• 농약과학회지
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• 제19권3호
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• pp.185-194
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• 2015

본 연구는 대부분의 농작물 중 살균제 carpropamid의 잔류량을 정밀하게 분석할 수 있는 단성분 분석법을 개발하고자 하였다. 대표 농작물로 배추, 사과, 현미, 고추를 선정하였으며, 균질화된 농작물 시료 중 carpropamid 잔류분을 acetone을 이용하여 진탕 추출하고 액-액 분배법과 Florisil 크로마토그래피법을 통해 정제하였다. C8 및 C18 역상컬럼이 장착된 액체크로마토그래피를 이용해 UV 220 nm 파장에서 carpropamid를 정량분석하였으며, 질량분석기를 통해 잔류분을 확인하였다. 본 분석법을 통한 carpropamid의 기기정량한계는 2 ng으로 분석정량한계는 0.02 mg/kg이었다. 표준용액을 3수준 (분석정량한계 ${\times}1$, ${\times}10$, ${\times}100$), 3반복으로 무처리 시료에 첨가하고 본 분석법의 회수율을 산출한 결과 84~112%이었으며, 농산물 종류에 상관없이 반복 간 분석오차는 10% 미만으로 우수한 정밀성을 보였다.

• Applied Biological Chemistry
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• 제27권
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• pp.3-17
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• 1984

Anaerobic digestion has recently attracted all over the world and Korea also shows no exception. The major benefits of anaerobic digestion are energy production, water pollution control, pathogen reduction and effective manure production. In Korea it was recognized in late sixties that there was a positive need to find alternative energy for farmers household. The main traditional energy sources in rural area were crop residues and forestry products. Therefore Office of Rural Development through its Rural Guidance Bureau disseminated about 29,000 household biogas units from 1969 to 1975 to provide cooking fuel for farmers household and to improve the mode of farmers living standards. The units were welcomed by farmers at that time. Now, however, most of them are not using due to a number of reasons associated with cold winter and some techno-economical problems (in those day, fossil fuel was quite expensive to compare with other prices and since then farmers income was quickly increased). The author studied on bag type household biogas plant to solve some technical problems of existing household biogas plants, but this also has little appeal for the farmers. From 1977 author studied on village scale biogas plant with two pilot plants. From the viewpoint of energy production, COD removal, kill rate of pathogen and fertilizer value, the results obtained from the experiments were quite promising, but the construction cost of the village scale biogas plant was too high for the farmers in Korea. To find most suitable biogas plant for farmers in Korea through the simplifying the biogas digester, the author developed batch-load biogas plant. By feeding coarse crop residues and manures, total solids concentrations of the batch-load biogas plant are about 28 percent which is much higher than continous digester of 5-8 percent. The batch-load biogas plant was welcomed by many farmers in Korea when it was reported on TV and newspapers. The plant was disseminated 154 units in 1982, 766 units in 1983 and 812 units in 1984 as a promissing project. Besides these biogas plant experiments, studies were also conducted 1) to determine gas production rate with agricultural wastes, 2) to evaluate the effect of loading rate, dilution, retention time on biogas production, 3) to project the amount of potencial energy from agricultural wastes.

• 한국식품과학회지
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• 제37권3호
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• pp.492-497
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• 2005

잔류농약과 관련된 포장시험 및 기준설정에는 데이터의 변이성이 뒤따르기 때문에 여러가지 허수(default value)를 채택하고 있다. 잔류농약 분석상의 오차는 $RSD\;{\pm}30-40%$에 이르고 있어 잔류허용기준(MRL)은 이것을 감안하여 geometric progression에 따르고 있다. 과거 5년간(1998-2002)의 JMPR 보고서에 의하면 포장시험에서의 변이계수(중앙치에 대한 최고치 비율)은 LOQ 이상에서의 486개 농약-작물 조합에서 평균 3.8배에 이르고 있고 기준설정시의 절상효과는 최고치의 1.5배로 나타났다. 한편 국내에서 기준설정시의 규제마진(최고잔류치에 대한 최대잔류기준의 비율)은 822개 농약-작물 조합에서 평균 4.8배로 나타났다. 이와 같은 규제마진을 적용하는 경우 국내의 잔류기준은 Codex보다 높게 설정될 것으로 예상된다. 앞으로 농약잔류 허용기준의 설정에서 Codex기준과 국내기준의 조화를 이루기 위한 검증작업이 이루어져야 할 것이다.

• 한국유기농업학회지
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• 제13권2호
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• pp.211-221
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• 2005

This experiment was conducted to evaluate the effect of animal slurry on nitrogen uptake of hairy vetch and growth of chinese cabbage in cropping system. Hairy vetch was seeded on September 20 in 2003 . We examined the effect of cover crop(hairy vetch (Vicia villosa Roth) and slurry application(0, l00, 200kg N/ha) on yield and N uptake. Dry matter yield and nitrogen uptake of hairy vetch were measured. The chinese cabbage succeeding cover crop was harvested in 2004. The nitrogen uptake of hairy vetch was 84, 121, 148kg N/ha respectively, when the slurry application was 0, 100 and 200kg N/ha. In addition. N uptake of hairy vetch at the plot of 100kg and 200 kg N/ha slurry were 44% and 76% higher than that of the plot without slurry application respectively. Slurry application of hairy vetch could increase nitrogen uptake by application of green manure at the harvesting time. the content of organic matter and P-content of soil with hairy vetch plot was higher than that of fallow plot due to inhibition of soil erosion. The organic matter levels tend to improve with the addition of hairy vetch. Hairy vetch could improve soil quality by reducing erosion compared with bare fallow. The green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage. The hairy vetch residues decomposed rapidly releasing half of their residues within 40 days after burial. The yield of chinese cabbage was 90% in the plot of manure of hairy vetch compared with chemical fertilizer. The yield in the plot treated with green manure of hairy vetch and 50% of chemical fertilizer was reduced 5% less than that of chemical fertilizer. Therefore, it was estimated that the green manure of hairy vetch-chinese cabbage cropping system could reduce nitrogen chemical fertilizer as much as 84~148kgN/ha. the green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage.

• 한국환경농학회지
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• 제28권4호
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• pp.333-339
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• 2009

Various cultural practices have been promoted as management options for enhancing soil quality and health. The use of soil management methods can cause changes in fertility by affecting soil chemical properties. This study aimed to evaluate interactions between soil chemical properties and soil management methods in protected cultivation, and to classify soil management methods that similarly affect soil chemical properties. Water-logging and irrigation reduced soil pH and available $P_2O_5$ content. Application of animal manures has a positive effect on levels of organic matter, Av.$P_2O_5$, K, Zn, and Cu. The electrical conductivites tened to be low in the application of organic amendments, including rice and wood residues. Deeper plowing caused a reduction in Ca content. Practicing soil nutrient-considering fertilization and fertigation did not exert an influence on nutrient element contents. In a cluster analysis of the soil management methods according to major nutrients, low similarities were found with deeper plowing and crop rotation with rice in comparison with other practices. In a cluster analysis by minor nutrient characteristics, crop rotation and application of animal manures and rice residues were linked at a high Ward's distance, while other practices were found to be relatively low distinct. Each soil management method has a similar or different effect on soil chemical properties. These results suggest the necessity of establishing limits and standards according to the effects of soil management methods on soil chemical properties for economic soil practices.

• 한국약용작물학회지
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• 제21권2호
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• pp.124-129
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• 2013

This study was conducted to investigate the residual contents of sulfur dioxide ($SO_2$) in commercial medicinal herbs in Korea in 2012. Among a total of 136 samples of 16 different kinds of herbs, 86 samples (15 Kinds) were domestic, and 50 samples (14 Kinds) were imported. Sulfur dioxide in the samples was measured by a modified Monier-Williams method. Of the 136 samples, 17 samples (12.5%, 6 Kinds) failed to meet the regulations for sulfur dioxide residues of KFDA in medicinal herbs. Among 17 unsuitable samples, 7 samples (8.1%, 3 Kinds) were domestic, and 10 samples (20.0%, 6 Kinds) were imported. The highest amount of sulfur dioxide residues was 3,167.94 mg/kg (Lycii Fructus) in the domestic samples. The detection frequency of sulfur dioxide by medicinal herb parts used, Rhizoma 25.7%, Flos 20.0%. Cortex 12.5%, Radix 15.3%, Fructus 7.6%, p-value 0.011. This results will be used as a basic data for the future legislation on the quality estimation and safety of medicinal herbs.

• 한국약용작물학회지
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• 제18권5호
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• pp.345-360
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• 2010

This study was conducted to investigate the content of sulfur dioxide residues in medicinal herbs in Seoul in 2009. Sulfur dioxide in the samples were determined by Monnier-Williams's modified method. A total of 1,821 samples of 205 different types of herbs were collected from Kyung-Dong Herb markets and Oriental medicine hospitals in Seoul. Of these samples, 642 samples were domestic, and 1,179 samples were imported. Of the 1,821 samples, 61 (3.3%, 31 types) failed to meet the regulations for sulfur dioxide residues of KFDA in medicinal herbs. Among these 61 unsuitable samples, 17 (7 types) were domestic, and 44 samples (26 types) were imported. The content of sulfur dioxide in the domestic medicinal herbs ranged from 0 to 809 mg/kg, while those in imported medicinal herbs ranged from 0 to 4,481 mg/kg. Approximately 84.6% of the samples contained less than 10 mg/kg of sulfur dioxide and about 10.0% of samples contained more than 30 mg/kg of sulfur dioxide.

• 한국토양비료학회지
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• 제47권2호
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• pp.120-126
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• 2014

An accurate analysis of nutrient balance in different cropping systems is necessary for improving soil fertilities, causing higher crop yields and quality. This study was carried out to investigate the nutrient balance, changes in soil properties, and their effects on crop yield in long-term field cultivation under mono- and rotation-cropping systems (MCS and RCS, respectively). The analytical results of the soil properties showed that the application of mineral fertilizers alone in the MCS leads the reduction of soil CEC, exchangeable Ca, and microbial biomass C and N. Compared with the MCS of soybean, the RCS of soybean and barley significantly improved the soil properties, which increased crop yield. It might be due to the barley residue added to the RCS soil. Mean nutrient balances for 4 years were -55.9 kg N, +34.7 kg $P_2O_5$, and -0.3 kg $K_2O$ $ha^{-1}$ for the MCS and +19.7 kg N, +107.4 kg $P_2O_5$, and -48.6 kg $K_2O$ $ha^{-1}$ for the RCS, respectively. These nutrient imbalances mean that conventional fertilizer recommendations were inadequate for maintaining soil nutrient balance. From these results, we can conclude that the crop rotation may change comprehensive physical, chemical, and biological soil properties. These changes could affect the nutrient balance and then the crop yield.

• 한국환경농학회지
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• 제33권4호
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• pp.414-418
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• 2014

BACKGROUND: Benzene, toluene, ethylbenzene and xylene (BTEX), which are volatile aromatic hydrocarbons and main constituents of gasoline, are neuro-carcinogenic organic pollutants in soil and groundwater. Korea Ministry of Environment has established the maximum permissible level of BTEX in arable soil to 1, 20, 50 and 15 mg/kg, respectively. METHODS AND RESULTS: To understand an arable soil contamination by BTEX, we collected 92 samples from the arable lands around oil reservoir, and analyzed the BTEX residue using a GC-MS with head-space sampler. A linear correlation between BTEX concentration and peak areas was detected with coefficient correlations in the range of 0.9807-0.9995. The method LOQ of BTEX was 0.002, 0.014, 0.084, and 0.038 mg/kg, respectively. Recoveries of 0.5 mg/kg BTEX were found to be 73.7-96.9%. The precision was reliable since RSD percentage (0.7-7.5%) was below 30, which was the normal percent value. Also, BTEX in all samples were detected under the LOQ. CONCLUSION: These results showed that the investigated arable soils around airport and oil reservoir in Korea were not contaminated by oils.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1998년도 21세기 한반도 농업전망과 대책(한국작물학회.한국육종학회 공동주관 심포지움 회보)
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• pp.288-312
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• 1998

In Korea, chemical fertilizers and agricultural chemicals have had a significant impact on food production and these are today thought to be an indispensable part of modern agriculture. On the other hand, socioeconomical and IMF and WTO status in Korea are constant reminders of the vulnerability of our fossil fuel dependent agriculture. A new crop production system to improve economic, environmental and production efficiency must be exploited. Our particular concern has been given to an integrated cropping system involving recycling of crop residues, soil and N management, biological N fixation and multipurpose legumes. As a new integrated crop production system, a no-till direct-sown rice-vetch relaying cropping system has been proposed in this paper. The formulation of this system is based on the conception that N fertilizers being neither limitlessly available nor affordable, the current high-input crop production systems have produced troubled results severe labour shortage ill rural areas, balance of payment, environmental degradation and reduction of human health far exceed economic concerns. A natural and logical consequence is that long-term sustainability of agricultural systems must rely on the use and effective management of internal resources. Based on the information obtained throughout a series of experiments last years we have proved that the no-till direct-sown rice-vetch relaying cropping system dictates biological alternative which can augment, and in some cases replace, N fertilizers. Comprehensive discussions were made for the proposed system and it concluded that the system can offer an economically attractive and ecologically sound means of reducing external nitrogen input and improving the quality and quantity of internal resources, and consequently improving the farmers as well as the national returns.