Impact of Soil Factors on the Yield and Agronomic Traits of Hemerocallis citrina Baroni in the Agro-Pastoral Ecotone of Northern China

Round 1

Reviewer 1 Report

Impact of Soil Factors on the Yield and Agronomic Traits of Daylily in the Agro-pastoral Ecotone of Northern China
 
Xingrong Ma

Hemerocallis citrina is a minor crop frequently cultivated in China. Here, they want to determine how the yield responds to variation in soil factors.
The paper is based on measurements of soil factors and crop performance in 37 sites.
I see three major issues with this paper.
First, the whole approach is empirical and descriptive. Such a correlative approach cannot be used to determine which factors are the most limiting ones; an experimental approach is required.
Second, the paper is based on 37 sampling points, all of which are taken from a small area (< 50x50 km); therefore, it is highly questionable if the 37 sampling points are representative of the range of soil conditions in which that crop is cultivated. This is a major issue, because the results are probably not generalizable to the whole area of cultivation in the farming-pastoral ecotone of China. It should be noted that the 37 sites are not homogeneously distributed, therefore, the dataset is subjected to autocorrelation bias, i.e. two sampling points close to each other are actually not mutually independent;
Third, and most importantly, the statistical analysis of the data is completely inappropriate /flawed.
Seven soil factors and 4 agronomic parameters have been assessed, but the whole analysis (except 1 multiple regression) is based on bivariate statistics! (correlation plots between each soil factor and each of the four performance indices). This is not acceptable. The statistics are flawed, because a large number of simultaneous tests are performed. Most importantly, there certainly exist correlations between different soil parameters, while the analyses consider them as mutually independent.
No less than 56 graphs are included, which is by far too many!
It is necessary to perform multivariate analyses. A principal component analysis should be used first, to explore the structure of correlations between soil factors, and between soil factors and response variables. The results should be used to decrease the number of independent variables.
Thereafter, a multiple regression analysis can be performed, using a subset of variables.
The details of the multiple regression analysis shouldbe better explained
Other remarks
It is unclear if the soil has received fertilisers or not; the history of each site is not known.
I missed a paragraph describing phytotechnical details of Hemerocallis cultivation; planting date, development cycle, harvest date, etc. Also, what parts of the plant are used for human consumption is unclear.
All the univariate correlation graphs should be moved to supplementary materials.
The same data are presented several times in different graphs, which is unacceptable (see for instance the relation between pH and yield.
Fig 3C is impossible to understand; how texture can be expressed on a linear axis is difficult to imagine… By the way, the methods used to assess soil texture are not explained.
The scientific name of the plant should be in the title.
All the legends of figures and tables should be considerably expanded; variable names in table 1 should be explained in the legends; do not mix up agronomic parameters and soil factors, please.

Some language editing required.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The purpose of the paper, "Impact of Soil Factors on the Yield and Agronomic Traits of Daylily in the Agro-Pastoral Ecotone of Northern China", is to investigate the effect of soil physicochemical properties on the yield and agronomic traits of a daylily (Hemerocallis Citrina Baroni) cultivated in the agro-pastoral ecotone of northern China. The study focuses on discovering how different soil parameters such as moisture, organic matter content, density, texture, nitrogen, phosphorus, potassium and pH affect key indicators of lily growth and productivity such as number of buds, number of stems and plant height. In addition, the study aims to identify the most critical soil factors that can be regulated to optimise lily production, which is particularly important in the context of the difficult soil and atmospheric conditions characteristic of the area studied.

The article presents a novelty and a research gap, but according to the reviewer, the Loklany programme is presented. It is rather a report on the basis of which a recommendation for the cultivation of Hemerocallis Citrina Baroni could be presented.

The article presents a comparison of cultivation and agronomic characteristics of Hemerocallis Citrina Baroni in different soil types and soil capacity. The article should develop a discussion to compare the results obtained with similar research carried out in other regions or countries. This may help to understand how local environmental conditions affect cultivation.

While the study provides valuable insights, acknowledging its limitations (e.g. geographical scope, year of study) would provide a balanced view. In addition, it would be useful to suggest areas for future research, perhaps involving long-term studies or exploring genetic variation among daylilies in response to soil conditions.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Impact of Soil Factors on the Yield and Agronomic Traits of Daylily in the Agro-pastoral Ecotone of Northern China

Xingrong Ma et al.

second round of review

Some of my comments have been taken into account, and the manuscript is improved.

However, it still needs further improvement:

104-105 : objective

“the adaptation strategies of crops in ecologically fragile areas to arid and poor soil conditions are unveiled,” :

This cannot be an objective of this paper. First, why writing “crops” in the plural? Second, contrary to what they write, they are not studying adaptation strategies! The objective should be reformulated into something that can be tested with the data presented.

In my first review, I wrote : “the methods used to assess soil texture are not explained “

The authors now write : “determination of soil texture (ST) by hand measurement[24].”.

Reference 24 in the reference list is “Zhang, P.; Lu, W.; Xu, J.; Lin, Z.; Chen, M.; Li, K. Site Classification and Quality Evaluation of Eucalyptus urophylla ×E. tereticornis Plantation in Hainan Island and Leizhou Peninsula Region. J. Research on forestry science. 2021, 34 (06), 130–139.

The title of the journal is wrong! (correct title: Forest Research). Moreover, the article is in Chinese. So, the method for soil granulometry assessment is not available to the reader.

The method must be clearly explained in this paper. I still do not know what “hand measurement” means. I also do not understand how soil texture (ST) can be represented by a single variable ; texture is represented by the percentage of clay, loam and sand. This needs further clarification!!

In all tables, I recommend NOT using abbreviation for the plant performance variable; write in full: bud number, scape number, yield, plant height.

A Principal component analysis has been performed, which is good. However, the results are not very well presented:

-Table 3 is essentially useless; delete it;

(notice that the word “ingredient” should be replaced by “Component”)

The difference between Table 4 and 5 is not apparent to me. What is needed, is only ONE table of the correlation coefficients of all variables with the four components. That table should also be used to construct a Figure showing the projection of all variables on the plane of PC1-PC2; each variable (i.e. 4 plant performance measurements + all soil factors) will be represented by a vector, and each sampling site will be represented by a point.

In this way, the results will be easily visualized, and the structure of the correlations among all the variables will become immediately apparent.

Multiple regression

Table 7 is impossible to understand because the names of the soil variables have been replaced by X1, X2, etc. Please use the real acronyms of the variables. The legend of Table 7 is poor; indicate what column “B” means.

Other remarks

Name of the study species: Hemerocallis citrina must be in italics everywhere. I recommend using the scientific name in the abstract, and, if possible in the title (unless the journal instructions are different).

Data Availability Statement: “No new data were created or analyzed in this study. Data sharing is not applicable to this article”:

This is unacceptable! Of course, data have been obtained. All original measurements of plant performance and soil analyses in all study sites must be made available.

acceptable

Author Response

Please see the attachment.

Author Response File: Author Response.pdf