Weed Management and Economic Analysis of a Robotic Lawnmower: A Case Study in a Japanese Pear Orchard

Round 1

Reviewer 1 Report

In the resubmission of the manuscript "Weed Management and Economic Analysis of a Robotic Lawnmower: A Case Study in a Japanese Pear Orchard", the Authors fully replied to my observations. The manuscript may be published after correcting some minor errors.

L16: define SD (standard deviation) the first time you use it.

L25: ever, the existing …

L47: water and nutrient …

L224: … if high? force …

L230: … as µm m^-1.

L303, 324, 348: … same lowercase letters …

L307, 312: correct Figure 2 as Figure 3

L407-429: correct all the references to Figure 2 as Figure 3.

 

Author Response

Thank you very much for your advice. The correction can be found in the attachment. 

Author Response File: Author Response.docx

Reviewer 2 Report

The authors have adequately justified some of the issues raised in the review. The work has improved a lot, but I think there are some issues that need to be clarified.

Table 3:

• Indicate the Actual field capacity of RLM
• Indicate the electrical consumption of the RLM (kWh, for example)
• Indicate the cost of electricity (USD/kWh, for example)
• The units of the costs of repair and maintenance are USD / year
• Review the calculations of the labor requirements for each mowing. The values must be related to the actual field capacity. For RM and WR the decimals do not match, but for BC there must be some error, the value must be 33.3.
• Does the total electric cost correspond to one RLM or three?

Lines 354-365: The footnote of table 3 is very extensive, there is text that should be included in the materials and methods, in the economic analysis section.

Lines 367-373: Detail how the values for 0.33 ha and 0.66 ha have been obtained, and review the calculations. According to the information provided in table 3:

• For 0.33 ha: RLM 1334USD/Y; RM 1761USD/Y; VM 2940USD/Y
• For 0.66 ha: RLM 2668USD/Y; RM 2135USD/Y; VM 3360USD/Y
• BC values must be reviewed

Figure 8: vertical axis units must be USD/Y

Author Response

Thank you very much for your suggestion. We have made the correction and can be found in the attachment. 

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The reviewed paper takes a robotic lawn mower (Husqvarna model) and compares its operation in pear orchard to riding mower, walking mower and brush cutter. Authors conclude that the BCR is higher for the RLMN when compared to other weed control options examined. This is a good study that checks the economics of robotic weeding machine versus the other options available in pear production. I believe the study can be improved with the following recommendations:

1. In describing the methodology of the tree hitting frequency, the authors should provide initial conditions for the test, such as the orientation and mowing direction of the RLM to the surrounding pear trees. (lines 192-199)
2. I believe 6 m is supposed to be 6 km on line 126.
3. It is unclear in lines 221-234 how the human intervention of restarting the RLM is used compared to the constant human running for the other 3 mowing options. It would seem that during the time fruit is on the ground, there requires constant human intervention to restart the RLM. Consequently, 24 hour operation is also not possible. Please provide more details about how these different human hour interventions will be accounted for in the BCR calculation of the RLM.
4.  The measurement of hitting force versus distance is not necessary. If the mower is at constant speed, this measurement should be the same regardless of distance, unless it is still accelerating, which is does not appear to be. You may see differences if you measure at 10, 20, 30, 40 and 50 cm. You should at least see how far it takes the mower to get up to speed.
5. In figure 6 and in the text, can you specify if these spikes in the graphs are from hitting the same tree or are they all hits on different trees.
6. Figure 7 needs to be fixed.
7. First sentence in Conclusions state that "The RLM performed better in pear orchard". This is incomplete sentence and needs to be changed.
8. The authors state in line 391-392 of the Conclusions, that the lower CE in terms of WH in the RLM can be controlled with "longer working period". This needs to be further explained as in the text it appears calculations for the RLM are for 24 hour operations.

 

 

Reviewer 2 Report

See the attached file

Comments for author File: Comments.pdf

Reviewer 3 Report

The authors present a work related to the use of autonomous equipment in agricultural work, specifically studying the profitability of a robotic lawnmower. They also identify the challenges of using RLM in a pear crop and its possible solutions. I believe that it is a very interesting line of work to face the challenges that agriculture currently has, among them, increase food production by reducing environmental impact and maintaining natural resources. However, the paper has some shortcomings that I comment below:

1. In the study, the equipment used for weed control are appropriate for small orchards. The authors must justify whether these types of orchards are frequent. Normally, commercial pear orchards have large areas (several hectares) and this type of equipment would not be efficient.
2. The methodology should explain in detail the interest of measuring the vibration of the robotic lawnmower, the striking load and the tree hitting. I do not understand what the data obtained contribute to the proposed study.
3. The most interesting part of the work is the economic study, however the approach has not been correct:
4. Some agricultural machinery cost estimation models should have been used, for example the one proposed by ASABE in the Standards. D497.7. "Agricultural Machinery Management Data"
5. The study should focus on comparing the costs of using different equipment. The benefit-cost ratio is of little interest, since it involves estimating pear production and the sale price, which must be the same for all the equipment analyzed, as well as other production factors (chemical, water, ...) that are not related to the use of machines.
6. The values used to calculate the costs must be indicated: price of equipment, useful life, residual value, ...
7. The appendix 1 indicated in line 295 is not in the paper
8. The authors use many abbreviations that make the document difficult to read (VH, CE, BCR, MAD, BC, WM, ...). Some of them could be avoided because the expression appears rarely throughout the text.

In general, I think the study has little practical application in agriculture, because it focuses on small equipment that can only be used on small farms. On the other hand, I believe that measurements have been made that do not contribute anything to the study (vibration of the robotic lawnmower, the striking load and the tree hitting, benefit-cost ratio). I think the work should focus on a detailed study of the costs of using each of the equipment.