Nitrogen Distribution and Soil Microbial Community Characteristics in a Legume–Cereal Intercropping System: A Review
Round 1
Reviewer 1 Report
The review of Lai et al. addresses the relationship between N and soil microbial communities in legume-cereal intercropping systems. The review is structured around three main themes: nitrogen, soil microbial communities and molecular techniques to study soil microorganisms. The chemistry of N-fertilizer is a too broad topic to be reviewed here and the molecular techniques used to study soil microorganisms do not seem relevant to this journal and manuscript. The core topic of interest is the soil microbial communities in intercropping. In my opinion this latter topic deserves a review manuscript but major re-working will be necessary.
- I am not sure why this manuscript was structured with a Section 1 and Section 2, which in fact should be merged under a one section only titled “Introduction”. This new introduction should be laying out a context, a scientific question and so on. At the present Section 2 is mainly a list of studies that does not address what stated in the title and introduction.
- It seems as if the entire Section 4 is out of place in this manuscript. The study of molecular techniques for soil application may very well warrant a review on its own. Although it is important to mention some of the advances and limitations of techniques used to determine soil microbe communities, an entire section seems out of place in this review that focus on microbes in intercropping system. Section 4 does not fit into the discussion of Section 1 to 3 either and it can either removed altogether or dramatically shortened and integrated in Section 3.
- In my opinion the focus of this review is Table 1. Considering the small number of summary tables, figures etc. this manuscript looks more like a mini-review with a focus on the specific Chinese situation. Therefore, the manuscript should be rewritten as a mini-review with the specific focus clearly highlighted. By the way, Figure 1 and Figure 2 reports the same concepts in different ways and should be merged together into one comprehensive figure that gives an overall view of the system.
- What is soil mineral N in Figure 2? I believe this should be simply “soil N”.
- Line 233. Explain or define what the Shannon diversity is
- The heading of Table 1 is not clear. What does it mean increased and reduced microorganism? I believe the authors means fraction of bacterial strains that increases under intercropping conditions. This needs to be better explained
Author Response
Point 1: I am not sure why this manuscript was structured with a Section 1 and Section 2, which in fact should be merged under a one section only titled “Introduction”. This new introduction should be laying out a context, a scientific question and so on. At the present Section 2 is mainly a list of studies that does not address what stated in the title and introduction.
Response 1: Thank you for your suggestion. The "introduction" of Section 1 has been revised according to your comments. The new introduction has a complete layout including scientific background, scientific question and research significance. Section 2 reviews nitrogen transfer and distribution in intercropping system. The amount of nitrogen fixation of legumes, the amount provided to cereals and the amount of nitrogen fixed by legumes further promoted by the competition of cereals for nitrogen are still unclear. Therefore, it is of great significance to clarify nitrogen distribution for the development of sustainable agriculture in the future, which is worth summarizing. (Line 51-Line 71)
Point 2: It seems as if the entire Section 4 is out of place in this manuscript. The study of molecular techniques for soil application may very well warrant a review on its own. Although it is important to mention some of the advances and limitations of techniques used to determine soil microbe communities, an entire section seems out of place in this review that focus on microbes in intercropping system. Section 4 does not fit into the discussion of Section 1 to 3 either and it can either removed altogether or dramatically shortened and integrated in Section 3.
Response 2: Thank you for your suggestion. I dramatically shortened this part to a certain extent and merged it into the Section 3 to ensure that the content structure is complete. (Line 387-Line486)
Point 3: In my opinion the focus of this review is Table 1. Considering the small number of summary tables, figures etc. this manuscript looks more like a mini-review with a focus on the specific Chinese situation. Therefore, the manuscript should be rewritten as a mini-review with the specific focus clearly highlighted. By the way, Figure 1 and Figure 2 reports the same concepts in different ways and should be merged together into one comprehensive figure that gives an overall view of the system.
Response 3: What you said is quite reasonable. We have merged Figure 1 and Figure 2 into a comprehensive figure renamed Figure 1 and updated the Figure. (Line 148)
Point 4: What is soil mineral N in Figure 2? I believe this should be simply “soil N”.
Response 4: Thank you for your suggestion. In the new comprehensive figure, we made a slight change and did not include the word mineral N.
Point 5: Line 233. Explain or define what the Shannon diversity is.
Response 5: Shannon's diversity index is a measurement index based on information theory, which is widely used in ecology. This index can reflect the heterogeneity of landscape, and is sensitive to the unbalanced distribution of various block types in the landscape, that is, it emphasizes the contribution of rare block types to information, which is different from other diversity indexes.
Point 6: The heading of Table 1 is not clear. What does it mean increased and reduced microorganism? I believe the authors means fraction of bacterial strains that increases under intercropping conditions. This needs to be better explained
Response 6: Thank you for your correction. The heading of Table 1 refers to the increase and decrease of the proportion of microorganisms under the intercropping system, and we have made the correction. (Line 286-Line287)
Author Response File: 
Author Response.docx
Reviewer 2 Report
The paper is an interesting review about the intercropping sistem between legumes and cereals. It sounds fine and well structured. It is easy to read and shows most of the new findings in this research field. Suitable for publications in the present form. Maybe some changing needed in the English language
Author Response
The paper is an interesting review about the intercropping sistem between legumes and cereals. It sounds fine and well structured. It is easy to read and shows most of the new findings in this research field. Suitable for publications in the present form. Maybe some changing needed in the English language
Response : Thank you for your advice and recognition of our work, we have invited a native English speaker to improve carefully in language.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors have implemented some changes to the original manuscript. However, in my opinion it is not yet clear what the contribution of this manuscript to the field would be. Table 1 is not particularly exciting given that the conditions of each of the studies cited is not given. Figure 1 (now improved) does not add much to what already existing in the literature. Section 3.4 has been shortened but it is still not related to the rest of the manuscript (the use of metagenetics etc. it is not specifically related to intercropping systems). I recommend the manuscript is not published.
