Effects of Seasonal Freezing and Thawing on Soil Moisture and Salinity in the Farmland Shelterbelt System in the Hetao Irrigation District
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
The article “Effects of seasonal freezing and thawing on soil moisture and salinity in the farmland shelterbelt system in the Hetao Irrigation District” presents the monitoring (between 10/2020 and 04/2021) of soil moisture, salinity, temperature and meteorological parameters during the period of freezing and thawing in an FSS, with assessments in depth and spatial distribution, in addition to estimates with RN and multiple regressions. The article is very consistent in measurements and has a good scientific structure, but it presents difficulties in understanding English and limitations to scientific writing. Furthermore, authors can better explore the measured data to provide robustness to the work’s contributions.
- Suggestions for improving the article:
- There are very long paragraphs with repetitive sentences (for example – 51 to 72)
- Present the physical-water characteristics of the soil in the cultivated area (farmland) at the evaluated depths, and if possible, with spatial variation by Figure 2 – soil texture, density, porosity, saturated hydraulic conductivity, among others – that allow us to understand water and heat flows in the soil – establish these relationships with humidity and salinity
- Improve the resolution of Figure 3; the caption in Fig. 3e is wrong (“T”)
- Is there a correlation between humidity, salinity, soil temperature and air temperature, in addition to the physical properties of the soil at the evaluated distances and depths? Present a Pearson correlation table or principal components analysis (PCA) to allow an understanding of these relationships and the extent to which spatial and temporal variations occur throughout the freezing cycle.
- The conclusions need to be rewritten (they look like the discussion in the article). Conclusions must be concise, direct, and short and respond to the objectives of the article.
Author Response
Response to reviewer #1 comments
- There are very long paragraphs with repetitive sentences (for example – 51 to 72)
Reply: Thank you for your suggestion. We deleted the repetitive sentences (see See 1.Introduction, Paragraph 2)
- Present the physical-water characteristics of the soil in the cultivated area (farmland) at the evaluated depths, and if possible, with spatial variation by Figure 2 – soil texture, density, porosity, saturated hydraulic conductivity, among others – that allow us to understand water and heat flows in the soil – establish these relationships with humidity and salinity
Reply: Thank you for your suggestion. This article focuses on studying the effects of farmland protective forest systems on soil moisture and salinity during the freeze-thaw period. Unfortunately, due to the soil being frozen during the local freeze-thaw period, it becomes very hard, making it difficult for the ring cutter to take soil samples. Therefore, we did not measure soil porosity, texture, and other data in our previous experiments. We will comprehensively consider these physical properties of soil in future research.
- Improve the resolution of Figure 3; the caption in Fig. 3e is wrong (“T”)
Reply: We revised it as you suggested. (See fig.3e)
- Is there a correlation between humidity, salinity, soil temperature and air temperature, in addition to the physical properties of the soil at the evaluated distances and depths? Present a Pearson correlation table or principal components analysis (PCA) to allow an understanding of these relationships and the extent to which spatial and temporal variations occur throughout the freezing cycle.
Reply: We added correlation analysis to illustrate the coupling relationship between soil moisture and salinity at different depths. (See section 3.3.3, L319-324)
- The conclusions need to be rewritten (they look like the discussion in the article). Conclusions must be concise, direct, and short and respond to the objectives of the article.
Reply: We have rewritten the conclusion as you suggested. (see 5. Conclusions, L513-527)
Thank you again for the reviewer's comments on the MS
Reviewer 2 Report
Comments and Suggestions for Authors
Overall a good paper with clarity in importance, methodology and findings. Recommend for publication. Specific comments follows:
1. Figure captions contain not enough information to understand the graphs. A figure caption should be a standalone textbody that lets the reader know how to read the figures and understand the key features without having to refer to the main text body. Recommend author to revise the figure captions.
2. line 88: BP is first used here. Please spell out what it stands for.
3. line 140: three (?) sampling points at each distance from the shelterbelt?
4. line 310: R2, subscript 2
5. line 309: section 3.4.1 "Multiple Regression Model": recommend address multicollinearity among the four independent variables. Multicollinearity may not impact prediction accuracy but interpretation on the coefficients is vulnerable.
6. line 348, BP prediction on soil moisture resulted much larger discrepancy for 20-40 cm soil depth (101.09%), any comments why this happened?
7. line 466-467, "... soil salt content distribution generally matched predicted values, though predicted values were ...". You probably mean matching the predicted soil salt content distribution pattern, while the predicted values are systematically lower than observed?
Author Response
Response to reviewer #2 comments
- Figure captions contain not enough information to understand the graphs. A figure caption should be a standalone textbody that lets the reader know how to read the figures and understand the key features without having to refer to the main text body. Recommend author to revise the figure captions.
Reply: Thank you for the author's suggestion. We have added annotations to the images.(see figs. 2-6)
- line 88: BP is first used here. Please spell out what it stands for.
Reply: We have added an explanation for BP.(See 1.Introduction, Paragraph 3, Line 87)
- line 140: three (?) sampling points at each distance from the shelterbelt?
Reply: We have revised it.(See 2.2. Experimental design, Paragraph 4, L142)
- line 310: R2, subscript 2
Reply: We have revised it.(See 3.4.1. Multiple regression model, Paragraph 1, L333)
- line 309: section 3.4.1 "Multiple Regression Model": recommend address multicollinearity among the four independent variables. Multicollinearity may not impact prediction accuracy but interpretation on the coefficients is vulnerable.
Reply: Thank you for your comments. In order to reduce the influence of collinearity of independent variables, there are only four independent variables in the multiple regression in this article, and the coupling parameters between multiple variables are not added to the equation. At the same time, we deeply recognize the advantages and disadvantages of multiple regression equation, so the results of this paper focus on the comparison of the prediction results of multiple regression model and BP neural network model.
- line 348, BP prediction on soil moisture resulted much larger discrepancy for 20-40 cm soil depth (101.09%), any comments why this happened?
Reply: Thank you for your comments. This value refers to the difference between the soil moisture values near the forest margin and those inside the farmland. One possible reason is that the roots of the shelterbelt mainly distribute in the 20-40cm layer in the farmland, leading to spatial heterogeneity in soil roots in this layer, which may cause significant changes in the physical and chemical properties of the soil. Another possibility is the effect of freezing and thawing. We will thoroughly investigate this issue in follow-up studies and further examine the soil condition of this layer。
- line 466-467, "... soil salt content distribution generally matched predicted values, though predicted values were ...". You probably mean matching the predicted soil salt content distribution pattern, while the predicted values are systematically lower than observed?
Reply: We have revised it.(See 4.3 Soil water and salt prediction model, L494-496).
Thank you again for the reviewer's comments.
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
Analysis of the second review of the article "Effects of seasonal freezing and thawing on soil moisture and salinity in the farmland shelterbelt system in the Hetao Irrigation District". Changes and improvements to the article can be observed and linked to the comments made in the first review. The authors justify that collecting soil samples during the freezing and thawing period was impossible, as the soil becomes "very hard". The lack of information linked to soil texture, density, porosity, and saturated hydraulic conductivity, among others, is the main limitation of the article, as it would allow an understanding of this behavior in soil that is not common in other regions. From a technical and scientific point of view, the article addresses the relationship between humidity and salinity in the FSS clearly and with conclusions that respond to the established objectives.
Two important and short pieces of information that need to be inserted in item 2.1
- According to the Soil Survey Staff, what is the FSS soil class?
- According to the Kopeen climate classification, what is the region's climate?
Author Response
Response to reviewer comments
Two important and short pieces of information that need to be inserted in item 2.1
- According to the Soil Survey Staff, what is the FSS soil class?
- According to the Kopeen climate classification, what is the region's climate?
Reply: Thank you for your suggestion. We added relevant information. (see L107 & L113)
