Soil Moisture, Nutrients, Root Distribution, and Crop Combination Benefits at Different Water and Fertilizer Levels during the Crop Replacement Period in an Apple Intercropping System
Round 1
Reviewer 1 Report
The manuscript titles “Soil Moisture, Nutrients, Root Distribution, and Combined Benefits at Different Water and Fertilizer Levels during the Crop Replacement Period in an Apple Intercropping System” investigate the effects of different irrigation methods, irrigation levels, fertilizer levels, on soil moisture, nutrients, root distribution.
The title is so long, please be more concise
The size of experiment plots not clear (Area coverage)
Page 3 Lines 139-141: the sentence “Five heavy rainfall …… which lasted 83 h and 24 h, respectively.” Is not clear, please consider revise it.
At which base the authors chose the fertilizer levels/treatments, please include Reference(s)
Page 6 Lines 188-189: the sentence “Five heavy rainfall …… were recorded in 2021.” Is already stated before in lines 139-141.
No references were cited for the laboratory analyses of soil properties.
The authors stated that “GY” is the seed yield in line 256 and is the grain yield in line 261 and 266, please be consistent
Page 8 Lines 275-276: the sentence “PC1, PC2, and PC3 explain more than 75% and 73% of the variability, respectively.” The authors stated 3 PC and referred to 2 values only, please explain.
I suggest to add list of abbreviations at the beginning of the manuscript, as the authors use abbreviations throughout the paper.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The amount of time, field work, and careful data collection and analysis are clearly evident in this paper, and I commend you for that. Overall, I think the research merits publication, but needs to be significantly shortened and focused, or perhaps divided into two separate papers.
The abstract is too long and should be shortened to 300 words.
Introduction - many statements are missing citations, such as line 65 is missing a citation of the previous two sentences. Every statement that is not opinion or general background information needs a citation. There is too much repeated information in the Introduction.
Line 68 - start a new paragraph at "Root". This is just one example of a lengthy paragraph that needs to be divided into shorter ones. You need to review the structure of a paragraph and employ it in this paper.
Lines 87-90 This sentence is an example of incomplete sentence.
Line 120 Objective #3 does not line up well with the first two. It seems more like an overall goal of your research rather than a specific objective. If you decide to keep it as such, it needs rewording to grammatically line up with the other 2.
Line 126 put Figure 1 in parentheses rather than "as shown in".
Line 129 - information about the soil texture needs to be included.
Lines 134-143 - this section should be combined with Section 2.3.1
Line 178 should be Figure 2 not Figure 1
Line 208 Soil should be capitalized
Lines 292-297 - where are the data? If not shown, you need to state that.
Line 304 - you state maize in both years but the design shows maize only in year (2020)
Figures 4, 5, 6, 7, 8, 9 and 10 are much too complicated and confusing. You should remove these and perhaps use some orthogonal contrasts to get at the most important comparisons, especially with so many significant interactions.
Soil nutrient results - you need to either refer to the figure with the relevant data or indicate that the data is not shown.
PCA Analysis. I think this is a unique aspect of this paper. However, in most PCA analyses, authors try to develop a description of each principal component, and I don't see that in this paper.
Discussion - once again, too long and the paragraphs need to be improved. However, you did well to incorporate results of other studies.
Conclusions - this was one of the better sections of the paper - just about the right length and focus on the most important results.
Most of the English in the paper is quite good. The journal editors should be able to help you clean up some of the issues with repetition, lengthy paragraphs and sentences, and incomplete sentences.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
This MS evaluated the maize and soybean growth, yield, crop ET, soil water and nutrient changes in the apple-maize/soybean intercropping system with different irrigation and fertilizer applications in North China based on two year experiments. Results shows both irrigation and nutrient have significant effects on maize and soybean growth and water and fertilizer use efficiency. Results in this study could help farmers improve field management to achieve high crop production and economic benefit.
Some comments and suggestions are listed as followings.
(1) In abstract line 13, the intercropping system should be specified here.
(2) In line 156, maize was sowed on August 13 in 2020. In this case, the maize could be not grow in a whole season. The real growth condition should be described.
(3) In 2.3.2, why there are two water measurement plans when considering the soil depth and time intervals.
(4) For maize grain yield, Considering the maize was sowed too late, approximately 3 month later the normal period, I suggest just compare the dry matter. the yield calculated using the method in this study could cause large error.
(5) In lines 292-294, It is hard to understand because there were at least two tapes between apple trees. soil water change maybe mainly influenced by tape layout and irrigation scheduling.
(6) In Lines 315-316, This difference in SWC in the two years should be considered seriously because of the differences in the crops, irrigation and rainfall amounts between the two years.
(7) In 3.4 section, the statement in lines 502-505 should be reconsidered. For a whole maize growth stage, the ET in the seeding stage generally is lower than those from elongation to milking stage. also ET is increasing with the N application increasing because higher N application could result in higher LAI。
(8) In 4 discussion section, radiation distribution in this intercropping system could be a main factor influencing the plant growth, ET as well as soil water and nutrient distribution at horizontal and vertical direction. this also could interpret the reason why plant growth better at 1.7 m distance away from the trees. I suggest that the influence of radiation distribution and trees characteristics, for example plant height and LAI as well as canopy size, on plant growth and ET should be discussed.
Other comments can be found in the pasted file.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
The main question addressed by the research is the influece of soil moisture, nutrients, root distribution, and combined benefits a during the crop replacement period in an apple intercropping system. The topic is relevant and addresses important issues in agriculture. The study allows the evaluation of a whole set of different parameters: moisture, fertilizer, use of additional crops (soybean and corn) to improve the condition of apple trees. The references are appropriate. The conclusions consistent with the evidence and arguments presented and address the main question posed.
Notes to authors:
Methodological questions for the authors: it is not clear what the biological and statistical repeatability was in each variant of the experiment.
Figures 4, 6, 7, 8, 9 are not quite clear because of the abundance of data presented. Is it possible to simplify them somehow for better perception?
Author Response
Please see the attchment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
My comments and questions are well responded. therefore, it can be accepted at present.
