Effects of Plant-Soil Feedback on Switchgrass Productivity Related to Microbial Origin

Round 1

Reviewer 1 Report

Dear authors,

I enjoyed reading your manuscript. The methods are described adequately and in details. Figures and tables are easy to read and have all important information in them. I also liked that the authors mentioned potential additional work that could be done. Therefore, I don't have any concerns that this manuscript can published in its present form.

Author Response

See attached file for responses to reviewers

Author Response File: Author Response.docx

Reviewer 2 Report

The paper contains interesting research results and may be published in the scientific journal Agronomy. Prior to publication, steps should be taken to improve the paper. I suggest corrected the title. The title should indicate the research problem and not the result of its solution. Materials and methods If the authors have more information about soils (Table 1), they should show them, e.g. the content of organic matter, pH, nutrient content, etc. Results Table 3 should be located in the paper before Fig. 1. The authors first comment on the results in Table 3 and then discuss Fig. 1. Information in the chapters Results and Discussion should be clearly distinguished. For example, the sentence "Causes for the decrease in tiller number are unclear, possibly due to the longer daylengths or higher temperatures when the cooling system may not have been able to handle the high temperatures in the warmest part of the year. However, tiller number depended on the interaction of cultivar and soil, and no single soil inoculum source was consistently best. " (lines 168-172) should be included in the results discussion. In the Results chapter, the results presented in the tables and figures should be commented on in more detail. Especially with regard to the investigated interactions of cultivar x soil. The results should be described precisely, eg Lines 190-191 "Plants were also ~ 1.5 × larger when grown 191 with soil inoculum from Temple and Colombia compared to Stillwater and Mt. Vernon. " What does ~ 1.5 × larger mean? The captions of Figs should be placed below the graphic, not above. Discussion The authors focused mainly on comparing their own results with the results of previous studies. It would be good to expand this chapter with an analysis of the reasons for obtaining such and not other results.

Author Response

See attached file for responses to reviewers

Author Response File: Author Response.docx

Reviewer 3 Report

Effect of plant-soil feedback on switchgrass productivity is an interesting topic. The manuscript is written well. I do have a few concerns that the authors need to address before the paper can be accepted for publication. 

1. 5 replicated might have been too small to show significant effect. 
2. Authors need to provide the soil chemistry of the potting soil. The soil was collected from different location, along with microbial feedback there could be some influence of the soil chemistry like pH, organic matter, nitrogen etc. 
3. How many root fragments were used to analyze root colonization?
4. What was the temperature and PAR in the green house? Do these cultivars have different tolerance range for temperature?
5. The reported root colonization by septate hyphae is low, but switchgrass has been reported to enhance shoot growth. It would be interesting to see the relationship between the plant growth parameters and the septate hyphae. 

Author Response

See attached file for responses to reviewers

Author Response File: Author Response.docx

Reviewer 4 Report

Generally: Manuscript correctly written.
Fill in the missing information. I am concerned about the very small volume of the pots - this limits the possibility of drawing conclusions about the effects in the field.

introduction

The introduction lacks information: where (geographically) this species is grown, what is the scale of production. Whether the interest in growing this species is rising or falling - what are the reasons for this? The authors present a hypothesis, there is no definition of the research goal.

Materials and Methods

Specify the physical and chemical properties of the soil (pH, N, P, K content) - expand Table 1

Water conditions determine to the greatest extent the production of biomass. Even slight variations in water application result in a large experiment error. What was the soil moisture in the pots? Why in the methodology so laconically defined the conditions of soil moisture in the pots? My guess is that a drip system was used for irrigation, and maybe another. What was the water dose control - soil moisture probe - what? (TDR FDR may other - link to manual). Maybe the moisture was regulated by the weight of the pots - which was the criterion for the water dose? How many reference pots were there to determine the water dose? e.t.c

Were the pots single-layer or double-layer - was the soil protected against heating?

in my opinion that the pots had a very small volume for this type of experiment - interactions: soil - microorganisms - plant, in the field they can be completely different.

Results

Line 168-170. This is incomprehensible to me, because all the plants grew at the same temperature.

Author Response

See attached file for responses to reviewers

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors have addressed my comments. I saw a couple of grammatical errors. There could be more, please revise.