Assessing the Efficiency of Different Nitrogen Fertilization Levels on Sorghum Yield and Quality Characteristics
Round 1
Reviewer 1 Report
Title: Assessing the efficiency of different nitrogen fertilization levels on sorghum yield and quality characteristics
The described experiment is a typical field experiment. The study of the effect of nitrogen fertilization on sorghum and other plants is very well known and proven. The influence of the variety on the yield and other characteristics is obvious. In EU countries, there are institutions that test these features before and after they are introduced to the commercial market, one pattern should be selected (leaving unregistered geotypes) and the discussion should be supplemented with post-registration research from a given area. The authors write conclusions in the context of crop rotation, which was not presented in the methodology and results. The description of the experiment in the spit-plot system is provided only partially. Based on the description of the experiment, it is not possible to be fully sure whether appropriate statistical methods were used. The description of the statistical methods was limited to the indication of ANOVA, without specifying the model used. The period of the 2019-2020 experiment years was significantly below the norm in terms of precipitation in the initial stages of plant development. It is worth analyzing the results in more detail in relation to genotype and rainfall. Standard statistical methods should be extended by statistical multivariate methods.
Minor notes to the text:
Line 47 "particularly in current growing year (2021)" - this is not the year of research.
Line 48-49 “The last decade, higher amounts of fertilizers, particularly nitrogen fertilizers, are used to increase agricultural yield. … [9, 10]” – the quoted literature does not concern Sogro or Greece as the place of the experiment
Line 75 the word "sub-factor" used suggests the use of a hierarchical ANOVA with a nested factor. Give details of the model used.
Lina 137 "it seems that there are statistically..." Mathematical statistics give certainty at the P-alpha level (significance level).
Author Response
- Line 47 has changed
Line 48-49, the used literature is for the used nitrogen in general
Line 75. We are using a split plot design
Lina 137. Has changed
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The article is very relevant - especially due to climate change and the growing demand for crop production - mainly in areas suffering from drought and water scarcity. Overall, the experiment was well planned and conducted. Some doubts are raised by its short time (only two years). From the description of the experiment and the results presented in the article, it is not known what values refer to individual doses of nitrogen fertilizer - are these data averaged or do they refer to a specific variety of sorghum?
Some detailed questions and comments are listed below:
Line 48 – “…of nitrogen fertilizers has doubled” - some source of information?
Lines 54 – 56 – “Nitrogen absorption and crude protein concen-54 tration rise as N fertilizer rates rise, whereas nitrogen utilization efficiency and N recovery 55 fall as N fertilizer rates rise” - repetition in a sentence - it is worth revising it
Lines – 65 – 67 - There is no specifically defined purpose (aims) of the research presented in the article.
Line 75 - were all varieties treated with all doses of nitrogen fertilization in both years? If yes – see comment for Table 1
Line 83 – “6.78” – lack of unit
Line 135 – Table 1 – part with Nitrogen data: were all varieties treated with all doses of nitrogen fertilization in both years? If yes - why table not include data on yields for individual varieties at different rates (doses) of fertilization? What variety of sorghum does the data here refer to? (the same problem in Table 2)
Line 190 - this part should be extended - more comparisons and interpretations with other studies
Line 230 – “cultivation, contributes to the increase of the yield of the second one.” - Was the experiment conducted without using peas as green manure? If not, is this statement justified?
Comments for author File: Comments.pdf
Lines 54 – 56 – “Nitrogen absorption and crude protein concen-54 tration rise as N fertilizer rates rise, whereas nitrogen utilization efficiency and N recovery 55 fall as N fertilizer rates rise” - repetition in a sentence - it is worth revising it
Author Response
The text has changed according to reviewers comments.
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript contains interesting results, but their value is diminished by the fact that they are from a two-year rather than a three-year study period. There is a lack of detailed characterisation of soil conditions, for example mineral nitrogen, assimilable phosphorus, potassium and magnesium content. The description of the agrotechnology used in the experiment is poor, lacking information on phosphorus and potassium fertilisation, among other things.
Comments
Line 72, please include a figure with the location of the test site
Line 84, correct (surface 0-30 cm)
Line 106, please provide full details of the statistical software producer
Line 111, 'Climatic data' is part of Materials and Methods, not Results.
Table 1, dry matter yield unit missing
Line 155, correct higher (Table 2).
References, please remove publications older than 10 years, especially from the last century.
Author Response
Manuscript changed according to reviewers comments and a figure with the place has been included
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors introduced significant additions and corrections to the text. The described experiment can now be better understood. The discussion and conclusions have been significantly supplemented, which better reflects the purpose of the work.
The obtained material of the experiment results was not used to the maximum. The team of authors lacked the knowledge and ability to apply multivariate statistical methods.
Reviewer 3 Report
No comments.
