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Article
Peer-Review Record

Alley Cropping Increases Land Use Efficiency and Economic Profitability Across the Combination Cultivation Period

by Huasen Xu 1,2,3, Huaxing Bi 1,4,5,6,*, Lubo Gao 7 and Lei Yun 1
Reviewer 1: Anonymous
Reviewer 2: Anonymous
Submission received: 24 October 2018 / Revised: 3 January 2019 / Accepted: 11 January 2019 / Published: 15 January 2019

Round  1

Reviewer 1 Report

Review of “Improving the Economic Profitability of Alley Cropping Systems by Optimizing Intercropping Distance and Associated Crops”.  Journal: Agronomy

This paper has been very extensively revised and has improved very much, but some work remains to be done.

Particularly there is still missing information in the M&M, still some questionable approaches and conclusions, and some remaining language problems.

The main problems still unresolved are:

The authors have planted the intercrops in an increasingly narrow alley over the years, and there is no proof that planting on larger alleys also in later years would have resulted in greater LER. Wider alleys would have probably reduced both apple and crop yields, but not necessarily LER. The authors assume instead that their results suggest that narrower alleys (greater distance from trees) are better as LER did not decrease, compared to larger alleys.  But this comparison was based only on two years for peanut and millet and 4 years for maize, out of nine, and only on a difference of 25 cm. Additionally the comparison is between two experiments which are carried out in different years, so the direct comparison of yield and LER for each year is not appropriate. It was suggested to the authors to not overly emphasize the IID concept and instead focus more on the positive LER with intercropping. This implied changing the title as well. The current MS still emphasizes that reduced alley cropping over time is the main result, when indeed it is an assumption, and the results are not suited to support this assumption. Thus, this can be accepted only as a working hypothesis, but should not be the focus of the paper.

Aslo it had been suggested to show the yield of the intercrops both in terms of yield per unit area of crop and per unit of alley cropping area. This allows to evaluate whether the decreased yield of the intercrops, compared to sole crops, is solely due to reduced area, or also reduced yield per unit crop area. This would give insights on the actual competition between trees and crops and could help much in providing good arguments in the discussion, in palace of the unsubstantiated ones mentioned above.

Below more details:

M&M

Line 120. Crop obstacles? Not clear.

Distance from sole crop and alley copping is not specified. Please specify to understand that there are no possible border effects of trees on sole crops.

Line 139: 200 kg N ha-1 is said to be given to “all plots”. Later, however, it is reported that fertilization had different costs among the different crops. In fact, it seems strange that peanut (a N fixer) would receive this amount of N, as maize. Perhaps this is a mistake. Also, it is not clear whether sole apple also received the N fertilization and compound fertilizer, as the crop did, in addition to the fertilization given specifically to trees. Please specify these details and then discuss their effects: could the sole apple have produced more because it received the same fertilization as in the alley cropping, but without competition from crops? Or could the crops in alley cropping have produced less because they had to share with the apple trees the same fertilization the sole crop had?

M&M report measurements of canopy height and radius, which are not used in this paper: omit talking about them.

When was the root distribution measured? Once per year? When? What period? On how many trees? Can the sampling position be reported in figure 1? The reader needs to know how many measurements concur in the averages shown in figure 2.

Similarly, for incident light: was PAR measured? Or total radiation? How many times per year? Once? Ok, but when? What was the timing of apple and crop leafing out? At what time of day? Is this a single measurement at noon? Or during what interval in the day? How is the 85% light absorption calculated from those measurements? How do you establish a general value (85%) with only one measurement in the year, ignoring the dynamics of apple and crop growth?

By the way, how where the tree and crop lines oriented? This might affect the symmetry, or non-symmetry, of the distances at which 85% light is achieved.

For Maize, how was the 85% light distance calculated? At what time in the year? And in the day?

In line 191 the authors assume 25 cm for canopy radius. But in line 205 they mention that canopy radius was obtained from crop monoculture system, giving the impression that it was directly measured?

The formula for the NPV allow to quantify today the future (i.e. in the following years) cash flows (positive and negative). But the data in the figure showing the results on NPV shows yearly values. This is confusing. The figure with yearly values is useful, but then the authors could show the actual NPV, which summarizes in a single present value all the future flows. This would also help in interpreting the data basing the crop choice on a single, whole-including, value. Or is this not possible because of the rotation of the crops? If so a single NPV can be still shown for alley cropping (i.e. all crops) vs. sole crop and sole apple.

Similarly, it is not clear how the overall LER value (authors speak of 37.7%, which I assume implies LER = 1.37) is obtained. This should be explained. And the overall value could be reported as the last row of data in table 3, for each crop, as done for the individual years, or, if not possible because of the rotation, then for alley cropping (i.e. all crops) vs. sole crop and sole apple.

Conclusions are a bit long and repetitive and once again emphasize that results of optimized distance based on LER comparison between two experiments, which is not a strong point in the paper.

Language: still too often the article “the” is used in place of “a”, which is a trivial mistake, but it does make it difficult to follow. Same thing for using incorrectly the verb tenses (present vs. past or “ing” forms). When speaking of other research finding, use the present form. For instance: “trees take several years to …, which is a long term investment (9,10)”, not “trees took several years to …, which was a long term investment (9,10)”. Unless you say: Such and such authors found that trees took …: in this case you can use the past form. Using the past tense as you do, make it sound like it is data from the current study. Also, some words are inappropriate, for instance yields are “lower”, not fewer, and “reduced”, not “squeezed”. Numbering, in English, goes 1st, 2nd, 3rd, and then 4th and so on. Not 1th, 2th and 3th. Replaces “justly” with “solely”.

I think the authors intend to say “organic” when they say “organ”.

Trees do not germinate, they sprout.

I don’t have time to point out all the small mistakes, there are too many.

Author Response

Response to Reviewer 1 comments

Point 1: The authors have planted the intercrops in an increasingly narrow alley over the years, and there is no proof that planting on larger alleys also in later years would have resulted in greater LER. Wider alleys would have probably reduced both apple and crop yields, but not necessarily LER. The authors assume instead that their results suggest that narrower alleys (greater distance from trees) are better as LER did not decrease, compared to larger alleys. But this comparison was based only on two years for peanut and millet and 4 years for maize, out of nine, and only on a difference of 25 cm. Additionally the comparison is between two experiments which are carried out in different years, so the direct comparison of yield and LER for each year is not appropriate. It was suggested to the authors to not overly emphasize the IID concept and instead focus more on the positive LER with intercropping. This implied changing the title as well. The current MS still emphasizes that reduced alley cropping over time is the main result, when indeed it is an assumption, and the results are not suited to support this assumption. Thus, this can be accepted only as a working hypothesis, but should not be the focus of the paper.

Aslo it had been suggested to show the yield of the intercrops both in terms of yield per unit area of crop and per unit of alley cropping area. This allows to evaluate whether the decreased yield of the intercrops, compared to sole crops, is solely due to reduced area, or also reduced yield per unit crop area. This would give insights on the actual competition between trees and crops and could help much in providing good arguments in the discussion, in palace of the unsubstantiated ones mentioned above.

 

Response 1: Thank for pointing out this mistakes. We have changed the title as “Alley Cropping Increases Land Use Efficiency and Economic Profitability across the Rotation Period”, and focused on the positive LER in alley cropping systems compared to monocultures. For example, replaced the content of IID with the LER (lines 56-64) to introduce that little is known on whether or not appropriate intercropping distance between trees and crops can reduce the competition and keep a higher land use efficiency. Deleted the discussion about the reasonability of the IID and discussed more content for the LER (lines 389-406), to discussion the outstanding point (land use efficiency) in this paper.

We retained the part of IID to show the result that the broaden intercropping distance in Exp.2 had no significant negative effect on LER compared to that in Exp.1 after the apple tree produced fruits. This result implied that the improved distance in Exp.2 could reduce the production costs. Additionally, determining the dominate sequence of the resources by the IID is an interesting result to regulate and improve the land use efficiency and plant growth.

The yields per unit of crop area was adopted in the new Table 1 (line 285), which confirmed that the reduced yield came from the competition with the apple trees, rather than the decreased cultivation area (lines 279-281 and402-406).

Point 2: Line 120. Crop obstacles? Not clear.

 

Response 2: Thank for pointing out this mistakes. We have revised it in the new text (line 109) as “Crop rotation was employed to avoid continuous cropping obstacle in Exp.1”

 Point 3: Distance from sole crop and alley copping is not specified. Please specify to understand that there are no possible border effects of trees on sole crops.

 

Response 3: Thank for pointing out this mistakes. We have added details about the distance between sole crop plots and alley cropping plots (sole apple plots). Please see lines 118-120.

 Point 4: Line 139: 200 kg N ha-1 is said to be given to “all plots”. Later, however, it is reported that fertilization had different costs among the different crops. In fact, it seems strange that peanut (a N fixer) would receive this amount of N, as maize. Perhaps this is a mistake. Also, it is not clear whether sole apple also received the N fertilization and compound fertilizer, as the crop did, in addition to the fertilization given specifically to trees. Please specify these details and then discuss their effects: could the sole apple have produced more because it received the same fertilization as in the alley cropping, but without competition from crops? Or could the crops in alley cropping have produced less because they had to share with the apple trees the same fertilization the sole crop had?

 

Response: Thank for pointing out those mistakes. Sorry for making such a silly mistake. We have revised them in the new manuscript (lines 125-135). It is a mistake that peanut was described to receive the same fertilizing as maize and millet. It should be reported that “The compound fertilizer was also applied in alleyways for maize and millet at a rate of 600 kg ha-1, before the crops were planted. And peanut received 200 kg of the compound fertilizer per hectare”.

A discussion for the fertilizer effect on intercrops in lines 395-398. The competition is not able to further reduce the yield and partial LER of peanut, compared to maize and millet, which only adopted one-third of fertilizer of them. Increased N2 fixation of legume promote by the dominant species may explain the fertilizer effect among three intercrops (Li et al 2016).

 Point 5: M&M report measurements of canopy height and radius, which are not used in this paper: omit talking about them.

 

Response 5: Thank for pointing out this mistake. The canopy height and radius were conventional measured parameters in our experiments, but they are not used in this study. So deleting it may be more reasonable for this manuscript.

 Point 6: When was the root distribution measured? Once per year? When? What period? On how many trees? Can the sampling position be reported in figure 1? The reader needs to know how many measurements concur in the averages shown in figure 2.

 

Response 6: Thank for pointing out these defects. These details have added in new text. The root distribution was measured in mid-July yearly. This time is the critical stage for second growth peak of apple roots, tasseling of maize and millet, and pegging of peanut. The root distribution of two apple trees was measured in each replicated plot. Root sampling positions have added into the Figure 1. Please see the lines 138-145 and 160.

 Point 7: Similarly, for incident light: was PAR measured? Or total radiation? How many times per year? Once? Ok, but when? What was the timing of apple and crop leafing out? At what time of day? Is this a single measurement at noon? Or during what interval in the day? How is the 85% light absorption calculated from those measurements? How do you establish a general value (85%) with only one measurement in the year, ignoring the dynamics of apple and crop growth?

 

Response 7: Thank for pointing out these defects. We have added these details of measuring methods of tree shading and maize shading.

Daily light interception of trees during 08:00 to 18:00 was obtained by measuring the photosynthetically active radiation (PAR) under the canopy. The accumulated light interception of apple trees during the crop growing season was calculated by summing the daily values of light interception. The 85% tree shading was calculated by the regression equation between the light sampling positions and measured light interception values. Please see lines 145-157 and 197-199.

 Point 8: By the way, how where the tree and crop lines oriented? This might affect the symmetry, or non-symmetry, of the distances at which 85% light is achieved.

 

Response 8: Thank for pointing out this confusion point. We have added detail of the orientation of trees and crops. The apple tree and crop lines oriented north-south, which would produce a symmetrical effect of tree shading on intercrop. Please see lines 104 and 199-120.

 Point 9: For Maize, how was the 85% light distance calculated? At what time in the year? And in the day?

 

Response 9: Thank for pointing out these defects. We have added these details of measuring methods of tree shading and maize shading.

One cardinal point was above the canopy in sole maize. Six cardinal points below the canopy (away from the border row at 0 m, 0.1 m, 0.2 m, 0.3 m, 0.4 m, 0.5 m) and 1.5 m above ground in maize monoculture. Daily light interception of maize during 08:00 to 18:00 was obtained by measuring the photosynthetically active radiation (PAR) under the canopy. The accumulated light interception of maize was only measured from 8th leaf (V8) to harvest of maize. Canopy shading is the fraction of the accumulated light interception, and is one minus the ratio between the accumulated light interception below the canopy and the measured PAR values above the canopy. The 85% maize shading was calculated by the regression equation between the light sampling positions and measured light interception values. Please see lines 148-157 and 197-199.

 Point 10: In line 191 the authors assume 25 cm for canopy radius. But in line 205 they mention that canopy radius was obtained from crop monoculture system, giving the impression that it was directly measured?

 

Response 10: Thank for pointing out this mistakes. Such describe is indeed a confusion, and we have deleted the conflict point “The data of the canopy radius of crops were also obtained from crop monoculture systems”.

 Point 11: The formula for the NPV allow to quantify today the future (i.e. in the following years) cash flows (positive and negative). But the data in the figure showing the results on NPV shows yearly values. This is confusing. The figure with yearly values is useful, but then the authors could show the actual NPV, which summarizes in a single present value all the future flows. This would also help in interpreting the data basing the crop choice on a single, whole-including, value. Or is this not possible because of the rotation of the crops? If so a single NPV can be still shown for alley cropping (i.e. all crops) vs. sole crop and sole apple.

 

Response 11: Thank for pointing out this mistake and providing good suggests. The actual NPVs of all cropping systems have been added into the Figure 3 (line 369). The actual NPV and yearly NPV will provide ample evidence to prove the economic advantage of alley cropping systems compared to monocultures.

 Point 12: Similarly, it is not clear how the overall LER value (authors speak of 37.7%, which I assume implies LER = 1.37) is obtained. This should be explained. And the overall value could be reported as the last row of data in table 3, for each crop, as done for the individual years, or, if not possible because of the rotation, then for alley cropping (i.e. all crops) vs. sole crop and sole apple.

 

Response 12: Thank for pointing out these mistakes and your good suggests. We have revised the mistake about “37.7%” in line 424. We are fail to describe the meaning of 37.7% in previous text. In fact, the 37.7% presented the advantage in yearly NPV, and this was motivated by the greater LER after apple trees produced fruit.

We have added the total LER during the whole alley cropping period into the Table 3 (line 327). And three alley cropping patterns were independently showed in this Table 3.

 Point 13: Conclusions are a bit long and repetitive and once again emphasize that results of optimized distance based on LER comparison between two experiments, which is not a strong point in the paper.

 

Response 13: Thank for your good suggests. We have condensed the part “Conclusions”. And we focused on the comparison of LER and NPV between alley cropping systems and monocultures in new conclusions, which supported that alley cropping increases land use efficiency and economic profitability. Please see the lines 461-473.

 Point 14: Language: still too often the article “the” is used in place of “a”, which is a trivial mistake, but it does make it difficult to follow. Same thing for using incorrectly the verb tenses (present vs. past or “ing” forms). When speaking of other research finding, use the present form. For instance: “trees take several years to …, which is a long term investment (9,10)”, not “trees took several years to …, which was a long term investment (9,10)”. Unless you say: Such and such authors found that trees took …: in this case you can use the past form. Using the past tense as you do, make it sound like it is data from the current study. Also, some words are inappropriate, for instance yields are “lower”, not fewer, and “reduced”, not “squeezed”. Numbering, in English, goes 1st, 2nd, 3rd, and then 4th and so on. Not 1th, 2th and 3th. Replaces “justly” with “solely”.

I think the authors intend to say “organic” when they say “organ”.

Trees do not germinate, they sprout.

I don’t have time to point out all the small mistakes, there are too many.

 

Response 14: Thanks for your point these mistakes. We have revised them in new text. And

English language of this manuscript has been further improved by us and the editor from English editing service of MDPI.

 


Author Response File: Author Response.pdf

Reviewer 2 Report

The MS covers a field of high interest and the authors have invested much time and effort in creating a valuable databody.

Obviously the authors responded meticulously to comments of reviewers and revised the MS accordingly.

In the interest of international readers I would wellcome if the economic figures would be displayed in a currency like e.g. Dollars or Euros. This would make it more accessible, compared to giving the conversion rate in the text.

Authors use the unit Y/hm-2. I do not understand the meaning "hm-2".

Still there are a lot of spelling errors in the text, which need to be solved.

Author Response

Response to Reviewer 2 Comments

Point 1: In the interest of international readers, I would welcome if the economic figures would be displayed in a currency like e.g. Dollars or Euros. This would make it more accessible, compared to giving the conversion rate in the text.

 

Response 1: Thank for your good suggest. We have conversed the CN yuan as US dollar in new text.

Point 2: Authors use the unit Y/hm-2. I do not understand the meaning "hm-2".

 

Response 2: Thank for pointing this mistake. We have revised the hm-2 as ha-1 in new text.

Point 3: Still there are a lot of spelling errors in the text, which need to be solved.

 

Response 3: Thanks for your point these mistakes. We have revised them in new text. And

English language of this manuscript has been further improved by us and the editor from English editing service of MDPI.


Author Response File: Author Response.pdf

Round  2

Reviewer 1 Report

The paper has been greatly improved. One main problem remains the language: while it has been greatly improved, there remain many small mistakes and few unclear parts. I will try to point out a few (only for the introduction, as an example), but some good editing by a native speaker is strongly recommended.

Here are few suggestions to finalize the paper.

Abstracts:

L 22: “with different tree ages (1-9 years old)” is reported for the long term experiment, while it should be for the short term one.

L 29: presence of, not present.

L 37: replace “the land use and economic advantage will be not available” with: it is no longer suitable/profitable.

L 51: crops (not crop); tree growth (not trees growth). This point is repeated several times.

L 56: resources are (not is) limited. Replace “The wealth of” with “Many”

L 57 and 58: remove “the” before “alley” and before “competition”.

L 58 and many other places: when talking about your results on LER, talk about LER, not about land use efficiency, or land use advantage or other. Just say directly and clearly “land equivalent ratio”.

L 60: omit “pattern”

L 61: replace “could compensate or beyond” with “can more than compensate”

L 65: replace “generate a consumable output, which is naturally” with “bear fruit, and planting trees is”

L 72: not sure if “swidden” exists? Anyway, replace “swidden cultivation systems” with “separate cultivations”

L 73: replace “a varied net benefit advantage” with “varied net benefits”. Omit “more” (“additional” already means more).

L 76: replace “correlated with” with “available on”

L 78: include “the” between “address” and “above”.

L 82: similarly: “… quantify THE land use…”

L 83: again: “… including above THE apple/crop…”

 The above corrections are only for the introduction. The rest of the paper need similar editing, but I clearly cannot do this for the whole text.

Table 1: the caption should clearly indicate that the yield of “inter” are expressed per unit of crop area and not per total area of the alley cropping system. And thus, the decreases in yield are due to competition and not to reduced cultivation area. The reader does no know this. The authors explain this in the rebuttal, but not in the text.

Is there a reason to not show a similar table, with yields per unit of crop area, for experiment two (short-term)?

L 316: Since LER of the sole apple is zero, it is not correct to say 46-88% increase in LER (not land use efficiency). Just say that LER increased by 0.46-0,88. This applies also elsewhere in the text (e.g. L 390).

Things are (or not) significantly different; thigs are not “significant difference”. Multiple times in the text…

L 333: it is not clear how the “weighted average” is calculated.  

Fig. 3: why do the single year NPVs of the 3 monocrops decrease over time? Shouldn’t they be constant?

L 379: should Fig 2 be indicated instead of Tab 2?

L 424: Authors say: the results confirmed the yearly NPV advantage by 37.7%... But this value has not been reported before in the text. As mentioned last time the origin of this value should be explained, since it is not apparent in any table or figure.

The Acknowledgements repeat the same information given in the Funding.

Author Response

Point 1: L 22: “with different tree ages (1-9 years old)” is reported for the long term experiment, while it should be for the short term one.

Response 1: Thank for pointing out this mistakes. We have revised it (lines 23 and 27).

Point 2: L 29: presence of, not present.

Response 2: Thank for pointing out this mistakes. We have revised it (line 30).

Point 3: L 37: replace “the land use and economic advantage will be not available” with: it is no longer suitable/profitable.

Response 3: Thank for your editing for this point. We have revised it (lines 39-40).

Point 4: L 51: crops (not crop); tree growth (not trees growth). This point is repeated several times.

 

Response 4: Thank for your editing for those points. We have revised them (line 54). And “trees shading” have revised as “tree shading” (line 272 and 307), “resources exploitation” have revised as “resource exploitation” (line 310), and so on.

 Point 5: L 56: resources are (not is) limited. Replace “The wealth of” with “Many”

 

Response 5: Thank for your editing for those points. We have revised them. Please see the line 58 and 59.

Point 6: L 57 and 58: remove “the” before “alley” and before “competition”.

 

Response 6: Thank for your editing for those points. We have revised them. Please see the line 59.

Point 7: L 58 and many other places: when talking about your results on LER, talk about LER, not about land use efficiency, or land use advantage or other. Just say directly and clearly “land equivalent ratio”.

 

Response 7: Thank for pointing out this mistakes. We have revised it (lines 60, 326 and 400).

Point 8: L 60: omit “pattern”

Response 8: Thank for your editing for this point. We have revised “Alley cropping as an efficiency land use pattern” as “Alley cropping is an efficient land use pattern”, and smoothing out the mistake of this sentence. Please see the lines 62-63.

Point 9: L 61: replace “could compensate or beyond” with “can more than compensate”

Response 9: Thank for your editing for this point. We have revised them. Please see the line 63.

Point 10: L 65: replace “generate a consumable output, which is naturally” with “bear fruit, and planting trees is”

Response 10: Thank for your editing for this point. We have revised them. Please see the line 67.

Point 11: L 72: not sure if “swidden” exists? Anyway, replace “swidden cultivation systems” with “separate cultivations”

Response 11: Thank for your editing for this point. We have revised them. Please see the line 73-74.

Point 12: L 73: replace “a varied net benefit advantage” with “varied net benefits”. Omit “more” (“additional” already means more).

Response 12: Thank for your editing for those points. We have revised them. Please see the line 74-75.

Point 13: L 76: replace “correlated with” with “available on”

Response 13: Thank for your editing for this point. We have revised them. Please see the line 77.

Point 14: L 78: include “the” between “address” and “above”.

Response 14: Thank for your editing for this point. We have revised them. Please see the line 79.

Point 15: L 82: similarly: “… quantify THE land use…”

Response 15: Thank for your editing for this point. We have revised them. Please see the lines 83-84.

Point 16: L 83: again: “… including above THE apple/crop…”

Response 16: Thank for your editing for this point. We have revised them. Please see the line 85-86.

Point 17: Table 1: the caption should clearly indicate that the yield of “inter” are expressed per unit of crop area and not per total area of the alley cropping system. And thus, the decreases in yield are due to competition and not to reduced cultivation area. The reader does no know this. The authors explain this in the rebuttal, but not in the text.

Is there a reason to not show a similar table, with yields per unit of crop area, for experiment two (short-term)?

Response 17: Thank for pointing this mistake. We have added “The crop yields in alley cropping systems were expressed per unit of crop area” into the caption of Table 1 (lines 294-295).

We also have added the yield data in Exp.2 (Table S1 in “Supplementary Material”, lines 483-484) The three crops showed a decreased yield in the alley cropping systems across the alley cropping period both in Exp.1 and Exp.2. The two tables verified that the decreases in yield are due to competition and not to reduced cultivation area. However, the apple yields were only reduced in Exp.1, not changed in Exp.2.

Point 18: L 316: Since LER of the sole apple is zero, it is not correct to say 46-88% increase in LER (not land use efficiency). Just say that LER increased by 0.46-0,88. This applies also elsewhere in the text (e.g. Line 390).

Response 18: Thank for pointing this mistake. We have revised them in the text (lines 326 and 400).

Point 19: Things are (or not) significantly different; thigs are not “significant difference”. Multiple times in the text…

Response 19: Thank for pointing this mistake. We have revised them in the text.

Point 20: L 333: it is not clear how the “weighted average” is calculated. 

Response 20: Thank for pointing this mistake. We have revised the “weighted average” as the “average” (line 341).

Point 21: Fig. 3: why do the single year NPVs of the 3 monocrops decrease over time? Shouldn’t they be constant?

Response 21: Thank for pointing out this mistakes. We are sorry that the net present value (NPV) and present value (PV) was confused. Actually, the single year NPV should be called annual PV. We have revised it in the text (lines 357-365 and 354-370, Figure 3).

Specific explanations are as follows:

The NPV is the total value of all future cash flows over the entire life of an investment discounted to the present, which was used to estimate the total economic profitability over the entire alley cropping period among various planting systems in terms of the current criterion. Present value (PV) was applied to determine the annual revenue in different intercropping years discounted to the present. The PV means future revenues (actual profitability without discount at a given year) are discounted at the interest rate, and is always less than the future value because money has interest-earning potential. This characteristic refers to as the time value of the money. For the long-term investment, as the alley cropping systems, the PV is the key to properly valuing whether farmers are earning at a certain point in time.

So the NPV in single year of the monocrop decrease over time, not a constant as the actual profitability at a given year.

Point 22: L 379: should Fig 2 be indicated instead of Tab 2?

Response 22: Thank for pointing this mistake. We have revised it in the manuscript (line 390).

Point 23: L 424: Authors say: the results confirmed the yearly NPV advantage by 37.7%... But this value has not been reported before in the text. As mentioned last time the origin of this value should be explained, since it is not apparent in any table or figure.

Response 23: Thank for pointing this mistake. We have added this result into the part of “3.4” (line 355).

Point 24: The Acknowledgements repeat the same information given in the Funding.

Response 24: Thank for pointing out this mistakes. We have revised it in the text (lines 493-494).

Author Response File: Author Response.docx

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