Effect of Soil Type on Calcium Absorption and Partitioning in Young Avocado (Persea americana Mill.) Trees
Round 1
Reviewer 1 Report
Dear Authors:
Thank you for this well-written article. It was presented well and completed when submitted. Avocado is an important global crop and any new information on mineral nutrition and management practices is a valuable contribution.
I have two suggestions. The first is optional and the second should be addressed prior to publications.
1) The acronyms for C, CL, SL and S don't work very well, in my opinion. To say, the C soil or the clay soil doesn't really save many characters and simply takes away from the value of soil texture nomenclature. In fact, you write the clay soil on line 224! I think this works and the acronyms don't help. I think this change is optional but, should be done to facilitate readability.
2) The hypothesis presented on lines 75 and 76 is weak. This may be a good applied outcome and could be mentioned in the discussion or even the conclusions within the context of sustainable management. But, saying "Ca application may not be necessary" is not a hypothesis. In fact, you don't even refer back to this statement in the conclusion. You should rethink what is the question you aimed to answer in the paper and make that your hypothesis. I think this change should be done prior to publications.
Sincerely,
Reviewer
Author Response
Reviewer 1:
1.About suggestion of changing the acronyms for soil treatments:
Response: The acronyms C, CL, SL and S for Clay, Clay Loam, Sandy Loam and Sandy soils were used to abbreviate soil textures instead of using for example T1, T2, T3, T4, because we believe that it is easier to relate to the textures, and also because it is useful for graphs and for saving space in the text. Thus, we think is the better way to express the treatments throughout the text. Changing to the long format for each soil texture, would complicate the graphic format and waste space in the text.
2. About the request of changing the hypothesis:
Response: We agree with the opinion of Reviewer 1 about having a stronger hypothesis. The original hypothesis “We hypothesize that the need for external application of Ca to avocado orchards…..” (lines 75-77 of the original manuscript) has been replaced by “We hypothesize that Ca content in avocado trees is not only related to Ca supply by the soil, but is dependent on root growth and absorption capacity, which in avocado is related to the soil air capacity and resistance to tree growth” (see lines 77-79 of the new version).
Reviewer 2 Report
The current manuscript deals with a topic that is of high agronomical importance for researchers, agronomists and other scientists who work on the management of avocado orchards. However, I believe that the manuscript has to be improved substantially. Please see my comments in the attached pdf file. In case that the authors will revise the manuscript according to my comments, I'm willing to reevaluate it with a positive point of view.
Comments for author File: 
Comments.pdf
Author Response
Reviewer 2:
1. The suggested sentence “absolute quantities, not concentrations” is now presented in abstract of the new version (see lines 19 and 20) and Results (line 194).
2. The suggested article is now included in the Introduction and in the Reference section (see reference number 11, lines 50 and 398).
3. Order of the cited references was checked after citing new articles.
4. The words “of Ca” were deleted from the text. See line 69.
5. The reference Tzatzani et al. (reference number 13) was included in the Introduction and in the Reference section (see lines 52 and 403).
6. As requested, chemical measurements methods were added to the Material and Methods (see lines 87 to 93).
7. According to the reviewer we added in the legend of Table 1 the sentence “derived from different orchards located” (see line 112).
8. About the suggestion of adding CaCO3 contents: the focus in this research is soil calcium supply, and in the area of study, high pH is not an issue, thus specific measurements of CaCO3 and active CaCO3 were not done. Also, soil effervescence was not found in the in situ soil study.
9. The sentence “Irrigation water and soil analyses indicated no chemical limitations to plant growth [21]” was moved from Materials and Methods to the Results section (see line 177).
10. As indicated by reviewer 2, Kg/season/plant was replaced by g/season/plant (see line 132).
11. As requested by Reviewer 2, 1300 to 1400 was replaced by 10:00 to 13:00 (see line 146).
12. As requested by Reviewer 2, 70°C was replaced by 70°C (see line 156).
13. As requested, the description of how nutrient contents were calculated was added to the methodology and more references were added to the text and reference section (see lines 163 to 165).
14. As requested, letters A, B, C and D were add to the figures, and an explanation about each graph was clearly stated in the figure legend. See Figure 1.
15. As requested, letters A and B were added to the figures, and an explanation about each graph was clearly stated and corrected in the figure legend. See Figure 3.
16. As requested, standard errors were added to the Results. See Table 2.
17. As requested, letters A and B were added to the figures, and an explanation about each graph was clearly stated and corrected in the figure legend. See Figure 4.
18. As requested, net CO2 assimilation was added to the Subtitle 3.2 (see line 215).
19. Results of plant water status and Pn were used for PCA and in the text it is stated that those specific data are non-shown in the table. Table 3 was previously available in the text but finally was not shown to avoid being redundant. Table 3 was listed in the text by mistake. The new version does not include Table 3 (see line 220).
20. As requested, extra explanation about PCA analysis was added to the Results. See lines 223 to 226).
21. As requested, the word developed was replaced by grown (see line 247).
Round 2
Reviewer 2 Report
I'm pleased to recommend the manuscript for publication in its current form.
