Effects of Continuous Ridge Tillage at Two Fertilizer Depths on Microbial Community Structure and Rice Yield

Round 1

Reviewer 1 Report

Introduction

·         Write a brief about the importance of rice as a staple food for the world population and the world food gap and the available methods to fill that gap.

·         Write about the effect of tillage, and fertilizer on rice production.

·         Write a brief about the effect of zero tillage, limit tillage, conservation tillage, and other conventional tillage types on microbial community structure.

·         Show the direct effect of conservation tillage on soil microbial is it positive or negative effect?

·         Write a brief about the relation between soil microbial and soil organic matter, physical properties, also the relation between soil microbial and fertilizer.

·         Write a brief about ACE, Chao, Simpson, and Shannon indexes, and how they are used to determine the enrichment of microbial.

·         Lines 25-26: (The current rice field farming system has caused structural damage to soils) how did it cause this damage?

·         Lines 30-31: (Soil microorganisms are an important part of farmland ecosystems), what is the importance of Soil microorganisms in agricultural ecosystems and productions?

·           Methodology

·         Show the technical specification of the tillage machines and tools.

·         What was the depth of ridge tillage?

·         Lines 85-86: (Conventional flat cropping (P treatment) used an artificial simulation of conventional mixing and leveling), what do you mean by this? Explain more about P treatment, was there any tillage? If so what was it? What is the depth and width of tillage? What is the type of leveler? What was the mixing? Show the land preparation practices clearly.

·         Do you keep saying (continuous tillage) what do you by continuous tillage? How much tillage did you do every year? You should differentiate between the two experiments and clearly describe the land preparations between the two experiment 

·         Lines 85-86: (The soil moisture was allowed to dry naturally, and the soil maintained a 3–5 cm layer of water until late maturity) show how you maintained this water depth?

·         Show how many samples you took per plot for bulk density and soil porosity, soil pH, and soil organic matter, and when did you take the samples before and after tillage.

·         I cannot judge your method for determining bulk density because I could not find the reference that referred to [31] on the internet, and I found it I would not be able to read because it was written in Chinese as in Lines 445-446: (Chinese Academy of Sciences. Soil physical and chemical analysis. Shanghai Science and Technology Press: Shanghai, China, 1978. (In Chinese), with respect to the Chinese language and to my native language which is not English, you should write your paper for international concerns not for local, so it is better to use an international reference that readers could read.

·         Lines 112-113: (After 3 years of continuous farming, soil samples (0 –20 cm) were taken from the two test pilots, and three replicates were taken for each test plot in 2018). Did you determine soil microbial once? Did not you measure the microbial before and after the treatment? In your result you presented the increase and decrease in microbial such as in lines 190-194: (Ridge tillage at two fertilizer depths increased the numbers of Ascomycota, Chytridiomycota, and Cercozoa by 38.00%, 27.41%, and 77.71%, respectively. However, the L treatment also decreased the numbers of Aphelidiomycota, Basidiomycota, and Mortierellomycota by 87.89%, 42.10%, and 33.09%, respectively). So, how could you measure the increment or decrement ratio unless you measure the values before and after? Or maybe you measured but why you did not show it in your methods?

·         Lines 97-105: show how did you collect samples for NPK tests? Did you use an auger or what? Or did you use the same samples that were collected for bulk density? Clearly. How many measures per plot? When? The day-date, before after.

·         Lines 112-122, show how did you collect samples for microbial community structure tests? What tool did you use and how? How many measures per plot? When? The day-date, before or after tillage, planting, or harvesting.

·         Lines 112-122, here you presented the methods for collecting and analyzing data for microbial, but you did not mention ACE, Chao, Simpson, and Shannon indexes then suddenly readers find them in the result!!!! You should define these indexes, and show briefly how they could be calculated.

·         Define all the abbreviations in your article such as ACE, and PCR.

Result

·         Lines 112-113: (Notes: capital letters represent significant differences at the 1% level; lowercase letters represent significant differences at the 5% level) in Table 7, there are capitals A and B, and small (a, and b), what each letter set for? What A, a set for and what B, b set for?

·         Figure 5 is difficult to read, make the font bigger.

·         Figures 6 and 7, the correlation between what and what? I think the correlation between rice yield and alpha diversity of soil bacteria and fungi, you should state this clearly in your result.        

·         Lines 184 -194 and Figure 3, Lines 197 -207 and Figure 4, your result showed that there were some bacteria and fungi increased in treatment L, and also there were some bacteria and fungi decreased, how can you read and analyze this? So could we say that ridge tillage at two fertilizer depths has a different effect on bacteria and fungi? Increases some and decreases some? Please give more explanation. Can you show how many bacteria and fungi increased and how many decreased in every level phylum and genus levels? (Just give a number)    

·         Please put (L) and (P) in Figures 6 and 7 vertically each one over the other to make it clear to read especially for the hard copy.

Conclusions

Write a conclusion to conclude your findings in this research paper.

References

 

I could not check 24 references out of 50 references because they were written in Chinese. From their titles, it seems that they related to the research

Author Response

Please refer to the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

1. Methods - please provide methods for extracting components from soil or methods for mineralization. Please also provide the solution in which the pH of the soil was determined.

2. Table 3. What caused the large differences in the content of some elements in the soil. After all, small doses were used, especially P and K.

3. Figures 5, 6 and 7 should be corrected - they are illegible.

4. Discussion - regarding point 4.1. - there are no elements of scientific discussion.

5. Please complete the work with conclusions.

Author Response

Please refer to the attachment

Author Response File: Author Response.pdf