional information, explanations from the authors, and a few corrections are necessary:

1. The manuscript title is too long and narrative; it should be approximately 15 words. I invite the authors to adjust the title.
2. On lines 71 and 289, the citation format for authors was not followed according to the publication guidelines. I ask the authors to check this throughout the manuscript.
3. In the Introduction section, the authors provide few comments regarding the role of microbial biomass in the nutrition of grassland plants. This section could be improved.
4. In Section 2.1.1.: The readability of Figure 1 should be improved. The size of the figure could be increased.
5. In Section 2.1.2.: The unit of measurement for plant biomass should be corrected to g m^-2, not g.m-2.
6. In Section 2.2.1.: Table 1 does not specify the unit of measurement for species dominance. The comment in lines 140–143 is partially consistent with the data in Table 1. The lowest abundances in 2024 for the species Gentiana straminea, Oxytropis ochrocephala, and Artemisia smithi are recorded under the DPMF2 treatment, not DPMF3! I ask the authors to adjust the comment in the manuscript. I also ask the authors to verify the accuracy of the names and spelling of the species in Table 1, ensuring a consistent presentation (some include the author, others do not; in some cases, there is no space between the genus and species).
7. In Section 2.2.2.: on line 149, Table 3 is incorrectly cited in the text; the correct reference is Table 2. I ask the authors to correct this. I also ask the authors to expand on their comments, establishing correlations between the analyzed diversity indices.
8. In section 2.3.4., there is a numbering error: instead of 2.3.4., it should be 3.4.: Analysis of the correlation coefficient for productivity and soil nutrient indicators
9. In section 4.1.: Study site

Essential information about the experimental site is missing: for example, soil pH, given that phosphorus availability is closely linked to pH values;

There is no information on the sum of exchangeable bases, hydrolytic acidity, and total cation exchange capacity, parameters that are quite important for phosphorus availability and uptake.

There is also no information on the soil content of active Ca, active Fe, and exchangeable Al³⁺, which play an important role in phosphorus immobilization.

10. In Section 4.2.: Experiment Design

I believe it would be useful to have more specific information about the microbial fertilizer used: types and number of bacteria, given that the efficiency in solubilizing phosphates varies depending on the bacterial species. Furthermore, the authors did not specify the concentration of the microbial product, the number of colony-forming units per gram or ml.

The authors used some units of measurement in the manuscript that are rarely used in agricultural practice and agrochemistry, kg hm^-2 instead of kg ha^-1, though this is mathematically correct. I also request that the superscript be corrected.

11. In Section 4.3.1: Vegetation characteristics

The study method using sampling plots is correct, but I find it risky for the accuracy of the weighings that the plants harvested for determining fresh weight are packed in paper bags and transported to the laboratory (statement on lines 374–375). In lines 381–384, the procedure for determining fresh grass weight is different: it is performed immediately after cutting, then the grass is packed in paper bags and transported to the laboratory for drying in an oven. Please clarify this point.

The authors did not specify the stage of plant development at the time of harvesting and height measurement: were they only vegetative stages or also generative stages?

12. The authors should explicitly mention the limitations of this study in the final conclusions, particularly regarding the determining mechanisms within soil microbiology and the intentions for future research directions.

The results obtained are correctly interpreted and clearly expressed, highlighting the effect that the applied treatments had on the monitored parameters, in correlation with previous research conducted by various authors on similar topics.

To support the study, 45 references relevant to the topic were selected and used, although there are other relevant articles on the use of microbial fertilizers.

The tables and figures presented in the manuscript are correctly prepared and well integrated into the text; they are clear, expressive, and appropriate for the highlighted parameters, with the exception of Figure 1, where readability needs to be improved, and the reference to Table 2 in the text needs to be corrected.

The conclusions expressed by the authors both during the presentation of the results and at the end of the manuscript are consistent with the results obtained; they are relevant and clear, but I believe that studies spanning several years are necessary for their sustainability and validation.

In conclusion, with the clarifications and corrections requested above, I believe the manuscript is ready to proceed to the next stages of the editorial process. It would be useful for agricultural practice if these studies were supplemented with results regarding the quality parameters of above-ground biomass, which are influenced by microbial activity in the soil.

 

Comments on the Quality of English Language

The English is acceptable and makes the text understandable, but some phrases could be refined.

Author Response

Dear reviewer,

Thank you so much for your kind comments and suggestions for our manuscript. I have completed the point-to -point responses according to the journal's format. I try to paste them on here, but they are so disorganized in the format. So I upload a Word version  response file here for you to reviewer.  I hope this can be appropriate.

Thank you again for your hard working for the manuscript.

Yajuan Li

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have ammend the manuscript in a very strict way, attending all my comments, for what I thank them. I have nothing else to add to this manuscript.

Comments on the Quality of English Language

The English requires substantial revision due to:

• Grammatical errors
• Incorrect syntax
• Repetitions
• Incorrect use of verb tenses
• Punctuation problems

I have introduced a number os suggestions that I fell improve fluency, but I strongly recommend thorough editing by a professional language service or a fluent/native English speaker.