Effects of Organic Fertilizer Replacement Nitrogen Fertilizer on Nitrogen Utilization and Growth of Mung Bean: Evidence from 15N-Tracing Technology
Round 1
Reviewer 1 Report
I revised the manuscript “Effects of organic fertilizer replacement nitrogen fertilizer on nitrogen utilization and growth of mung bean: Evidence from 15N tracing technology” submitted to the Agronomy.
The authors presented the topic on use of organic fertilizer.
The interactions of the effect of different organic fertilizers with nitrogen fertilizers on the nitrogen use and growth of mung beans in the context of applying different organic fertilizers instead of chemical fertilizers is discussed.
The topic of the article is up to date, the introduction is easy detailed. This problem is relevant for journal scope.
The concept and aim are clearly defined. The presentation and discussion of the presented topicis clear and very detailed.
Other weaknesses to be corrected:
1. Keywords should be in alphabetical order.
2. No explanation of some abbreviations, e.g. CK
The manuscript follows the formal regulations of MDPI journals.
I suggest the acceptance after minor revision.
Author Response
Question 1: Keywords should be in alphabetical order.
Answer 1: All keywords have been in alphabetical order.
Question 2: No explanation of some abbreviations, e.g. CK
Answer 2: The Note in Figure 1 explains the abbreviations.
Author Response File: 
Author Response.docx
Reviewer 2 Report
A field experiment was carried out with 10 treatments based on isotope tracing technology. The nitrogen fertilizer utilization, residual, loss and dry matter transportation, leaf area, photosynthetic potential and wet-basis moisture content of mung bean were discussed. The authors did important work on nitrogen utilization by the crops under study.
I have some suggestions to improve it:
1. Please add only the reviews related to the \nitrogen fertilizer in your introduction part.
2. Mungbean is a leguminous crop so it already fulfills its N requirements by N fixation in its rhizosphere, so how to differentiate its N utilization from root nodules and N utilization from fertilizer? I didnt find any relevant information in Introduction or discussion.
3. Table 1 should be more clear about rate of fertilizers in soil?
4. Please revise the sentence, "The 45.0 kg/hm2 P2O5 and 22.5 kg/hm2 K2O nitrogen fertilizers and organic fertilizers were applied immediately before sowing." it is unclear.
5. Section 2.3: which isotope was determined by the authors? Was this part of any treatment? it is not mentioned.
6. Language and presentation need serious improvements.
Author Response
Comments of reviewer 2
Question 1: Please add only the reviews related to the \nitrogen fertilizer in your introduction part.
Answer 1: A review of nitrogen fertilizer has been added to the introduction part, Please see References 14-18 for details.
Question 2: Mungbean is a leguminous crop so it already fulfills its N requirements by N fixation in its rhizosphere, so how to differentiate its N utilization from root nodules and N utilization from fertilizer? I didnt find any relevant information in Introduction or discussion.
Answer 2: The nitrogen fixation of plant rhizosphere is from in the air, in the soil, and in some nitrogen fertilizers. The fixed in nitrogen fertilizers is included in the absorption of nitrogen by plants. We mainly study the utilization rate of applied nitrogen fertilizer. Therefore, we used isotope tracing technology to study the absorption of nitrogen fertilizer by plants, the residue and loss of nitrogen in soil.
Question 3: Table 1 should be more clear about rate of fertilizers in soil?
Answer 3: Table1 Data is provided by Heilongjiang Bayi Agricultural University. Only these data can be measured before sowing.
Question 4: Please revise the sentence, "The 45.0 kg/hm2 P2O5 and 22.5 kg/hm2 K2O nitrogen fertilizers and organic fertilizers were applied immediately before sowing." it is unclear.
Answer 4: The sentence " The 45.0 kg/hm2 P2O5 and 22.5 kg/hm2 K2O nitrogen fertilizers and organic fertilizers were applied immediately before sowing." has been revised.
Question 5: Section 2.3: which isotope was determined by the authors? Was this part of any treatment? it is not mentioned
Answer 5: In Section 2 and 3, isotopes of each organ and soil layer of mung bean plants treated by T1-T9 were determined respectively.
Question 6: Language and presentation need serious improvements.
Answer 6: Language and presentation have been revised.
Author Response File: Author Response.docx
