The Contribution of Soil Tillage and Nitrogen Rate to the Quality of Maize Grain
, Vesna Dragičević, Snežana Mladenović Drinić, Jelena Vukadinović, Branka Kresović, Marijenka Tabaković and Milan BrankovRound 1
Reviewer 1 Report
The authors describe an interesting study across 3 years at the Maize Research Institute on the quality of maize grain based on three soil tillage practices with 3 different N rates. The study is detailed in its approach to study the different parameters that reflect the quality and quantity of the grain in response to the practices described.
The main change would be to include a few points in the discussion on - The observed results can be considered in the context of the data from years previous years to support the cumulative benefit of the practice recommended for the quality of the soil and yield for the coming years.
A few minor comments that would help the results be more clear:
- Correction of misspelled words on line 139, 148
- Figure 1, y-axis units. The year can be included on the graph
- Table 2 - the letters for significant differences are better as Superscript
Author Response
Answers to the suggestions of the Reviewer 1
We acknowledge anonymous referee 1 for his/her constructive comments on the paper. The effort is highly appreciated. We agree with all comments made by Reviewer 1.
Suggestion 1. English language and style are fine/minor spell check required
Answer 1. The minor corrections of English language are done through the text of whole manuscript
Suggestion 2. The main change would be to include a few points in the discussion on - The observed results can be considered in the context of the data from years previous years to support the cumulative benefit of the practice recommended for the quality of the soil and yield for the coming years.
Answer 2. This is accepted and included into Discussion when is explained benefits from long-term experiment, 2005-2016 (reference 11), thank you.
A few minor comments that would help the results be more clear:
- Correction of misspelled words on line 139, 148 – Corrections done
- Figure 1, y-axis units. The year can be included on the graph – Corrections are done
- Table 2 - the letters for significant differences are better as Superscript – It is corrected
Sugestion 3. Are the conclusions supported by the results?
Answer 3. We modified Conclusion and supported it by the results in proper manner.
Reviewer 2 Report
This is an interesting paper studying the effect of soil tillage, N fertilisation and weather on maize grain production and its quality. I have several comments especially in the description of the experiment. The paper needs some editing. Especially removal of many articles that do not fit.
My comments are:
L98 The authors state that the experiment started in 1978 and their work was carried out in 2016-18. Do they mean that the NT, RT and conventional plots are all these years the same? In that case the soil properties like soil organic matter cannot be the same in the three tillage treatments. Obviously the three treatment plots would have different SOM. One advantage of NT is SOM increase which in this paper does not exist.
L 21 respectively in behalf of it is better to write compared to or relative to
L43-46 Under variable climatic conditions 43 and frequent occurrences of dry years, soil tillage adjusted to the soil type, agro-ecological 44 conditions and the crop requirements, can contribute to the achievement of maximum yield 45 potential
Not clear what you mean
The authors define reduced and No tillage as different systems. In L56 you give difference between conventional and reduced but not of NT.In this case reduce include NT?
L66-67 Results gained by Singh et al. [18] showed that maize yields have increased from 10.5 t ha-1 (at 66 the 0 kg N ha-1) to 11.5 t ha-1 (at the highest N level of 202 kg N ha-1).
L11-116. I am confused. Did you use different plots each year with maize after winter wheat? Or after winter wheat you have three years of maize? How did you harvest wheat? Did you chop and spread straw or you removed straw?
In reduced tillage did you have any seedbed preparation? Soils during winter are compacted and some weeds are growing. Did you have any of these problems?
L124-125 what is finally the ploughing depth? You need to check it.
L126. How N fertiliser was applied? No top dressing? How N fertiliser was incorporated in NT? What was weed populations before seeding in the three tillage treatments?
Table 1 **Significant at the 1% probability level; *Significant at the p < 0.05; ns- non significant; df: degrees of freedom; CV: coefficient of variation
Please use same terms. CV is irrelevent
Table 2 is confusing. a,b,c after some values mean stat significance? Then in GY for the three years with LSD 2.005 9.92a and 8.60b are not different. The same applies for N. With LSD 3.304 there is not difference. The same applies for T. Please make it clear and correct any mistake.
L300 You used N for nitrogen application. Now you use F instead.
L343-345 This effect can be surpassed through the use of higher N rates or inclusion of straw-retained practice that could contribute to N mineralisation due to increased organic matter in the soil.
Does this mean the in your experiment you removed all crop residues?
Author Response
Answers to the suggestions of the Reviewer 2
We acknowledge anonymous referee 2 for his/her constructive comments on the paper. The effort is highly appreciated. We agree with all comments made by Reviewer 2.
Suggestion 1. Moderate English changes required
Answer 1. The corrections of the English language are done through the whole manuscript in accordance to Reviewer 1 suggestions, too.
Comment and suggestion 2. Introduction provides sufficient background and includes all relevant references and Remove articles that do not fit…
Answer 2. We concluded from those two statements (first from questionnaire and the second from general comment of the Reviewer 2) that some references in the manuscript have to be removed but not from Introduction part. Thank you, 3 references are removed.
Suggestion 3.
L98 The authors state that the experiment started in 1978 and their work was carried out in 2016-18. Do they mean that the NT, RT and conventional plots are all these years the same? In that case the soil properties like soil organic matter cannot be the same in the three tillage treatments. Obviously the three treatment plots would have different SOM. One advantage of NT is SOM increase which in this paper does not exist.
Answer 3. The additional data about soil organic matter and N content are provided in the M&M part
Suggestion 4. L 21 respectively in behalf of - it is better to write compared to or relative to
Answer 4. The sentence needed rewriting and “in comparison to” is accepted
Suggestion 5. L43-46 Under variable climatic conditions 43 and frequent occurrences of dry years, soil tillage adjusted to the soil type, agro-ecological 44 conditions and the crop requirements, can contribute to the achievement of maximum yield 45 potential
Not clear what you mean
Answer 5. This sentence is madden more clearly
Suggestion 6. The authors define reduced and No tillage as different systems. In L56 you give difference between conventional and reduced but not of NT. In this case reduce include NT?
Answer 6. Yes, it was not clear. The needed explanations are done. The average data for ten years period are provided for all three tillage systems.
Suggestion 7. L66-67 Results gained by Singh et al. [18] showed that maize yields have increased from 10.5 t ha-1 (at 66 the 0 kg N ha-1) to 11.5 t ha-1 (at the highest N level of 202 kg N ha-1).
Answer 7. We properly cite this reference. The authors Singh et al. 2005, gave the same values for maize grain yield in dependence of N rate as we used in the manuscript.
Suggestion 8. L11-116. I am confused. Did you use different plots each year with maize after winter wheat? Or after winter wheat you have three years of maize? How did you harvest wheat? Did you chop and spread straw or you removed straw?
Answer 8. The more detailed explanations are included in the text.
Suggestion 9. In reduced tillage did you have any seedbed preparation? Soils during winter are compacted and some weeds are growing. Did you have any of these problems?
Answer 9. You are right; we conducted actually pre-sowing seedbad preparation within reduced tillage in order to destroy weeds which germinated during winter. For spring and summer weeds control, the herbicide application is conducted, Line 139-145.
Suggestion 10. L124-125 what is finally the ploughing depth? You need to check it.
Answer 10. Thank you, we checked the ploughing depth, it is relevant and presented.
Suggestion 11. L126. How N fertiliser was applied? No top dressing? How N fertiliser was incorporated in NT? What was weed populations before seeding in the three tillage treatments?
Answer 11. The N fertilizer was applied as top dressing by spreader MR 300 (Agroart, Stara Pazova, Serbia) in the spring before seedbad preparation in all treatments of soil tillage.
The weed abundance evaluation is conducted each year but it is not the part of this work.
Suggestion 12. Table 1 **Significant at the 1% probability level; *Significant at the p < 0.05; ns- non significant; df: degrees of freedom; CV: coefficient of variation. Please use same terms. CV is irrelevent
Answer 12. Thank you, we accepted and adjusted levels of significance and all suggestions
Suggestion 13. Table 2 is confusing - a,b,c after some values mean stat significance? Then in GY for the three years with LSD 2.005 9.92a and 8.60b are not different. The same applies for N. With LSD 3.304 there is not difference. The same applies for T. Please make it clear and correct any mistake.
Answer 13. Thank you, the mistakes are corrected and accordingly comments in the text are changed.
Suggestion 14. L300 You used N for nitrogen application. Now you use F instead.
Answer 14. Thank you, it was mistake and we changed all F into N in whole text
Suggestion 15. L343-345 This effect can be surpassed through the use of higher N rates or inclusion of straw-retained practice that could contribute to N mineralisation due to increased organic matter in the soil.
Does this mean the in your experiment you removed all crop residues?
Answer 15. No, it does not mean this. Residues of winter wheat are left on the soil surface in all three systems of soil tillage and text is corrected to be understandable.
Round 2
Reviewer 2 Report
The authors responded to most of the comments. The following could be added:
L137 with top dressing we mean applications after crop emergence. In your case you men that you applied N fertiliser on top of the soil. In conventional and NT you incorporated it by tillage. IN NT? What type of fertiliser you used? How you minimised losses in NT? Please discuss it.
Some English editing especially in artivles is needed.
Author Response
Answers to the suggestions of the Reviewer 2 Round 2
We acknowledge anonymous referee 2 for his/her constructive comments on the paper. The effort is highly appreciated. We agree with all comments made by Reviewer 2.
Suggestion 1. Moderate English changes required
Answer 1. The manuscript was checked by professional translator and accordingly, modifications were done.
Suggestion 2. Methods description: L137 with top dressing we mean applications after crop emergence. In your case you men that you applied N fertiliser on top of the soil. In conventional and NT you incorporated it by tillage. IN NT? What type of fertiliser you used? How you minimised losses in NT? Please discuss it.
Answer 2. As N fertilizer Urea was applied by spreading on the surface before sowing. Rain served for incorporation into the soil as it was explained with more details into the manuscript.
Suggestion 3: Some English editing especially in artivles is needed.
Answer 3: The corrections are done.
