• Journal of Applied Biological Chemistry
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• 제63권3호
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• pp.275-282
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• 2020

농약의 안전범위 확대와 Positive List System이 시행되면서 토양 중 농약 안전관리방안에 대한 관심이 증가하였다. 토양 중 농약 안전관리를 위해서는 농경지 내 잔류량 저감화와 농산물 전이 저감방안이 대표적이다. 이번 연구에서는 토양 중 농약 안전성 향상을 위해서 시험농약은 azoxystrobin, procymidone 및 tricyclazole을 사용하였고, 저감화 방법으로 바이오차와 생석회를 이용했다. 실험방법은 토양에 바이오차와 생석회를 토양(15 cm) 무게 기준 0, 0.5, 1.0, 2.0%를 첨가한 후 0, 10, 20, 35, 50일 동안 경시적 잔류양상을 확인하였다. 바이오차 처리에 의한 작물 흡수·이행 저감효과 구명을 위해 얼갈이 배추의 뿌리, 잎, 줄기로 나뉘어 잔류량을 분석했다. 실험결과 생석회 처리할 때 2.0% 처리할 때 azoxystrobin (36-96%), procymidone (40-117%), tricyclazole (26-83%) 저감효과가 있었다(p <0.05). 바이오차 처리할 때 1.0% 이하 처리할 때 토양 중 잔류량 저감효과는 없었다. 그러나 바이오차 2.0%처리한 토양에서 재배한 얼갈이 배추의 뿌리(0.11-1.62 mg/kg), 잎(0.05-0.29 mg/kg), 줄기(0.06-0.1 mg/kg)에서 전이량이 감소되었다(p <0.05). 생석회와 바이오차는 농업에 활용성이 높은 토양개량제로 농약 안전관리방안에 이용할 수 있는 방법으로 판단된다.

• 한국초지조사료학회지
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• 제17권3호
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• pp.293-304
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• 1997

A field experiment was conducted at the forage experimental plots, Seoul National University, Suweon h m 1995 to 1996 to determine the effect of legume residues as a N source and N fertilizer on corn (Zea mays L.) silage yield, N uptake, and availability of inorganic N in the soil. Corn was grown following (i) red clover (Trifolium pratense L.), (ii) crimson clover (Trifolium incarnatum L.), (iii) alfalfa (Medicago sativa L.) and (iv) winter fallow. The plots were split into two rates of fertilizer N (0 and 90kg Nlha) in a split-plot experimental plan. Compared with fallow treatment, legumes depleted soil water in the surface 15cm at corn planting by 17 to 26%. As a result, corn emergence was markedly delayed with legume residues by 8 to 11 days. Corn silage DM yield was significantly reduced in the presence of legume residues by 2.0 to 3.4 and 1.5 to 2.5 tonlha compared with winter fallow treatment at 0 and 90kg fertilizer Nlha, respectively, but no significant difference in the corn DM yield was found between legume residue treatments. There was an overall tendency for increased corn yields with 90kg fertilizer Nlha compared to Okg fertilizer Nlha, although not all yield increases were significantly greater. The corn yield response to applied N suggests that a source of N from legume residues was not sufficient for a succeeding corn crop. There was significantly more N (P

• 한국작물학회지
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• 제48권6호
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• pp.452-459
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• 2003

땅콩의 완전종실생산을 위해서는 150-180일의 생육기간이 소요되나 풋땅콩용으로 출하하면 총생육일수를 20-30일 정도 단축할 수 있을 뿐만 아니라 수확후 지상부 잔존유기물도 많이 남게 된다. 땅콩재배기간 단축에 따른 풋땅콩-무, 보리, 마늘과의 relay-cropping system에서 수확후 잔존 유기물의 토양환원 유무에 따른 각 작물들의 생육과 토양의 이화학성, 미생물상의 변화양상에 관한 기초자료를 얻어 남부지역 풋땅콩 안정생산기술을 확립하고자 수행한 시험결과를 요약하면 다음과 같다. 1. 작부체계별 시험후 토양경도는 풋땅콩 단작에서 가장 높았고, 토양 공 극율은 풋땅콩 단작 대비무, 보리, 마늘과 2모작 작부체계 처리에서 높 았으며 수확후 잔존유기물을 환원하였을 때 더욱 높아졌다. 2. 단작의 풋땅콩은 보리, 마늘과 2모작 작부체계상에서 재배된 풋땅콩에 비하여 도복 및 병 발생이 심하였다. 작부체계별 풋땅콩 수량은 단작에 비하여 풋땅콩-보리 및 풋땅콩-마늘 작부체계에서 증수하였으나, 유기 물 환원에 따른 수량 차이는 없었다. 3. 풋땅콩 후작의 마늘과 보리의 수량은 유기물 환원에 의하여 증대되었다. 4. C/N율이 높은 보리짚의 토양 환원에서 질소무기량이 증가하였고, 풋땅콩-보리와 풋땅콩-마늘의 작부체계에서 Pseudomonas spp.균 및 Trichoderma spp.균의 밀도가 높아져 풋땅콩의 친환경 작부체계로 추정되었다

• 한국환경농학회지
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• 제24권1호
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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.

• 한국환경농학회지
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• 제36권3호
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• pp.184-192
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• 2017

BACKGROUND: This study was performed to evaluate the residue dissipation of boscalid and spinetoram on crown daisy and sweet pepper affected by the morphology of the crop. The half-lives and dissipation rate constants for boscalid and spinetoram on crown daisy and sweet pepper were calculated. And then lower limit of 95% confidence interval for dissipation rate constant could be used to propose the pre-harvest residue limit. METHODS AND RESULTS: The pesticide products diluted according to the pesticide label were applied one time on crown daisy and sweet pepper at 2 field sites, respectively. Initial concentration of boscalid and spinetoram on crown daisy after application were in the range of 72.80~117.15 mg/kg and 2.82~4.67 mg/kg, respectively. And Initial concentration of boscalid and spinetoram on sweet pepper were in the range of 1.58~1.62 mg/kg and 0.10~0.21 mg/kg, respectively. Boscalid and spinetoram for crown daisy dissipted below the maximum residue limit(MRL) at 10 and 2 days after application, respectively. All residues concentration of boscalid and spinetoram for sweet pepper below the MRL at 0 day after application. The half-lives based on dissipation rate constant for boscalid and spinetoram on crown daisy were 4.2~4.9 days and 3.0~2.4 days respectively. And the half-lives for boscalid and spinetoram on sweet pepper were 6.7~7.0 days and 2.8~4.0 days respectively. CONCLUSION: The difference in initial concentration of boscalid and spinetoram among crop commodities were due to different crop morphology with larger surface areas. This study was suggested that pre-harvest residue limit would be calculated from lower limit of 95% confidence interval for dissipation rate constant and would be useful to protect consumers by controlling the pesticide residues in crop.

• 한국작물학회지
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• 제48권5호
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• pp.402-406
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• 2003

Greenhouse and laboratory studies were conducted to determine the allelopathic potentials of extracts or residues from sweet potato (Ipomoea batatas L. (Lam). The extracts applied on filter paper in a Petri dish bioassay significantly inhibited root growth of alfalfa. Aqueous leachates at 40g dry tissue $\textrm{L}^{-1}$ (g $\textrm{L}^{-1}$) from leaves showed the highest inhibition against alfalfa, and followed by stems and roots. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. The effect of residue incorporation into soil on seedling growth of com, soybean, barnyard grass and eclipta was examined in the greenhouse, and results showed that the leaf residues at 200g $\textrm{kg}^{-1}$ by plant parts inhibited shoot dry and root dry weights of test plants by 60-80%. By means of HPLC, causative allelopathic substances present in plant parts of sweet potato "Sinyulmi" were identified as coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid, and chlorogenic acid. Total content of these compounds for leaves extracts were detected as the greatest amount in EtOAc fraction, especially trans-cinnamic acid was the greatest component. These results suggest that sweet potato plants have herbicidal potentials, and that their activities exhibit differently depending on plant parts.ant parts.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권1호
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• pp.199-204
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• 2009

The newly cloned Bacillus thuringiensis cry1-5 gene showed high activity to both Plutella xylostella and Spodoptera exigua, while cry1Ac only showed high activity against P. xylostella but low to S. exigua. Through the alignment of amino acid sequences between Cry1Ac and Cry1-5, we found 12 different residues in domain I (6 residues) and domain II (6 residues). In this study, the modified cry1Ac gene, which is constructed according to a crop-preferring codon usage, was used as a template to construct mutant B. thuringiensis cry1Ac genes based on cry1-5 gene through multi site-directed mutagenesis. Total 63 various mutant cry genes were obtained at 12 positions randomly. Among them, ten mutant cry genes, whose domain I was totally converted and domain II was randomly, were selected to express in baculovirus expression system as a polyhedrin fusion form. The recombinant proteins were 95 kDa in size and were stably activated as 65 kDa by trypsin. The expressed mutant Cry proteins were applied to bioassays against P. xylostella and S. exigua. All mutants showed high insecticidal activity both to P. xylostella and S. exigua similar to cry1-5. These results suggest that these mutant cry genes might be expected of desirable cry genes for introduction to transgenic crops.

• 한국농공학회논문집
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• 제57권6호
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• pp.9-20
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• 2015

The demand of renewable energy is expected to grow in the long run in spite of current stable lower oil prices. Energy consumption for heating in horticulture greenhouse is large and affects the profits of the farms. This study analyzed the availability of biomass in rural area and proposed the strategies for utilizing the biomass for greenhouse heating. Data reveal the annual average fuel consumption in greenhouses is about 78 TOE/ha. Considering biomass resource in rural areas, agricultural residues are not sufficient to meet the biomass demand from greenhouses. Therefore it is recommended to secure further biomass including wild herbaceous biomass and woody biomass from forest. Based on the conditions of biomass gasification equipment investment and fuel prices, maximum allowable price of biomass turned out about 100,000 KRW/t to be competitive to kerosine. Biomass supply chain should be established for facilitating biomass trading between biomass consumers and biomass producers such as farmers who provide crop residues. An online trading system is an example of the system where consumers who utilize biomass make payments to suppliers and get the information about the biomass. Intermediate collection storages are required to store biomass from distributed sources. Operation of biomass heating systems in demonstration greenhouses is necessary to get information to refine and further develop commercial biomass heating systems. Relatively large greenhouses are desirable to have biomass heating systems for economic viability. The location of the greenhouse farms should be selected within the area where enough biomass resources are available for feeding the biomass facility.

• 한국환경농학회지
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• 제41권1호
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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.

• 농약과학회지
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• 제14권1호
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• pp.37-48
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• 2010

HPLC-UVD/MS를 이용하여 농산물 중 diacylhydrazine계 살충제인 methoxyfenozide, chromafenozide 및 tebufenozide의 잔류 분석법을 확립하였으며, 대상 농산물은 현미, 콩, 사과, 배추 및 고추를 선정하였다. 시료에 acetone을 가하여 추출된 methoxyfenozide, chromafenozide 및 tebufenozide 성분을 dichloromethane 분배법과 florisil 흡착 크로마토그래피법으로 정제하여 HPLC-UVD/MS 분석대상 시료로 하였다. 대상 농약의 동시분석을 위한 최적 HPLC 분석조건을 확립하였으며, 분석대상 농약의 분석정량한계(MQL)는 0.04 mg/kg 이었다. 각 대표 농산물에 대해 정량한계의 10 및 50배 수준에서 회수율을 검정한 결과 모든 처리농도에서 89.0~104.8% 수준을 나타내었으며, 반복 간 변이계수(CV)는 최대 3.9%를 나타내어 잔류분석 기준인 회수율 70~120% 및 분석오차 10%이내를 충족시키는 만족한 결과를 도출하였다. 본 연구에서 확립된 diacylhydrazine계 살충제인 methoxyfenozide, chromafenozide 및 tebufenozide의 HPLC-UVD 분석법은 검출한계, 회수율 및 분석오차 면에서 국제적 분석기준을 만족할 뿐만 아니라, LC/MS SIM을 이용한 분석법 또한 회수율이 우수하여 확인 및 정량법으로 사용가능한 방법이었다.