Requirements and Effects of Surface Drip Irrigation of Mid-Early Potato Cultivar Courage on a Very Light Soil in Central Poland

Round 1

Reviewer 1 Report

The manuscript presents the observations of the potato (Courage cultivar) yield parameters and irrigation water use and fertilizer efficiency in experiment with drip irrigation combined with broadcast fertilization and fertigation over the period of 2011-2013 in Poland.

The study presents valuable significantly different observations between 4 treatments that confirm the already known fact that drip irrigation and fertigation is an efficient combination in the agricultural practice. I personally miss a bit control treatment without irrigation and fertilization; however, I understand that showing the efficiency of fertilization alone was not the aim of this study. By this I do not want to say that the study does not bring the new knowledge, however, the authors should justify the need of such study in the Introduction section in more detail.

The readability of English in the manuscript is generally good, however there are sections (mainly material and methods and results and discussion) that needs some significant reorganization of the text – to keep the structure and provide the information where it should be without further repetitions. There are several cases, when the same statement is mentioned in different sections – these repetitive statements should be checked and dealt with. Further text modification is needed especially at the weather conditions description and results analysis as the word order is often not correct and the long sentences are not clear enough. Some of these issues were pointed out directly in the revised text of the manuscript.

Regarding the description of the results the authors sometimes present completely opposite observations as the data show. Also, at the beginning of the result section the acronyms of the treatments seem to be a bit unnecessary as they describe the treatments here by full word description. Control treatment with acronym O is after methodology mentioned only in the abstract section.

Another reason of the necessity of the revision is that the methods used are not described clearly or sufficiently and some necessary information and references are missing.

All these required or suggested changes are manageable and I believe the authors can deal with them to increase the clarity of the manuscript.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

COMMENTS

NOVELETY OF THE CONTENT

The manuscript describes some new results, but the number of treatments is very low, only 2 different fertilization systems under 2 different water regimes.

2) POTENTIAL IMPACT OF THE MANUSCRIPT IN THE RELEVANT FIELD WORK

The impact of this manuscript is not high. It is already well-known the advantages of drip irrigation and fertigation on potato yield. If the number of treatments was higher (only 2 water and 2 fertilization treatments) was higher, the impact of the manuscript could be greater and the manuscript more interesting. If it is a problem of area or production factors, geostatistical irrigation and fertilization experimental designs could be used. 

3) STANDARD OF ENGLISH

English language is correct.

4) SUITABILITY TO  "AGRONOMY"

The subject of the manuscript is within the scope of the Journal "Agronomy"

5) STUDY DESIGN AND METHODS

Experimental desig and methods are not new, but they are reasonably  adequate to obtain the needed results. Tensiometers and crop evapotranspiration are useful control tools to determine the irrigation schedule and the estimation of crop water requirements in the experimental plots; however, these irrigation tools are too empirical and they need to be periodically  complemented with other tecnique/s to be obtained a better control. The statistical procedures are adequate and are the statistical procedures generally used for this kind of experiments. The description of material and methods are not sufficiently informative and some corrections and elucidations must be done, as follows:

5.1) Emitter flow rate should be probabily 5 l m^-1 h^-1. So, please write the real emitter flow rate instead of "expenditure of af about 5 l m^-1 (line 104).

5.2) Substitution of "soil water potential" by "soil matric potential" (lines 106 and 160), once that the tota lsoil water potencial includes several potentials, being the most important the soil matric potential and the soil osmotic potential.

5.3) Plant density, plant space and distance between emitter lines must be mentioned.

5.4) Please mention the number of tensiometers per plot and their depths, related to irrigation depth.

5.5) If possible, mention the water distribution efficiency. The loss of irrigation water is due to the non-uniformity of the  irrigation water over the field, evaporation during the irrigation, retention of water in the foliage, percolation and run-off. This is very important to comparative several  aspects, as the irrigation levels of the experiments with normal irrigation practices.

5.6) No need to write the concluding remark "In general, drip irrigation combined with drip fertigation applying during the growing season allows to increase the productivity of study mid-season cultivar Courage grown on a light soil, what significantly contributes to the sustainable crop production". This is not new. It is already well-known the advantages of drip irrigation and fertigation on potato yield.

6) ADDITIONAL COMMENTS TO IMPROVE THE TEXT OF THE MANUSCRIPT

The paper ias aceptable to be published after major corrections, which are described in section 5 (Study design and methods). However, some additional improvements could be done, to clarify some subjects (probably not possible because the experiments are already finished), as follows:

6.1) Usually, along these kind of experiments, the determination of soil water content and soil matric potential is periodically done, additionally to the use of the tensiometer and of the determination of crop evapotranspiration, in order to obtain a better control. On the same way, the determination of soil water balance should be done due to soil water content variations provoked by rainwater and the wet bulb of the emitters.

6.2) It should be mentioned the irrigation depth and the the percentage of wet soil, once that drip irrigation is a localized irrigation system.

6.3) It should be explained clearly how the crop water requirements and irrigation schedule were estimated through the tensiometers and crop evapotranspiration.

6.4) It should be referred how many tensiometers were placed per plot and their depths related with irrigation depth and the dimention of emitter wet bulbs or emitter wet lines. 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors have corrected adequatelly the original manuscript and therefore, in my opinion, the actual manuscript may be published now.

Author Response

Dear Academic Editor,

We would like to thank you for the thorough revision of our manuscript and valuable suggestions. We have considered all your suggestions and made the appropriate changes.

• … the authors should justify the need for such a study in the Introduction section in more detail and and in a special context of Central / Eastern Europe…

We made appropriate additions, which we marked in green (lines 75-82):

The results of this study on drip irrigation and fertigation of potato – as an efficient combination in the agricultural practice – can be very useful for farmers from the countries of Central and Eastern Europe. Common use of fertigation in agricultural practice can reduce the risk of environmental contamination. On the other hand, the widespread usage of the drip system may contribute to the protection of limited water resources. The results of the study can demonstrate that the drip irrigation system is an effective factor for drought mitigation during the vegetation period of such the crops as potato from the perspective of climate change.

(2) … please adding a general information about the climate, mean annual rainfall and mean annual air temperatures for WMO reference period or even better for the new WMO reference period (1981 - 2020) from the nearest official climate station….

We made appropriate corrections, which we marked in green (lines 130-133):

It should be added that the mean rainfall for the vegetation period (April-September) during the WMO reference period (1981-2010) amounted 308 mm, and the mean value of air temperature was 14.5 °C.

[3]  Moreover, we noticed a certain inaccuracy in Table 1 and we adjusted the units accordingly.

Once again, thank you very much for your kind help and valuable suggestions which helped us to improve our manuscript.

Yours sincerely,
Authors