Empirical Setting of the Water Stressed Baseline Increases the Uncertainty of the Crop Water Stress Index in a Humid Temperate Climate in Different Water Regimes

Round 1

Reviewer 1 Report

General comments: In this paper, the authors used a simple linear regression to examine the performance of estimated non-water stressed baseline (NWSB) and WSB for rice in a humid climate and CWSI sensitivity under different scenarios. The study is based on a 2-year pot trial under a phytotron and field environment with two rice genotypes (IRAT109 and Takanari) in flooded (FL) and aerobic (AR) water regimes. The study found that the dynamics of CWSI are dependent not only on the water regimes but could be strongly influenced by genotype sensitivity to vapor pressure deficit (VPD).

The methods are well written and the research procedures and techniques used are standard and reproducible. The result section is clear, well presented and is well complemented with figures to help in results visualization. The discussion section supports many aspects of the findings and done within the content of previous studies. In general, I find the manuscript interesting and informative, especially with including micro-meteorological characteristics in the study.

The manuscript has the potential to be published after the authors carefully clarify or fix the queries raised below.

Major comments:

Abstract: No quantitative results are provided? I suggest authors include quantitative results in this section.

Introduction: The introduction in its current is difficult to read. I suggest this section should be re-written and re-structured again. The motivation of the study is not clearly stated and should be highlighted. I strongly suggest English language editing to improve the manuscript in this section.

Minor comments: Line 59-76: What was the reason for this paragraph? (Especially when the readers can infer from the references provided). I suggest the entire paragraph should be removed and rephrased.

Comments for author File: Comments.docx

Author Response

Thank you very much for your valuable time to review and make suggestions to improve the current version of our manuscript.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This article applies the concept of crop water stress index, which is based on sensitive differences in crop canopy temperature and simultaneous air temperature. The authors search for differences in the index values if temperature measurements are based on different baselines, which could influence the meaning of the stress index. Therefore, the authors designed an experiment with two cultivars of rice crop irrigated with two watering regimes, the most common continuous flow, and an alternating watering – drying regime. Temperature measurement techniques and equipment were carefully chosen and installed, looking for confident data.

The objectives, procedures, results, and discussion are clearly explained and developed. Therefore, in my opinion, the article may be published in its present form.

 

 

Author Response

Thank you very much for your valuable time to review and comment on our manuscript.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The subject of the manuscript entitled “Empirical setting of the water stressed baseline increases the uncertainty of the crop water stress index in a humid temperate climate in different water regimes” falls within the general scope of the journal. According to the authors, “this study examined the performance of estimated NWSB and WSB for rice in a humid climate and CWSI sensitivity under variable reference baseline scenarios in a 2-year pot trial under phytotron and field environment with two rice genotypes in flooded and aerobic water regime”.

 

It is an original and interesting contribution. The article structure is correct; it is divided into clearly defined, numbered sections and subsections, but in my opinion, minor changes are required to be published in Water.

 

Authors should explain the air temperature values shown in Figure 1 b if they indicate (Line 117) “in the phytotron was set at 29/22 °C day/night”. They should explain how they controlled the temperature.

 

Authors should clarify “in a completely randomized and randomized complete block design” (Line 123).

 

In line 190, and where applicable, authors should present the time as hh:mm, instead of hhmm.

 

Line 286: In Table 1, it is indicated that (Tc – Ta)_WSB (°C) is estimated from Equation (3). In my opinion, authors should detail how.

 

The authors should clarify the sentence in line 301.

 

In Figure 6 (a-d) are shown the p-values, which means “p-values indicate t-test at p < 0.05”?.

 

Lines 319-320: “Figure 6. Boxplots of the crop water stress index between flooded and aerobic water regime based on two (phytotron only (a, c)) and four (field environment only (b, d))…”. Are the authors sure?

 

Line 326: “statistically significant differences (p <0.05) between water regimes were observed for only …”. Does it mean “statistically significant differences (p < 0.05) between CWSI corresponding to water regimes were observed for only …”.

 

Author Response

Thank you very much for your valuable time and suggestions to improve the current version of our manuscript.

Please see the attachment.

Author Response File: Author Response.docx