Leguminous Alley Cropping Improves the Production, Nutrition, and Yield of Forage Sorghum

Round 1

Reviewer 1 Report

The paper is well written and emphasizes that significant forage sorghum yield can be obtained with low input system utilizing leguminous alley cropping. 

Following are some suggested edits:

Page 4

Line 128- 129

Sorghum yield was increased and showed a direct relationship to the presence of alleys.

Page 11

Lines 342 - 346- consider rephrasing the paragraph. Try relating the findings with the published study instead.

Author Response

Response to Reviewer 1 Comments

Comentários na página da Agronomy:

Point 1: Sorghum yield was increased and showed a direct relationship to the presence of alleys.

Response: This suggestion was combined with Point 2 in the discussion section.

Point 2: Lines 342 - 346- consider rephrasing the paragraph. Try relating the findings with the published study instead.

Response: Reviewer 2 suggested the insertion of the phrase of Point 1 in the discussion section. The paragraph was rewritten.

Reviewer 2 Report

The manuscript is not ready for publication in its current form because of the following reasons. I have also used Track Changes to highlight some proposed edits for the author’s consideration in the attached manuscript.

Overall, English grammar and writing style are rather compromised, impacting the manuscript’s readability and clarity, making it difficult to follow and adequately review or edit in many sections, in particular, the Results, Discussion and Conclusion sections. It is obvious the author(s)' native language is not English. I would strongly suggest the author(s) use a professional English editing service to check the grammar and improve on writing style.

Literature Review

The literature review is not exhaustive, the authors could have done an in-depth and much better job of discussing the benefits and successful application of alley cropping systems. In addition, the importance of forage sorghum in the Brazilian cattle industry is not shown, and hence the justification for the study in terms of the need to increase productivity and nutritional content of forage sorghum grown on poor soils is not clearly articulated.

Materials and Methods

There is a need for a clearer description and discussion of the materials and methods used so as to allow readers/other researchers to easily follow and be able to “visualize or repeat” the experiments. For instance, the authors talk of harvesting and adding tree residues but without stating how much was added, which is not only crucial if other researchers are to repeat the experiment, but also how do you compare different treatments?

Results

For clarity and visualization, I would suggest the authors use a balanced mix of tables and graphic illustrations. Currently, there is one graph vs. 6 tables.

Discussion

Two pages of discussion without any subheadings/subsections? I would suggest use of subheadings for better clarity and specificity, as in the Results section?

Recommendation: During your revision, please see a paper: Agronomy 2019, 9, 443; doi:10.3390/agronomy9080443

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 2 Comments
Comentários na página da Agronomy:

Point: Overall, English grammar and writing style are rather compromised, impacting the manuscript’s readability and clarity, making it difficult to follow and adequately review or edit in many sections, in particular, the Results, Discussion and Conclusion sections. It is obvious the author(s)’ native language is not English. I would strongly suggest the author(s) use a professional English editing service to check the grammar and improve on writing style.

Response: The English of the manuscript was carefully revised and improved by a qualified professional.

Point: The literature review is not exhaustive; the authors could have done an in-depth and much better job of discussing the benefits and successful application of alley cropping systems. In addition, the importance of forage sorghum in the Brazilian cattle industry is not shown, and hence the justification for the study in terms of the need to increase productivity and nutritional content of forage sorghum grown on poor soils is not clearly articulated.

Response: This issue was solved. There were changes in the introduction section, which emphasized the importance of sorghum cultivation in forage production and the positive effects that legume alleys bring to cultivation.

Point: There is a need for a clearer description and discussion of the materials and methods used so as to allow readers/other researchers to easily follow and be able to “visualize or repeat” the experiments. For instance, the authors talk of harvesting and adding tree residues but without stating how much was added, which is not only crucial if other researchers are to repeat the experiment, but also how do you compare different treatments?

Response: The scheme showed in Fig. 2 illustrates the experimental units for a better understanding of the experiment. The same amount of residues was added in the crop and double crop experiment and the added amount is shown in Table 2 (dry mass of residue).

Point: For clarity and visualization, I would suggest the authors use a balanced mix of tables and graphic illustrations. Currently, there is one graph vs. 6 tables.

Response: We followed your suggestion and transformed the morphological data of growth and production into graphs for better visualization.

Point: Two pages of discussion without any subheadings/subsections? I would suggest use of subheadings for better clarity and specificity, as in the Results section?

Response: Two subtitles were added in the discussion section.

Abstract

Point 1: Be specific......leaf content of what? Protein? Macronutrients?

Response 1: Leaf contents of macronutrients.

Point 2: Compared to mineral fertilization?

Response 2: The idea is to compare sorghum cultivation systems (single, gliricidia alleys and leucaena alleys) with and without mineral fertilization.

Point 3: Not very very clear...please rephrase for better clarity

Response 3: In this case, "double crop" refers to the cultivation right after the main crop. Therefore, the first experiment (2016/2017) was implemented in double crop. As for the second experiment (2017/2018), it was implemented as the main crop, which is named "Season" or "Crop". It was rephrased.

Point 4: Again, be specific......mention the variables that were improved?

Response 4: Morphological variables: plant height, stem diameter, panicle diameter, and panicle length. Production variables: leaf dry mass, stem dry mass, and total green mass and dry mass.

Point 5: Shouldn’t your keywords appear in the manuscript text? Agroforestry and Green fertilization are not in text?

Response 5: Indeed, the keywords were unrelated to the study. New keywords are included in the manuscript.

Introduction

Point 6: Is it all Brazilian soils...give a % estimate/fraction and a reference source/citation?

Response 6: This paragraph was rewritten, showing the % of poor soils and their
categories.

Point 7: This section of the literature review needs to be expanded to really emphasize the benefits of alley cropping.

Response 7: This section was revised and new citations were included to better
emphasize the benefits of alley cropping.

Point 8: Expand and explain why these two plant species are the prefered species in this area of Brazil?

Response 8: They are drought resistant species that produce large amounts of biomass and can be used in animal feed. The paragraph was rewritten.

Point 9: Here you really want to justify why you conducted the study on forage sorghum? I would suggest to first, discuss and distinguish the different types of sorghums...grain, forage (are these the new improved cultivars?), bioenergy sorghum. Then, the importance of forages to the Brazilian cattle industry, and why forage sorghum is your chosen study forage?

Response 9: Yes, the idea is to justify the study with forage sorghum. The text was rewritten and the difference between the two most important categories of sorghum, forage and grain was explained. It is emphasized the importance of forage sorghum in forage production, due to the high proportion of leaf and stem. The importance of these studies in livestock areas was also included.

Point 10: As pointed above, this review of the benefits of alley cropping can be improved?

Response 10: This paragraph was revised.

Materials and methods

Point 11: I would suggest you use a Table with columns of these variables. Title of Table could be ‘Preplant soil analysis data at the experimental site’

Response 11: There is a new table showing the soil analysis results before the
experiment.

Point 12: Here again, you could use a schema to clearly describe your experimental design. See attached paper for example i.e. Figure 3

Response 12: An illustrated scheme was added for better clarity.

Point 13: What was cut? Leaves+stems? And how much was added to the soil? This is very critical if other researchers are to fully understand and try and repeat this study?

Response 13: The biomass that was deposited on the soil surface refers to leaves and thin branches. The amount (dry mass) present in Table 2 was added for both crop and double crop. The thicker branches were eliminated. More information was included for better clarity.

Point 14: How much?

Response 14: Information added in Table 2.

Point 15: Be specific...what data was collected?

Response 15: The variables are: growth; yield; leaf macronutrient contents; and forage sorghum productivity.

Point 16: How was this done?

Response 16: The root was removed using a shovel, followed by washing with water. This information was included in the manuscript.

Point 17: Mention the specific variables that were analyzed for better clarity

Response 17: It was mentioned.

Results

Point 18: This sentence belongs to the discussion.

Response 18: This sentence was included in the discussion section.

Point 19: Again, be more specific by mentioning the actual components e.g. plant height, stem diameter.

Response 19: It was included in the manuscript.

Point 20: Vague...30% superior in what? Rephrase

Response 20: This sentence was rephrased. It was superior considering plant height, stem diameter, panicle diameter and panicle length.

Point 21: Why not use the oven dried mass?

Response 21: We intended to show the productivity of forage sorghum, since field productivity is calculated using total fresh mass minus root mass. It was changed to productivity instead of fresh mass.

Discussion

Point 22: Two pages with no subheadings? I would suggest using subheadings for better clarity??
Response 22: Subheadings were added.

Round 2

Reviewer 2 Report

Although the author(s) did a good job at responding to most of the issues and concerns previously raised, the manuscript is still not ready for publication in its current form. Again, English grammar and writing style are still very much compromised. The author(s) say they sought the services of a qualified English professional, but still, the text has numerous, and in some cases, simple grammar and writing style issues/errors.

Again, I would strongly suggest the author(s) SERIOUSLY seek the services of a professional English editing service to check the grammar and improve on writing style.

Here are some specific examples of grammar and writing style issues/errors section by section:

Suggested Keywords: Forage sorghum; alley cropping; leguminous; Gliricidia sepium; Leucaena leucocephal;

Literature Review

Overall, the literature review has improved.

Line# 88. ‘Alley cropping is a viable option for increased biomass production, since it can be incorporated into the soil,…….’ BUT is it not plant residues that are incorporated and NOT ‘Alley cropping’ ?

Line# 112. ‘plant fractions’ OR ‘plant species’

Materials and Methods

This section has also improved, BUT can be improved further?

Line# 189. Figure 2. The schema improved the clarity of the methodology.

Line# 167. Table 1. I would have expected available N (unless there was no N?) to have been included in the analysis since one of the key benefits of adding leguminous plant residues is increased available soil N? Also this leads me to another question: its not stated as to why a pre-plant soil analysis was conducted? To decide on the level of dry matter additions based on N, P and K content?

Line# 129 – 130. Shouldn’t this sentence: ‘It presents two defined crops:’ read as ‘It represents two growing seasons’ OR ‘It represents two cropping seasons’

Line#195-196 and 202. Table 2. What were the amounts of the added dry matter based on? The need to supply an xxxx amount of NPK?

Line# 246. How were the leaves sampled? From which plants? Which rows? How much….100g?

Line#253. If a researcher were to repeat this exercise, how would they know the size of the area and to what depth of soil were the roots sampled? Was a sieve used to catch any small roots during washing? Please, why not look up some root excavation studies?

Results

Graphs definitely improved the clarity and visualization of results presented.

Line# 324-326. ‘cultivation of alleys increased leaf dry mass (LDM…….’. Shouldn’t this read as ‘addition of plant residues increased leaf dry mass (LDM…..’ OR ‘cultivating forage sorghum between the leguminous alleys increased leaf dry mass (LDM…..’

Line#346-347. ‘In the double crop, in the absence of mineral fertilization, it was also verified a greater green mass production of sorghum cultivated between alleys……’ Not very clear…..needs rephrasing.

Line# 427. ‘Nevertheless, the cultivation in leucaena alleys was smaller than single sorghum.’ Again not very clear…..needs rephrasing.,

Throughout the text the author(s) intermix ‘N’ and ‘nitrogen’. Once abbreviated, they should use ‘N’ e.g. lines #506 and 594

Discussion

Conclusion

Line# 598. ‘ The presence of mineral fertilization potentiated these results’ Meaning?

These are just a few of the grammar and writing style issues?

Author Response

Response to Reviewer 2 Comments

 Point: Again, I would strongly suggest the author(s) SERIOUSLY seek the services of a professional English editing service to check the grammar and improve on writing style.

 Response: The manuscript was checked for grammar and writing style by a qualified professional.  

 Point: ‘Alley cropping is a viable option for increased biomass production, since it can be incorporated into the soil, ’ BUT is it not plant residues that are incorporated and NOT ‘Alley cropping’ ?

Response: This sentence was rephrased.

 Point: ‘plant fractions’ OR ‘plant species’

 Response: Plant species.

 Point: Table 1. I would have expected available N (unless there was no N?) to have been included in the analysis since one of the key benefits of adding leguminous plant residues is increased available soil N? Also this leads me to another question: its not stated as to why a pre-plant soil analysis was conducted? To decide on the level of dry matter additions based on N, P and K content?

Response: The soil analysis prior to the experiment was carried out to understand the fertility level of the area. Since nitrates leach more rapidly from sandy soils, available N was not evaluated. We decided to add all available alley residues into the soil, rather than considering the contents of N, P and K.

Point: Shouldn’t this sentence: ‘It presents two defined crops:’ read as ‘It represents two growing seasons’ OR ‘It represents two cropping seasons’

Response: The text was rewritten.

 Point: Table 2. What were the amounts of the added dry matter based on? The need to supply an xxxx amount of NPK?

Response: The addition of dry mass was not based on the contents of macronutrients. All available dry plant residues were added to the soil.

 Point: How were the leaves sampled? From which plants? Which rows? How much….100g?

Response: The fourth leaf was collected from the apex of the plants from the central rows. Eight leaves were sampled per experimental plot.

 Point:  If a researcher were to repeat this exercise, how would they know the size of the area and to what depth of soil were the roots sampled? Was a sieve used to catch any small roots during washing? Please, why not look up some root excavation studies?

Response: The roots were sampled at a depth of 20 cm and washed using a sieve. Since the study was focused on increasing crop yields, the evaluation of roots was complementary, as a way of confirming the improved yields.

 Point: ‘cultivation of alleys increased leaf dry mass (LDM…….’. Shouldn’t this read as ‘addition of plant residues increased leaf dry mass (LDM…..’ OR ‘cultivating forage sorghum between the leguminous alleys increased leaf dry mass (LDM…..’

 Response: The text was rewritten.

 Point: ‘In the double crop, in the absence of mineral fertilization, it was also verified a greater green mass production of sorghum cultivated between alleys……’ Not very clear…..needs rephrasing.

Response: The text was rewritten.

 Point: Nevertheless, the cultivation in leucaena alleys was smaller than single sorghum.’ Again not very clear…..needs rephrasing.,

Response: The text was rewritten.

 Point: Throughout the text the author(s) intermix ‘N’ and ‘nitrogen’. Once abbreviated, they should use ‘N’ e.g. lines #506 and 594

Response: It was corrected throughout the manuscript.

Point: The presence of mineral fertilization potentiated these results’ Meaning?

Response: The presence of mineral fertilization improved the results of all studied cultivation systems (single sorghum, sorghum grown in leucaena alleys and sorghum grown in gliricidia alleys) when compared with the absence of fertilization. Nevertheless, the cultivation in alleys was not significantly different when considering the presence and absence of mineral fertilization. This demonstrates the potential of alley residues to increase the growth of sorghum plants.