Effects on Soil Chemical Properties and Carbon Stock Two Years after Compost Application in a Hedgerow Olive Grove
, Rui Bajouco 1,4, Jacqueline D. S. Leal 3, José O. Peça 2,4 and António B. Dias 2,4
Round 1
Reviewer 1 Report
General comments
It is an interesting manuscript. However, the authors need to improve some details, especially the introduction and conclusions.
Specific comments
Line 24: What is 2:1
Line 50: What are the main characteristics of olive leaves?
Line 58: Why did you study sheep manure; I did read it in the introduction. You need to improve the introduccion
Line 177: You must change m3 by m3
Line 241. You can write this information 104 g kg-1 for sand, 44 g kg-1 for silt, and 107 g kg-1 for clay in percentage
Line :265: You can delete control or T0. You need to choose a word
Line 286: Two compost dosage
Table: You need to change all the tables because the standard deviation is together with the mean. For example, 15.7 ± 0.7.
Figure 5: You must do the graphic in another program
Line 452: You must improve the discussion. It is weak
Line 505: You must add a conclusion
Author Response
The authors acknowledge the pertinence of most of the critics done and tried to implement all the corrections proposed in the new version of the manuscript. Below there is a brief answer to each of the specific comments of the reviewer.
Specific comments
Line 24: What is 2:1
It is the proportion. It was corrected in the text.
Line 50: What are the main characteristics of olive leaves?
Unfortunately, we do not have any specific analysis of the used olive leaves, besides the C, N, and the C/N ratio.
Line 58: Why did you study sheep manure; I did read it in the introduction. You need to improve the introduccion
We have introduced an additional explanation of the rationale for the choice of sheep manure.
Line 177: You must change m3 by m3
Corrected.
Line 241. You can write this information 104 g kg-1 for sand, 44 g kg-1 for silt, and 107 g kg-1 for clay in percentage
Corrected.
Line :265: You can delete control or T0. You need to choose a word
Corrected, we choose T0.
Line 286: Two compost dosage
Corrected.
Table: You need to change all the tables because the standard deviation is together with the mean. For example, 15.7 ± 0.7.
Corrected.
Figure 5: You must do the graphic in another program
Sorry, I did not understand the problem with the graphic. If it is the quality of the image I can send an image of better quality.
Line 452: You must improve the discussion. It is weak
We extended and deepened the discussion.
Line 505: You must add a conclusion
Considering that the Agronomy journal admits a facultative section of ‘Conclusions’, we decided that our main conclusion could be summarized in the last paragraph of the Discussion, and would not justify a separate section. Anyway, we reformulated that last paragraph trying to improve the final conclusion.
Reviewer 2 Report
This manuscript used compost of olive leaves plus sheep manure (2:1) applied in the row of olive grove to explore the effect of the compost on soil physical and chemical characteristics in the Portalegre, Portugal. The results found that the compost could improve soil fertility. However, there are still much left need for improvement. I could suggest this paper for publication in Agronomy after carefully modifying with the following suggestions:
(1) The Title needs improvement, not only soil chemical properties.
(2) It didn’t find the detail results of the experiments in the Abstract. It needs to add some key quantitative data.
(3) Why do you choose the sheep manure? Please explain it in the Introduction. And I suggest adding the present experiments design in the last paragraph of the Introduction.
(4) The climate data is very important for field experiments, please add the monthly data during 2020-2022, the Table 1(air temperature (T) deviations from the climate normal temperature, and accumulated precipitation (R) ratios with normal precipitation, for the indicated quarters, during the time span of this study) couldn't describe the truth.
(5) Why did you consider three levels of the compost? And why did you choose 2:1 proportion of these two components (olive leaves plus sheep manure). You should explain them in the Materials and Methods. The other suggestion is you might add a treatment of only olive leaves as compost.
(6) Line 237, How to mix the compost? Please add it.
(7) Line 149. Please attention, the copper content is high in the compost.
(8) Many data in the results hadn't the same years, it is not easy to compare with the control. Such as Table 2, there is only one year of coarse and fine fraction.
(9) Each table and figure requires a clear description of the results. Here we do not need to discuss the results.
Line19-20, "and the Circular Economy.", Why do you add it?, and it missed verb.
Author Response
The authors acknowledge the pertinence of most of the critics and tried to implement all the corrections proposed in the new version of the manuscript. Below there is a brief answer to each of the specific comments of the reviewer.
(1) The Title needs improvement, not only soil chemical properties.
The title of the manuscript was changed, trying to correspond better to its content.
(2) It didn’t find the detail results of the experiments in the Abstract. It needs to add some key quantitative data.
In fact, some quantitative results were missing in the Abstract. The situation was corrected and the most relevant results obtained were included in the Abstract, with some additional alterations in the text to avoid its substantial increase.
(3) Why do you choose the sheep manure? Please explain it in the Introduction. And I suggest adding the present experiments design in the last paragraph of the Introduction.
Both suggestions were incorporated in the text of the Introduction.
(4) The climate data is very important for field experiments, please add the monthly data during 2020-2022, the Table 1(air temperature (T) deviations from the climate normal temperature, and accumulated precipitation (R) ratios with normal precipitation, for the indicated quarters, during the time span of this study) couldn't describe the truth.
This was a very important suggestion that gave rise to Figure 2 in this new version of the manuscript and contributed to a better understanding of the field study.
(5) Why did you consider three levels of the compost? And why did you choose 2:1 proportion of these two components (olive leaves plus sheep manure). You should explain them in the Materials and Methods. The other suggestion is you might add a treatment of only olive leaves as compost.
In fact, there were only two levels of compost, because the T0 is the control (without compost). But the comment is pertinent, and a more complete explanation of all the previous questions is given in the new (and extended) version of the sub-section “2.3.Compost” (section Material and Methods).
(6) Line 237, How to mix the compost? Please add it.
That explanation was incorporated in the subsection Compost of the section Material and Methods
(7) Line 149. Please attention, the copper content is high in the compost.
The authors are aware of that and tried to explain better the copper origin (lines 550-555).
(8) Many data in the results hadn't the same years, it is not easy to compare with the control. Such as Table 2, there is only one year of coarse and fine fraction.
This is true because the variables presented in Table 2 were not considered for soil monitoring, that is, they were assumed as soil properties that would not change in the two years’ time of the study.
(9) Each table and figure requires a clear description of the results. Here we do not need to discuss the results.
Some rearrangements were also done, transferring some parts that could be considered ‘discussion of the results’ from the Results to the Discussion section.
Reviewer 3 Report
Indeed, there are differences in the numerical values of the bulk density, but they are statistically and practically insignificant. Unfortunately, 2 years is too short an evaluation period for typical mineral soils. Hence, the explanation in line 303-304 is absolutely true.
It is unclear why soil pH in T1 and T2 increases in 2022 compared to the previous year. As a rule, decaying organic matter acidifies the soil. How can this be explained? In the control, during observation, the pHH2O fluctuates and the pHKCl decreases.
What does 'regular soil fertilization' (line 105)/'the fertilizer regularly use' (line 422) mean? Every year, every 2 years? How do you explain the high potassium content in 2021 and the lower the following year? A similar trend is observed for phosphorus, except that the phosphorus content in the control increases year by year. The explanation in lines 417-423 is fine, but it doesn't explain the increase of the content in the control.
It seems to me that it would be a good idea to give an estimate of the amount of nutrients introduced with the compost, taking into account the nutrients from fertilizers and the initial nutrient content in the soil.
Minor editing of English language required - for example
run-on sentences Dominant soils are Skeletic Regosol and Vertic Luvisol, both with intermediate textures (loam to clay loam) in the superficial horizons and with occasional occurrence of carbonates, especially in deeper layers, but that can appear near soil surface as result of previous deep soil tillage [10]. punctuation (e.g. lack of comma before 'which') We have also to consider two effects that contribute to underestimate the mass of the compost by this method: only the residues > 1 mm were quantified, and the time spanning of 5 months during a warmer and more humid spring than normal (Table 1) which should have already reduced its mass. nonsensical sentences The organic matter as a lowering effect in the soil bulk density that is well known.Author Response
The authors acknowledge the pertinence of most of the critics and tried to implement all the corrections proposed in the new version of the manuscript. Below there is a brief answer to each of the specific comments of the reviewer.
It is unclear why soil pH in T1 and T2 increases in 2022 compared to the previous year. As a rule, decaying organic matter acidifies the soil. How can this be explained? In the control, during observation, the pH fluctuates and the pH decreases.
The authors tried to give a better and more detailed explanation for the pH results – please see lines 538-552.
What does 'regular soil fertilization' (line 105)/'the fertilizer regularly use' (line 422) mean? Every year, every 2 years?
More details were given about this subject in lines 132-136.
How do you explain the high potassium content in 2021 and the lower the following year? A similar trend is observed for phosphorus, except that the phosphorus content in the control increases year by year. The explanation in lines 417-423 is fine, but it doesn't explain the increase of the content in the control.
It seems to me that it would be a good idea to give an estimate of the amount of nutrients introduced with the compost, taking into account the nutrients from fertilizers and the initial nutrient content in the soil.
Better and more detailed explanations about these subjects were given in lines lines 212-217 and 465-473. However, in the framework of the present study, this discussion is always limited, because it would require an approach that was not implemented in this study.
Comments on the Quality of English Language
Minor editing of English language required - for example
run-on sentences Dominant soils are Skeletic Regosol and Vertic Luvisol, both with intermediate textures (loam to clay loam) in the superficial horizons and with occasional occurrence of carbonates, especially in deeper layers, but that can appear near soil surface as result of previous deep soil tillage [10].
punctuation (e.g. lack of comma before 'which') We have also to consider two effects that contribute to underestimate the mass of the compost by this method: only the residues > 1 mm were quantified, and the time spanning of 5 months during a warmer and more humid spring than normal (Table 1) which should have already reduced its mass.
nonsensical sentences The organic matter as a lowering effect in the soil bulk density that is well known.
All the mentioned sentences, as well as some others, were rewritten and improved, hopefully.
Round 2
Reviewer 2 Report
I agree to the authors' modifications. One suggestion is the last parapraph of the discussion( as a conclusion) should be pointed out that the limited scope, the present work only test a compost of olive leaves plus sheep manure(ratio 2:1) applied in the row of Olive trees.
Author Response
The authors thank reviewer 2 for his suggestions for the last paragraph (conclusion). It has been substantially modified and, we hope, much improved.
