Nonadditive Effects on Decomposition of a Mixture of Rice Straw and Groundnut Stover Applied to a Sandy Soil
Round 1
Reviewer 1 Report
This is quite interesting paper, well organized and results a deep dicsussed. Citation of current literature seem to be enough for proper discussion.This paper provide new knowledges about kinetics of methabolical processes in soils, amended by various types of organic substances. Key suggestions of mine are related with the "Material and methods" chapter, namely:
- method of organic carob determination - need to be clarified.
- "Soil particle size distribution was determined using the pipette method, and the bulk density was determined using" - so, where the results of soil texture determination?
- "Subsamples of 0.5–1.0 g ground residue materials were dry-ashed at 550C" - ground of fine earth of soils? dry ashed - or determination of loss ignition rate?
- Results chapter- results of statistical treatment shoul be visualised better, may be with table or graphs. The same is related to given graphs - not only in text.
- You have mentioned that sandy soil are degraded - what kind of degradation - should clarified.
- I suggest to reconsider all the key words - not microbial biomass, but microbiological activity, replace Thailand and insert the soils name, delete SOM and insert respiration rate.
Author Response
Response to reviewers (agronomy-1210019)
Reviewer1
- method of organic carbon determination - need to be clarified.
Answer:
Organic C was determined by Walkley and Black wet digestion method (Walkley and Black, 1934). We have added the statement to indicate the method of soil organic C as well as total N determination in L. 224-226.
- "Soil particle size distribution was determined using the pipette method, and the bulk density was determined using" - so, where the results of soil texture determination?
Answer:
The results of soil particle size distribution and bulk density are in section 2.1, paragraph 1, L. 179.
- "Subsamples of 0.5–1.0 g ground residue materials were dry- ashed at 550C" - ground of fine earth of soils? dry ashed – or determination of loss ignition rate?
Answer: The residue materials collected from the field are likely to have some adhering soils which could not be totally removed from the residues using a brush. Therefore, the residue dry weight prior to subtracting the ash weight is the weight of the residue plus the weight of adhering soils. Conventionally, the ground residue materials with adhering soil are dry-ashed in a furnace at 550°C. The dry ashing is a standard method of transforming these adhering soils and minerals to ash the weight of which then subtracted from the residue total dry weight to get the so called “ash-free dry weight” signifying the condition of being free from the mineral or inorganic matter. It is not the determination of loss on ignition rate. To make it clearer to readers, we have added the phrase “For residue analysis,..” at the beginning of the sentence L. 249 to mark the new paragraph as the section that describes residue analyses.
- Results chapter- results of statistical treatment should be visualised better, may be with table or graphs. The same is related to given graphs - not only in text.
Answer: Do you mean the display of statistical significance among treatments in Fig. 1 and 2? We have inserted asterisks above the lines indicating significant differences among residue treatments in various DAI so that the significant difference can be visualized better. In addition, we have added the LSD values in the inset tables above the graphs as suggested by reviewer 2. Please refer to the revised Fig. 1 (L. 348) and Fig. 2 (L. 380).
- You have mentioned that sandy soil are degraded - what kind of degradation - should clarified.
Answer: The degradation is the loss of SOM due to land use change from forest to agriculture. We have added a statement in L. 34-36 to that effect.
- I suggest to reconsider all the key words - not microbial biomass, but microbiological activity, replace Thailand and insert the soils name, delete SOM and insert respiration rate.
Answer: We have added keywords that you have suggested including ‘microbial activity’, soil respiration; Ultisol (soil name); however we would like to maintain microbial biomass, Northeast Thailand and soil organic matter. For microbial biomass, it is an important soil parameter used in the calculations of microbial carbon and nitrogen use efficiencies which were key parameters for this study. Soil organic matter is the soil quality parameter that we strive to improve through application of organic residues which is the subject of this paper. Northeast Thailand is kept for literature searching purpose, so that this paper will be found under the search for data of this geographical region. Now our keyword list become:
Keywords: C and N use efficiencies; microbial activity; microbial biomass; Northeast Thailand; residue chemical composition; soil organic matter; soil respiration; Ultisol
Note that we are allowed for up to 10 keywords.
Reviewer 2 Report
Comments on agronomy-1210019
Overall, the paper is well organized and well written. I have some minor issues
Abstract
In abstract, quantitative description of results observed should be given.
A clear conclusion is missing
Introduction
It must be short not more than 2.5 pages
Also, papers from 2021 should be consulted
Results
The results presented in the Tables above Figures must include the LSD values recorded during statistical analysis
Conclusions
It should also be short, speculations must be avoided
Author Response
Response to reviewers (agronomy-1210019)
Reviewer 2
- Abstract: In abstract, quantitative description of results observed should be given. A clear conclusion is missing
Answer: We have added quantitative description of important results and the conclusion statements in the Abstract as suggested. Please refer to the Abstract section in the revised MS (L. 13, 14, 16-19).
We have added the conclusion in L. 23-25.
- Introduction: It must be short not more than 2.5 pages.
Answer: We have deleted some statements in the Introduction section including those in paragraph 1 (L. 44-50) : containing descriptions of labile and resistant types of C compounds in residues. Paragraph 2 (L. 61-63): describing how Thai farmers are encourage by government extension agents to use rice straw. Paragraph 6 (last paragraph) (L. 143-145): the opening sentence.
- Also, papers from 2021 should be consulted
Answer: We have added two new relevant references published in 2021 in the Introduction :
Paragraph 3 (L. 81-83) Jaman et al. (2021) and L. 94-98 Almagro et al. (2021). We have added these two new references in the References section no. (L. 658-660 and L. 668-670).
- Results: The results presented in the Tables above Figures must include the LSD values recorded during statistical analysis.
Answers: We have added LSD values in all inset tables in Fig. 1 (L. 348) and 2 (L. 380) as suggested.
- Conclusions: It should also be short, speculations must be avoided
Answer: We have shortened the Conclusions by about one fifth and have deleted the parts considered speculative as well as modified the writing (L. 599-611).
