Response of Cellulose Decomposition and Nodulation in Soils Amended with Biochar for Peri-Urban Agriculture
, Hossam Abdelmageed 1,2, Abdelaziz Saleh 1, Samia Ahmed 1, Mohieyeddin M. Abd El-Azeim 3, Joanna Lemanowicz 4, Gaber E. Eldesoky 5 and Omar Saad 1Round 1
Reviewer 1 Report
Introduction
1. Lines 59-61, please provide more details of [16] or insert more references; Is biochar addition improved cellulose decomposition of biochar, or cellulose decomposition of other organic matters?
2. please define the meaning or the importance of “ peri-urban agricultural regions” why the authors are interested soils in those areas.
Materials and Methods
1. Lines 124-125, the pots were incubated for 12 weeks ( = 84 days), but samples were obtained after 15, 30, 60 and 90 days (lines 126-128). Please clarify.
2. Lines 128-137, please insert the method for actinomycetes.
3. Lines 136-137, please explain why the authors did not include actinomycetes, but select only fungal/bacterial ratio.
4. Lines 184-193, please indicate sampling time for enzymatic hydrolysis.
Results and Discussion
1. Figure 3, please insert error bars ( +/- S.D. or S.E.) on line graphs, and it will be good for readers, if the authors make Y-axis with the same scale between clay and sandy soils.
2. Figure 3, microorganisms of the control groups also increased from 15-60 days, please explain, and discuss the reasons.
3. Figure 3 showed B3 was the best for cellulose decomposing bacteria, but Figures 6-7 showed B4 was the best for cellulose decomposition %. Please discuss the possible reasons in the result and discussion.
4. Overall, the discussion section lacks the in-depth discussion/explanation, please consider.
-
Author Response
(Reviewer 1):
Introduction
- Lines 59-61, please provide more details of [16] or insert more references; Is biochar addition improved cellulose decomposition of biochar, or cellulose decomposition of other organic matters?
Revised, reference added. Biochar addition improved cellulose decomposition in general not the cellulose decomposition of biochar. Biochar is a carbon-rich product produced when biomass is burned without oxygen (pyrolysis). We studied its effect on cellulose decomposition.
- please define the meaning or the importance of “peri-urban agricultural region” why the authors are interested soils in those areas.
Thank you very much for this comment, Revised, Line 35-37
Materials and Methods
1. Lines 124-125, the pots were incubated for 12 weeks ( = 84 days), but samples were obtained after 15, 30, 60 and 90 days (lines 126-128). Please clarify.
Thank you, yes it was a mistake, it is 13 weeks. Revised Line 127
- Lines 128-137, please insert the method for actinomycetes.
Revised, Line 133
- Lines 136-137, please explain why the authors did not include actinomycetes, but select only fungal/bacterial ratio.
It is frequently hypothesized that high soil fungal/bacterial ratios are indicative of more sustainable agricultural systems. As stated by de Vries et al. 2006. (Fungal/bacterial ratios in grasslands with contrasting nitrogen management). Line 139.
- Lines 184-193, please indicate sampling time for enzymatic hydrolysis.
Revised. Line 195
Results and Discussion
- Figure 3, please insert error bars ( +/- S.D. or S.E.) on line graphs, and it will be good for readers, if the authors make Y-axis with the same scale between clay and sandy soils.
Revised
- Figure 3, microorganisms of the control groups also increased from 15-60 days, please explain, and discuss the reasons.
Yes, we agree with that but the other treatments with biochar were higher than the control. This means that biochar had a positive effect.
Moreover, the numbers of microbes are linked to their growth curve, which begins with an increase, then stability, and then a decrease again
- Figure 3 showed B3 was the best for cellulose decomposing bacteria but Figures 6-7 showed B4 was the best for cellulose decomposition %. Please discuss the possible reasons in the result and discussion.
Completely agree. Please see lines 337 - 378
- Overall, the discussion section lacks the in-depth discussion/explanation, please consider.
Thank you very much, we consider this very much, we updated the references with new ones and did our best in discussing and explaining all the results we had from the little available literature on this topic.
Finally, thank you very much for your time and effort in helping us improve our manuscript. Hopefully, the corrections required have been adequately made.
Reviewer 2 Report
This work reported response of cellulose decomposition and nodulation in soils amended with biochar for peri-urban agriculture. The manuscript is well-prepared, and provide useful infromation about biochar application to peri-urban agriculture. It is suggested to be accepted after minor revisions.
English should be improved in the manuscript.
Research advances about the impact of biochar on microbial communities should be summarized in Introduction.
The major components of lignocellulose biomass derived form plants are cellulose, lignin, and hemicellulose, why cellulose decomposition was studied in this work?
Is there any pretreatment of clay soil and sandy soil used in this work before experiments?
Some references closely related to biochar application to soil are suggested to be added to support this work. References: Phosphorus adsorption by functionalized biochar: a review, Environmental Chemistry Letters, 2023, 1-28; Biochar-based slow-release of fertilizers for sustainable agriculture: A mini review. Environmental Science and Ecotechnology, 2022, 100167; Arsenic availability and transportation in soil-rice system affected by iron-modified biochar. Journal of Central South University, 2021, 28(6), 1901-1918.
Error bars should be added in the figures of experimental results.
Conclusions section should be improved to highlight the key findings from this work.
English should be improved in the manuscript.
Author Response
(Reviewer 2):
This work reported response of cellulose decomposition and nodulation in soils amended with biochar for peri-urban agriculture. The manuscript is well-prepared and provide useful information about biochar application to peri-urban agriculture. It is suggested to be accepted after minor revisions.
Thank you very much for your positive reply and support.
English should be improved in the manuscript.
Revised
Research advances about the impact of biochar on microbial communities should be summarized in Introduction.
Revised (lines 61-62)
The major components of lignocellulose biomass derived from plants are cellulose, lignin, and hemicellulose, why cellulose decomposition was studied in this work?
Cellulose is the most abundant carbon input in soil. Cellulose can account for up to 60% of plant material (dry wt.), and its difficult decomposition (polysaccharides) is of major importance to the biogeochemical cycling of carbon (C) and essential plant nutrients. In structure, cellulose is a carbohydrate composed of glucose units bound together in a long, linear chain by b-linkages at C atoms 1 and 4 of the sugar molecule. Cellulolytic enzymes for degrading the polymer are produced by a host of microorganisms (bacteria, actinomycetes and fungi) (Paul and Clark, 1996). Also, artificial substrate such as filter paper is used because it is easier to handle, and 99% of its component is cellulose.
Is there any pretreatment of clay soil and sandy soil used in this work before experiments?
No
Some references closely related to biochar application to soil are suggested to be added to support this work. References: Phosphorus adsorption by functionalized biochar: a review, Environmental Chemistry Letters, 2023, 1-28; Biochar-based slow-release of fertilizers for sustainable agriculture: A mini review. Environmental Science and Ecotechnology, 2022, 100167; Arsenic availability and transportation in soil-rice system affected by iron-modified biochar. Journal of Central South University, 2021, 28(6), 1901-1918.
Thank you for the suggested references. Reference added
Error bars should be added in the figures of experimental results.
Revised
Conclusions section should be improved to highlight the key findings from this work.
Revised
Finally, thank you very much for your time and effort in helping us improve our manuscript.
We did all your suggested points listed in your report as much as we can. Hopefully, the corrections required have been adequately made.
Reviewer 3 Report
1. On Abstract: I suggest downgrading the unit of biochar application rate. Instead of ton/ha, make it kg/sq.m. as the study was pot experiment.
2. Lines 26-27: Please specify, what significantly increased?
3. Line 77: “the goals…” instead of primary goal…
4. Figure 1. Please improve the maps. Provide names of country, city and even the specific area in the city.
5. Line 101 says Source and type of biochar – please provide the real source of biochar or the producer of biochar used in the study. If you produced it with your own experiment, then mention it in the methodology.
6. Line 114: Scanning electron microscope not “scan”, also provide the manufacturer, city and country.
7. Lines 122-123: Discuss how you measure the MC of soil in the pot.
8. Lines 123-124: I suggest downgrading the units used, ton/ha is for large applications, kg/sq.m. might be appropriate.
9. Lines 246-247: Stating the hypothesis in Results and Discussion is discouraged, it should have included in the Introduction.
10. On Conclusions: In Objectives, you stated “a) improve our understanding of biochar’s effect on the cellulose decomposition process” so please included these “processes” in the Conclusion.
11. On Conclusion, it is worth mentioning the best or the optimum biochar application rates on different types of soil in relation with cellulose decomposition rates, plant growth and other parameters. In short, include in the Concluding statement some important numerical values gathered from this study.
Minor editing
Author Response
(Reviewer 3):
Thank you very much for sending us very detailed reviews of this Manuscript, we tried as much as we can to do all of your valuable comments and corrections in your report.
On Abstract: I suggest downgrading the unit of biochar application rate. Instead of ton/ha, make it kg/sq.m. as the study was pot experiment.
Revised
- Lines 26-27: Please specify, what significantly increased?
Fresh and dry weight
3.Line 77: “the goals…” instead of primary goal…
Revised, Line 81
4.Figure 1. Please improve the maps. Provide names of country, city and even the specific area in the city.
Revised
5.Line 101 says Source and type of biochar – please provide the real source of biochar or the producer of biochar used in the study. If you produced it with your own experiment, then mention it in the methodology.
The real source of biochar is the corncob) and we produced it with our own (line 105)
6.Line 114: Scanning electron microscope not “scan”, also provide the manufacturer, city and country.
Revised
7.Lines 122-123: Discuss how you measure the MC of soil in the pot.
During plant growth, the soil moisture in each pot were maintained at 60% of the field's capacity by randomly weighing the pots and adding water as needed (lines 181-182).
- Lines 123-124: I suggest downgrading the units used, ton/ha is for large applications, kg/sq.m. might be appropriate.
Revised (nines 127 -128)
- Lines 246-247: Stating the hypothesis in Results and Discussion is discouraged, it should have included in the Introduction.
Deleted
- On Conclusions: In Objectives, you stated “a) improve our understanding of biochar’s effect on the cellulose decomposition process” so please included these “processes” in the Conclusion.
Revised
- On Conclusion, it is worth mentioning the best or the optimum biochar application rates on different types of soil in relation with cellulose decomposition rates, plant growth and other parameters. In short, include in the Concluding statement some important numerical values gathered from this study.
Revised (lines 483-485)
