Testing Novel New Drip Emitter with Variable Diameters for a Variable Rate Drip Irrigation

Round 1

Reviewer 1 Report

No comments

Author Response

Greeting 

We thank you for taking the time to review our manuscript.

Reviewer 2 Report

The article is quite interesting and brings new scientific outputs based on statistical analyses. The theme of the article is focused on the evaluation of the Novel New Drip Emitter when changing the working pressure and hole diameters for the Variable Rate Irrigation. The obtained results were evaluated by single factor ANOVA analysis and Tukey's test. The authors of the achieved results expressed the conclusions of dependence/independence of the results assessed.

Weaknesses and strengths side:

- The introduction is provided at a sufficient level.

- Methodology - I miss a more detailed description of the invented device - the Novel New Drip Emitter, its principle of changing diameters. Although the authors state that they published it in another article, I consider it necessary to provide details in this article as well.

- In my opinion, there is insufficient database of results to draw proven conclusions.

- The Discussion is clearly insufficient.

- The conclusion is sufficient.

- Used literature - is at an insufficient level, there are many other authors who have addressed the problematics.

Author Response

Greeting

You can chick our responses to your comments, our responses are in italics below. 

Comments and Suggestions for Authors

The article is quite interesting and brings new scientific outputs based on statistical analyses. The theme of the article is focused on the evaluation of the Novel New Drip Emitter when changing the working pressure and hole diameters for the Variable Rate Irrigation. The obtained results were evaluated by single factor ANOVA analysis and Tukey's test. The authors of the achieved results expressed the conclusions of dependence/independence of the results assessed.

Thank you for your review, we have endeavored to address your specific comments below.

Weaknesses and strengths side:

- The introduction is provided at a sufficient level.

- Methodology - I miss a more detailed description of the invented device - the Novel New Drip Emitter, its principle of changing diameters. Although the authors state that they published it in another article, I consider it necessary to provide details in this article as well.

We have added the following sentences to the methodology to provide additional detail.

 In brief: the emitter encapsulated and pierces an irrigation hose.  Water is routed through a tortuous path consisting of 20 microchannels in succession, each 2.0 mm high and 2.593 mm in width.  The purpose of this element is to reduce the pressure and flow rate.  Next, water is routed through a micro-solenoid (DC12V G 1/4" Electric Solenoid Valve N/C Feed for RO Water Air Quick Connector from eBay) before exiting a small nozzle.  Drops are released from this orifice based on the force balance between gravity (pulling the drops down) and surface tension (pulling droplets upward).  The net effect of this process creates drops of consistent mass.  Once the drops fall, they pass through a measurement chamber where the water briefly connects 2 electrical leads.  A microcontroller maintains a running count of the drops and operates the solenoid valve to commence or halt the flow. 

A modified version was constructed for this manuscript.  The modified version was designed such that the variable inner and outside diameter of the emitter nozzle could be evaluated in the lab with a factorial experimental design.  A critical design question is whether the inner or outer diameter of this nozzle form the contact line for surface tension and subsequently determine the drop mass and volume.

- In my opinion, there is insufficient database of results to draw proven conclusions.

We respectfully disagree.  Through the total number of replicates and treatments could have been increased.  The current experimental setup provided adequate statistical power to reject the null hypotheses that were investigated.

- The Discussion is clearly insufficient.

Thank you for this comment, we have added additional clarifications and detail to the discussion section

- The conclusion is sufficient.

- Used literature - is at an insufficient level, there are many other authors who have addressed the problematics.

We would be very happy to get these references.  To our extensive literature search, we were only able to find 1 paper dedicated to variable rate drip irrigation.  If you can provide these references, we will include them.

Reviewer 3 Report

This paper provides experimental results for a variable drip systems created by the authors.  There is no theory presented or discussed.  Therefore, the results have limited use to the reader. 

There is no explanation of why the outer diameter of the drip pipe has a significant effect on the flow rate.  Is this due to fluid mechanics, surface energy, surface tension, the wall thickness?

There is no drawing of the emitter's components, rather a photograph of its outside. 

What is the cost of having a controller on each emitter?  Will this overwhelm the cost of the water saved?

There are confusing sentences (lines 23-24, and  165-166): Even the flow rate was increased...  It doesn't make sense and needs to be clarified.

Line 62: pH not PH

Line 62: what is meant by "rain sap flow"?

Line 84: pressure not Pressure

Line 129: Figures 3 and 4 not Figure 3 and 4

Line 140: estimating, not Estimating

Line 165: "increased that similar"  Is there a word missing?

Line 167: The percentage water flow difference between not The water flow rate difference percentage

Author Response

Greeting

you can see our responses to your comments, our responses are in italics below.

Comments and Suggestions for Authors

This paper provides experimental results for a variable drip systems created by the authors.  There is no theory presented or discussed.  Therefore, the results have limited use to the reader. 

There is no explanation of why the outer diameter of the drip pipe has a significant effect on the flow rate.  Is this due to fluid mechanics, surface energy, surface tension, the wall thickness?

Your intuition is correct, the underlying physics is a force balance between gravity and surface tension.  This explanation was added both in the methodology and in the discussion.

There is no drawing of the emitter's components, rather a photograph of its outside. 

We have included a schematic drawing (Figure1-a).

What is the cost of having a controller on each emitter?  Will this overwhelm the cost of the water saved?

Water savings is not the economic driver.  Yield uniformity and quality in high value crops account for the economic gains.  This is discussed in (Sanchez et al 2017) who found a 10% increase in yields and a 17% increase in water use efficiency.

Thanks for your notices. We changed all the below comments.

There are confusing sentences (lines 23-24, and  165-166): Even the flow rate was increased...  It doesn't make sense and needs to be clarified.

Line 62: pH not PH

Line 62: what is meant by "rain sap flow"?

Line 84: pressure not Pressure

Line 129: Figures 3 and 4 not Figure 3 and 4

Line 140: estimating, not Estimating

Line 165: "increased that similar"  Is there a word missing?

Line 167: The percentage water flow difference between not The water flow rate difference percentage

Round 2

Reviewer 2 Report

I unequivocally propose to look for other associations that would expand the issue.

Author Response

Greeting 

Thank you for your comments. We add additional references.

Best Regards

Reviewer 3 Report

See attached file

Comments for author File: Comments.pdf

Author Response

Greeting

Thank you for your comments.

Best Wishes