• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.357-366
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• 2011

BACKGROUND: Mathematical model such as GLEAMS have been developed and successfully applied to upland fields to estimate the level of pesticide residues in soil. But, the GLEAMS model rarely applied to the Korean conditions. METHODS AND RESULTS: To evaluate pesticide transport in soil residue using the GLEAMS model from pepper plot, Alachlor, Endosulfan, Cypermethrin and Fenvalerate were applied for standard and double rate. Soil sampling was conducted and decaying patterns of pesticides were investigated. Observed climate data such as temperature and irrigation amount were used for hydrology simulation. The observed pesticide residue data of 2008 were used for parameter calibration, and validation of GLEAMS model was conducted with observed data of 2009. After calibration, the $K_{oc}$ (Organic carbon distribution coefficient) and WSHFRC (Washoff fraction) parameters were identified as key parameters. The simulated concentrations of the pesticides except Fenvalerate were sensitive to $K_{oc}$ parameter. Overall, soil residue concentrations of Alachlor, Cypermethrin and Fenvalerate were fairly simulated compared to those of Endosulfan. The applicability of the GLEAMS model was also confirmed by statistical analysis. CONCLUSION(s): GLEAMS model was eligible for evaluation of pesticide soil residue for Alachlor, Cypermethrin and Fenvalerate.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.3
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• pp.58-64
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• 2014

Management of organic waste such as livestock manure has been considered as very important issue in terms of the environment. The anaerobic digestion of livestock manure become more attractive treatment method and has been widely applied. In this work, the properties of the residue after the anaerobic digestion of livestock manure was evaluated for providing the basic data to develop new application. The lignin and the ash contents of the residue were much higher than those of other biomass such as wood. The components of the residue were also analyzed with SEM-EDS and Elemental Analyzer. The addition of the residue into the handsheet paper resulted in the higher bulk and he higher air permeability with the loss of the strength properties. The water holding capacity of the handsheet were increased until the 40 % addition of the residue.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.193-202
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• 2023

Residue monitoring of propiconazole (PCZ) in cabbage, shallot, and spinach was conducted under multi-trial greenhouse conditions. This study aimed to understand the fate of the applied fungicide in these vegetables. Furthermore, the associated health risk of PCZ in leafy vegetables was assessed through dietary risk assessment. Commercially available PCZ (22% suspension concentrate) was administered thrice according to the OECD fungicide application interval guideline. The plant samples were extracted using a slightly modified QuEChERS technique and analyzed using gas chromatography-tandem mass spectrometry. The average PCZ recovery was between 84.5% and 117.6%, with a <5% coefficient of variance. The dissipation of PCZ residue in cabbage, shallot, and spinach after 14 days was 96%, 90%, and 99%, respectively, with half-lives of <5 days. Meanwhile, dietary risk assessments of PCZ residues in the studied vegetables using the risk quotient (RQ) were significant < 100 (RQ < 100). Thus, the population groups considered in this study were not at substantial risk from consuming leafy vegetables sprayed with PCZ following critical, good agricultural practices.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.50-56
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• 2017

BACKGROUND: The present study was carried out to identify the residue patterns of insecticide pyridalyl and fungicide fluopicolide in watermelon and calculate the biological half-lives for establishing the pre-harvest residue limits (PHRLs). METHODSANDRESULTS:The watermelon samples for residue analysis were harvested 7 times during 0~10 days (Field 1) and 0~20 days (Field 2) after treatment of pesticides on watermelon in two different fields at the recommended dose, respectively. The residue analysis was conducted with HPLC/UVD. The method limit of quantitation (MLOQ) were set at 0.05 and 0.02 mg/kg, respectively, and overall mean recoveries were 81.2~90.5% for pyridalyl and fluopicolide. The residues in sample were stable for 43~47 days. The initial residue amount in field 1 and 2 were 0.12~0.16 mg/kg for pyridalyl and 0.23~0.24 mg/kg for fluopicolide, which were below maximum residue limit (MRL). The biological half-lives in field 1 and 2 were 26.9 and 17.9 days for pyridalyl and 16.6 and 94.2 days for fluopicolide, respectively. CONCLUSION: The PHRL for watermelon were estimated as 0.21 and 1.03 mg/kg for pyridalyl and flopicolide at 10 days before harvesting. The residue patterns of pyridalyl and fluopicolide were characterized by a very slow decrease of residue levels in watermelon.

• Korean Journal of Environmental Agriculture
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• v.41 no.1
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• pp.1-8
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• 2022

BACKGROUND: The pesticide residue in rotational crop is one of the main concerns to agricultural products because it has the potentiality of violating positive list system (PLS). Thus, the crops used for the rotational cultivation should be considered the pesticide residue patterns to meet the PLS guideline. In this study, we evaluated the residue patterns of fungicide azoxystrobin in radish based on plant back interval (PBI) experiment. METHODS AND RESULTS: Azoxystrobin was treated onto greenhouse soil at 217 g a.i./10a in two different regions. Radishes were sown onto the soil 30 and 60 days after azoxystrobin treatment. The soil and plant samples were subjected to a modified QuEChERS method and LC/MS/MS analyses to determine the residues of azoxystrobin. The methods were validated to meet the guidelines of the pesticide residue analysis recommended by the Rural Development Administration, Republic of Korea. Azoxystrobin was dissipated significantly in soil during the experimental period and found as a level less than 0.01 mg/kg in radish 30 and 60 days after treatment. Azoxystrobin residues in radish samples were lower than the maximum residue limit (MRL) for root vegetables. CONCLUSION(S): This study suggests 30 days as a PBI for rotational cultivation of radish in greenhouse soil that had been treated with azoxystrobin at a level of 217 g a.i./10a.

• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.45-55
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• 2005

This study was undertaken to find out necessary measures to improve the tolerance setting system of pesticide residues on food crops in Korea which is scientifically reasonable and harmonizable with international standards. Information on tolerance setting systems of pesticide residues by Codex Alimentarius Commission, Joint FAO/WHO Meeting of Experts on Pesticide Residues, USA, EU, Japan and Taiwan was collected and analyzed. On the basis of information in the above countries, necessary actions to be taken by the Korean regulatory authorities were recommended with respect to priority setting, maximum residue limits (MRLs) setting based on field residue data, group MRLs, minor crop problems, quantitation limit and dietary intake assessment.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1717-1725
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• 2013

Traditional soybean paste from Shandong Liangshan and Tianyuan Jiangyuan commercial soybean paste were chosen for analysis and comparison of their bacterial and fungal dynamics using denaturing gel gradient electrophoresis and 16S rRNA gene clone libraries. The bacterial diversity results showed that more than 20 types of bacteria were present in traditional Shandong soybean paste during its fermentation process, whereas only six types of bacteria were present in the commercial soybean paste. The predominant bacteria in the Shandong soybean paste were most closely related to Leuconostoc spp., an uncultured bacterium, Lactococcus lactis, Bacillus licheniformis, Bacillus spp., and Citrobacter freundii. The predominant bacteria in the Tianyuan Jiangyuan soybean paste were most closely related to an uncultured bacterium, Bacillus licheniformis, and an uncultured Leuconostoc spp. The fungal diversity results showed that 10 types of fungi were present in the Shandong soybean paste during the fermentation process, with the predominant fungi being most closely related to Geotrichum spp., an uncultured fungal clone, Aspergillus oryzae, and yeast species. The predominant fungus in the commercial soybean paste was Aspergillus oryzae.

• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.45-51
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• 2012

BACKGROUND: This study was carried out to establish pre-harvest residue limit of fungicides pyrimethanil and trifloxystrobin in persimmon, based on dissipation and biological half-lives of two fungicides residue. METHODS AND RESULTS: Both pyrimethanil and trifloxystrobin were extracted with acetonitrile, clean-up with $NH_2$ SPE cartridge and residue were analyzed by HPLC/DAD. Limit of Detection was 0.01 mg/kg. Average recovery were $81{\pm}1.62%$, $98{\pm}1.58%$ of pyrimethanil, and $91{\pm}2.94%$, $98{\pm}1.25%$ of trifloxystrobin at fortification levels at 0.1 and 0.5 mg/kg, respectively. CONCLUSION: The biological half-lives of pyrimethanil were 15.6 and 11.6 days at sprayed with recommended and double dosage, respectively. The biological half-lives of trifloxystrobin were 10.4 and 10.3 days at sprayed with recommended and double dosage, respectively. The pre-harvest residue limit of pyrimethanil and trifloxystrobin were recommended as 2.69 and 0.83 mg/kg for 10 days before harvest, respectively.

• Korean Journal of Environmental Agriculture
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• v.15 no.2
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• pp.262-272
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• 1996

The objective of this paper is to present relevant information and for proposing legal standards on pesticide residues around golf courses. Among 67 pesticide ingredients used for the courses in Korea, 30 items necessary for standard setting were selected and theoretical residue limits were computed. Pesticide residue limits applicable to golf courses in Korea were for 16 pesticides in run-off water on the health and ecotoxicological bases and in soil on the health basis, as selected by practical use pattern. It is recommended to accumulate scientific data by continuous research efforts in order to justify the pesticide residue limits in run-off water and soils of golf courses.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.412-418
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• 2009

This study is conducted in order to know the residue patterns of insecticide cypermethrin and fungicide diethofencarb in ginseng sprayed by various application methods. Two pesticides were sprayed separately on ginseng using traditional, soil and vinyl mulching applications. The vinyl mulching application was that head part of ginseng protected from pesticides. When cypermethrin was sprayed on ginseng by traditional application, its residue amount in ginseng was 0.25 mg/kg which exceeded 0.1 mg/kg, maximum residue limit(MRL) established by Korea Food & Drug Administration(KFDA). But in case of vinyl mulching and soil application, its residue amounts were 0.04 and 0.07 mg/kg, respectively. The residue amount of diethofencarb in ginseng was 3.01 mg/kg which exceeded the MRL, 0.3 mg/kg. Further, in case of vinyl mulching and soil application, its residue amounts were 1.71 and 9.39 mg/kg which exceeded the MRL 0.3 mg/kg. Although the residue amounts of both pesticides exceeded the MRLs for ginseng, we can explain that pesticides remained in head part of ginseng is probably the reason why higher pesticides residue levels were observed.