Biogas Slurry as an Alternative to Chemical Fertilizer: Changes in Soil Properties and Microbial Communities of Fluvo-Aquic Soil in the North China Plain

Round 1

Reviewer 1 Report

Comments:

In this work, the author investigated the effects of repeated applications over six years on the soil properties and microbial characteristics of a fluvo-aquic soil in the North China Plain. The experiment comprised biogas slurry (BS), chemical fertilizer (CF) and half substituting chemical fertilizer with biogas slurry (BSCF) treatments with equivalent nitrogen inputs and a control with no fertilizer addition. Soil samples were collected and determined for physicochemical properties and high-throughput sequencing was adopted to assess microbial community diversity and composition. In sum, the author got some interesting results. However, I still have several questions about the article that I would like the author to answer.

 

1. As far as I know, the first author Jiao Tang also published an article called “Effects of Biogas Slurry on Crop Yield, Physicochemical Properties and Aggregation Characteristics of Lime Concretion Soil in Wheat–Maize Rotation in the North China Plain” in journal “Journal of Soil Science and Plant Nutrition” in March 2022. What is the difference between the two articles? Whether there is a succession relationship.

 

2. In this paper and the previous paper, the author explored how marshes affect the physical and chemical properties of soil. What interesting conclusions can be found by comparing the data of the two data?

 

3. The authors did not involve parallel experiments when conducting the microbiome analysis, and whether the results of a single experiment have errors or interfere with the analysis of the final results

 

4. If the author can express the results of the microbial alpha diversity indexes in the form of pictures instead of just using tables to present the results. This means that the authors need to convert the contents of Table 3 to the figure form. This can make the article easier to read and have better dissemination.

 

5. In the results of PCoA, the authors adopted two principal component analysis results. However, the total variance explained by the two principal components in this paper is not large, especially for PCoA analysis of fungi. I suggest that the author should adopt three principal components to achieve PCoA analysis, which can explain the total duty of samples as much as possible and make the analysis of PCoA results more reliable.

 

6. There are a lot of grammatical errors in the article. Please correct them.

Line 483: “Chemical fertilizer treatments significantly enhanced abundance of Basidiomycota and biogas slurry application alone could suppress its abundance, which suggested a higher potential risk of soilborne diseases with intensive agriculture that relies on chemical fertilizers and [10].”

Line 485: “Microbial diversity, is the basis for maintaining soil ecological functions ”

……

 

7. In the passage, the expression of “figure” does not correspond to. In the main text, the author refers to the figure as “fig.”, while the final figure is labeled as “figure”. Please correct it.

 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Tang and co-authors investigated the effect of biogas slurry on soil physiochemical properties and microbial communities in a fluvo-aquic soil of North China Plain. They stated that biogas slurry as an alternative to chemical fertilizer not only achieved agricultural wastes recycles, but also had beneficial influences on soil physical structure and chemical properties as well as microbial community composition and diversity, which follows concept of agricultural recycling. Half substitution of the chemical fertilizer by biogas slurry gave the greatest improvement in soil structure and nutrient availability and this was associated with greater microbial diversity and better-balanced microbial communities, which has generally representativeness and important practical significance in this region. The results are interesting and novelty, the manuscript was well written. It is my opinion that this manuscript meets the required standard of Sustainability and needs minor revision for acceptance. Besides, I have given some comments below and I hope they can help to improve it.

 

Abstract

Lines 37-38: “Soil samples were collected and determined…” " I suggest adding “topsoil” in it.

Line 49: “fertilizer applications” is suggested to replacing by “fertilization treatments”.

 

Introduction

Line 115: Remove the parentheses and describe it in one sentence.

 

Materials and methods

Lines 136-229: There are too many subheading in this section, I suggest deleting or merging them, these sections should be titled following: “Experimental area description”, "Experimental design and agricultural managements ", "Soil sampling and physicochemical analysis".

Lines 161-163: the field experiment was conducted over 6 years. Is the composition of biogas slurry varied among 6 years? Are the authors measured its composition during 6 years?

Line 245-248: check the wet sieving method and correct it.

 

 

Discussion

Line 430: “manure” is inappropriate, I suggest replacing it.

Line 451: Delete "contents".

Line 429: Delete "and".

Line 577-579: Please check the source of these data and provide more detailed information of medium- and large-scale animal productions.

 

Figure 3. "Relative abundance (%)" should be the Y-axis.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

no