Effectiveness of Rhizobium tropici sp. Strain UD5 Peat Biofertilizer Inoculant on Growth, Yield, and Nitrogen Concentration of Common Bean
, Ashwell Rungano Ndhlala 1, Mireille Asanzi Mvondo-She 2 and Semakaleng Mpai 1Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript entitled "Effectiveness of Peat Biofertilizer formulation of (Bradyrhizobium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry Bean (Phaseolus vulgaris L.)" is important for agricultural practice for dry bean cultivation using rhizobia biofertilizer. However, the manuscript is not clear and the authors should revise it very carefully.
The major problems are as follows:
1) Introduction: There is no indication for the treatments, T0, T1, T2, T3 in the abstract.
2) Is the inoculant density 6.5 x 109 CFU g-1 peat inoculant OK?
From lines 90-94, 60mL of liquid inoculant containing 6.5 x 109 CFU mL-1 was added to 250 g sterile peat. Then the 1 kg of the ultimate formulation contains 6.5 x 109 CFU g-1. So did the rhizobia multiply during preparation?
3) What is the main difference between two experimental sites?
Lines 98-114: The information for two experimental site were introduced, but it is not clear what are the main difference between two sites. Soil properties, climatic conditions such as temperature, or rain fall, or yield of dary bean, etc. In addition, I think the term "bioclimatic" should be changed to "climatic".
4) Lines 115-124: The experimental design is not clear. how many rows or what m of width for one plot of 50 m long.
Please explain precisely on T3. Readers cannot understand a registered standard inoculum previously used. Please explain what strain and density of the standard inoculum and what was the carrier materials to prepare.
Was the peat inoculant for example 250g was applied onto 50 kg of dry bean seeds in T1?
5) For figures a vertical axis should start from 0.
Figure 3: What is the unit of root length? m/m2, or m/plant?
Figure 4: What is the unit of number of nodules? nodule number/plant, nodule number/m2?
Figure 5: What is the unit of nodule size? average nodule size (mm) ?
Figure 6: What is the unit of yield? t/ha?
Figure 7: This figure is not N uptake because the unit shows g/kg.
Figure 7 may be N concentration (gN/kgDW).
I recommend showing the N contents (gN/m2) of (gN/plant) instead of N concentration. This will indicate the effectiveness of inoculants better.
Minor points
Line 10: nutrient values → valuable nutrients
Line 11: good fertilizers →chemical fertilizers
Line 13: Peat formation →peat formation
Lien14: tropici sp → tropici sp strain UD5
Line 16: bioclimatic zones →climtic zones
Line 18-: Please add the explanations for treatments, such as
Four treatments were applied, T0: control without inoculation, T1: 250g of peat inoculant of strain UD5 for 50 kg seeds, T2: 500g of peat inoculant of strain UD5 for 50 kg seeds, T3: 200 g of ? inoculant of ? for 50 kg seeds.
Please explain what is the number of T1=18.22%. The percentage increase compered to T0. The number should be three digits, like 18.2% instead of 18.22.
Line 55: noculant → inoculant
Line 57: [9] also → Chianu et al. [9] also
Comments on the Quality of English Language
English is not good. Please ask a native English speaker or professional English editing before submission.
Author Response
6th January 2024
Dear Reviewer,
We appreciate your comments and suggestions, which improved the quality of the manuscript. Please find below the response to your comments and suggestions
Comments and Suggestions from the reviewer
The manuscript entitled "Effectiveness of Peat Biofertilizer formulation of (Bradyrhizobium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry Bean (Phaseolus vulgaris L.)" is important for agricultural practice for dry bean cultivation using rhizobia biofertilizer. However, the manuscript is not clear and the authors should revise it very carefully.
The major problems are as follows:
1) Introduction: There is no indication for the treatments, T0, T1, T2, T3 in the abstract.
Response 1: T0 = 0 g without inoculation, T1 = 250 g of peat inoculant of strain UD5 for 50 kg seeds, T2 = 500 g of inoculant of strain UD5, and T3 = 200 g of comparative peat inoculant). The indication was addressed in the abstract.
2) Is the inoculant density 6.5 x 109 CFU g-1 peat inoculant OK?
Response 2: Yes, the inoculant 6.5 x 109 CFU g-1 peat inoculant is OK?.
When preparing the Rhizobium tropici culture, culture was grown on yeast mannitol broth and a 10 mL inoculum was transferred to 750 mL Yeast extract mannitol broth and shaken at 150 r.p.m. at 30 °C for 3-5 days until attaining a concentration of 6.5 x 109 cells mL -1. A combination of formulation additives was aseptically added and then, a 60 mL of yeast mannitol broth containing both Rhizobium tropici and additives were homogenously mixed with 250 g sterile peat. The final formulation product is presented with normalised values, showing a breakdown of reagents (g) required to make 1 kg of the formulation. Rhizobium. tropici peat inoculant contained 6.5 x 109 (6.5 billion) viable cells or Colony Forming Unit (CFU).
Comment:
From lines 90-94, 60mL of liquid inoculant containing 6.5 x 109 CFU mL-1 was added to 250 g sterile peat. Then the 1 kg of the ultimate formulation contains 6.5 x 109 CFU g-1. So did the rhizobia multiply during preparation?
Response: Yes, the above from lines 90-94 are correct. Please see above explained culture preparation. The rhizobium did not multiply after 5 days (attaining concentration of 6.5 x 109 cells mL-1
3) What is the main difference between two experimental sites?
Lines 98-114: The information for two experimental site were introduced, but it is not clear what are the main difference between two sites. Soil properties, climatic conditions such as temperature, or rain fall, or yield of dry bean, etc. In addition, I think the term "bioclimatic" should be changed to "climatic".
Response 3: The first trial was in Gauteng province, Pretoria. The location is categorized under a humid subtropical climate defined as C-wa (Gauteng province of South Africa) and positioned at 25° 48′ 30″ S latitude and, 28° 44′ 26″ E. Sandy clay loam soil was used in the trial. The second site experiment was done in the Northwest province of South Africa and is classified as an arid climate characterized by BWwh. The site is positioned at 26° 47′ 16″ S latitude and 26° 53′ 59″ E longitude with a sandy loam soil. The rainfall of the area is 670 mm for both annual seasonal.
4) Lines 115-124: The experimental design is not clear. how many rows or what m of width for one plot of 50 m long.
Please explain precisely on T3. Readers cannot understand a registered standard inoculum previously used. Please explain what strain and density of the standard inoculum and what was the carrier materials to prepare.
Was the peat inoculant for example 250g was applied onto 50 kg of dry bean seeds in T1?
Response 4: Thank you for the comment, the sentence was corrected as followed. The trial experiments were conducted in randomized split plot designs and each plot consisted of four treatments and six replicates. The inter-row and intra-row spacing used were 0.9 m and 0.075 m respectively, giving a plant population density of with 148.148 per hectare which gives 67.5 m2.
T3 was the comparative standard used and the peat inoculant for T3= 250g was also applied onto 50 kg of dry bean seeds. I mean T1, T2 and T3 (each treatment was applied onto 50 kg of dry bean seeds.
The plant population density of 148.148 mentioned above is population density per ha-1
5) For figures a vertical axis should start from 0.
Response: All figures a vertical axis were corrected as suggested above
Figure 3: What is the unit of root length? m/m2, or m/plant?
Response: The unit for root length is cm and comment was added.
Figure 4: What is the unit of number of nodules? nodule number/plant, nodule number/m2?
Response: The unit for number of nodules is number of nodules per 20 plants. The correction was made in the main document.
Figure 5: What is the unit of nodule size? average nodule size (mm) ?
Response: The unit for nodule size is (mm). The comment was added in the main manuscript.
Figure 6: What is the unit of yield? t/ha?.
Response: The unit of yield is t/ha-1. The comment was added.
Figure 7: This figure is not N uptake because the unit shows g/kg.
Figure 7 may be N concentration (gN/kgDW).
I recommend showing the N contents (gN/m2) of (gN/plant) instead of N concentration. This will indicate the effectiveness of inoculants better.
Response: The comment was corrected to N content g/kg-1 DW as suggested by the reviewer
Minor points
Line 10: nutrient values → valuable nutrients
Response: Valuable nutrients was added in the sentence
Line 11: good fertilizers →chemical fertilizers
Response: Chemical fertilizers was corrected in the main documents.
Line 13: Peat formation →peat formation
Response: peat formulation was added
Lien14: tropici sp → tropici sp strain UD5
Response: tropici sp strain UD5 was added
Line 16: bioclimatic zones →climtic zones
Response: Climatic zones sentence was corrected in the main document.
Line 18-: Please add the explanations for treatments, such as
Four treatments were applied, T0: control without inoculation, T1: 250g of peat inoculant of strain UD5 for 50 kg seeds, T2: 500g of peat inoculant of strain UD5 for 50 kg seeds, T3: 200 g of ? inoculant of ? for 50 kg seeds.
Response: The explanation for the four treatments was added
Please explain what is the number of T1=18.22%. The percentage increase compared to T0. The number should be three digits, like 18.2% instead of 18.22%.
Response: For T1, the increased percentage in comparison to T0 equal to 18.22%.
Line 55: noculant → inoculant
Response: The inoculant was corrected and add.
Line 57: [9] also → Chianu et al. [9] also
Response: Suggested writing style was added.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIn my opinion, the article titled Effectiveness of Peat Biofertilizer formulation of (Bradyrhizobium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry Bean (Phaseolus vulgaris L.). lacks scientific value. This study is a preliminary research, article having very basic experiments and results compilation. The authors may need to add more results from advanced analysis to improve the quality of their research
Author Response
6th January 2024
Dear Reviewer,
We appreciate your comments and suggestions, which improved the quality of the manuscript. Please find below the response to your comments and suggestions
Comments and Suggestions from the reviewer
In my opinion, the article titled Effectiveness of Peat Biofertilizer formulation of (Bradyrhizobium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry Bean (Phaseolus vulgaris L.). lacks scientific value. This study is a preliminary research, article having very basic experiments and results compilation. The authors may need to add more results from advanced analysis to improve the quality of their research
Response: The research’s objectives were to assess the effectiveness of peat formulation of Rhizobium tropici sp UD5 on growth, yield and nitrogen concentration of dry Bean. Rhizobium. tropici sp UD5 strain.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe manuscript addresses the effect of using biofertilizer formulations with Bradyrhizobium tropici on nitrogen uptake in beans.
Considering that the nitrogen cycle and uptake in legumes is addressed, the manuscript is interesting from the point of view of the sustainability of cropping systems based on crop rotation that include legume crops.
My main concern is related to the estimating of nitrogen uptake indirectly and only through nodule counting and measurements. I believe that in the discussion this limit should be appropriately discussed, perhaps strengthening the information on the relationship between the number and sizes of nodules and nitrogen absorption and discussing the results also citing other investigations conducted with other observations on nitrogen absorption in legumes. The influence of soil nitrogen absorption is also neglected.
Additional information could be found by reading the below suggested papers:
Sulas et al., 2016, DOI: http://dx.doi.org/10.1590/0103-9016-2015-0299;
I suggest further checking of the English language and the text, as I found some repetitions in the text. See for example in line 46.
Author Response
6th January 2024
Dear Reviewer,
We appreciate your comments and suggestions, which improved the quality of the manuscript. Please find below the response to your comments and suggestions
Comments and Suggestions from the reviewer
The manuscript addresses the effect of using biofertilizer formulations with Bradyrhizobium tropici on nitrogen uptake in beans.
Considering that the nitrogen cycle and uptake in legumes is addressed, the manuscript is interesting from the point of view of the sustainability of cropping systems based on crop rotation that include legume crops.
My main concern is related to the estimating of nitrogen uptake indirectly and only through nodule counting and measurements. I believe that in the discussion this limit should be appropriately discussed, perhaps strengthening the information on the relationship between the number and sizes of nodules and nitrogen absorption and discussing the results also citing other investigations conducted with other observations on nitrogen absorption in legumes. The influence of soil nitrogen absorption is also neglected.
Response: Thank you for the comments and suggestions. The discussion related to relationship between the number and sizes of nodules and nitrogen concentration were added in the discussion.
Additional information could be found by reading the below suggested papers:
Sulas et al., 2016, DOI: http://dx.doi.org/10.1590/0103-9016-2015-0299;
Response: The above suggested article information was checked.
Comments on the Quality of English Language
Response: The quality of English language was edited by expert in English.
I suggest further checking of the English language and the text, as I found some repetitions in the text. See for example in line 46.
Response: The checking English language was done and repetition from Line 46 was corrected
and added.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsIn my opinion the paper with title: “Effectiveness of Peat Biofertilizer formulation of (Bradyrhizo-2 bium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry 3 Bean (Phaseolus vulgaris L.).” could be published in the journal Nitrogen if the authors will make the corrections and specifications suggested:
1. The title should be reformulated to be clearer. I don't think the Latin names of the plant species are necessary in the title.
2. Please specify in the text the meaning of the term: yield crop production per year, lines 46 and 47.
3. In Chapter 1, lines 78-81, the paragraph
The objectives of this research were to assess the effectiveness of peat formulation of B sp on growth, yield and Nitrogen update of dry Bean in two South African bioclimatic zones, the term of yield was used. Please mention the meaning of this notion. It is similar to the yield crop production per year?
4. Please revise the English language! For example, in Chapter 2.3. -Analysis of Soil, the sentence: In order to assess physical and chemical properties of the soil, it is not complete.
5. In Section 2.5. Collection of date, Growth and Yield Parameters, please specify the equipment used for Kjeldahl nitrogen determination, lines 143-144
6. In Chapter 3, Results, Section 3.1.1. isn’t clear that represent percentage emergence. Please explain using mathematical equation or a definition! I recommend modifying the notion of percentage emergence with germination percentage.
What is the meaning of the numbers 6.61 and 8.01 and how were they calculated in the following sentence:
Figure 1. Treatment sharing same letters are not significantly different (Lsd Zone A) = 6.61 and (Lsd Zone B) = 8.01, (lines 163-164)
Similar for Figures 2- 6.
7. In Section 3.1.6. Please explain what the dry bean yield means, definition and the relation of calculation.
Author Response
6th January 2024
Dear Reviewer,
We appreciate your comments and suggestions, which improved the quality of the manuscript. Please find below the response to your comments and suggestions
Comments and Suggestions for the reviewer
In my opinion the paper with title: “Effectiveness of Peat Biofertilizer formulation of (Bradyrhizobium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry 3 Bean (Phaseolus vulgaris L.).” could be published in the journal Nitrogen if the authors will make the corrections and specifications suggested:
- The title should be reformulated to be clearer. I don't think the Latin names of the plant species are necessary in the title.
Response: The Latin names of the plant species was removed.
- Please specify in the text the meaning of the term: yield crop production per year, lines 46 and 47.
Response: The sentence was corrected in the main text.
- In Chapter 1, lines 78-81, the paragraph
The objectives of this research were to assess the effectiveness of peat formulation of B sp on growth, yield and Nitrogen update of dry Bean in two South African bioclimatic zones, the term of yield was used. Please mention the meaning of this notion. It is similar to the yield crop production per year?
Response: The yield crop production per year was corrected in the manuscript.
- Please revise the English language! For example, in Chapter 2.3. -Analysis of Soil, the sentence:In order to assess physical and chemical properties of the soil, it is not complete.
Response: The sentence was corrected in the manuscript.
- In Section 2.5. Collection of date, Growth and Yield Parameters, please specify the equipment used for Kjeldahl nitrogen determination, lines 143-144.
Response: Kjeldahl digestion tubes were used for nitrogen extraction.
- In Chapter 3, Results, Section 3.1.1. isn’t clear that represent percentage emergence. Please explain using mathematical equation or a definition! I recommend modifying the notion of percentage emergencewith germination percentage.
Response: The percentage of emergence is the number of plants that emerge from the soil divided by the total number of seeds planted, expressed as a percentage.
What is the meaning of the numbers 6.61 and 8.01 and how were they calculated in the following sentence:
Response: The meaning of 6.61 and 8.01 are Minimum Significant Differences obtained from Statistical Analysis System.
Figure 1. Treatment sharing same letters are not significantly different (Lsd Zone A) = 6.61 and (Lsd Zone B) = 8.01, (lines 163-164)
Similar for Figures 2- 6.
Response: Yes, in all figures, treatment sharing same letters are not significantly different as differentiated in the graphs. We do have all Statistical Analysis System for each parameter.
- In Section 3.1.6. Please explain what the dry bean yield means, definition and the relation of calculation.
Response: Dry bean yields refer to the amount of beans produced per ha-1.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors revised the manuscript well.
The figure 7 was changed from N concentration (gN/kg) to
N content, but (gN/Kg) indicates not N content (gN/m2). Please change the title of vertical axis to "N concentration" or please multiply seed yield and N concentration to obtain N content (gN/m2).
Comments on the Quality of English Language
The quality of English has been much improved.
Author Response
Dear Reviewer,
Thank you again for reviewing the manuscript for the second round. We appreciate your comments and suggestions. Please find below the response to your comments and suggestions
Reviewer 1
Comments and Suggestions for Authors
The authors revised the manuscript well.
The figure 7 was changed from N concentration (gN/kg) to N content, but (gN/Kg) indicates not N content (gN/m2).
Please change the title of vertical axis to "N concentration" or please multiply seed yield and N concentration to obtain N content (gN/m2). Comments on the Quality of English Language. The quality of English has been much improved.
Response: The figure 7 was changed from N Content g/kg to N concentration g/kg.
Reviewer 2 Report
Comments and Suggestions for AuthorsI appreciate the author's effort on this manuscript, which indeed improves the quality. In my opinion, the authors should consider using more advanced research methods in their future experiments. Authors should revise the reference list by following the rules described in the guidelines for authors.
Author Response
20th January 2024
To reviewer 2
Dear Reviewer,
Thank you again for reviewing the manuscript for the second round. We appreciate your comments and suggestions. Please find below the response to your comments and suggestions
Reviewer 2
Comments and Suggestions for Authors
I appreciate the author's effort on this manuscript, which indeed improves the quality. In my opinion, the authors should consider using more advanced research methods in their future experiments. Authors should revise the reference list by following the rules described in the guidelines for authors.
Response: More advanced research methods in the experiment were improved. The references were also revised according to the journal guidelines.
Reviewer 4 Report
Comments and Suggestions for AuthorsIn my opinion the paper with title: “
Effectiveness of Peat Biofertilizer formulation of (Bradyrhizo-2 bium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry 3 Bean (Phaseolus vulgaris L.).” should be published in the journal Nitrogen. The authors made the corrections in accordance with the requirements.
Author Response
Dear Reviewer,
Thank you again for reviewing the manuscript. We appreciate your feedback that the article should be published in the journal of Nitrogen.
Reviewer 4
Comments and Suggestions for Authors:
In my opinion the paper with title: Effectiveness of Peat Biofertilizer formulation of (Bradyrhizobium tropici sp) on Growth, Yield and Nitrogen Uptake of Dry 3 Bean (Phaseolus vulgaris L.).” should be published in the journal Nitrogen. The authors made the corrections in accordance with the requirements.
Response: We appreciate the reviewer’s feedback that the article should be published in the journal Nitrogen.
