Agricultural and Environmental Sciences

Current Issue 2025. Vol.44

Orginal Articles

• Physiological and Morphological Characteristics of the New Variety of Schisandra chinensis ‘Geumbitsaeul’ for Forest Environment Cultivation

  Je-Min Park, Mi-Yun An, Hyun-Jin Song, Ro-Young Lee, Soon-Ho Kwon, In-Chol Choi, Byeong-Hoon Yang / Korean Journal of Environmental Agriculture / 2025 / v.44, 1-11

  https://doi.org/10.5338/KJEA.2025.44.01

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  This study investigates the morphological characteristics of the new variety of Schisandra chinensis ’Geumbitsaeul’, developed for cultivation in forest farming applications. To determine whether distinct traits of S. chinensis ‘Geumbitsaeul’ were consistently distinguishable from the control variety, two cultivation trials were conducted over two years. As a result, S. chinensis ‘Geumbitsaeul’ consistently exhibited traits such as shorter and wider tepals and a higher number of aggregate fruits compared to the control variety. In qualitative evaluation, compared to control species, S. chinensis ‘Geumbitsaeul’ had no anthocyanin pigmentation on the petiole, no intraterminal pigmentation, and there was a clear difference in yellow fruit color. As a result of phenotypic confirmation, it is judged to be a variety with low pigment content. These characteristics enhance the ornamental and industrial value of S. chinensis ‘Geumbitsaeul’ positioning it as a valuable addition to the diversification of S. chinensis varieties. The purpose is to provide basic data needed to foster new forest varieties and establish S. chinensis standard varieties, and to contribute to expanding the diversity of varieties.

• Residual Characteristics of Trunk-Injected Oxolinic Acid for Control Fire Blight

  Jae-In Lee, Kwang-Sik Kang, Eun-Seo Park, Woo-Sik Park, Young-Joon Choi, Han-Ju Jeong, Min-Su Kang, Tae-Yong Yun, Hyeok-Woo Nam / Korean Journal of Environmental Agriculture / 2025 / v.44, 12-20

  https://doi.org/10.5338/KJEA.2025.44.02

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  Fire blight is a pathogen that is prohibited from being introduced, such as causing the entire tree to wither. It is virtually impossible to completely eradicate and treat it once it breaks out. Therefore, because it causes economic and psychological losses to farms, this study was conducted to develop more effective pesticide by supplementing the pesticides that have been previously used. oxolinic acid (10%) SL, which is effective in controlling pathogens, was selected as the target pesticide. The spraying method was changed to a method that has a more direct effect, and the apple and pear trees were trunk-injected right before flowering. samples were collected and the pretreatment method and instrumental analysis method were established. Based on the analysis results, there was a possibility of developing a new pesticide even within the limited experimental method. However, it is difficult to apply it to commercial orchards, so further review is necessary.

• Occurrence of Antibiotic-resistant Bacteria to Streptomycin and Oxytetracycline in Agricultural Soils of Gangwon State

  Chaemin Sim, Jieun Lim, Youri Yang / Korean Journal of Environmental Agriculture / 2025 / v.44, 21-28

  https://doi.org/10.5338/KJEA.2025.44.03

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  Soil can be a natural reservoir of antibiotic-resistant bacteria (ARB) and is capable of transferring them to the environment. The spreading of ARB can be affected by geographical factors such as land type and altitude. This study investigated the occurrence of antibiotic-resistant bacteria from agricultural soils in five regions of Gangwon State, South Korea, focusing on two commonly used agricultural antibiotics, streptomycin (ST) and oxytetracycline (OTC). Soil samples were collected from two plane land fields (Cheorwon, Chuncheon) and three high land fields (Gangneung, Jeongseon, Taebaek) for isolation of ARB against ST and OTC. Thirty-four bacterial strains were isolated, showing resistance to ST and OTC. Examination of cross-resistance between the two antibiotics found that some strains resistant to ST also exhibited reduced susceptibility to OTC, and vice versa. Remarkably, the bacterial strains, CW1 and TB7, showed the highest cross-resistance between the two antibiotics and they were from either plane land fields or high land fields. The strains were identified as diverse genera such as Pseudomonas sp., Lysobacter sp., Telluria sp., Pseudarthrobacter sp., Stenotrophomonas sp., Microbacterium sp., and Flavobacterium sp. The results in this study infer the potential for the spread of ARB or related genes from high land in sloped fields. Taken together, it should be emphasized that a need for careful monitoring of the occurrence of ARB in different types of fields to protect the environment as well as sustainable agriculture by preventing the further spread of these bacteria and related antibiotic-resistant genes in the environment.

• Effect of Fertilizer Deep Placement on Reducing Nitrogen Fertilizer Usage and Increasing Yield of Several Upland Crops

  Sung-Chang Hong, Min-Ji Lee, Byung-Wook Oh, Chang-muk Lee / Korean Journal of Environmental Agriculture / 2025 / v.44, 29-36

  https://doi.org/10.5338/KJEA.2025.44.04

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  Nitrogen fertilizers must be applied repeatedly during crop cultivation. The agricultural sector has set a goal of reducing nitrogen fertilizer usage to 23%, from 2022 to 115kg/ha, 2030. Currently, fertilizer is spread on the farming fields and then mixed with the field soil using rotary operations. Deep fertilization treatment entailed injecting basal fertilizer 25-30cm deep into the soil using a deep fertilization device attached to a tractor. For onions, added fertilization using nitrogen fertilizer was omitted once out of three times, and for wheat, once out of two times. For forage corn, added fertilization was reduced by 50%. After crop cultivation, the yield of the deep fertilization treatment significantly increased by 52% for onion, 26% for wheat, and 29% for forage corn, respectively, compared to the conventional surface fertilization treatment. Therefore, deep fertilization could reduce the amount of nitrogen fertilizer used as fertilization by 22% for onions, 25% for wheat, and 25% for forage corn. It was concluded that deep fertilization of basal fertilizer in cultivating onions, wheat, and forage corn can reduce the amount of nitrogen fertilizer used to increase production. The deep fertilization technology is expected to be a low-carbon agricultural technology.

• Trade-off between Increasing Rice Productivity and Reducing Nutrient Loss Using Organic Amendment with Food Waste in South Korea

  Hye Jin Park, Seul Bi Lee, Song Rae Cho, Byung Keun Hyun, Na-Hyun Kwon, Jeong-Gu Lee / Korean Journal of Environmental Agriculture / 2025 / v.44, 37-44

  https://doi.org/10.5338/KJEA.2025.44.05

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  The increasing issue of food waste necessitates solutions that prioritize resource recycling and environmental sustainability. This study evaluated the effects of combining food waste-derived organic fertilizer with inorganic fertilizer on rice productivity, nutrient utilization efficiency, and water pollution. The experiment included seven treatments: a control group (Control), a nitrogen-only treatment (PK), a standard inorganic fertilizer treatment (NPK), a full organic fertilizer treatment (OA), an organic fertilizer mixed treatment (MFW), and combinations of NPK+OA and NPK+MFW. Results showed that the organic fertilizer treatment zones (OA, NPK+OA) had significantly lower soil pH after harvest compared to other treatments, while soil electrical conductivity (EC) was higher (p<0.05). Additionally, organic fertilizer-containing zones exhibited 124% and 106% greater water retention and nutrient uptake capacity, respectively, compared to the NPK treatment. The water productivity index was highest in the NPK+MFW treatment, reaching 138%. Nitrogen concentrations in water were highest in the NPK treatment (11.3 mg L^⁻1 on average) but decreased significantly to 6.1–9.6 mg L^⁻1 in the organic fertilizer treatments. In conclusion, the combined use of inorganic fertilizers and food waste-derived organic fertilizers in rice cultivation provides an optimal strategy for enhancing productivity while ensuring environmental sustainability.

• Dissipation Analysis and Risk Assessment of Fungicides Thiophanate-methyl and Pyribencarb According to Olive Characteristics

  Ji-Won Shin, Min-Ho Song, Ji-Woo Yu, Jung-Hoon Lee, Hui-Yeon Ahn, Geon-Woo Park, Ji-Yeon Lee, Ha-Jin Son, Eun-Song Choi, Young-Soo Keum, Ji-Ho Lee / Korean Journal of Environmental Agriculture / 2025 / v.44, 45-54

  https://doi.org/10.5338/KJEA.2025.44.06

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  In this study, the residual characteristics and half-lives of thiophanate-methyl and pyribencarb were compared after treatment on olives, followed by a risk assessment. Total residual levels of the two pesticides ranged between 2.43–5.57 mg/kg and 1.65–6.52 mg/kg, respectively, with half-lives of 25.7 days and 13.1 days. Compared to previous studies, the longer half-lives of thiophanate-methyl and pyribencarb in olives can be attributed to the differences in cuticle wax content. The composition and content of cuticle wax differ depending on the crop cultivar, influencing the adsorption and dissipation of pesticides. Because of wax on the crop surface, the half-life of pesticides can be extended, suggesting a correlation between the surface characteristics of olives and the half-lives of pesticides. The risk assessment, based on the worst-case scenario (99^th percentile consumer group for olive consumption), resulted in Hazard Index (HI) values of 0.032 and 0.077, indicating low risk (HI < 1).

• Effects of Nitrogen or Phosphorus Deficiency and Light Treatment on Anthocyanin Biosynthesis in Tomato Hypocotyls

  Subeen Mun, Yeonjong Koo / Korean Journal of Environmental Agriculture / 2025 / v.44, 55-67

  https://doi.org/10.5338/KJEA.2025.44.07

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  Anthocyanins are pigment ingredients with great potential as health-functional materials, and they are processed and used in various fields. These compounds function as antioxidants and are synthesized in response to various stress conditions. In the case of tomatoes, they have an unstable flavonoid biosynthesis pathway. So, they are rich in lycopene in a normal state and produce red fruits. However, when plants detect specific environmental changes, they can synthesize anthocyanins. In this study, we observed the expression of anthocyanin biosynthesis genes in tomato hypocotyls under nutrient deficiency conditions and various light treatments. Under nitrogen or phosphate deficiency conditions, the anthocyanin content in hypocotyls increased compared to the control, and similar levels were shown under nitrogen-deficient and phosphorus-deficient conditions. The expression levels of most anthocyanin biosynthesis genes were higher in the nutrient-deficient treatment group. Under light-treatment conditions, the anthocyanin content was higher in the light-treated groups. and the expression levels of anthocyanin biosynthesis genes were also higher in the light-treated group. These data provide insight into how anthocyanin accumulation is regulated through distinct genetic induction pathways in response to nitrogen deficiency, phosphate deficiency, and light signaling.

• Analysis of Spray Efficiency and Drift Characteristics of Tower Sprayers in Multi-Leader Apple Orchards Under Varying RPM, Driving Speeds, and Airflow Conditions

  Jong Hoon Jeon, Baek Gyun Choi, Seunghyun Ban / Korean Journal of Environmental Agriculture / 2025 / v.44, 68-77

  https://doi.org/10.5338/KJEA.2025.44.08

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  In this study, we evaluated the spraying efficiency and drift characteristics of tower sprayers in multi-leader apple orchards and proposed optimal spraying standards. This research addresses the challenges of pesticide drift and uneven droplet distribution, which impact spraying precision and environmental sustainability. The results demonstrated that disabling the air-assist significantly reduced pesticide drift, while the combined effect of revolutions per minute (RPM) and driving speed on spraying efficiency and drift patterns was significant. Air-assist was shown to increase droplet drift beyond the fifth row, whereas disabling it substantially mitigated this effect. Furthermore, droplet size and distribution varied considerably under different air-assist conditions, emphasizing the need for tailored spraying strategies in planar orchard layouts. The results of this study provide essential insights for improving spraying efficiency and minimizing environmental impacts, thereby supporting the development of precision spraying technologies and sustainable orchard management practices.

• Residual Characteristics and Risk Assessment of Etofenprox and Deltamethrin in Cirsium japonicum spinosissimum

  Ji-Yeon Lee, Min-Ho Song, Ji-Woo Yu, Jung-Hoon Lee, Hui-Yeon Ahn, Geon-Woo Park, Ji-Won Shin, Ha-Jin Son, Eun-Song Choi, Young-Soo Keum, Ji-Ho Lee / Korean Journal of Environmental Agriculture / 2025 / v.44, 78-86

  https://doi.org/10.5338/KJEA.2025.44.09

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  The increase in pesticide use for agricultural production may affect consumer health due to pesticide residues in crops. Consequently, many countries have established maximum residue limits (MRLs) for pesticides. This study evaluated the characteristics of residues and conducted a risk assessment of etofenprox and deltamethrin in Cirsium japonicum spinosissimum. The residue levels of the two pesticides ranged from 0.99 to 8.07 mg/kg and 0.03 to 0.71 mg/kg, with half-lives of 5.0 days and 3.5 days. The risk assessment based on the highest exposure scenario (99th percentile) indicated hazard index (HI) values of 0.369 and 0.097, suggesting a low-level risk (HI <1). Considering actual intake scenarios within the agricultural environment, risk assessments were conducted for treated plots at 3, 7, and 14 days after pesticide application. The results showed that the pesticide exposure risk decreased less than 0.1 at 7 and 0 days after treatment compared to the harvest day (etofenprox, deltamethrin HI = 0.090, 0.097). From this research, it was suggested that for safety standards regarding pesticide use, etofenprox should be applied twice as a foliar spray at least 7 days before harvest, while deltamethrin should be no later than 3 days before harvest.

• Physicochemical Characteristics of Biochar and Their Influence on Sorption Mechanisms of Clothianidin Neonicotinoids in Agricultural Soils

  Mohamed R. Fouad, Hesham M. Aly, Noura A. Hassan / Korean Journal of Environmental Agriculture / 2025 / v.44, 87-100

  https://doi.org/10.5338/KJEA.2025.44.10

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  This paper aims to two types of biochar were prepared from different sources: the pruning residues of Pinus roxburghii and Cupressus sempervirens trees at 700℃. Electron dispersive X-ray (EDX) analysis of both types of biochar revealed an abundance of carbon and oxygen with traces of other elements. The vessels of C. sempervirens biochar, as observed by scanning electron microscopy (SEM), are wider than those of P. roxburghii biochar, which may reflect the efficiency of C. sempervirens biochar compared to P. roxburghii biochar. Additionally, the fourier transform infrared (FTIR) spectra show that both types differ in their functional group content, which may reflect differences in their effects. These types of biochar were added at a rate of 5% to the soil to study their effect on the absorption capacity of clothianidin neonicotinoids by sandy clay loam soil, sandy loam soil and sandy soil. Adding biochar to tested soils enhanced the adsorption of clothianidin, especially when C. sempervirens biochar was added. All soil parameters agree with the Freundlich equation through high value of R², and low value of SE.

• Influence of Sowing and Harvesting Periods on Yield Enhancement of ‘Hongsan’ Garlic

  Tae-Jun Lim, Joong-Won Lee / Korean Journal of Environmental Agriculture / 2025 / v.44, 101-109

  https://doi.org/10.5338/KJEA.2025.44.11

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  Garlic (Allium sativum L.) is an economically important crop that requires region-specific cultivation strategies for yield improvement. This study evaluated the optimal sowing and harvesting periods for ‘Hongsan’ garlic in South Korea through two-year field trials (2022–2024) in Muan (southern region) and Taean (central region). Plant morphological and yield parameters were recorded. Garlic was sown at 10-day intervals from late September to mid-October (2022) and 20-day intervals from mid-September to late October (2023) in Muan, with no significant yield differences. In Taean, sowing at 20-day intervals from mid-September to late October showed no yield difference between mid-September and early October, but late October sowing decreased yield (p≤0.05). Meanwhile, garlic harvested at 10-day intervals from mid-May to mid-June in Muan and early June to mid-June in Taean showed an increased yield due to delayed harvesting time in both regions (p≤0.05). These findings suggest that the optimal sowing period is late September to late October in the southern region and until early October in the central region. Furthermore, the optimal harvesting time is after June 1^st or 2^nd in the southern region and June 2^nd in the central region to achieve the highest yield of ‘Hongsan’ garlic. Hence, this study provides a basis for future multi-regional trials to refine sowing and harvesting guidelines across diverse garlic-growing environments.

• Monitoring of Diquat and Paraquat in Livestock Products by LC-MS/MS Combined with Modified QuEChERS Methods

  Seung Won Lee, Ji You Kim, Seon Hwa Kim, Hyung Wook Jo, Joon Kwan Moon, In Seon Kim / Korean Journal of Environmental Agriculture / 2025 / v.44, 110-120

  https://doi.org/10.5338/KJEA.2025.44.12

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  The continued growth in domestic meat consumption has prompted the development of pesticide analytical methods for quality control of livestock products. Among the pesticides managed by national safety programs, diquat and paraquat pose a significant challenge for conventional multi-residual analysis due to their strong polarity and high solubility in water. The objective of this study was to develop analytical methods for diquat and paraquat to monitor their residues in livestock products distributed in domestic markets. Five livestock products such as beef, pork, chicken, milk and eggs were selected as typical test samples. The analytical methods of diquat and paraquat were established by optimizing all the steps to meet with the criteria of CODEX guidelines. The optimized extraction methods were achieved by using the mixtures of water and acetonitrile containing 0.5% formic acid as the extraction solvent and acetonitrile containing 0.5% formic acid as the subsequent extraction solvent. C₁₈ dispersive solid-phase extraction was found to be effective for sample clean-up prior to LC-MS/MS analysis. The standard calibration curves of diquat and paraquat showed good linearity with the coefficients of determination (R²) ranging from 0.9902 to 0.9986 for diquat and from 0.9968 to 0.9997 for paraquat. The established methods achieved recoveries ranging from 66.5 to 100.4% for diquat and ranging from 73.5 to 95.6% for paraquat. A total of 409 livestock samples from domestic markets were investigated for monitoring of diquat and paraquat by the established methods coupled with LC-MS/MS. Diquat and paraquat were found in the livestock samples at levels below the limit of quantitation (0.01 mg/kg). The analytical methods developed in this study could be successfully applied for monitoring diquat and paraquat in real livestock samples from domestic markets.

• Residual Characteristics and Risk Assessments of Acetamiprid, Afidopyropen and Emamectin benzoate in Noni

  Su Hyeong Heo, Sojin Kim, Jiwon Kim, Kwan Woo Jeon, Chang Sook Kim, Kyung-Hwan Boo / Korean Journal of Environmental Agriculture / 2025 / v.44, 121-130

  https://doi.org/10.5338/KJEA.2025.44.13

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  This study aimed to investigate the residual characteristics and safety assessment of acetamiprid, afidopyropen, and emamectin benzoate in Noni under greenhouse conditions. The Noni samples were treated with the pesticides twice at 7-day intervals and harvested on days 0, 7, 14, and 21 after the last treatment. The average recoveries of all pesticides ranged from 73.2% to 99.1%, which was sufficient for residue analysis. The residual amounts of acetamiprid, afidopyropen, and emamectin benzoate in noni were 0.09-0.15 mg/kg, 0.05-0.07 mg/kg, 0.01-0.03 mg/kg, respectively, indicating a tendency for dissipation over time. The biological half-lives of acetamiprid, afidopyropen, and emamectin benzoate were 28.6, 34.6, and 8.8 days, respectively. The %ADI values for these pesticides were below 1%, indicating a safe level of residue. These results provide important fundamental data for the future establishment of PHI (Pre-Harvest Interval) and MRL (Maximum Residue Limit) for Noni.

• Study on Emission Characteristics of Designated Odor Substances by Emission Source in Busan Industrial Complex Area Using SIFT-MS

  Tae-Uk Jeong / Korean Journal of Environmental Agriculture / 2025 / v.44, 131-142

  https://doi.org/10.5338/KJEA.2025.44.14

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  In this study, the emission characteristics of designated odor substances emitted from 11 odor emission sources in the industrial complex area were investigated using SIFT-MS for efficient management of malodor emission facilities in the industrial complex area of Busan. The concentration distribution, odor activity value (OAV), odorous contribution rate (OCR), and odor intensity (OI) of designated odorous substances for each emission source were identified. By creating a pollution rose map, we identified the direction and distance affecting the measurement point and secured basic data for management and reduction of odor in the industrial complex area. The concentrations of acetaldehyde and trimethylamine were high in wastewater treatment companies. High concentrations of butanoic acid were detected in food manufacturers and feed manufacturers that handle something related to food. The sum of the concentrations of 20 designated odor substances was highest (4.732 mL/m³) at the SS-3 site of the wastewater treatment company, followed by SS-2 > GJ-2 > SS-1. In the case of OAV of designated odor substances, it was the highest (5352.9 mL/m³) at SS-3 site, followed by SS-2 > GJ-2 > SH-1. Based on OVA, the OCR of trimethylamine among amines, methyl mercaptane among sulfur compounds, acetaldehyde among aldehydes, and butanoic acid and valeric acid among organic acids was high. The result of odor intensity was that TMA in wastewater treatment companies and methyl mercaptane in food waste disposal company was high. As a result of creating a pollution rose map, the SH-3 site which is located in precision machinery facilities showed a high concentration of odorous substances when the north wind blew. In the case of the SH-4 site, a food manufacturer, it was greatly affected by the southeast wind blowing from manufacturers are scattered. At GS-1 site, casting manufacturing business, the high concentration was observed when the northeast wind blew from the industrial complex area, which is in the opposite direction to the sea.

• Effect of Reducing Cadmium Phytoavailability Using Biochar Derived from Rendered Animal Carcass Residues

  Jin-Ju Yun, Ju-Sik Cho / Korean Journal of Environmental Agriculture / 2025 / v.44, 143-151

  https://doi.org/10.5338/KJEA.2025.44.15

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  This study evaluated the chemical properties of cadmium (Cd)-contaminated soil and reduction in Cd bioavailability following the application of biochar derived from rendered animal carcass residues (RACR-C). The results demonstrated that RACR-C improved soil quality by increasing soil pH, organic matter content, available phosphate, and exchangeable cations. The Cd fractionation analysis revealed the decrease in the highly mobile exchangeable form (F1) and an increase in the carbonate-bound form (F2) derived from biochar. Furthermore, as the RACR-C application rate increase, plant growth improved, while Cd content and uptake decreased. Especially, Cd immobilization led to 60% reduction in Cd uptake in the 10% RACR-C treatment compared to untreated control, effectively suppressing Cd translocation to crops. Therefore, RACR-C is expected to function as a soil amendment and heavy metal stabilizer by improving soil conditions and reducing Cd transfer to plants. Further long-term studies are needed to assess its environmental impact and effectiveness across various crop and soil conditions.

• Evaluation of Growth Responses and Greenhouse Gas Emissions with Application of Biodegradable Coating Fertilizer during Rice Cultivation

  SeungHa Lee, JaeYee Choi, OhYeon Kwon, HyunJong Cho, JongWon Lee, JaeHyeok Choi, JooHyeok Lee, JoungDu Shin / Korean Journal of Environmental Agriculture / 2025 / v.44, 152-161

  https://doi.org/10.5338/KJEA.2025.44.16

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  The non-biodegradable resins are used and increased every year with about 1,103 tonnes of non-biodegradable resins for the production of controlled release fertilizers since 2020. Hence, the objective of this study was to investigate the effect on paddy rice growth and greenhouse gas emissions by application of the controlled release fertilizer coated with a biodegradable polymer. This experiment was conducted in a paddy rice field, a farm affiliated with Seoul National University. The experimental design was the randomized complete block design method (RCBD) with 3 treatments to three replications. The treatment consisted of 1) non-fertilizer, 2) biodegradable coating fertilizer (31-6-8) with 30 kg/10a of application rates, and 3) the conventional farming practice (21-17-17) with 40 kg/10a of application rates. For the growth responses, there were no significant differences in leaf color, plant height, number of tillers, and yield components between the biodegradable polymer coating treatment and the conventional treatment. The cumulative CH₄ and N₂O emissions in the biodegradable coating polymer treatment were 91.25 kg/10a and 150.80 g/10a with 35.9% and 53.9% of mitigation rates, respectively, compared to the conventional treatment. Overall, application of biodegradable coating polymer fertilizer reduced 25% of the fertilized amount and 36.4% of greenhouse gas emissions (CO₂-equiv.) with no reduction of yield during rice cultivation.

• Effect of Amino Acid Liquid Fertilizer with Proline Treatment on Frost Damage during Flowering Period and Fruit Quality in ‘Fuji’ Apple

  Jingi Yoo, Ik-Jo Chun, Jung-Geun Kwon, Nay Myo Win, In-Kyu Kang / Korean Journal of Environmental Agriculture / 2025 / v.44, 162-169

  https://doi.org/10.5338/KJEA.2025.44.17

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  This study was conducted to analyze the effects of amino acid liquid fertilizer (ALF) and proline (Pro) treatment on frost damage during the flowering period, as well as on tree growth and fruit quality of ’Fuji’ apple trees. When the ALF + Pro treatment was applied before flowering, the number of fruits per flower cluster in the untreat group was less than 2.0 for both terminal and axillary buds in ’Fuji’ apple trees. The ALF + Pro 50 and 100 mg/L treatments showed a significantly increase, with 2.6 fruits per cluster on terminal buds. Additionally, when ’Fuji’ apple flowers were exposed to –1℃ after flowering, the untreat group showed a frost damage rate of 48.4%, whereas the ALF + Pro 100 mg/L treatment resulted in the lowest frost damage rate of 29.3%. In the amino acid contents of the fruit peel tissue, glutamic acid increased significantly in the ALF + Pro 10 and 50 mg/L treatments, while isoleucine and lysine increased significantly in the ALF + Pro 10 and 25 mg/L treatments. In the fruit flesh tissue, hydroxyproline, citrulline and isoleucine were not detected in the untreated fruit, but were detected in all ALF + Pro treatments. In particular, hydroxyproline content was 196.5, 177.7 and 214.9 mg/L in the ALF + Pro 10, 25 and 50 mg/L treatments, respectively. Glutamic acid content was 266.6~1,073.7 mg/L in all ALF + Pro treatments.

• Analysis of Residual Pesticides in Agricultural Products with Different Lipid Contents Using Macroporous Diatomaceous Earth Column

  Suin Cho, Hey-In Cho, Jang-Eok Kim, Jeong-In Hwang, Chi-Hwan Lim / Korean Journal of Environmental Agriculture / 2025 / v.44, 170-179

  https://doi.org/10.5338/KJEA.2025.44.18

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  Due to their similar properties to pesticides, lipids in agricultural products can interfere with the analysis of pesticide residues. This study tested the analytical recoveries of three pesticides with varying polarities, namely, bifenthrin, chlorpyrifos, and acetamiprid, across three agricultural products with different lipid contents: oriental melon, brown rice, and peanuts. The analysis was conducted using a method established by the Ministry of Food and Drug Safety. The results indicated that higher lipid content in agricultural products and lower polarity of pesticides were associated with lower recovery rates, leading to significant emulsion during the liquid-liquid partitioning process. To resolve the recovery issue, the liquid-liquid partition was replaced with acetonitrile as an extraction solvent and a macroporous diatomaceous earth column. The recovery rates using these improved analytical methods ranged from 81.8% to 94.8%, with coefficients of variation for triplicates between 0.7% and 5.6%. These results meet the criteria for pesticide residue analysis, which require recoveries of 70-120% and CVs of <10%. The methods developed in this study effectively enhance pesticide extraction from agricultural products while minimizing the effects of lipids and emulsion.

• Effects of Organic Fertilizer Combined with Rice Husk Biochar on Soil Quality and Crop Productivity

  Yun-Gu Kang, Jun-Yeong Lee, Jiwon Choi, Jun-Ho Kim, Ji-Hoon Kim, Yeo-Uk Yun, Taek-Keun Oh / Korean Journal of Environmental Agriculture / 2025 / v.44, 180-187

  https://doi.org/10.5338/KJEA.2025.44.19

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  As global warming accelerates, carbon sequestration in agricultural soils is essential for mitigating climate change. This study investigated the effects of organic fertilization with the 0%, 10%, and 30% (w/w) of rice husk biochar on soil quality and Chinese cabbage yield. The field-based experiments were conducted with four treatments, including non-organic fertilization and three mixing ratios of rice husk biochar in organic fertilizer. The combination of organic fertilizer and rice husk biochar at a 7:3 ratio improved the soil fertility, as indicated by increased available nitrogen (219.00 mg/kg) and phosphorus (404.77 mg/kg) contents for crop plants. Additionally, carbon sequestration efficiency increased with higher biochar ratios in organic fertilizer, reaching 23.60 Mg C/ha in the 7:3 mixture of organic fertilizer and rice husk biochar. Although the crop yield decreased as the mixing ratio of biochar increased, the differences were not significant across treatments. This study found that combination of organic fertilizer and biochar improved soil carbon stock and nutrient availability, but crop yield was not varied by mixing ratio of biochar. For effective soil improvement, combining organic fertilizer and rice husk biochar at a ratio of 7:3 (w/w) is the optimal strategy.

• Performance Measure of Agricultural Environment Conservation Program and Suggestions

  Seung-Beom Lee, Ye-Rim Oh, Juyoun Song, Jin-Hyeob Kwak / Korean Journal of Environmental Agriculture / 2025 / v.44, 188-199

  https://doi.org/10.5338/KJEA.2025.44.20

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  The Agricultural Environment Conservation Program (AECP) has been implemented in South Korea to mitigate environmental pollution from agricultural activities and enhance ecosystem services. This study evaluates the effectiveness of AECP by analyzing changes in soil and water quality and farmers’ perceptions in 25 participating villages over a 4-5 year period. The analysis was conducted using soil test results from the RDA Soil Information System, water quality monitoring data from farm reservoirs, and survey responses from program participants. The results indicate that while no consistent trends were observed across all sites, certain positive outcomes were identified, such as a reduction in available phosphorus concentrations in soil and improvements in water quality in some reservoirs where both soil erosion prevention and nutrient runoff reduction activities were implemented. Effectiveness of AECP activities was not consistent because of conventional farming practices and external environmental factors. Participation rates were higher for less complex and more familiar activities, while participation in technically challenging or labor-intensive activities was relatively low. However, positive aspect is that farmers directly involved in AECP activities reported high levels of satisfaction and increased environmental awareness. To enhance the impact of AECP, detailed guidelines, periodic farmer education, and payment adjustments based on activity difficulty should be considered.

• Study on the Wintering Home Range and Habitat use of Mallard (Anas platyrhynchos) using GPS Tracking Devices

  Tae Wan Kim, Dae Han Cho, Sang-Min Jung, Tehan Kang, Kee-Sung Hong, Yong Jin Lee, Ji Hye Kim, Hong-Shik Oh / Korean Journal of Environmental Agriculture / 2025 / v.44, 200-210

  https://doi.org/10.5338/KJEA.2025.44.21

  Abstract Full-Text PDF

  Abstract

  

  This study analyzes the home range and habitat use of wintering mallards (Anas platyrhynchos) in the Mangyeong and Dongjin rivers, western Korea, using a GPS tracking device (WT-300). It provides insights into habitat conservation and management. The study area consists of rivers, wetlands, and farmland. Nine mallards were tracked using GPS devices in riparian zones. Home range was analyzed using the Minimum Convex Polygon (MCP) and Kernel Density Estimation (KDE). The mean MCP home range was 766.4 km² (SD=836.9, n=9). KDE analysis showed a 90% utilization area of 137.0 km² (SD=220.5 km², n=9) and a 50% area of 30.3 km² (SD=51.4 km², n=9). Mallards primarily used hydrospheres, rice fields, and inland wetlands, gradually shifting to rice fields over time. They used hydrospheres most at noon and rice fields at night. Habitat selection was influenced by factors such as water depth, food availability, and disturbances. Mallards’ winter behavior reflects survival strategies, underscoring the need for stable habitats. These findings provide fundamental data for conservation efforts and the sustainable management of wintering habitats.