Soil Sulfur Deficiency Restricts Canola (Brassica napus) Productivity in Northwestern Russia Regardless of NPK Fertilization Level
, Ludmila Kozyreva 1, Mariia Fesenko 1, Victoria Dubovitskaya 1 and Sofia Sushko 1,3,4Round 1
Reviewer 1 Report
In the attached file
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: 
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Reviewer 2 Report
The manuscript mainly assessed heat and water stress with FAO-AquaCrop using a four-season dataset of canola cultivation, evaluated soil fertility stress with MLR taking into account soil pH, S and organic matter content, and so on, and yield prediction by MLR was used to calibrate the FAO AquaCrop "fertility stress" block and simulate the canola canopy cover. It aimed to develop a site-specific canola model based on a combination of FAO-AquaCrop CSM and multiple linear regression for north-western Russia. This research is of great significance for predicting the yield and growth of canola under fertilizer stress. However, there are some details that should be addressed to make the manuscript more academic.
Line 157: Initial values for soil volumetric moisture content were 0.30 in 2012; 0.34 in 2013; 0.32 in 2014 and 0.35 in 2015. Why is the initial volume moisture content in soil profile one value？the water content should be different at different soil depths.
What do symbols such as C1, C2 ,C3, B and Ap+AE mean in Horizon column in Table 1
Why is SOM negatively correlated with canola yield in formula 6？
In Figure 3, R2 of the relationship between each statistical factor and yield is very low, does it mean that the linear relationship between them is not very appropriate?
Table 8 shows the fertility stress 233 parameters calibrated for 7,8,9 plots . but FAO-AquaCrop models for estimating canola canopy cover and yield response to different. Were not done, For this study, this is insufficient，this also means that the aim of the paper was not achieved.
Line 259: plans should be plants.
This study lacks a conclusion.
Figures and tables are non-standard and should be modified according to the requirements of the journal.
Comments for author File: Comments.pdf
The quality of the English language of this manuscript is still acceptable, except for a few spelling mistakes
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Manuscript 'Combining FAO-AquaCrop Model and Multiple Linear Regression for Canola (Brassica napus) Under Different Soil Fertility Conditions'. This study aimed to develop a site-specific canola model based on a combination of FAO-AquaCrop CSM and multiple linear regression (MLR) for north-western Russia (Leningrad region).
The topic of the MS is interesting, however, the logic throughout the MS is somewhat unclear and does not demonstrate the importance and innovation of this study. Specifically, descriptions of experimental design and data analysis are confusing which makes it difficult to understand what the author intended to express. Therefore, I suggest rejecting the MS and encouraging a thorough revision before resubmitting.
The logic in the introduction is rather disordered and does not highlight the originality and significance of this study.
What is the experimental design of this MS? First, I suggest placing the experimental design in section 2.1 of the Materials and Methods. And, how was the experimental plot designed, and were there any replicates in the experimental treatments? Tables or graphs can be used to demonstrate experimental site and design more clearly.
L129-130 what means ‘Plot locations changed every growing season within the Agroecological Station’
What does Ap+AE, B, and C1.. represent in Table 1?
Why are there only soil data for 2011 in Table 2? How can the same type of soil have such significant differences in fertility? Also, it is necessary to supplement the soil fertility changes from 2012 to 2015.
Different NPK treatments should have a significant impact on the dates (dd.mm) of canola phenological phases in Table 3, and it should not be assumed that it is a single time point.
Why was plot 7-9 chosen for Table 4?
Table 5, use treatment names instead of plot numbers.
Is Table 6 the result of your study? If it is not, it is recommended to put it in the supplementary file.
There are many colloquial expressions in this MS. It is recommended to edit the entire MS.
L215-216 Due to the significant differences in soil fertility among experimental plots in different treatment groups, and the fact that NPK treatments were varied, it's uncertain whether the changes in yield were affected by soil fertility or the NPK management practices.
Was the Multiple Linear Regression Model calculated using soil data from 2011? The fitting effect was not good, with a maximum R2 value of only 0.439. Why didn't you use data from 2012-2015 to correspond the soil properties and yield for each year?
Extensive editing of English language required
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Please add the response of point 6 to the manuscript.
Comments for author File: Comments.pdf
Author Response
Point 1: Please add the response of point 6 to the manuscript.
Response 1: Done.
Reviewer 3 Report
The MS has been sufficiently improved to warrant publication in Agriculture. And kindly suggest further expanding the depth and breadth of the discussion section in the MS.Minor editing of English language required
Author Response
Point 1: And kindly suggest further expanding the depth and breadth of the discussion section in the MS.
Response 1: We expanded the discussion and highlighted the changes
Point 2: Minor editing of English language required
Response 2: We reviewed the article with a professional translator and a colleague who writes fluent English. We highlighted the changes we made in red.
