• 한국약용작물학회지
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• 제22권2호
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• pp.140-146
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• 2014

This study was carried out to investigate the difference of the content of soil chemical components and growth characteristics in six years old ginseng affected by application of decomposing plant residues in paddy-converted field. The results show that aerial parts of ginseng are no difference between press cake (PC) 200 kg/10a and control but subterranean parts of ginseng PC 200 kg/10a, especially quantity related root fresh weight and tap root diameter, are statically about 1.6 times heavier and about 1.2 times thicker than the ginseng control. Furthermore, the survival rate of PC 200 kg/10a is 67.1% rise significantly compare with the control 50.7%. But compared with the PC 200 kg/10a and the PC 400 kg/10a, ginseng root growth and survival rate of PC 400 kg/10a get worse and that increase physiological disorder occurrence rate than PC 200 kg/10a. Even though there are no significant differences between the ginseng of decomposing plant residues except press cake treatment and the ginseng of control in growth characteristics, it does tend to increase the survival rate and decrease the physiological disorder occurrence rate in most fertilizer treatment except for RSC 2 ton/10a, RSC 4 ton/10a and RH 4 kL/10a. Noted that EC is highly increased and exceeded 1.7 ds/m in RSC 2 ton/10a, RSC 4 ton/10a and RH 4kL/10a. It would be caused physiological disorder in many ways and affected ginseng growth characteristics, survival rate.

• 한국잡초학회지
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• 제31권2호
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• pp.175-182
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• 2011

헤어리벳베치 잔류물의 제초효과와 작물안전성에 미치는 영향을 연구하기 위하여 헤어리벳치 잔류물을 온실, 비닐하우스 및 포장조건에서 복토처리하여 실험을 수행하였다. 온실조건에서 헤어리벳치와 토양(60:40) 혼합처리에서 90% 이상 방제효과를 나타냈으며 90:10 혼합비율에서는 100% 고사되었다. 제초효과는 일반적으로 화본과잡초에 비해 광엽잡초에서 높은 경향을 나타났다. 헤어리벳치 잔류물은 비닐하우스에서는 갈퀴덩굴, 명아주, 질경이와 소리쟁이에서 우수한 제초효과를 보였고, 포장조건에서는 갈퀴덩굴, 소리쟁이와 털비름에서 제초효과가 높았다. 헤어리벳치 혼합비물(60:40)을 0.5~0.75cm 깊이로 복토하였을 때 비닐하우스와 포장조건에서 약 80% 이상의 제초효과를 나타냈다. 헤어리벳치 잔류물은 상추를 제외한 옥수수, 콩, 무, 고추, 배추, 오이, 토마토, 들깨에서 모두 작물의 생장에 영향이 없었다.

• 한국환경농학회지
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• 제29권2호
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• pp.165-175
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• 2010

A gas chromatographic (GC) method was developed to determine residues of captan, folpet, captafol, and chlorothalonil, known as broad-spectrum protective fungicides for the official purpose. All the fungicide residues were extracted with acetone containing 3% phosphoric acid from representative samples of five agricultural products which comprised rice, soybean, apple, pepper, and cabbage. The extract was diluted with saline, and dichloromethane partition was followed to recover the fungicides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were then determined by gas chromatography using a DB-1 capillary column with electron capture detection. Reproducibility in quantitation was largely enhanced by minimization of adsorption or thermal degradation of analytes during GLC analysis. Mean recoveries generated from each crop sample fortified at two levels in triplicate ranged from 89.0~113.7%. Relative standard deviations (RSD) were all less than 10%, irrespective sample types and fortification levels. As no interference was found in any samples, limit of quantitation (LOQ) was estimated to be 0.008 mg/kg for the analytes except showing higher sensitivity of 0.002 mg/kg for chlorothalonil. GC/Mass spectrometric method using selected-ion monitoring technique was also provided to confirm the suspected residues. The proposed method was reproducible and sensitive enough to determine the residues of captan, folpet, captafol, and chlorothalonil in agricultural commodities for routine analysis.

• 한국환경농학회지
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• 제40권2호
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• pp.99-107
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• 2021

BACKGROUND: Pesticide uptake by a rotational crop after being used for the primary crop is a potential cause of violation against the pesticide law if the pesticide is not registered in the secondary crop. This study was conducted to investigate the plant back interval (PBI) of fluopyram for the rotational cultivation of radish. METHODS AND RESULTS: Two experimental approaches were performed the evaluation of residues in radish cultivated successively in soil 16 days after treated with fluopyram onto pepper plant (T1) and in radish cultivated in bare soil treated with fluopyram at PBI 30 and PBI 60 days (T2). A modified QuEChERS method coupled with LC/MS/MS analysis showed good linearity of matrix-matched standard calibration of fluopyram with the coefficient values of determination greater than 0.995. Recovery values at levels of 0.01, 0.05, 0.1 and 0.25 mg/kg ranged from average 84.9 to 117.6% with RSD less than 10%. Fluopyram residues in radish harvested from T1 and T2 were found as levels less than maximum residue limit. CONCLUSION: This study suggests 20~30 days as the PBI of fluopyram for the rotational cultivation of radish in the greenhouse soil treated with fluopyram used for pepper as the primary crop.

• 한국환경농학회지
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• 제28권4호
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• pp.397-402
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• 2009

In Korea, salt stress is one of the major problems limiting crop production and eco-environmental quality in greenhouse soil. The objective of this study was to evaluate the effectiveness of organic residues (Chinese milk vetch, maize stalk, rice straw, and rye straw) for reducing salt activity in greenhouse soil. Organic residues was incorporated with salt-accumulated soil (EC, 3.0 dS $m^{-1}$) at the rate of 5% (wt $wt^{-1}$) and the changes of electrical conductivity (EC) was determined weekly for 8 weeks under incubation condition at $30^{\circ}C$. The EC, microbial biomass carbon (MBC), and water soluble ions in soil was strongly affected by C/N ratio of organic residues. After 8 weeks incubation, the concentration of water soluble $NO_3{^-},\;Ca^{2+}$, and $Mg^{2+}$ was significantly decreased in organic residues having high C/N ratio (maize stalk, rice straw, and rye straw) incorporated soil compared to organic residues having lower C/N ratio (Chinese milk vetch) incorporated soil. The EC value in Chinese milk vetch incorporated soil was higher than control treatment. In contrast, maize stalk, rice straw, and rye straw amended soil was highly decreased the EC value compared to control and Chinese milk vetch applied soil after 4 weeks incubation. Our results indicated that incorporation of organic residues having high C/N ratio (>30) could reduce salt activity resulting from reducing concentration of water soluble ions.

• 한국환경농학회지
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• 제40권3호
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• pp.203-210
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• 2021

BACKGROUND: Pesticides can persist in soil due to multiannual uses. To decrease the concerns for potential carry-over of such residues from treated soil during preceding crop cultivation to non-target crops grown in rotation, an uptake study of procymidone was conducted under the actual cultivation conditions in Korea. METHODS AND RESULTS: Procymidone was sprayed twice by foliar application with recommended and double dose according to the safe use guidelines for Korean cabbage up to 14 days before harvest. Arable land was kept fallow for 4 days after harvesting Korean cabbage, and spinach was cultivated as a succeeding crop. Initial residues in soil were 5.670-14.175 mg/kg that were degraded to 3.098-4.555 mg/kg until harvest of Korean cabbage, and then persisted at 1.026-1.300 mg/kg by spinach harvest. Procymidone residues in edible part of succeeding crops from soil uptake were in range of 0.020-0.048 mg/kg for recommended dose and 0.055-0.116 mg/kg for double dose. Root concentration factor (RCF) values of procymidone at different concentration ranged from 0.053 to 0.123, and translocation factor (TF) ranged from 0.176 to 0.768 for spinach. The value of TF was higher than RCF, indicating that the capability of translocation to shoot was relatively higher than that of root uptake and accumulation. CONCLUSION: Procymidone applied on Korean cabbage can be carried-over to spinach and detected at a level similar to MRL (0.05^T mg/kg). Therefore, this study suggests a follow-up study for establishment of plant back interval (PBI) of succeeding crops reflecting the actual agricultural conditions as this study.

• 한국환경농학회지
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• 제38권3호
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• pp.173-184
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• 2019

우리나라 주요 하천수의 사용 중인 농약의 실태조사를 위해서 전국 50지점을 선정 후, 1차 (농약 사용 비성수기, 4/5월)및 2차(농약 사용 성수기, 8/9월)로 나누어 실시를 하였다. 하천수 모니터링 결과 농약 1차, 2차 때 각각 11, 28개의 농약이 검출되었다. 농약은 7월부터 기온이 올라가면서 병 해충 방제를 위해 농약사용량이 증가하기 때문에 2차시기에 농약검출량이 증가한 것으로 판단된다. 검출빈도 10회 이상의 농약은 1차 시기에는 butachlor, carbofuran, 2차 시기에는 tricyclazole, azoxystrobin, chlorantraniliprole, thiamethoxam, isoprothiolane 5종이었다. 검출농약은 대부분 수도용 농약으로 검출비율은 90%, 81%로 높게 나타났다. 이러한 이유는 하천수 중 잔류농약은 논에서 사용된 농약이 비산되어 직접적으로 하천수로 잔류되기도 하며 또는 토양에 잔류된 농약이 논물을 방류하면서 하천수로 이동하기 때문이다. 네 개의 scenario를 이용하여 위해성 평가를 진행하였을 때, butachlor, carbofuran, carbendazim, chlorantranilprole 및 oxadiazon에서 잠재위해성 및 위해성이 있는 것으로 평가되었다. 추후 모니터링 연구와 수서생물에 위해성이 나타나지 않는 농도 이하로 잔류할 수 있도록 농약안전사용기준 설정연구가 필요할 것으로 보인다.

• 유기물자원화
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• 제16권4호
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• pp.50-56
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• 2008

본 연구는 볏짚, 보리짚, 밀짚 및 유채대를 이용한 액화공정을 적용하여 중유를 생산할 때 그 생산량을 비교하였다. 촉매제로 $K_2CO_3$, NaOH 및 KOH와 같은 촉매제를 사용하여 반응온도 $320^{\circ}C$에서 10분간 반응시켰다. 액화공정 시스템은 외부전기화로, 교반기 및 5,000ml 반응기로 구성되어 있다, 반응기에 식물체 잔사 160g, 증류수 2,000ml 및 촉매제를 혼합하였으며, 촉매제량은 식물체 잔사량의 10%(wt/wt)를 투입하였다. KOH 촉매제를 사용하며, 보릿짚을 이용할 경우 바이오매스 투입량과 비교하여 최고 중유 생산량은 29%였다. 바이오매스 발열량과 비교하여 식물체 잔사로부터 전환된 중유의 발열량은 55~66% 범위이었다. 밀짚으로부터 전환된 중유의 발열량은 약 6190 kcal/kg으로 가장 높게 관측되었다.

• 농업과학연구
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• 제43권4호
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• pp.634-640
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• 2016

The objective of this study was to evaluate the effectiveness of using HR-GC/MS for the rapid screening of dieldrin residues in soils. Persistent organic pollutants (POPs) of organochlorine pesticides such as dieldrin, were analyzed in sedimentary rock and granite rock collected from greenhouses, Niigata, Japan. Dieldrin remains in Japanese farming soils, more than 40 years after their use as insecticides was prohibited. The averages in soil moisture ranged from 2.79% to 7.20% in soils derived from sedimentary rock and from 25.59% to 31.40% in soils derived from granite rock. Mean concentrations of dieldrin residues in sedimentary rock and granite rock were $39.7ng\;g^{-1}$ and $40.51ng\;g^{-1}$, respectively. Dieldrin residue was detected at a slightly higher concentration in granite rock than sedimentary rock samples. There was no consistency between the two soils or between surface and subsurface soils. The coefficients of variation of the two soils were 10.6% and 8.7%, respectively. These results suggest that our high-resolution mass spectrometry detector (HR-GC/MS) is effective at analyzing residual organochlorine pesticides in soil. In order to increase the precision and sensitivity for chemical analysis of POPs, high-resolution gas chromatography coupled with a HR-GC/MS is highly recommended.

• 한국유기농업학회지
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• 제6권2호
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• pp.127-140
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• 1998

Organic farming excludes any use of the herbicide. The present paper reviews what can be done for effective weed control with existing weed control technology by farmers crop-ping paddy rice, field crops, vegetables, and fruit trees. If condition of the crop-land-al-lows diversified rotational use of the paddy land as paddy and upland field would minimize weed problem. Practising this is limited in acreage due to extremely limited governmental investment to the land for the purpose. Secondly, rotation of crops in the upland field breaking life cycles of various weeds adapted to each crop should reduce the weed problem. This is also limited as only a few crops are making the farmer profitable. In addition climate and tolerance of crops to high and low temperature. Monsoon rains and poor drainage restrict the freedom of choice. For any crop land year-round multiple cropping in denser planting shall lessen the weed problem, this multiple cropping practiced by 1960s has been abandoned due to laborshortage and increased production cost. Deep flooding the rice is impractical at present in Korean. Mulching crop with transparent, black , or combinated polyethylene sheet, hs been in-creasingly used. Progresses in development and use of mulch with allelopathic crop residues. inexpensive paper mulch, allelopathic crop residues, inexpensive paper mulch, allelopathic crop cultivar development, recently developed ex-perimental weeding machinaries, flamers, microbial herbicides, biological control organisms, soil sterilization techniques have been critically reviewed for their adoption into existing in-tegrated weeding system. Unfortunately, information on cost-benifit, and labor-benefit, for the various methods above mentioned are lacking. Urgent need for the research on rational weeding in organic farming, and herbicide low-input farming is emphasized.