Soil Nutrient Retention and Yield Effect of Nitrogen, Phosphorus Synergists on Wheat/Maize Rotation in Brown Soil
Round 1
Reviewer 1 Report
the manuscript is clear and relevant for the field. the experimental design, figures, table are appropriate.
General comments:
- from an ecological perspective, hydroquinone is dangerous for ecosystems and especially for water because it is not easily biodegradable. So, have the authors taken this connsiderartion perhaps in future research?
- the result section is too long! it conntains many data explanation that should be in discussion section.
- Please verify the ponctuation of all the text
Abstract:
* The methodologies and the experimental design are not clear.
* line 23-25: "The capacity of holding and keeping nutrient from leaching rose obviously; Simultaneously, the assimilative capacicy for nitrogen and phosphorus increased distinctly, which could lower the eutrophia risks from nitrogen and phosphorus."
this sentence is not clear
Introduction:
line 29: "chemicla" please change it.
line 31: "agriculturalsoil" please separate the words.
line 31: "Hower" please change it.
line 41: "regrowh" please change it.
line 42: "HHHR" please explain it.
line 48: "Pa" is it assimilable phosphorus? please don't give abreviation without the initial explanation
line 50: "Moreover....field crops" please rephrase this sentence.
line 55- 58: "Urease....denitrification" i think this idea is out of place.
line 64: "Biochar ...contains high phosphorus" at which pyrolysis temperature?
line 67: "CMFs" please explain it
Materials and methods:
line 86-88: "the yearly....-13.7°C" please add the year of obtaining the climatic data.
line 88-92: is this data the initial characterization of the studied soil?
line 126: "conmplete" please change it
line 155-157: why the obtained data of soil analysis (20-21)and crop yield(19-21) are from different years? wouldnn't it be better to analyze the data for the year 2020-2021 for all ?
Results
line 185: "the deeper...NH4+" please rephrase
line 194-199:" However....decreasing trend" please rephrase
line 319-320: "the leaching... reduced" as function as what??
the discussion section is consistent and very intersting. the conclusion is consistent with the evidence. however it would be preferable to mention the Hydroquinone toxicity and the environmental risk.
Author Response
Reply to reviewer 1
General comments:
- from an ecological perspective, hydroquinone is dangerous for ecosystems and especially for water because it is not easily biodegradable. So, have the authors taken this connsiderartion perhaps in future research?
Reply: Yes，in the following research, we have detected the dynamic trend of hydroquinone in soil.
- the result section is too long! it conntains many data explanation that should be in discussion section.
Reply: Modified, see the new revison
- Please verify the ponctuation of all the text
Reply: Modified, see the new revison
Abstract:
* The methodologies and the experimental design are not clear.
* line 23-25: "The capacity of holding and keeping nutrient from leaching rose obviously; Simultaneously, the assimilative capacicy for nitrogen and phosphorus increased distinctly, which could lower the eutrophia risks from nitrogen and phosphorus." this sentence is not clear
Reply: Modified, the assimilative capacicy of crops for nitrogen and phosphorus increased distinctly.
Introduction:
line 29: "chemicla" please change it. Reply: Modified
line 31: "agriculturalsoil" please separate the words. Reply: Modified
line 31: "Hower" please change it. Reply: Modified
line 41: "regrowh" please change it. Reply: Modified
line 42: "HHHR" please explain it. Reply: Modified to test region
line 48: "Pa" is it assimilable phosphorus? please don't give abreviation without the initial explanation Reply: see abstrate line 16
line 50: "Moreover....field crops" please rephrase this sentence. Modified to “Moreove, the phosphorus fertilizer supply often far exceeds crop demand.”
line 55- 58: "Urease....denitrification" i think this idea is out of place. Reply: I think there is no better place than this one
line 64: "Biochar ...contains high phosphorus" at which pyrolysis temperature? Reply: Here high phosphorus means total phosphorus not available phosphorus "
line 67: "CMFs" please explain it. Reply: see abstract line 13
Materials and methods:
line 86-88: "the yearly....-13.7°C" please add the year of obtaining the climatic data. Reply: added 2011-2021
line 88-92: is this data the initial characterization of the studied soil? Reply: Yes
line 126: "conmplete" please change it. Reply: Modified
line 155-157: why the obtained data of soil analysis (20-21) and crop yield (19-21) are from different years? wouldnn't it be better to analyze the data for the year 2020-2021 for all ? Reply: (1) Because coefficient variation of nutrient from field experimental generally is a little higher, while the nutrient accumulation is relatively stabler. (2) Maybe it is better, but it does not accord with the Journal rule.
Results
line 185: "the deeper...NH4+" please rephrase: Reply: Modified “The deeper the soil, the lower the NH+ 4 content.”
line 194-199:" However....decreasing trend" please rephrase. Reply: deleted the sentence‘However, there was no statistically significant’, modified other mistake.
line 319-320: "the leaching... reduced" as function as what? Reply: I don’t understand the reviewer’s meanning. It seems no place is wrong.
the discussion section is consistent and very intersting. the conclusion is consistent with the evidence. however it would be preferable to mention the Hydroquinone toxicity and the environmental risk. Reply: Added two sentences in discussion section.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
There is clarity in the approach to the problem and the results that seek greater efficiency in supplying chemical fertilizer to increase grain yield due to farmers' limited education level and cognition. However, the overfertilization phenomenon is widespread, leading to a serious unbalance between the available nutrients the soil provides and the current demand for crops.
The method and experimental design are straightforward and transparent and show innovation in implementing and analyzing fertilization strategies.
Author Response
Thanks to the respected reviewer for this paper! The authors have modified some content according the other reviewer’s comment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The article is of interest to specialists in the field of crop production and agrochemistry. The tasks of increasing soil fertility through the introduction of new methods of applying mineral fertilizers are key to increasing crop yields. Therefore, the article is relevant. For the article has a number of questions and suggestions for improving the presentation of research results.
1. The introduction describes the importance of nitrogen and phosphorus (line 27-28), but nothing is said about potassium and its role in the balance of mineral fertilizers, as well as the importance of this element for plant development. It is important to note that only a balanced use of nitrogen, phosphorus and potassium makes it possible to obtain consistently high yields of high-quality crop products. The question also arises why potassium was not studied in the work.
2. In the introduction, it should be noted that increased doses of nitrogen lead to the formation of nitrates in crop products, which are toxic to humans (line 35-36).
3. In paragraph 1.1, it is necessary to indicate the years of the experiment.
4. In paragraph 1.3, it is important to justify why, in addition to the root layer of 0-20 cm, soil samples were taken to a depth of 60 cm.
5. It is necessary to indicate what the symbols are, a and b in fig. 1. In addition, when analyzing fig. 1, it is necessary to describe in more detail the statistically significant differences between the experimental options, since the results are quite close.
6. Fig. 2 it is better to designate a, b, c, and transfer the days to the title of the figure.
7. Fig. 3 is the same remark as in Fig. 1 see point 5.
8. Fig. 4 is the same remark as in Fig. 2 see point 6.
9. Fig. 5 it is also not clear where the statistically significant differences are and what the symbols mean: a, b, c, ab, etc.
10. Fig. 6 the same correction.
11. For all the figures, it is not clear whether these are the data of one year or averaged for 2019-2021?
12. Table 1 symbols in the values - is it a rating? Not very clear.
13. Table 2 only considers the content of elements in the grain. It was also important to study the quality of the grain: the content of protein, fat, gluten, fiber, etc. As a result, it is necessary to give a comprehensive assessment of the quality of the product, and not just the yield. This is the significantly scientific importance of the work.
14. There are too many works on agriculture in China in the references. It will be useful to consider how similar problems are being dealt with in other countries. It will also be useful to enhance the relevance of the study.
Author Response
The article is of interest to specialists in the field of crop production and agrochemistry. The tasks of increasing soil fertility through the introduction of new methods of applying mineral fertilizers are key to increasing crop yields. Therefore, the article is relevant. For the article has a number of questions and suggestions for improving the presentation of research results.
- The introduction describes the importance of nitrogen and phosphorus (line 27-28), but nothing is said about potassium and its role in the balance of mineral fertilizers, as well as the importance of this element for plant development. It is important to note that only a balanced use of nitrogen, phosphorus and potassium makes it possible to obtain consistently high yields of high-quality crop products. The question also arises why potassium was not studied in the work.
Reply：In fact，relevant indexes about potassium were also determined as nitrogen and phosphorus. The resons not adopted are mainly as followed (1) If nitrogen, phosphorus and potassium were all analyzed in this paper, the amount of data was too large beyond publication requirements; (2) The key point of this work was focus on leaching status and the environmental risk from nitrogen and phosphorus.
- In the introduction, it should be noted that increased doses of nitrogen lead to the formation of nitrates in crop products, which are toxic to humans (line 35-36).
Reply：added “or over-doses”
- In paragraph 1.1, it is necessary to indicate the years of the experiment. Reply：added the year, see line 87 and line 156-158
- In paragraph 1.3, it is important to justify why, in addition to the root layer of 0-20 cm, soil samples were taken to a depth of 60 cm. Reply：0-20 cm was the main cultivated soil, most crop roots concentrated this layer. As soil as concerned, we aimed to surney the certical trace of nitrogen, phosphorus.
- It is necessary to indicate what the symbols are, a and b in fig. 1. In addition, when analyzing fig. 1, it is necessary to describe in more detail the statistically significant differences between the experimental options, since the results are quite close. Reply：modified some details, see the text.
- Fig. 2 it is better to designate a, b, c, and transfer the days to the title of the figure. Reply：The authors think the present symbols more refect or convey the aim of this research.
- Fig. 3 is the same remark as in Fig. 1 see point 5. Reply：modified some details, see the text.
- Fig. 4 is the same remark as in Fig. 2 see point 6. Reply：The authors think the present symbols more refect or convey the aim of this research.
- Fig. 5 it is also not clear where the statistically significant differences are and what the symbols mean: a, b, c, ab, etc. Reply：deleted some sentences.
- Fig. 6 the same correction. Reply：The authors think the present symbols more refect or convey the aim of this research.
- For all the figures, it is not clear whether these are the data of one year or averaged for 2019-2021? Reply: See line 155-158
- Table 1 symbols in the values - is it a rating? Not very clear. Reply: See line 155-158
- Table 2 only considers the content of elements in the grain. It was also important to study the quality of the grain: the content of protein, fat, gluten, fiber, etc. As a result, it is necessary to give a comprehensive assessment of the quality of the product, and not just the yield. This is the significantly scientific importance of the work.
Reply: In fact, we also deteimined some quality indexed, due to space limitations, this paper could not include so much data about the protein, fat, gluten, fiber, etc. Besides, the purpose of this work is mainly to detect the leaching trace of nitrogen and phosphorus, not the grain quality.
- There are too many works on agriculture in China in the references. It will be useful to consider how similar problems are being dealt with in other countries. It will also be useful to enhance the relevance of the study.
Reply: Yes, I agree with this point.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
all corrections have been made.
Reviewer 3 Report
The authors corrected all the comments of the reviewer. The article has improved.
