Soil Properties of a Tef-Acacia decurrens-Charcoal Production Rotation System in Northwestern Ethiopia
Round 1
Reviewer 1 Report
please improve your article title
please improve your introduction section with latest information
Its better to more attractive sentence for the justification of novelty statement.
Why use 2 mm sieve for chemical analysis. its better to use 0.5 mm sieve for analysis.
please check superscript and subscript.
please revise conclusion according to your results.
Please address typo-mistake
Author Response
Response to Reviewer 1
Point 1. Please improve your article title
Response 1. The tittle has been improved to “Soil properties under tef-Acacia decurrens-charcoal production agroforestry system in northwestern Ethiopia”
Point 2. please improve your introduction section with latest information
Response 2. Latest literatures have been added in the introduction (Reference: 3; 4; 13; 14; 16; 23; 39; 50; 65)
Point 3. Its better to more attractive sentence for the justification of novelty statement.
Response 3. More attractive sentence has been provided for the justification of novelty statement (Lines:99-102)
Point 4. Why use 2 mm sieve for chemical analysis. its better to use 0.5 mm sieve for analysis.
Response 5. We preferred 2 mm sieve because it t includes all primary soil particles we analyzed in our study, and 2mm and smaller soil particles are considered as agricultural soil. It is the standard size according to the Norma ISO 11464. (1994). Soil Quality – Pretreatment of samples for physico-chemical analysis. International Organization for Standardization.Geneva, Switzerland. 9 p.
Point 5. please check superscript and subscript.
Response 5. Line 242, 242,244 corrected
Point 6. please revise conclusion according to your results.
Response 6. The conclusion has been revised; unrelated statements related with Al and Fe contamination have been removed
Point 7. Please address typo-mistake
Response. All have been addressed
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Manuscript: Effect of tef-Acacia decurrens-charcoal production agroforestry system on soil properties in northwestern Ethiopia:
This paper deals with the evaluation of the impact of charcoal production on soil properties in agroforestry systems in a region of northwestern Ethiopia in two directions: (1) selected charcoal production spots vs. adjacent tef mono-cropping system and (2) inside and outside of randomly selected charcoal production spots. Although the effort of the authors should be recognized, after careful reading of the manuscript, I think that the manuscript's material and methods, discussion and results need to be improved.
I have a lot of concerns, which need to be addressed before considering for final publication. I recommend reject but encouraging resubmission.
- Introduction; line 48: ”or remove GHG”; please provide here the meaning of this abbreviation (not in line 54). Check, please.
- Introduction; line 59: ”referred hereafter as TACPA”; I think that here is the first time that this abbreviation appears in the Introduction (It is better not to link Abstract (where TACPA appears) to Introduction). Check, please.
- Introduction; line 101: ”TM system”; please provide here the meaning of this abbreviation. Check, please.
- Material and Methods; Figure 1. I think that a brief reference to the study area (its colour) should be appear in the footnote of the figure.
- Material and Methods; line 115. Soil Classification System? Check, please.
- Material and Methods; Table 1. Why SE abbreviation has dots? All other abbreviations in the text do not have dots. Please provide here the meaning of this abbreviation. Please provide the meaning of all the abbreviations which appear in this table heading. Check all the table headings of the manuscript. Why means have four significant figures whereas standard errors have three? Please match the significant figures in this table (check all the tables).
- Material and Methods; lines 145-152. “The sampling design covered seven different areas (treatments) (TM system plus first, second and third rotation in the TACPA system, both from inside and outside charcoal production spot).” So, seven or six? “The sub soil samples were combined to a single composite soil sample for each depth and replication”. So, do you have replications or pseudo-replications? Explain more clearly the design for a better comprehension.
- Material and Methods; lines 164-165. Why total and not available nutrients? Please explain in scientific or technical terms. In the case of P and K, why both available and total? Please explain in scientific or technical terms. If the soil of the region are in the medium to strongly acidic range (line 216), why do not to evaluate available Ca and Mg (present in soil solution and exchangeable complex)? as well as Al in better extractant (i.e. Solution of KCl 1M which extracts exchangeable Al)?
- Material and Methods; lines 168-177. A new subsection is required (2.2 Data analysis?).
- Material and Methods; charcoal characterization is required and mandatory.
- Results; soil characteristics at the beginning of the experiment are required (not only soil textural fractions).
- Results; line 1820. “(BD, cm-3)”. BD, g cm-3? I think that is better that units do not appear in the text of sections and sub-sections. Check all the manuscript.
- Results; lines 182-183. Where are the F-statistic values? (and optionally accompanied by degree of freedoms). Check all the manuscript.
- Results; Figure 4. “SOC Contnet”. SOC Content? But not TN Content? Perhaps is best to delete the term Content in both axes.
- Results; line 211. “pH (H2O)” Please, delete H2O, you do not provide in line 159 this style for soil/water suspension.
- Results; line 229. “available magnesium” It does not appear in material and methods section. How was extracted?
- Results; why table 5 appears before table 4? Please check.
- Results; line 245. why upper case letter(s) and no letters (like lower case) Please check.
- Results; Table 4. Where are available Na and Mg? Please check.
- Results; Table 4. “nutrient content” or total nutrient contents? Please check
- Results; Figure 5. Locate letters into the figures with best location and provide the letter (d). Line 272: “gm kg-1” Please check
- Results; lines 279-280. “Figure. 5”; why a dot after Figure? (again in line 284) Please check throughout the manuscript.
- Results; line 288. “3.2.1”; 3.2.2? Please check.
- Results; line 291. “respectively,”; respectively;? Please check.
- Results; line 294. “Contents of soil nutrients”; You refer to total content (like in line 298), do not you? Please check.
- Results; line 299. “problematic elements”; Why are problematic? Please explain. Because the acid nature of the soil? And if so, perhaps another study strategy for soil nutrients is better? ... available content and not total content?
- Discussion; line 313. “A. decurrens”; Italic letters? Please check throughout the manuscript scientific names.
- Discussion; lines 348-349. “the higher pH in TACPA”; mean values of table 2 are lowers, are not they? Please check.
- Discussion; lines 353-357. “the higher P available”; only in rotation 1 and 2, are not you? Please specify and check. Associated with higher pH of TACPA system? These findings are not connected (TM-pH > TACPA-pH, is not it?). This paragraph requires reformulation.
- Discussion; lines 363-366. “Na availability”; perhaps charcoal composition could be explain this and another things contrary to your expectations? Charcoal characterization is required (What is its pH, electrical conductivity and nutrient composition?). I think that a better discussion (and conclusions) will be possible (for example in C/N ratios and total N content, as well as in several nutrient contents), when charcoal characterization will be provided.
- Discussion; line 381. Close the parenthesis after [93-95].
- Discussion; line 430. Do not begin a paragraph with [39]; instead “Orguntunde et al. (2008), ...”.
- References; line 693. “Internaitonal 2004” International?
Author Response
Response to Reviewer 2
Point 1. Introduction; line 48: ”or remove GHG”; please provide here the meaning of this abbreviation (not in line 54). Check, please.
Resposne 1. Meaning of the abbreviation, GHG, has been provided at the end of paragraph 2 (Line 48) beforehand
Point 2. Introduction; line 59: ”referred hereafter as TACPA”; I think that here is the first time that this abbreviation appears in the Introduction (It is better not to link Abstract (where TACPA appears) to Introduction). Check, please.
Response 2. The abbreviation TACPA system has been removed from the abstract to dissociate it from the introduction
Point 3. Introduction; line 101: ”TM system”; please provide here the meaning of this abbreviation. Check, please.
Response. Meaning of the abbreviation, TM system, has been provided (Lines: 66 -67). And it has also further characterized in the materials and methods (131-169).
Point 4. Material and Methods; Figure 1. I think that a brief reference to the study area (its colour) should be appear in the footnote of the figure.
Response 4. To make Figure 1 clearer (with colors and legends), the map of the study area has been changed; in the map the position of the study site has been put relative to African and Ethiopia; copy right caption added
Point 5. Material and Methods; line 115. Soil Classification System? Check, please.
Resposne 5. The predominant soil types in the study area are Nitisol and Acriso (Line 117)
Point 6. Material and Methods; Table 1. Why SE abbreviation has dots? All other abbreviations in the text do not have dots. Please provide here the meaning of this abbreviation. Please provide the meaning of all the abbreviations which appear in this table heading. Check all the table headings of the manuscript. Why means have four significant figures whereas standard errors have three? Please match the significant figures in this table (check all the tables).
Response 6. The dots have been removed from the abbreviation SE; the meaning of the abbreviation has been given at the bottom of table 1.
Regarding the difference in significant figures, some variables have so minute weight and many zero significant digits we were forced to make the significant figure different.
Point 7. Material and Methods; lines 145-152. “The sampling design covered seven different areas (treatments) (TM system plus first, second and third rotation in the TACPA system, both from inside and outside charcoal production spot).” So, seven or six? “The sub soil samples were combined to a single composite soil sample for each depth and replication”. So, do you have replications or pseudo-replications? Explain more clearly the design for a better comprehension.
Response 7. The seven number treatments have been written in full to make it clearer (Lines 150-154). Six (Line 148) is the number of composite sub samples to be complained to a single sample. The four replications have been clearly written in line …
Point 8. Material and Methods; lines 164-165. Why total and not available nutrients? Please explain in scientific or technical terms. In the case of P and K, why both available and total? Please explain in scientific or technical terms. If the soil of the region are in the medium to strongly acidic range (line 216), why do not to evaluate available Ca and Mg (present in soil solution and exchangeable complex)? as well as Al in better extractant (i.e. Solution of KCl 1M which extracts exchangeable Al)?
Resposne 8. Total nutrients are preferred to available nutrients for analysis because of technical ease. The amounts of soil nutrients in chemical forms accessible to plant roots (available nutrients) are technically difficult to measure except for P and K. therefore, total nutrient, which is relatively easy to was measure, was considered for our analysis.
Ca and Mg were also measured but they were not in detectable limit in our analysis.
Point 9. Material and Methods; lines 168-177. A new subsection is required (2.2 Data analysis?).
Resposne 9. A new sub section has been provided for 2.2 for analysis
Point 10. Material and Methods; charcoal characterization is required and mandatory.
Resposne 10. The charcoal was not characterized in our study separately, because the charcoals in our study are contained in the soil samples as charcoal debris and were analyzed with the soil samples. Above all our study was conducted completely in the farmers’ setting, not in pre-arranged experimental setting.
Point 11. Results; soil characteristics at the beginning of the experiment are required (not only soil textural fractions).
Response 11. The experiment was done under the local farmers’ setting, It was not pre-set by authors.
Point 12. Results; line 1820. “(BD, cm-3)”. BD, g cm-3? I think that is better that units do not appear in the text of sections and sub-sections. Check all the manuscript.
Checked
Point 13. Results; lines 182-183. Where are the F-statistic values? (and optionally accompanied by degree of freedoms). Check all the manuscript.
Resposne 13. Inserting columns for F-statistics and degree of freedom in the result tables, we are afraid, could have made the tables very large. And therefore, we have not included them in the table for the sake of clarity.
Point 14. Results; Figure 4. “SOC Contnet”. SOC Content? But not TN Content? Perhaps is best to delete the term Content in both axes.
Resposne 14. Yes, thank you! The term content has been deleted from the box
Point 15. Results; line 211. “pH (H2O)” Please, delete H2O, you do not provide in line 159 this style for soil/water suspension.
Response 15. H2O has been deleted, thank you
Point 16. Results; line 229. “available magnesium” It does not appear in material and methods section. How was extracted?
Response 17. Available Mg has been now included in the material and method (Line 166)
Point 18. Results; why table 5 appears before table 4? Please check.
Resposne 18. The error has now been corrected, thank you
Response 19. Results; line 245. why upper-case letter(s) and no letters (like lower case) Please check.
Response 19. Because the letters designating significant difference was either a single letter or double letter in our case
Point 19. Results; Table 4. Where are available Na and Mg? Please check.
Resonse 19. Na is present in the table but Mg were below detection limit in comparison of spot of charcoal production with the area outside of it, and not included in the table (it has now been mentioned at the bottom of table 4 and table 5)
Point 20. Results; Table 4. “nutrient content” or total nutrient contents? Please check
Resposne 20. It is total nutrient, corrected
Point 21. Results; Figure 5. Locate letters into the figures with best location and provide the letter (d). Line 272: “gm kg-1” Please check
Resposne 21. Corrected
Point 22. Results; lines 279-280. “Figure. 5”; why a dot after Figure? (again in line 284) Please check throughout the manuscript.
Resposne 22. The dots have now been removed, thank you
Point 23. Results; line 288. “3.2.1”; 3.2.2? Please check.
Response 23. Corrected
Point 24. Results; line 291. “respectively,”; respectively? Please check.
Response 24. Yes respectively, in different rotations (the phrase ‘in different rotations’ has now been mentioned above it)
Point 25. Results; line 294. “Contents of soil nutrients”; You refer to total content (like in line 298), do not you? Please check.
Response 25. Total contents of nutrients
Point 26. Results; line 299. “problematic elements”; Why are problematic? Please explain. Because the acid nature of the soil? And if so, perhaps another study strategy for soil nutrients is better? ... available content and not total content?
Response 26. The concept of problematic has been removed form the manuscript to avoid confusion. It was actually, related with the contamination Al and Fe.
Point 27. Discussion; line 313. “A. decurrens”; Italic letters? Please check throughout the manuscript scientific names.
Response 27. It has been italicized
Point 28. Discussion; lines 348-349. “the higher pH in TACPA”; mean values of table 2 are lowers, are not they? Please check.
Response 28. Higher in relative terms, not in absolute sense. This now has been mentioned in the place with the phrase ‘relative to’ (Line 376)
Point 28. Discussion; lines 353-357. “the higher P available”; only in rotation 1 and 2, are not you? Please specify and check. Associated with higher pH of TACPA system? These findings are not connected (TM-pH > TACPA-pH, is not it?). This paragraph requires reformulation.
Resonse 28. It has now been specified in the place as rotation 1 (Line 380). The higher pH was mentioned in relative term, not absolute. The paragraph has now been changed a little.
Point 29. Discussion; lines 363-366. “Na availability”; perhaps charcoal composition could be explain this and another things contrary to your expectations? Charcoal characterization is required (What is its pH, electrical conductivity and nutrient composition?). I think that a better discussion (and conclusions) will be possible (for example in C/N ratios and total N content, as well as in several nutrient contents), when charcoal characterization will be provided.
Resposne 29. As mentioned above, in our study, the charcoal was analyzed along with the soil. We did not nee to characterize the charcoal separately. The explanation given hold true for both the soil and the charcoal in the soil.
Point 30. Discussion; line 381. Close the parenthesis after [93-95].
Resposne 30.The parenthesis has been closed
Point 31. Discussion; line 430. Do not begin a paragraph with [39]; instead “Orguntunde et al. (2008), ...”.
Response 31. Thank you, it has been corrected.
Point 32. References; line 693. “Internaitonal 2004” International?
Point 32. It has been corrected, thank you for the indication
Author Response File: Author Response.pdf
Reviewer 3 Report
Agroforestry systems, particularly small-scale farmers’ tree plantation systems, have been receiving coverage in discussions in recent decades. This holds on a global scale, where reducing deforestation is expected to yield environmental benefits, e.g., greenhouse gas emission reduction, however, it also implies potential economic losses for deforestation on regional and national scales in both developing and developed economies. The expansion of tree plantations is often driven by public and private sectors’ investments rather than initiatives by small-scale producers. In general, large-scale tree plantations have received little positive feedback globally, if not in all regions, particularly in developing countries, they were often associated with concerns about land grabs, displacement of local populations, poor worker conditions, declining water availability and its quality, high chemical use, and low levels of biodiversity.
Extensive clearing of natural forests has exacerbated deforestation in the Ethiopian highlands caused by the expansion of crop cultivation into fragile environments, such as degraded hillsides. Apart from causing soil degradation, the high deforestation rate has diminished households’ wood supplies required for cooking, heating, and construction purposes.
Climate-smart agriculture is an integrated approach to managing landscapes, livestock, forests and fisheries, that address the interlinked challenges of food security and accelerating climate change. The tef-Acacia decurrens-charcoal production agroforestry widely discussed in the submitted article is a unique and rapidly developing agroforestry system. The authors studied in detail the effects of the TACPA system on soil properties in three rotations compared to the TM system and evaluated the effects of TACPA charcoal production on soil properties by comparing soil properties at and outside the charcoal production sites.
I have gone through the manuscript titled, " Effect of tef-Acacia decurrens-charcoal production agroforestry system on soil properties in northwestern Ethiopia", and find it very interesting to read.
The paper is in general well written and well-illustrated, and logically structured, while at the same time adequately concise. The title clearly describes the contents of the paper. The abstract looks good and contains all the important information, it encapsulates the entire study (a bit of introduction, aim, result and outcome). The introduction is well written as it gives a good background of the research in question. Also, the aim of the study is evident in the beginning and concluding parts. I believe that the Materials and Methods section is well structured and scientifically sound. Literature reviews in the discussion section of the manuscript are good. The manuscript is well concluded as the main outcomes are well captured with some recommendations.
Specific comments:
Lines 74: “stimulation of microbial” – delete a space
Figure 2: The unchanged chart was copied from another article: https://doi.org/10.1016/j.tfp.2020.100044 This is plagiarism! I am asking the authors to make a new figure or delete this data.
Line 123: I have a doubt: should table 1 not be included in the results or discussion chapter? Was this table made by the authors?
Line 299: “Among the three potentially problematic elements …” -sentence requires rephrasing, please clarify
Line 377: “…rotations. But notice …” – delete the space
Line 424: “…experiment. The non-significant…” – delete the space
Line 453: the same problem, please remove the space.
Author Response
Response to Reviewer 3
Point 1. Lines 74: “stimulation of microbial” – delete a space
Resposne 1. It has been deleted, thank you for indication
Point 2. Figure 2: The unchanged chart was copied from another article:
https://doi.org/10.1016/j.tfp.2020.100044 This is plagiarism! I am asking the authors to make a new figure or delete this data.
Response 2. A new figure has been made.
Point 3. Line 123: I have a doubt: should table 1 not be included in the results or discussion chapter? Was this table made by the authors?
Response 3. Table 1 was completely the work of the authors. Soil texture was removed from the results and discussion not to make the paper unnecessarily bulky. It was included in material and method to make the soil description of the study area complete.
Point 4. Line 299: “Among the three potentially problematic elements …” -sentence requires rephrasing, please clarify
Response 4. The concept of problematic elements associated with contamination Al and Fe has been removed from the manuscript to avoid confusion.
Point 5. Line 377: “…rotations. But notice …” – delete the space
Response 5. The space has been deleted
Point 6. Line 424: “…experiment. The non-significant…” – delete the space
Response 6. The space has been deleted
Point 7. Line 453: the same problem, please remove the space.
Response 7. The space has been deleted
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Manuscript: Soil properties under Tef-Acacia decurrens-Charcoal Production Agroforestry System in Northwestern Ethiopia:
The authors have taken into account a large part of the previous comments and recommendations in the version 1 and have made a improvement of the article. I appreciate the effort made by the authors and its corrections.
However, a few small suggestions and corrections must be carried out in the article:
- Material and Methods; charcoal characterization is required and mandatory. The author’ response letter said: “The charcoal was not characterized in our study separately, because the charcoals in our study are contained in the soil samples as charcoal debris and were analyzed with the soil samples”. I think that an explanation like this should be added in this section.
- Material and Methods; line 117: “ ... soil types are Nitisol and Acrisol ...” Soil Classification System? Check, please and provide it (USDA or FAO system). Please, check.
- Asterisks in tables 4 and 5 are best positioned in headings. As an example, in table 4 you have positioned the asterisk in Total nutrient*, but several available nutrients do not appear, so the asterisk must be refer not only to total nutrients. Please, check.
- Results; line 327. “problematic elements”; Why are problematic? Please explain. Because its toxic levels or perhaps because their blocking interaction? Check in the manuscript.
Author Response
Response to Reviewer 2
The authors have taken into account a large part of the previous comments and recommendations in the version 1 and have made a improvement of the article. I appreciate the effort made by the authors and its corrections.
However, a few small suggestions and corrections must be carried out in the article:
Point 1: Material and Methods; charcoal characterization is required and mandatory. The author’ response letter said: “The charcoal was not characterized in our study separately, because the charcoals in our study are contained in the soil samples as charcoal debris and were analyzed with the soil samples”. I think that an explanation like this should be added in this section.
Response: In section 2 paragraph one, lines 147-148, we have modified the sentence so that it explains the fact that the soil samples contain charcoal debris (biochar) from the charcoal production in the TACPA system: “In the TACPA system, the sub soil samples containing charcoal debris (biochar) from the charcoal production were taken from inside and outside of six randomly selected charcoal production spots at the end of the cropping period”
Point 2. Material and Methods; line 117: “ ... soil types are Nitisol and Acrisol ...” Soil Classification System? Check, please and provide it (USDA or FAO system). Please, check.
Response 2: We found this information from FAO Assistance to Land Use Planning Ethiopia Geomorphology and Soils.; FAO: Addis Ababa, Ethiopia, 1984. (Reference 10), which was also used by other researchers:
e.g. Yihenew, G. Selected Physical and Chemical Characteristics of Soils of Adet Research Center and Its Testing Sites in Northwestern Ethiopia. Ethiopian Journal of Natural Resources 2002, 4, 199–215. (Reference 32). Our field observation also confirms this. The fact has been mentioned in elaborated in the sentence.
Point 3: Asterisks in tables 4 and 5 are best positioned in headings. As an example, in table 4 you have positioned the asterisk in Total nutrient*, but several available nutrients do not appear, so the asterisk must refer not only to total nutrients. Please, check.
Response 3: We have moved the asterisks in the table 4 and 5 up to the headings. We have not used the asterisks for the other tables. These tables don’t contain variables that were analyzed but not detected.
Point 4: Results; line 327. “problematic elements”; Why are problematic? Please explain. Because its toxic levels or perhaps because their blocking interaction? Check in the manuscript.
Response 4: We have removed the concept to” problematic elements”, a different topic by its own, from the result as we have removed it from the abstract, introduction, material and methods, and conclusion in the first-round review. We have presented the result of Al, Mn and Fe like the rest of the total nutrients in our study. Hence the last paragraph of section 3.2.4 was modified accordingly.
Finally, the title has been improved to “Soil Properties of a Tef-Acacia decurrens-Charcoal Production Agroforestry System in Northwestern Ethiopia”.
Author Response File: 
Author Response.docx
Reviewer 3 Report
The authors have adequately addressed my comments and suggestions towards improvement and/or correction. I have no further comments.
Author Response
Thank you very much!
The Revised PDF Version for all reviewers attached.
Author Response File: Author Response.pdf
