• Title, Summary, Keyword: Crop residues

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Monitoring of Pesticide Residues Concerned in Stream Water (전국 하천수 중 잔류우려 농약 실태조사)

  • Hwang, In-Seong;Oh, Yee-Jin;Kwon, Hye-Young;Ro, Jin-Ho;Kim, Dan-Bi;Moon, Byeong-Chul;Oh, Min-Seok;Noh, Hyun-Ho;Park, Sang-Won;Choi, Geun-Hyoung;Ryu, Song-Hee;Kim, Byung-Seok;Oh, Kyeong-Seok;Lim, Chi-Hwan;Lee, Hyo-Sub
    • Korean Journal of Environmental Agriculture
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    • v.38 no.3
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    • pp.173-184
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    • 2019
  • BACKGROUND: This study was carried out to investigate pesticide residues from fifty streams in Korea. Water samples were collected at two times. Thee first sampling was performed from april to may, which was the season for start of pesticide application and the second sampling event was from august to september, which was a period for spraying pesticides multiple times. METHODS AND RESULTS: The 136 pesticide residues were analyzed by LC-MS/MS and GC/ECD. As a result, eleven of the pesticide residues were detected at the first sampling. Twenty eight of the pesticide residues were detected at the second sampling. Seven pesticides were frequently detected from more than 10 water samples. Ecological risk assessment (ERA) was carried out by using residual and toxicological data. Four scenarios were applied for the ERA. Scenario 1 and 2 were performed using LC50 values and mean and maximum concentrations. Scenarios 3 and 4 were conducted by NOEC values and mean and maximum concentrations. CONCLUSION: Frequently detected pesticide residues tended to coincide with the period of preventing pathogen and pest at paddy rice. As a result of ERA, five pesticides (butachlor, carbendazim, carbofuran, chlorantranilprole, and oxadiazon) were assessed to be risks at scenario 4. However, only oxadiazon was assessed to be a risk at scenario 3 for the first sampling. Oxadiazon was not assessed to be a risk at the second sampling. It seems to be temporary phenomenon at the first sampling, because usage of herbicides such as oxadiazon increased from April to march for preventing weeds at paddy fields. However, this study suggested that five pesticides which were assessed to be risks need to be monitored continuously for the residues.

Comparative Crude Oil Productions on Liquefaction of Crop Residues (액화기술 적용 식물체 잔사별 원유 생산량 비교)

  • Shin, JongDo;Yoon, SunCheol;Paek, Yee;Park, SangWon;Choi, HongLim
    • Journal of the Korea Organic Resources Recycling Association
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    • v.16 no.4
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    • pp.50-56
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    • 2008
  • Aqueous thermal liquefaction of rice, barley, wheat, and rapeseed straws was investigated to compare the amount of heavy oil with catalysts such as $K_2CO_3$, NaOH and KOH in the reaction temperature at $320^{\circ}C$ for 10 minutes. The reaction was carried out in a 5,000ml liquefaction system with dispenser and external electrical furnace. Raw materials (160g), 2,000ml of distilled water and 10% (wt/wt) of catalyst to plant residue were fed into the reactor. It was observed that the maximum heavy oil yield was about 29% from the feeding stock, barley straw, with addition of KOH. The caloric values of crude oil from different crop residues were ranged from 55% to 66% relative to the raw materials depend on crop residue. It was appeared that its maximum calorific value from wheat straw was approximately 6190 kcal/kg.

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Evaluation of pesticide residue analysis of dieldrin in soil using a high resolution gas chromatograph/mass spectrometer (HR-GC/MS)

  • Hwang, Jae-Bok;Park, Tae-Seon
    • Korean Journal of Agricultural Science
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    • v.43 no.4
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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.

Status and Prospect of Weed Control Technology for Organic Farming (유기농업을 위한 잡초방제기술의 현재 미래)

  • 전용웅
    • Korean Journal of Organic Agriculture
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    • v.6 no.2
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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.

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Liquid Chromatographic Determination of Etofenprox Residues in Foods with Mass-Spectrometric Confirmation

  • Lee, Young-Deuk;Kwon, Chan-Hyeok;Kwon, Ki-Sung
    • Korean Journal of Environmental Agriculture
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    • v.30 no.4
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    • pp.432-439
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    • 2011
  • BACKGROUND: An official analytical method was developed to determine etofenprox residues in agricultural commodities using high-performance liquid chromatography (HPLC). METHODS AND RESULTS: The etofenprox residue was extracted with acetone from representative samples of five raw products which comprised rice grain, apple, mandarin, cabbage, and soybean. The extract was then serially purified by liquid-liquid partition and Florisil column chromatography. For rice and soybean samples, acetonitrile/n-hexane partition was additionally coupled to remove nonpolar lipids. Reversed phase HPLC using an octadecylsilyl column was successfully applied to separate etofenprox from co-extractives. Intact etofenprox was sensitively detected by ultraviolet absorption at 225 nm. Recovery experiment at the quantitation limit validated that the proposed method could apparently determine the etofenprox residue at 0.02 mg/kg. Mean recoveries from five crop samples fortified at three levels in triplicate were in the range of 93.6~106.4%. Relative standard deviations of the analytical method were all less than 10%, irrespective of crop types. A selected-ion monitoring LC/mass spectrometry with positive atmospheric-pressure chemical ionization was also provided to confirm the suspected residue. CONCLUSION(s): The proposed method is simple, rapid and sensitive enough to be employed in routine inspection or monitoring of agricultural products for the etofenprox residue.

Emission of Air Pollutants from Agricultural Crop Residues Burning (농업잔재물 소각에 의한 대기오염물질의 배출 특성)

  • Park, Seong-Kyu;Hong, Young-Shil;Kim, Daekeun;Kim, Dong Young;Jang, Young Kee
    • Journal of Korean Society for Atmospheric Environment
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    • v.31 no.1
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    • pp.63-71
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    • 2015
  • The gaseous and particulate emissions from agricultural crop residues burning were investigated. The test residues included white soybean stem, pepper stem, apple branch, peach branch, pear branch, grape branch, sesame stem, perilla stem, and barley stem. Particulate emissions were dominated by fine particles (< $0.1{\mu}m$ in size). The highest $PM_{2.5}$ Emission factors were from barley stems (35.2 g/kg), and the lowest from pepper stems (7.9 g/kg). Emission factors for CO, NO, and VOCs were 146~305 g/kg, 4.94~15.02 g/kg, 27.4~353.3 g/kg, respectively. Benzene played an important role in VOCs emissions from biomass burning.

An Assessment of Allelopathic Potential of Korean Black Soybean Plant Parts

  • Chon, Sang-Uk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.4
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    • pp.345-350
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    • 2003
  • A series of aqueous extracts and residues from leaves, stems, roots, pods and seeds of Korean black soybean (Glycine max (L.) Merr.) were assayed against alfalfa (Medicago sativa) and barnyard grass (Echinochloa crus-galli) to determine their allelopathic activities through petri-dish and greenhouse experiments, and the results showed highest inhibition in the extracts or residues from the seeds, and followed by pods. The extracts of 40g dry tissue $\textrm{L}^{-1}$ applied on filter paper in petri-dish bioassay significantly inhibited root growth of alfalfa, and especially extracts from seeds and pods reduced root length of alfalfa more than those from leaves, stems, or roots. Plant height, root length, shoot and root dry weights of barnyard grass were reduced significantly by residue incorporation of seeds and pods as the incorporated amount increased. These results suggest that black soybean plants had herbicidal potential, and their activities were exhibited differently depending on plant parts.

Determination of Nitrogen Balance of Agricultural Land among OECD Nutrient Balance Indexes (OCED 농업양분지표중 질소 균형지표 설정)

  • Lee, Chun-Soo;Kim, Pil-Joo;Park, Yang-Ho;Kwak, Han-Kang
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.5
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    • pp.347-355
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    • 2000
  • To determine nitrogen balance (Input-Output) of Korea that was asked by Joint Working Party of the Committee for Agriculture and the Environment Policy Committee, OECD, nitrogen input and output were separately investigated as followings: nitrogen input included the amounts of chemical fertilizer consumption, cattle manure production, and biological nitrogen fixation in the national scale, and nitrogen output summed amounts withdrawn by crop and pasture harvesting, and crop residue removal, and lost by denitrification. In 1997, nitrogen balance of Korea was $158kg\;ha^{-1}$ and $211kg\;ha^{-1}$ on including and excluding denitrification loss, respectively. N balance excluded N loss by denitrification and N withdrawal by crop residues on nitrogen output was $250kg\;ha^{-1}$, which OECD asked to except two items from N balance determination because participants were not enough their data. Nitrogen balance was increased to 1.7~2.3 times in 1997 compared with 70 and $162kg\;ha^{-1}$ in 1985, which calculated on the condition of including denitrification and excluding denitrification and removal of crop residues in nitrogen output, respectively. This increase was caused mainly by increasing livestock manure production and chemical fertilizer consumption together with agricultural land area decrease. Nitrogen input was composed with 59% of chemical fertilizer. 42% of cattle manure and 5% of others in 1997, and output was with 73% of crop production, 23% of crop residue withdrawal and 4% of pasture production. Average nitrogen balance excluded N loss by denitrification and N withdrawals by crop residues in 1995~1997 calculated by OECD was $253kg\;ha^{-1}$, which was the second highest rank in OECD participants following $262kg\;ha^{-1}$ of Netherlands. Japanese N balance that has similar farming system with us was $135kg\;ha^{-1}$.

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Allelopathic and Autotoxic Effects of Alfalfa Plant and Soil Extracts

  • Chon, Sang-Uk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.49 no.1
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    • pp.7-11
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    • 2004
  • Alfalfa (Medicago sativa L.) plants have been reported to be autotoxic as well as allelopathic. Laboratory and greenhouse experiments through petri-dish and pot test were conducted to determine autotoxic effects of alfalfa leaf and soil extracts on the germination or early seedling growth of alfalfa, and to evaluate allelopathic effects of alfalfa leaf residues on alfalfa, barnyard grass, com, eclipta and soybean. Alfalfa seed germination was delayed depending on aqueous extract concentration, with no difference in final germination after 48 hours. Alfalfa root length was more sensitive to the autotoxic chemicals from leaf extracts than was germination or shoot length. Root growth of alfalfa was significantly inhibited at extract concentration of more than 1 g dry tissue/L (g $\textrm{L}^{-1}$). Hypocotyl growth, however, was not affected by all the concentrations of leaf extracts. Soil extracts from 4-yr-old alfalfa stand significantly reduced alfalfa root length by 66%, while soil extracts from 0,1, and 3yr-old stand stimulated root length up to 14-32% over the control. Residue incorporation with dry matters of alfalfa leaf at 100 g $\textrm{kg}^{-1}$ reduced seedling length of several crop and weed species, ranging from 53 to 87% inhibition. Addition of nutrient solution into alfalfa leaf extracts alleviated alfalfa autotoxic effect. This result indicates alfalfa leaf and soil extracts or residues could exert autotoxic as well as allelopathic substances into soil environments during and after establishment.