Sustainable Paddy Farming in Edirne: Evaluating the Impacts of Excessive Fertilizer and Pesticide Use
Naoki Motoyama
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe work done by the authors is well structured and their grasp of the English language is very good. That said, here are some minor questions or recommendations.
-In line 140, it is mentioned that farmers do not use fungicides or insecticides. How do you control potential pests? Do they make use of any type of biocontrol, such as ducks or crabs?
-In line 146, the authors report the amounts of herbicides used by farmers. Depending on the method of application, there are several mechanisms by which the active ingredient in pesticides is lost, forcing farmers to use excessive amounts to achieve the desired biological response (in this case, pest control). Which of these mechanisms may be affecting the herbicides mentioned? Are the active molecules susceptible to degradation by UV light, or are they highly volatile, for example?
-In line 184, the authors mention a surplus in applications of N and P. Is this surplus large enough to generate eutrophication problems?
-In line 185, they report a significant deficit in the application of K. How does this lack of K impact production? Would the economic return of a better production be greater than the savings of using only 16% of the recommended amount of fertilizer?
-In the references section, the name of the journal should be italicized, and the year should be bold.
Author Response
Thank you for your thorough review of our manuscript and for your valuable feedback. We appreciate the time and effort you have taken to provide insightful comments and suggestions, which have been very helpful in improving the quality of our work. Below, we have provided responses to each of your comments and have made the necessary revisions in the manuscript accordingly.
Comment 1.
In line 140, it is mentioned that farmers do not use fungicides or insecticides. How do you control potential pests? Do they make use of any type of biocontrol, such as ducks or crabs?
Response 1:
Based on our survey results, the farmers indicated that they do not use insecticides because they have not faced significant pest infestations in their fields. Regarding fungicide use, farmers reported that they apply fungicides only during periods of heavy rainfall when fungal diseases are more prevalent. However, during the time of our study, rainfall was low, and therefore, fungicides were not utilized. We have updated the manuscript (line 140) as “Farmers reported that they do not use insecticides as they have not encountered significant pest issues in their fields. Fungicides are applied only during periods of high rainfall, which are conducive to fungal growth. During the study period, there was minimal rainfall, hence no fungicides were used.” to clarify these points and provide more context about the farmers' pest and disease management practices.
Comment 2.
In line 146, the authors report the amounts of herbicides used by farmers. Depending on the method of application, there are several mechanisms by which the active ingredient in pesticides is lost, forcing farmers to use excessive amounts to achieve the desired biological response (in this case, pest control). Which of these mechanisms may be affecting the herbicides mentioned? Are the active molecules susceptible to degradation by UV light, or are they highly volatile, for example?
Response 2.
Based on our discussions with farmers, the primary reason for applying higher amounts of herbicides is a lack of trust in the recommended dosages provided on the packaging. Farmers believe that by using more than the suggested amount, they can better mitigate the risk of weed infestation. However, we acknowledge that the factors you mentioned, such as UV degradation and volatilization, could also contribute to the loss of herbicide effectiveness. Additionally, continuous paddy farming on the same land without crop rotation contributes to increased weed resistance. We have added the following paragraph in the Conclusions section, discussing these potential effects and suggesting further research on this matter, as per your recommendation.
“Farmers often apply herbicides at rates higher than the recommended dosages listed on product labels because of a lack of confidence in their effectiveness in controlling weeds. However, environmental factors such as UV light degradation and evaporation can reduce the effectiveness of herbicides, causing application rates to increase to achieve the desired control. Moreover, continuous paddy farming on the same land without crop rotation contributes to increased weed resistance and reduces herbicide effectiveness over time.”
Comment 3
-In line 184, the authors mention a surplus in applications of N and P. Is this surplus large enough to generate eutrophication problems?
Response 3
The excess application of nitrogen (N) and phosphorus (P) observed in our study is indeed higher than recommended levels for optimal crop growth. Although we have not specifically measured the direct impact of these excesses on surrounding water bodies, application of nutrients at such high levels may have the potential to contribute to eutrophication if these nutrients leach into nearby water systems.
Comment 4
-In line 185, they report a significant deficit in the application of K. How does this lack of K impact production? Would the economic return of a better production be greater than the savings of using only 16% of the recommended amount of fertilizer?
Response 4
As you mentioned, too low K usage can have a negative impact on yield. We agree that in this case, it is possible for the total profitability of the business to decrease. For this purpose, it would be appropriate to conduct a research on this subject by comparing the economic analyzes of rice farmers in the region according to their fertilizer use.
Comment 5
In the references section, the name of the journal should be italicized, and the year should be bold.
Response 5
We have formatted the journal names in the references section to be italicized and the years to be bold.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe study is of interest evaluationg economical impacts of excessive fertilizer and pesticide use for paddy farming. However, the manuscript needs improvement before being accepted. 1. (Table 2) There must be different formulations (such as granule or flowable) of the herbicides containing different concentrations of active ingredients. How were recommended and actually used amounts (active ingredient ml/ha) caluculated, assuming not all farmers surveyed use the same formulations? Also, some of the formulations allow application more than once during farming. Was it considered in caluculating Recommended (ml/ha)? 2. (Table 3) What is 5lt in Product Price (USD/5lt)? 3. (Table 4) If only 30.2% of farmers surveyed conducted soil analysis before fertilizer application, it would be interesting to give Used (kg/ha) by farmers who did soils analysis and who did not do soil analysis. 4. (Abstract) Since no research was done in the present study on envirnmental damages as well as on health risks to consumers by the current level of excessive ferilizer and pesticide use, the last sentence should be moderated (such as the situation harms the economy, and may have adverse effects on the environment and possible health efects to consumers). 5. (4th paragaph in page 7) The emphasis of importance of farmer education on environmental sustainability is very good.
Author Response
Thank you for your thorough review of our manuscript and for your valuable feedback. We appreciate the time and effort you have taken to provide insightful comments and suggestions, which have been very helpful in improving the quality of our work. Below, we have provided responses to each of your comments and have made the necessary revisions in the manuscript accordingly.
Comment 1: (Table 2) There must be different formulations (such as granule or flowable) of the herbicides containing different concentrations of active ingredients. How were recommended and actually used amounts (active ingredient ml/ha) calculated, assuming not all farmers surveyed use the same formulations?
Response to Comment 1: Since not all farmers used the same herbicide formulations, we standardized the data by taking into account the different active ingredient concentrations of each formulation. We collected information on the type and formulation of herbicides used by each farmer and adjusted the amounts accordingly. Additionally, the calculations considered the number of applications reported by each farmer. We have added a note under Table 2 as “The amounts of active ingredients (ml/ha) were standardized based on different herbicide formulations and active ingredient concentrations, considering the number of applications reported by each farmer.” in the revised manuscript to reflect these details.
Comment 2: (Table 3) What is 5lt in Product Price (USD/5lt)?
Response to Comment 2: The "5lt" in the Product Price column was intended to denote "5 liters” which is a typographical error. All the products were typically sold in 5-liter packages. However, we have removed the "Product Price" column from Table 3, as it is sufficient to include only the unit price of the active ingredient in USD/ml.
Comment 3: (Table 4) If only 30.2% of farmers surveyed conducted soil analysis before fertilizer application, it would be interesting to give Used (kg/ha) by farmers who did soil analysis and who did not do soil analysis.
Response to Comment 3: We have reviewed the data, and there is no significant difference in fertilizer use between farmers who conducted soil analysis and those who did not. It is worth noting that institutions providing agricultural loans often require soil analysis as a prerequisite. As a result, many farmers who conduct soil analysis do so primarily to meet the requirements for obtaining agricultural loans.
Comment 4: (Abstract) Since no research was done in the present study on environmental damages as well as on health risks to consumers by the current level of excessive fertilizer and pesticide use, the last sentence should be moderated (such as the situation harms the economy, and may have adverse effects on the environment and possible health effects to consumers).
Response to Comment 4: We have revised the sentence as “This situation harms the economy and may have adverse effects on the environment and potential health effects on consumers.” according to your recommendations.
Comment 5: (4th paragraph on page 7) The emphasis on the importance of farmer education on environmental sustainability is very good.
Response to Comment 5: Thank you for your positive feedback. We are pleased to hear that the emphasis on farmer education for environmental sustainability has been well received.
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe study is valuable in making good suggestions based upon their findings to improve sustainable paddy farming in the country.
