• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.127-133
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• 2021

BACKGROUND: Dithiocarbamte fungicides have been used in crop cultivation for diseases protection and treatment. And cultivated agricultrual products were used as feedstuff, and residual pesticides are likely to be absorbed and transferred to livestock. But the maximum residue limits (MRLs) were not established for dithiocarbate fungicides in livestock products, and thus an analysis method was developed and validated for dithiocarbamate fungicides to establish MRLs. METHODS AND RESULTS: Samples were prepared using CS₂ trap method and detected with UV/VIS spectrophotometer. Calibration line (0.1 ~ 10 ㎍/mL) was linear with r² > 0.99. For validation, the recovery tests were carried out at three fortification levels (MLOQ, 10 MLOQ and 50 MLOQ) from livestock samples (egg, milk, beef, pork, and chicken). The results for mancozeb, propineb, and thiram ranged between 76.8 to 109.6%, 79.4 to 108.8%, and 80.2 to 107.8%, respectively and % RSD (relative standard deviation) values were below 9.5%. Furthermore, inter-laboratory analysis was performed to validate the method. CONCLUSION: All values were corresponded with the criteria ranges requested by both the CODEX (CAC/GL 40-1993, 2003) and MFDS guidelines (2016). This might be used as an official analytical method for determination of dithiocarbamate fungicides at established MRLs and monitoring.

• Journal of Conservation Science
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• v.37 no.6
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• pp.638-647
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• 2021

Organic residues are substances derived from diverse natural sources. Recent scientific analysis of organic residues has yielded important information in restoring the lifestyles of ancient peoples. In this study, the organic material contained within the celadon oil bottle of the Goryeo dynasty, excavated from the Soejoul site in Geumneung-dong, Chungju, was analyzed using Fourier-transform infrared spectroscopy (FT-IR) and gas chromatograph-mass spectrometer (GC-MS). The results showed that the organic materials in the bottle were plant-derived oils. In particular, polyunsaturated fatty acids and phytosterols were detected using GC-MS analysis. Sesamin components were also identified. Sesamin, which is a characteristic component of sesame seeds, is a lignan and an antioxidant. As the organic residues in the oil bottle were derived from sesame seeds, it is presumed that sesame oil was stored in the bottle.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.2
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• pp.304-310
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• 2024

Ricin is a highly toxic protein which is produced in the seeds of the castor oil plant. Ricin toxin A chain has ribosomal RNA N-glycosylase activity that irreversibly hydrolyses the N-glycosidic bond of the adenine residue at position 4324 within the 28S rRNA. In this study, we developed non-toxic recombinant ricin vaccine(R51) in E. coli expression system, and evaluated efficacy of the R51 according to adjuvants. When the R51 was administered using aluminum hydroxide as an adjuvant, the vaccine efficacy was higher than that of TLR agonists or aluminum phosphate. Because it is time-consuming to administer the vaccine three times at three-week intervals, we investigated the survival rate and antibody titer of mice according to the change of time interval of vaccination. Interestingly, there was no difference in survival rate and antibody titer when R51 was administered at 0, 1, and 3 weeks or 0, 2, and 4 weeks compared to when administered at 0, 3, and 6 weeks. Therefore, the developed R51 vaccine is promising to protect soldiers from Ricin attack.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.4
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• pp.336-341
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• 2024

In this study, the economic and environmental feasibility of seaweed by-products as livestock feed ingredients was evaluated. In the last three years (2021-2023), the estimated average annual production of domestic seaweed by-products, including processing residuals from sea mustard and kelp, was 210,000 tons. The economic feasibility analysis of using seaweed by-products as livestock feed indicated a net benefit of 482,237 KRW per ton. Additionally, substituting seaweed by-products at 0.25% 0.5%, 1%, and 2% in livestock compound feed generated net benefits of 6.5, 12.9, 25.9, and 51.7 billion KRW, respectively. The potential market value was analyzed from an environmental perspective by examining the greenhouse gas reduction potential of seaweed additives. By adding 2% laver, 2% sea mustard, and 0.25% sea mustard sporophyll to the feed, greenhouse gas emissions could be reduced by economic values estimated at 10.8, 11.4, and 15.6 billion KRW, respectively. The findings of this study suggest that the use of seaweed by-products livestock as feed ingredients can generate economic and environmental benefits.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.313-320
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• 2013

Biofilm formed on stainless and copper in water treatment plant was investigated for sixteen weeks. Biofilm reactor was specially designed for this study. It was similar to that of a real distribution pipe. Raw water, coagulated, settled, filtered and treated water were used in this study. The average number of heterotrophic bacteria counts was $1.6{\times}10^4CFU/ml$, $5.8{\times}10^3CFU/ml$, $1.8{\times}10^3CFU/ml$, $1.3{\times}10^2CFU/ml$, 1 CFU/ml, respectively. Density of biofilm bacteria formed on stainless and copper pipes in raw, coagulated and settled water increased above $2.9{\times}10^3CFU/cm^2$ within second weeks while more biofilm bacteria counts were found on the stainless pipe than on the copper pipe. In case of filtered water (free residue chlorine 0.44 mg/L), there was no significant difference in the number of biofilm bacteria on both pipes and biofilm bacteria below $18CFU/cm^2$ were detected on both pipe materials after fifth weeks. Biofilm bacteria were not detected on both pipe materials in treated water (free residue chlorine 0.88 mg/L). According to the results of DGGE analysis, Sphingomonadacae was a dominant species of biofilm bacteria formed on the stainless pipe while the copper pipe had Bradyrhizobiaceae and Sphingomonadaceae as dominant bands. In case of filtered water, a few bands (similar to Propionibacterium sp., Sphingomonas sp., Escherichia sp., and etc.) that have 16S rRNA sequences were detected in biofilm bacteria formed on both pipes after fifth weeks. Stainless pipe had higher species richness and diversity than the copper pipe.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.6-14
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• 2008

Objective of this study was to investigate the residual levels of mercury (Hg) in soil for "Top-rice" area and its uptake into rice plant for making sure food safety as compared to "Top-rice" & common rice produced from 2005 to 2006. Hg was analyzed with the direct mercury analyzer (DMA 80, Milestone, Italy), which implements the US/EPA method 7473. The average concentration of Hg in paddy soil was 0.031 mg/kg, which was below at 1/25-1/65 fold of the threshold levels (concern level 4 mg/kg, action level 10 mg/kg) for soil contamination designated by "The Soil Environment Conservation Law" in Korea. The maximum residue level (MRLs) for Hg residue in the polished rice is not designated in Korea. Therefore, Hg contents in the polished rice of "Top-rice" brand and common rice were compared to other country's criteria. Hg contents in the polished rice of "Top-rice" brand was 0.0018 mg/kg, which was lower at 1/10-1/30 fold than the MRLs, 0.02 mg/kg of China criteria and 0.05 mg/kg of Taiwan criteria, respectively. Hg were 0.02788, 0.00896, 0.00182, 0.00189, 0.00166, 0.00452 and 0.00145 mg/kg in soil, rice straw, unhulled rice, rice hulls, brown rice, rice bran, and polished rice produced in 2006 "Top-rice" area, respectively. For the ratio of Hg as compared to Hg contents in soil, there were 0.321 of rice straw ${\gg}$ 0.162 of rice bran ${\gg}$ 0.068 of rice hulls > 0.065 of unhulled rice > 0.060 of brown rice> 0.052 of polished rice. And, the slope of Hg uptakes was steeped as following order; rice straw ${\gg}$ rice bran ${\gg}$ rice hulls > unhulled rice > brown rice > polished rice. It means that the more slope steeped was the more uptakes. For the distribution of Hg uptaken, there was 83.8% into rice straw, and 16.2% into unhulled rice, 2.8% into rice hulls, 12.4% into brown rice, 3.5% into rice bran and 9.7% into polished rice. Consequently, it was appeared that the Hg contamination in the polished rice should not be worried in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.667-673
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• 2011

There is relatively high vulnerability of soil erosion in slope highland agriculture due to a reclamation of mountain as well as low surface covering in early summer season with high rainfall intensity time. The aim of this study was to evaluate various surface covering methods for reducing soil loss in highland radish cultivation in highland. The experiment was conducted in 17% sloped lysimeter ($2.5m{\times}13.4m$) with 8 treatments including covering with cut rye, sod culture of rye, Ligularia fischeri var. spiciformis Nakai, Arachniodes aristata Tindale, Aster koraiensis Nakai, Festuca myuros L. and mulching with black polyethylene film, and runoff water, eroded soil and radish growth were investigated. Surface covering with sod culture and plant residue, especially cut rye treatment, had lower runoff water than non-covering, whereas black polyethylene film mulching had the reverse. The amount of eroded soil was also lowest in cut rye treatment, $0.3Mg\;ha^{-1}$, and increased in the order of rye sod culture, Ligularia fischeri var. spiciformis Nakai, Aster koraiensis Nakai, Festuca myuros L., Arachniodes aristata Tindale, black polyethylene film, and non-covering, $68.2Mg\;ha^{-1}$. The results showed that surface covering with sod culture or plant residue could be effective for reducing runoff water and soil erosion in the radish field, significantly in cut rye treatment. On the other hand, in sod culture of rye, Aster koraiensis Nakai and Ligularia fischeri var. spiciformis Nakai, radish yields were lower than in the non-covering. Unlike this, covering with cut rye, sod culture of Festuca myuros L. had similar radish yield to the non-covering radish yield. In conclusion, covering with cut rye and sod culture of Festuca myuros L. were beneficial for reduction of soil loss without decreasing in radish yield in highland sloped fields.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.586-593
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• 2014

Newly reclaimed tidal land is known to be in low status of soil fertility. The incorporation of crop residue is an effective method to improve soil properties and fertility in reclaimed saline soils. The objective of this study was to evaluate the efficiency of rice straw (RS) application to improve physico-chemical properties of saline-sodic soil and its contribution to productivity of whole crop barley. Increasing rate of rice straw improved growth parameter related to yield of whole crop barley, which increased tiller number significantly (p<0.05).The yield increased by 15% (F.W) and 9% (D.W) in rice straw-amended plots. The content of soil organic matter (SOM) in the surface soil (0-20cm) with rice straw incorporation increased by 5~9% (RS 2.5~RS 7.5) compared to RS 0, in which the content of SOM decreased after two consecutive cultivations. Rice straw incorporation promoted soil physico-chemical properties and nutrient-availability of the test crop, as indicated in change in soil bulk density, porosity and increased nutrient uptake of plant. Especially, the P content and uptake of whole crop barley increased with increasing the rate of rice straw application. In conclusion, the rice straw application at rates of $5.0-7.5ton{\cdot}ha^{-1}$ in reclaimed saline soils effectively improved soil properties and crop productivity, which has potentials to reduce the loss of chemical fertilizers and facilitate the favorable condition for crop growth under adverse soil condition.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.34-39
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• 2005

There are various crop diseases in green houses that are caused by the cultural environments, especially high temperature and moisture. To solve the forementioned problems, farmers are overusing agricultural chemicals, causing other damages by the chemical residue. In this study, antagonistic bacteria as biological control agents were isolated to produce the environmentally-friendly crops for use in green houses. Eighteen species of antagonistic bacteria were totally isolated from the soil and plants in the Perilla fields, and AK-17 showed the highest activity among the isolates. According to the results of anti-fungal spectrum against several pathogens by AK-17, the antagonism effect of the isolates was remarkable against grey mold rot by Botrytis cinerea, sclerotinia rot by Sclerotnia sclerotiorum, and stem rot by Rhizoctonia solini. To evaluate the biological control effects of the isolates against the major diseases of Perilla, studies were carried out to evaluate the preventive and the curative effects of the diseases throughout the pot experiments. According to the forementioned experiments, the preventive and the curative effects by the isolates against sclerotinia rot were respectively showed as 55% and 92%. For the grey mold rot, those were 40% and 78%, respectively. As to the evaluation of the growth-promoting effect by AK-17, the length and the biomass of the tested plants were increased to 120% and to 164%, respectively. For the leaf numbers and area were respectively increased to 120% and 220%. Furthermore, AK-17 was identified as Burkhoderia sp. according to the results of physiological properties and genetic methods.

• Korean journal of applied entomology
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• v.17 no.2 s.35
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• pp.115-123
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• 1978

Present status on the pesticides production, supply, manufacture and pests control in Korea are summarized. The data in the past several years (1971-76) are analyzed to find out the problems and solutions for the further development of plant protection and pesticide industry in Korea. Since the acreages of crop plantation and the quantities of pesticides uses are already near to the stage of plateau, pesticide formulation with imported technical grade should be modified by local synthesis with imported quality. The government pesticides management act and regulations must be modernized urgently in connection with the synthesis. formulation, tests, registration, quality control. price and supply system as well as the safety use of pesticides. Recommendation concerning acceptable daily intakes(ADI) and residue limits must be established for the strengthning pesticide safety use and plant protection activities as soon as possible. The use of fungicide-insectide mixture in dust formulation must be authorized and practiced immediately for the labor saving and one-hit cooperative mass control of rice disease and insect pests, especially. At present, serious considerations on pesticide safety use and integrated pest control are strongly urged to help the farmers, to save the industries and to keep the nature as it is required.