Empirical Modelling of Power Requirements in Olive Pruning Residue Shredding: Effects of Varying Moisture Content and Rotary Speeds
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript proposes that by studying the power demand for shredding olive pruning waste at different moisture contents and rotor speeds, Multivariate analysis of variance (MANOVA) and Tukey's test were used to assess the effect of different factors on machine power demand.Based on the experimental data, the authors created an empirical model that predicts the power demand of the shredder under different operating conditions, which is important for optimizing the performance and efficiency of the shredder.
（1）The paper mentions the performance evaluation metrics of the model, such as MAE, RMSE, and R², but it is recommended that more validation data or case studies be provided to demonstrate the applicability of the model under different conditions, which can be further augmented with specific steps of the experimental manipulation.
（2）This study represents a novel contribution that specifies the use of mechanical processes indispensable for biomass conversion and soil amelioration, providing valuable data and a reliable model for optimizing the power consumption of agro-residue shredders, a relatively unexplored area in agronomic machinery.
（3）The experiments were limited to specific water content ranges and rotor speeds and did not explore the effects of other potential variables, such as residue size and shape, the inclusion of which could improve the robustness of the model.
（4）Site conditions introduce variations in terrain, climate and environmental factors that can affect pulverizing performance. Extending the study to include the effects of different environmental conditions (e.g., humidity, temperature, and soil type) on power demand can provide a more comprehensive model.
（5）I think there is very little research on the effect of moisture content on comminution performance as recognized in lines 62-74. It is recommended that this be reinforced by discussing the reasons for this lack of research and emphasizing the significance of your research in addressing this knowledge gap.
（6）The authors may add more state-of-art computer vision articles in precision agriculture for the integrity of the manuscript (Dynamic visual servo control methods for continuous operation of a fruit harvesting robot working throughout an orchard; Computers and Electronics in Agriculture. A Performance Analysis of a Litchi Picking Robot System for Actively Removing Obstructions, Using an Artificial Intelligence Algorithm; Agronomy. A Study on Long-Close Distance Coordination Control Strategy for Litchi Picking; Agronomy.).
Author Response
This manuscript proposes that by studying the power demand for shredding olive pruning waste at different moisture contents and rotor speeds, Multivariate analysis of variance (MANOVA) and Tukey's test were used to assess the effect of different factors on machine power demand. Based on the experimental data, the authors created an empirical model that predicts the power demand of the shredder under different operating conditions, which is important for optimizing the performance and efficiency of the shredder.
Response: Thank you for your careful review, constructive feedback and insightful comments.
（1）The paper mentions the performance evaluation metrics of the model, such as MAE, RMSE, and R², but it is recommended that more validation data or case studies be provided to demonstrate the applicability of the model under different conditions, which can be further augmented with specific steps of the experimental manipulation.
Response 1
Sincerely thank you for your valuable contributions. In the study, a total of 27 trials, each with 3 repetitions, were carried out under different rotor speeds and material moisture content conditions. The validation trials are presented in Figure 7. To be honest, to test the accuracy of the model, we took measurements at a rotor speed of 2100 rpm without repetition, using the remaining pruning residues from our main experiments to address any uncertainties in our mind. The average power values from these measurements matched the values predicted by the model. However, since this experiment wasn't a special case, we decided not to include its data in this article. Thank you once again for your valuable suggestion to provide more validation data to demonstrate the applicability of the developed models under different conditions. We will definitely consider this in our future modeling work.
（2）This study represents a novel contribution that specifies the use of mechanical processes indispensable for biomass conversion and soil amelioration, providing valuable data and a reliable model for optimizing the power consumption of agro-residue shredders, a relatively unexplored area in agronomic machinery.
Response 2
Thank you for constructive feedback and valuable comments.
（3）The experiments were limited to specific water content ranges and rotor speeds and did not explore the effects of other potential variables, such as residue size and shape, the inclusion of which could improve the robustness of the model.
Response 3
We agree with this suggestion. In determining the performance of the shredding machine, the power requirements of the machine, energy requirement, machine capacity, particle size and shape, classification of particles, machine operating costs are taken into consideration. After the trials conducted in the study, power (kW), energy (kWh), material capacity (ton/h), particle size (cm, cm2) and cost values of the machine were determined. However, within the scope of the study, rather than the performance parameters of the shredding machine, the focus was on obtaining a model that can be used to predict the power values that greatly affect these values. In the calculations, power values were taken into account as the independent variable and rotor speed and material moisture content values as independent variables.
4）Site conditions introduce variations in terrain, climate and environmental factors that can affect pulverizing performance. Extending the study to include the effects of different environmental conditions (e.g., humidity, temperature, and soil type) on power demand can provide a more comprehensive model.
Response 4
Thank you for raising this point. As you mentioned, terrain, climate and environmental factors are influential in the realization of many agricultural activities. Like pulverization performance, shredding performance is also affected by these factors. In addition to conditions such as humidity, temperature, soil type during the shredding process in the field, different conditions such as land slope, feed rate, location and shape of the collecting unit, blade type, use of opposite blade, and screen type also have an effect on shredding performance. In this study, the effect of material moisture content and rotor speed variations on shredding performance, which we have the opportunity to control in the trials and which are thought to have a direct effect on shredding performance, were examined. Future studies are planned to be carried out combining the other different conditions mentioned above.
（5）I think there is very little research on the effect of moisture content on comminution performance as recognized in lines 62-74. It is recommended that this be reinforced by discussing the reasons for this lack of research and emphasizing the significance of your research in addressing this knowledge gap.
Response 5
Thank you for this recommendation. We have accordingly made additions to the relevant section. You can find the addition made on your suggestion in the text added between lines 68-77. The addition is as follows;
“For instance, field trials may require a waiting period of weeks, depending on weather conditions, to obtain pruning residues of the same material with different moisture contents. During this waiting period, the pruning residues left to dry on the land can be an obstacle for other processes in the production line. Furthermore, in practice, when operating machines that shred pruning residues in the orchard, questions such as "When should effective shredding take place? and at what rotor speed should the machine operate?" arise. To fill the gap in the literature and to meet practical needs, this study aimed to determine the power requirement for operating a pruning residue shredder equipped with a collection and screening unit under different conditions.”
（6）The authors may add more state-of-art computer vision articles in precision agriculture for the integrity of the manuscript
- Dynamic visual servo control methods for continuous operation of a fruit harvesting robot working throughout an orchard; Computers and Electronics in Agriculture.
- A Performance Analysis of a Litchi Picking Robot System for Actively Removing Obstructions, Using an Artificial Intelligence Algorithm; Agronomy.
- A Study on Long-Close Distance Coordination Control Strategy for Litchi Picking; Agronomy.
Response 6
Thank you for your valuable suggestion and contribution. Accordingly, the following phrase "In light of the projected shortage of agricultural labor in the future, the robust development and management of agricultural mechanization and automation technologies will become an imperative trend [23, 24, 25]" has been added between lines 58- 60 with reference to the studies you suggested.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsTwo suggestions for strengthening this manuscript.
In the methods section how many replications, the size of the replications (or subsamples) of each combination of moisture moisture content and rotor speed is not clear; could this be included.
Also, just curious, could you have done a factorial analysis, to see if a combination of rotor speed and branch moisture was significantly better than any other combination?
While this manuscript is focused on predicting needed power requirements the research is justified by its practical application. It would be a great value to applied horticulturists to suggest how to best use this information. for example, suggesting to growers how to handle their orchard prunings, for example "...let them dry for xxx days" before shredding".
I congratulate your ability to write in English, wish I could do as well in your language.
Author Response
Two suggestions for strengthening this manuscript.
- In the methods section how many replications, the size of the replications (or subsamples) of each combination of moisture moisture content and rotor speed is not clear; could this be included.
Also, just curious, could you have done a factorial analysis, to see if a combination of rotor speed and branch moisture was significantly better than any other combination?
Response 1
Thank you for pointing this out. Accordingly, we have added the following statement between lines 174-176 in the Method section, subheading 2.5. Experiment conditions; “The experiments were carried out at three different rotor speeds and material moisture contents, with three replicates for each different combination. In this way, a total of 27 experiments were conducted.”
In the analysis of variance performed at the end of the trials, rotor speed and moisture content change separately affected the power consumption, while the rotor speed - moisture content interaction was not found to be effective on the power consumption change.
- While this manuscript is focused on predicting needed power requirements the research is justified by its practical application. It would be a great value to applied horticulturists to suggest how to best use this information. for example, suggesting to growers how to handle their orchard prunings, for example "...let them dry for xxx days" before shredding".
Response 2
We thank you for this suggestion and agree with your view. Accordingly, in the introduction, lines 72-77 have been added to indicate that the study will contribute to solving problems in practice." Furthermore, in practice, when operating machines that shred pruning residues in the orchard, questions such as "When should effective shredding take place? and at what rotor speed should the machine operate?" arise. To fill the gap in the literature and to meet practical needs, this study aimed to determine the power requirement for operating a pruning residue shredder equipped with a collection and screening unit under different conditions.".
Also in the results section, the following statements were added to lines 317-325; “Based on the results from the shredding of olive pruning residues, it can be concluded that the shredding machine should be operated at low rotor speeds at all moisture contents to achieve low power requirements. Furthermore, given that the reduction in material moisture content also reduces power consumption, the most efficient shredding process is achieved with low moisture content and high rotor speed. Trials conducted in Antalya, Turkey between April and June showed that it took about six weeks to reduce the moisture content of olive pruning residues from 45% to 20%. For effective shredding in regions with similar climatic conditions, it is recommended that the pruning residues are left to dry in the field for this period and then shredded at low rotor speeds.”
- I congratulate your ability to write in English, wish I could do as well in your language.
Response 3
Thank you for this valuable comment.
Author Response File: Author Response.pdf
