Sustainable Paddy Farming in Edirne: Evaluating the Impacts of Excessive Fertilizer and Pesticide Use

Abstract

This study examines the environmental and economic impacts of chemical fertilizer and pesticide use in paddy fields in Edirne Province, Türkiye. Chemical fertilizers, especially nitrogen and phosphorus, are crucial for boosting paddy yield and ensuring food security. However, recent trends indicate significant potassium deficiency and excessive pesticide use, leading to environmental degradation and higher production costs. Incorrect fertilization techniques and pesticide usage can lower product quality and yield, adversely affecting farmers’ incomes and the national economy. Surveying 139 paddy farmers, the research found that farmers apply the herbicidal active ingredients Tefuryltrione, Clomazone, Tembotrione, and Quinclorac at rates of 129.35%, 34.27%, 18.06%, and 155.29% above the recommended levels, respectively. The excessive use of pesticides costs each farmer an additional USD 925.67, totaling USD 5.32 million for Edirne. The majority of farmers (69.2%) do not conduct soil analysis, indicating a potential gap in adopting the best practices for soil management and fertilization. Farmers use 84% less potassium than recommended while applying nitrogen and phosphorus 13% and 14% above the recommended levels, respectively. The extra cost of fertilizer use in Edirne is calculated as USD 833,135.49. This situation harms the economy and may have adverse effects on the environment and potential health effects on consumers.

1. Introduction

Rice is an important agricultural product and a staple food source in many parts of the world. Türkiye’s ecological conditions are highly favorable for paddy farming, producing yields per hectare that surpass the global average [1]. According to the FAO, between 2018 and 2022, Türkiye’s paddy production, covering an average of 124,388 hectares annually, falls short of domestic demand. Despite ranking seventh in the world in paddy yield, Türkiye is a net importer. While suitable regions for paddy farming extend beyond the Marmara and Black Sea river basins, planting is predominantly concentrated in these areas, which currently span 94.17% of total production areas [2].

The use of an appropriate number of fertilizers and pesticides in paddy production, despite creating additional production costs, ensures an increase in total income through yield improvement [3,4]. The optimal use of fertilizers and pesticides enhances profitability in paddy farming and positively contributes to sustainability [5]. However, the excessive use of fertilizers leads to carbon dioxide emissions, causing environmental damage [6]. The overuse of chemicals as fertilizers and pesticides is a common issue in paddy farming [7].

The knowledge level of farmers regarding the use of chemical fertilizers and pesticides is a crucial factor for their effective and efficient use. Studies have shown that many farmers lack sufficient knowledge in this area and either overuse or underuse these chemicals [8]. This can adversely affect crop productivity and cause environmental harm. For instance, the excessive use of fertilizers leads to soil and water pollution, which poses a long-term threat to agricultural sustainability [5]. Additionally, the overuse of pesticides affects not only the target pests but also beneficial organisms, disrupting the ecosystem balance. This situation presents serious environmental and public health risks. Moreover, the costs associated with chemical fertilizers and pesticides increase production expenses for farmers, creating economic pressure [8].

In the Edirne province of Türkiye, the extensive use of chemical fertilizers, particularly nitrogen (N) and phosphorus (P), has increased to enhance paddy yields. In a study conducted in Edirne, it was found that farmers tend to overuse fertilizers and agricultural chemicals, and their awareness levels are quite low [9]. This practice has escalated environmental and economic concerns, including pollution, ecosystem disruption, increased input costs, and land degradation.

The province of Edirne plays a critical role in Marmara’s leadership in paddy production. In 2023, Edirne accounted for 39.7% of Türkiye’s paddy plantations and 40.8% of its production, with an average yield of 8245.3 kg per hectare [2].

The significance of paddy farming in Edirne is enhanced by the availability of water from the Meriç and Ergene rivers. These rivers are vital for irrigation, particularly in areas along the Meriç where no other agriculture is feasible due to the high base water level, making paddy the most important crop. This geographical advantage is crucial, especially in the 170 km stretch along the Meriç river, which forms the border with Greece.

Paddy farming is not only economically viable due to its higher returns per unit area compared to other crops, but it is also critical for employing people in the region. Of the 32 factories that process paddy into rice, many are located in Uzunköprü, Keşan, İpsala, and Meriç, providing significant employment and contributing to the economic vitality of these areas.

In paddy agriculture across Türkiye, there is a noted tendency for the application of pesticides at doses exceeding recommended levels, often due to uninformed use. While fertilizer use is not excessive, the lack of soil analysis leads to incorrect application, particularly a significant deficiency of potassium. This overuse of pesticides and incorrect fertilization not only results in increased costs and decreased incomes for producers but also contributes to significant environmental pollution.

This paper investigates the environmental and economic impacts of chemical fertilizer use in Edirne’s paddy fields. By integrating primary data from 139 paddy farmers and secondary sources from governmental and academic entities, this study aims to provide a detailed assessment of current practices.

This research not only contributes to sustainable agriculture but also seeks to inform policy development to promote more sustainable paddy farming practices in Edirne, thus supporting environmental sustainability and economic resilience for local farmers.

2. Materials and Methods

2.1. Material

In this research, primary data were collected from paddy farmers of Edirne, using face-to-face interviews to ensure detailed and reliable information. Secondary data involved a literature review and analysis of documents and reports on the economics and policies of paddy farming.

2.2. Methods

2.2.1. Data Collection

The methodology of this study is based on the analysis of both primary and secondary data sources. Primary data collection involved face-to-face surveys with paddy farmers in Edirne through structured interviews, aiming to capture a wide array of practices and experiences within paddy farming.

2.2.2. Sampling

The study focused on Edirne and the sample size was determined based on the following statistical formula, incorporating a 7% margin of error at a 90% confidence level [10]:

$$\mathrm{n}={\displaystyle \frac{\mathrm{p}\ast \mathrm{q}\ast z_{\propto /2}^2}{{\mathrm{D}}^2}}$$

(1)

where

• n = Number of samples;
• z_(∝⁄2) = z-value (1.645 for 90% confidence);
• p = Probability of the unit being examined among the main population (those who have a positive approach to irrigated agriculture);
• q = 1 − p (Proportion of those who have no knowledge about irrigated agriculture and have a negative opinion);
• D = Error rate (7%).

Based on Formula (1), the sample size was calculated as 139. The survey included questions on agricultural practices, fertilizer and pesticide usage, soil analysis, and economic outcomes.

2.2.3. Data Analysis

The study involved calculating the pesticide application rates per unit area to quantify the extent of overuse. The recommended pesticide dosages were derived from the information provided on the packaging of the chemicals used by the farmers. These values were then compared with the actual quantities applied by the farmers.

Similarly, fertilizer usage rates were determined and compared to the recommended application levels. The recommended fertilizer amounts were based on soil analysis results provided by accredited laboratories, reflecting the specific needs of the soil. These recommendations were then contrasted with the actual amounts of fertilizers applied by the farmers to assess the degree of deviation from optimal usage practices.

3. Results

3.1. Paddy Production in Türkiye

Edirne stands out as the leading province in paddy production with a production area of 44,552.7 hectares, accounting for 39.7% of the total paddy farming area in Türkiye [2]. It produces 367,352 tons of paddy, which represents 40.8% of the country’s total paddy production. The yield in Edirne is 8245.3 kg per hectare, indicating that it not only has the largest production area but also achieves a high yield, making it a significant center for paddy farming (

Table 1. Paddy farming area, production, and yield values in Türkiye.

Province	Production Area (ha)	Area (%) of Total	Production Quantity (tons)	Area (%) of Total	Yield (kg/ha)
Edirne	44,552.7	39.7%	367,352	40.8%	8245.3
Samsun	19,410.3	17.3%	157,392	17.5%	8108.7
Balıkesir	17,270.0	15.4%	137,778	15.3%	7977.9
Çanakkale	6867.9	6.1%	51,861	5.8%	7551.2
Çorum	6196.1	5.5%	51,802	5.8%	8360.4
Other	17,823.4	15.9%	133,815	14.9%	7507.8
TOTAL	112,120.4	100.0%	900,000	100.0%	8027.1

).

3.2. Survey Results

According to a face-to-face survey conducted with 139 farmers in Edirne, the average age of the farmers is 57.8 years, and the average size of their paddy fields is 7.75 hectares. It has been determined that the farmers use herbicides with four different active ingredients: Tefuryltrione, Clomazone, Tembotrione, and Quinclorac. 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. Additionally, 30.2% of the farmers conduct soil analysis, while the remaining 69.8% apply fertilizers without performing soil analysis.

3.2.1. Pesiticide Usage Findings

The recommended and actual usage amounts of herbicides with different active ingredients in Edirne, along with the percentage differences, are shown on

Table 2. Recommended and actual usage amounts of herbicides by active ingredient *.

Active Ingredient	Recommended (mL/ha)	Actual Usage (mL/ha)	Difference (%)
Tefuryltrione	500	1147	129.35
Clomazone	1500	2014	34.27
Tembotrione	1000	1181	18.06
Quinclorac	1500	3829	155.29

* 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.

. The data reveal significant discrepancies between the recommended and actual usage amounts of these herbicides. For Tefuryltrione, the recommended amount is 500 mL/ha, whereas the actual usage is 1147 mL/ha, showing a 129.35% increase. Similarly, Clomazone is recommended at 1500 mL/ha but is used at 2014 mL/ha, which is a 34.27% increase. Tembotrione has a recommended usage of 1000 mL/ha, but the actual amount used is 1181 mL/ha, indicating an 18.06% increase. The most substantial discrepancy is observed with Quinclorac, where the recommended amount is 1500 mL/ha, but the actual usage is 3829 mL/ha, reflecting a 155.29% increase.

The economic impact of herbicide overuse among farmers, with a comparison of the recommended and actual usage amounts and their respective costs, is shown in Table 2. For Tefuryltrione, the recommended amount is 500 mL/ha at a cost of USD 22.7 per hectare. However, farmers are using 1147 mL/ha, which costs USD 52.1 per hectare, resulting in an overdose cost of USD 29.4 per hectare. Clomazone’s recommended usage is 1500 mL/ha, costing USD 40.9 per hectare. Farmers are applying 2014 mL/ha, costing USD 54.9 per hectare, leading to an overdose cost of USD 14.0 per hectare. Tembotrione’s suggested amount is 1000 mL/ha, with a cost of USD 30.3 per hectare. The actual usage is 1181 mL/ha, costing USD 35.8 per hectare, resulting in an overdose cost of USD 5.5 per hectare. Quinclorac has a recommended usage of 1500 mL/ha, costing USD 45.5 per hectare. Farmers, however, are using 3829 mL/ha, costing USD 116.0 per hectare. This results in a substantial overdose cost of USD 70.6 per hectare (

Table 3. Cost of overdose herbicide usage.

Active Ingredient	Unit Price (USD/mL)	Suggested Amount (mL/ha)	Cost of Suggested Amount (USD/ha)	Farmers’ Usage Amount (mL/ha)	Cost of Farmers’ Usage Amount (USD/ha)	Cost of Overdose Usage (USD/ha)
Tefuryltrione	0.0455	500	22.7	1147	52.2	29.4
Clomazone	0.0273	1500	40.9	2014	54.9	14.0
Tembotrione	0.0303	1000	30.3	1181	35.8	5.5
Quinclorac	0.0303	1500	45.5	3829	116.0	70.6
TOTAL			139.4		258.9	119.5

).

The total cost of overdose pesticide usage of paddy farming in Edirne can be calculated using the following formula:

Total cost of overdose pesticide use in Edirne
= Cost per ha × paddy plantation area of Edirne
= 1195 USD/ha × 445,527 ha
= USD 5,324,047.65

(2)

According to Equation (2), the excessive use of pesticides in Edirne’s paddy fields incurs an additional cost of approximately USD 5.32 million. This significant financial burden underscores the importance of adhering to recommended pesticide usage guidelines to optimize cost efficiency in agricultural practices.

3.2.2. Fertilizer Usage

The fertilizers used by the farmers and those recommended by soil analysis have been converted into pure nitrogen (N), phosphorus (P), and potassium (K) amounts. According to the farmers who conducted soil analysis, the differences between the suggested and used amounts of nitrogen (N), phosphorus (P), and potassium (K) in paddy farming are shown in

Table 4. Actual and suggested pure NPK usage per hectare by paddy farmers.

	Suggested (kg/ha)	Used (kg/ha)	Difference (kg/ha)	Difference %
Pure N	5420.5	6139.5	719	13%
Pure P	5245	5957.5	713	14%
Pure K	1155	187.5	−968	−84%

. The recommended amounts are 5420.5 kg/ha for N, 5245 kg/ha for P, and 1155 kg/ha for K. However, the amounts used by the farmers are 6139.5 kg/ha for N, 5957.5 kg/ha for P, and only 187.5 kg/ha for K. This results in a surplus of 719 kg/ha (13%) for N and 713 kg/ha (14%) for P, but a significant deficit of 968 kg/ha (−84%) for K.

According to the findings, farmers who conducted soil analysis were recommended to use fertilizers costing an average of USD 240.05 per hectare. However, the farmers actually incurred fertilizer costs of USD 258.75 per hectare, resulting in an overspending of 7.79%.

The extra cost of fertilizer usage in paddy farming in Edirne can be calculated using the following formula:

c = a × (u − s)
= 44,552.7 × (258.75 − 240.05)
= USD 833,135.49

(3)

where

• c: Extra cost of fertilizer use in Edirne;
• a: Paddy plantation area of Edirne (ha);
• u: Total used fertilizer cost (USD/ha);
• s: Suggested total fertilizer cost (USD/ha).

The extra cost of fertilizer use in Edirne is calculated as USD 833,135.49. While this amount may not seem excessively high, it is important to note that farmers are applying nitrogen and phosphorus above the recommended doses, while potassium is used well below the suggested amount. The low rate of soil analysis among farmers leads to insufficiently informed decisions regarding the amount of fertilizer to be applied. Consequently, this results in improper fertilizer usage. Potassium deficiency significantly reduces the water use efficiency of paddy farms [11].

4. Discussion

The careful application of chemical fertilizers is critical in paddy farming, especially given that paddy (Oryza sativa L.) is grown in waterlogged conditions. Yield increases significantly through the application of chemical fertilizers and pesticides [12,13]. However, caution must be exercised against the overuse of nitrogen (N) and phosphorus (P), as these practices not only contribute to environmental pollution but also elevate production costs [14].

Our study supports these findings, revealing that in Edirne Province, the overuse of N and P fertilizers is prevalent, leading to adverse environmental impacts such as soil degradation and water pollution. This is consistent with the broader literature, which underscores the risks of excessive fertilizer use. Specifically, our data show that farmers in Edirne apply N and P at rates 13% and 14% above recommended levels, respectively, while potassium (K) is underutilized by 84%. This imbalance in nutrient application exacerbates environmental degradation and undermines the sustainability of paddy farming in the region.

The emphasis on the careful application of chemical fertilizers due to the waterlogged conditions of paddy farming is also observed in studies on input usage decisions among farmers. It has been found that while farmers do consult agricultural engineers for guidance, there is still a heavy reliance on personal experience when making input decisions [15]. This reliance often results in suboptimal application practices, as evidenced by our findings in Edirne, where only 30.2% of farmers conduct soil analysis before applying fertilizers. This lack of scientific guidance likely contributes to the overuse of nitrogen (N) and phosphorus (P), aligning with concerns about the environmental risks associated with fertilizer overuse [14].

Moreover, the economic implications are directly relevant to our findings. The additional costs incurred due to the overuse of pesticides in Edirne, which amount to approximately USD 5.32 million, underscore the financial burden that improper input use can impose on farmers. These economic inefficiencies highlight the need for better-informed decision-making processes among farmers [15].

5. Conclusions

This study highlights the pressing need for sustainable agricultural practices in paddy farming, particularly in Edirne Province, Türkiye. The overuse of chemical fertilizers, especially nitrogen (N) and phosphorus (P), combined with the underutilization of potassium (K), poses significant environmental risks and economic inefficiencies. These practices result in soil degradation, water pollution, and increased costs for farmers, which threaten the long-term sustainability of paddy farming in the region.

To address these challenges, it is imperative to implement comprehensive agricultural extension programs aimed at increasing farmers’ awareness and understanding of sustainable farming practices. Educating farmers about the importance of balanced fertilizer use and the benefits of soil analysis is crucial. Training programs should provide farmers with the knowledge and tools necessary to apply fertilizers and pesticides at recommended levels, tailored to the specific needs of their soil and crops. This approach will help reduce the reliance on traditional practices that often lead to overuse and environmental harm.

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.

Additionally, agricultural extension services should actively promote sustainable farming practices, including the adoption of integrated pest management (IPM) strategies and the use of organic fertilizers. These practices can reduce the environmental impact of paddy farming while maintaining or even enhancing crop yields. The use of modern technologies, such as precision agriculture, should also be encouraged to optimize input use and improve resource efficiency.

Given that paddy farming is water-intensive, it is vital to protect and manage water resources effectively. Farmers should be educated about water-saving techniques, such as alternate wetting and drying (AWD), which can significantly reduce water usage without compromising yields. Protecting water sources from contamination by agricultural runoff is equally crucial, and farmers should be made aware of the importance of buffer zones and proper waste management practices.

Environmental sustainability must be a core focus of agricultural policies and practices. Farmers should be educated about the long-term consequences of chemical overuse, including soil and water degradation, and the impact on biodiversity. Extension programs should include components on environmental conservation, encouraging practices that minimize ecological disruption and support the health of local ecosystems.

To support these initiatives, government and agricultural organizations should develop policies that incentivize sustainable practices. This could include subsidies for soil testing, financial support for the adoption of sustainable technologies, and stricter regulations on the use of chemical inputs. Collaboration between policymakers, agricultural experts, and farmers is essential to create a framework that supports sustainable paddy farming at all levels.

In conclusion, the careful management of chemical fertilizers in paddy farming is crucial for both environmental and economic sustainability. Our study highlights the need for enhanced access to agricultural expertise and the more widespread adoption of soil analysis practices to ensure that inputs are used optimally. By addressing these issues, we can mitigate the negative impacts of overusing nitrogen (N) and phosphorus (P) fertilizers, thereby promoting more sustainable paddy farming practices in the Thrace region. Future policies should focus on improving the dissemination of scientific knowledge and encouraging practices that align with the ecological needs of the soil, ultimately supporting both the productivity and sustainability of paddy farming.