Long-Term Conservation Tillage Practices Directly and Indirectly Affect Soil Micro-Food Web in a Chinese Mollisol

Round 1

Reviewer 1 Report

 

The paper describes research directed to the effects of long-term tillage practices on soil biodiversity micro-food web in a specific soil in China. Although the research is based on modern methodology and fits the aim and scope of the journal, I would not recommend publishing the research without the following changes:

 

Major corrections-revisions are stated below:

1.       The novelty of the presented research needs to be justified. There are numerous papers with similar aims and even similar methodology but directed to other regions or other soil types. For a journal of this rank, the authors should pay much more attention to describe the additional value that those findings provide to modern science. Are there any globally applied conclusions or novel findings highlighting your work in a mass of similar ones? For example, references no. 11, 12, 15, 33, 45, 49, and 50 should be used to describe some additional value. As it stands, the authors are just confirming the results in other types of soil, which makes this paper lack novelty.

2.       Experimental design is not given in much detail. The duration of the conducted trial is given in the abstract, but not in the Material and Methods.

3.       There are numerous data given in the first paragraph of the Material and Methods without mentioning the source of the data (climate, soil type, chemical composition). Add reference for those data. When were those data collected?

4.       Line 104 -  use m² instead of m2

5.       Line 117 – use superscript/subscript when necessary

6.       Line 126 – Have you used some cryoprotectant before putting your samples into the freezer?

7.       Lines 129-135: If you used those methods to analyze soil, obtained results should be presented in the Results section, not in the first paragraph of the Material and Methods. Or do the results described in the first paragraph belong to some previous research?

8.       It is very hard to get representative results by using 0.5g of fresh soil to extract DNA, and to make some conclusions from those results. How did you get representative samples? You do not mention any replications, and it is evident that you have statistical analysis in that part.

9.       Lines 159-160: Actually, you can’t speak about their abundances, only about the abundances of specific genes. Some bacteria have several copies of the 16S gene, and some have one in their genome, so you can only speak about gene copy numbers.

10.    Figure 1 label, lines 273-274 – You do not have any lowercase letters in figure 1.

11.    Discussion section: The authors should not use literature only to confirm something that is done previously. The significance of the current research should be given, highlighting the importance of new findings/new approach.

12.    Lines - 541-543: There is actually an interconnection between physicochemical characteristics and soil biodiversity which is not one-sided. You should discuss possible feedback reactions since the microbial community can certainly have a significant effect on physicochemical soil properties.

13. More than half of the literature that is used is older than 5 years. This can be improved and useful to compare data with more novel findings.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Evaluation

The authors analysed the effects of four different tillage practices on soil microbial communities and soil fauna - gene abundance, species diversity and species composition. The study was conducted after 38 years of field experiment for two depths 0-20 and 20-40 cm. The research is interesting and important, not only the genetic diversity of bacteria and fungi but also protozoa and metazoa were considered. However, the work requires several corrections and clarifications:

-Manuscript requires linguistic correction as there are  typos in the text, e.g. “indrectly” instead of “indirectly” in the manuscript title.

-This was a long-term experiment - was maize grown throughout the experiment or only in the year of sampling? – please clarify

-Which method was used to determine total and available potassium and soil texture? – please specify

-What was the control in this field experiment? which tillage practices was considered as a control treatment? – please clarify

-Sample size (n=?) should be provided in each Table and Figure. – please correct

-ANOVA method should be mentioned in subchapter “2.6 Statistical analysis” – please correct

-The initial soil pH before the experiment was alkaline (7.6); after many years of tillage practices, the soils became acidic (pH decreased to values of 5.15-5.48 in the 0-20 cm layer). What was the reason for this? This is important because soil pH is one of the main determinants of soil biological life. – please address this in the manuscript

-Lines 194-196: “Under the ST and MP treatments, the SOC and TP contents were significantly higher, and the BD was lower than those under the other treatments. In addition, the NT treatment remarkably enhanced soil pH..” - this sentence is not supported by the results presented in Table 1, please check and correct.

-Figure 1. Results of ANOVA analysis (the statistical significance marked with different letters) were not shown in the Figure – please check and correct

-Lines 249, 252, 256, 257-258: it should be “20-40 cm soil layer” instead of “0-40 cm soil layer” – please check and correct

-Line 483: it seems that the correct sequence of tillage practices is: ST>NT>CT>MP – please check and correct

Author Response

Please see the attachment.

Author Response File: Author Response.pdf