Phosphorus Dynamics in Japanese Blueberry Field: Long-Term Accumulation and Fractionation across Soil Types and Depths

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

Please see attached file

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Regarding the quality of English language, I consider that moderate editing is required, as shown in the “Comments and Suggestions for Authors” section. With respect to the necessary changes, only those that concern the scientific content of the article were highlighted. Therefore, other relevant errors may not be noted.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Phosphorus is one of the essential major elements for plant growth and development. In agricultural practice, farmers often apply additional phosphorus fertilizers to ensure the crop's need for phosphorus fertilizers. However, the addition of large quantities of phosphorus fertilizer often leads to the over-accumulation of phosphorus in the soil or to eutrophication as it enters the water system. This study described a detailed analysis of phosphorus fractions across different soil depths and types after 20 years of agricultural practice in a Japanese blueberry field. It could provide valuable insights into soil fertility and management for sustainable agricultural development. In over 20 years of cultivating both highbush and rabbiteye blueberries, a common type of root system observed is the fibrous root system. Phosphorus cannot move in soil, so the distribution of phosphorus in soil is particularly important for plant growth. The content of this manuscript is of a significant practical importance. Nonetheless, its writing quality requires enhancement, particularly for the presentation of some figure. The following questions should be addressed before considering for publication.

 

1.      Abstract

In the abstract, some abbreviations that appear for the first time still need to have their full names, such as SOC, Total N, KS and FS soils, BFS and RYS soils.

Based on the analysis of the physical and chemical properties of the soil in the research location, especially the distribution characteristics of phosphorus content, does the author have any specific suggestions or guidance on the amount of phosphorus fertilizer added or the fertilization method during the local planting process.

It is suggested that the author provide a detailed description of the basis for selecting the soil for collection in the abstract, that is, the soil collected is typical of long-term blueberry planting areas in Japan. This is also the significance of this article.

2.      Introduction

The bi-availability of soil phosphorus is influenced by various elements including plant life cycles, climatic conditions, microbial activity, and human activities. The author's description of the bioavailability of plant phosphorus is not very accurate. Please refer to some relevant articles on plant phosphorus absorption and utilization. [Schachtman D P, Reid R J, Ayling S M. Phosphorus uptake by plants: from soil to cell[J]. Plant physiology, 1998, 116(2): 447-453; Zheng L, Karim M R, Hu Y G, et al. Greater morphological and primary metabolic adaptations in roots contribute to phosphate-deficiency tolerance in the bread wheat cultivar Kenong199[J]. BMC Plant Biology, 2021, 21: 1-18.]

3.      Materials and Methods

The author is able to collect soil near blueberry planting areas where blueberries have not been planted before, and compare the effects of blueberry planting on soil physicochemical properties, especially phosphorus distribution, over the past 20 years. I believe the author can achieve more meaningful results. However, the description of the collection characteristics of these two soils in the experimental method description is not detailed enough.

The samples were then crushed, thoroughly mixed, ground, sieved. What size of sieve was used in the experiment

Suggest describing the key instrument used, spectrophotometer, when conducting the molybdenum blue colorimetric method.

4.       Results

It is recommended to reduce the font size of Table 1, otherwise it may be difficult for readers to understand.

“(Figure 2 and Table 2) represented different phosphorus fractions in both 0-30 cm and” This sentence has a grammatical error.

Table 2 is still difficult for readers to understand, and it is recommended to use a graph to present the results for a more intuitive presentation. If Figure 2 and Table 2 represent the same result, Table 2 can appear as supplementary material at the same time. Moreover, the layout of Figure 2 is really ugly.

Suggest presenting Figure 2 in another way, using vertical stack bars to represent the proportions between different components of a soil.

Are Figure 2, Figure 3, and Table 2 presenting different results?

5.      Discussion

As the authors said: In addition, a large amount of evidence shows that mycorrhizae and acid phosphatase secreted by the blueberry rhizosphere may be involved in the reuse of organic phosphorus pools in the vertical soil layer, by converting organic phosphorus into inorganic phosphorus, or transfer available phosphorus from root’s senescent tissues to young tissues. If the authors can detect the enzyme activity of soil acid phosphatase, it will provide more powerful evidence for the article.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Please, in the future, have authors put line numbers in the manuscript so reviewers can be more specific in their comments. My main concern about the paper is:

1) I tried to figure out the narrative between the planting dates (1999, 2001, and 1968) and the sampling dates (in 2022). Why sampling after 56yrs (1968-2022)? This needs more explanation from authors: “The variety of blueberries was from the rabbiteye series, and all the blueberry trees were over 20 years old. The BFS area was planted in 1999, with soil sampling conducted on 12-12-2022. The FS area was planted in 2001, with soil sampling conducted on 24-04-2022. The RYS area was planted in 1986, with soil sampling conducted on 25-04-2022. The KS area was planted in 1968, with soil sampling conducted on 09-06-2022.”

2) The tables are confusing and as a result, insert border lines inside between variables so the data is more comprehensive. Figure 1 text also needs to be more readable. 

Please review my comments and address, and please give a short explanation for any rebuttals

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Needs minor improvement.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Please see attached file

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Please see response to the authors' cover letter (attached file)

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

The third review does not raise any further relevant comments from me, with the questions previously raised being clarified. However, I would like to add that regarding the quality of the English language, I am not qualified for a more detailed final review. Regarding the scientific component, this parameter seems appropriate to me.